[Federal Register Volume 67, Number 109 (Thursday, June 6, 2002)]
[Proposed Rules]
[Pages 39206-39235]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-14141]
[[Page 39205]]
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Part IV
Department of the Interior
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Fish and Wildlife Service
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50 CFR Part 17
Endangered and Threatened Wildlife and Plants; Designation of Critical
Habitat for the Rio Grande Silvery Minnow; Proposed Rule
Federal Register / Vol. 67, No. 109 / Thursday, June 6, 2002 /
Proposed Rules
[[Page 39206]]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
RIN 1018-AH91
Endangered and Threatened Wildlife and Plants; Designation of
Critical Habitat for the Rio Grande Silvery Minnow
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Proposed rule; notice of availability.
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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), propose to
designate critical habitat for the Rio Grande silvery minnow
(Hybognathus amarus) (silvery minnow), a species federally listed as
endangered under the authority of the Endangered Species Act of 1973,
as amended (Act). The silvery minnow presently occurs only in the Rio
Grande from Cochiti Dam, Sandoval County, downstream to the headwaters
of Elephant Butte Reservoir, Sierra County, New Mexico. We propose to
designate critical habitat within this last remaining portion of the
occupied range in the middle Rio Grande (Cochiti Dam to Elephant Butte
Dam) in New Mexico. The proposed critical habitat designation defines
the lateral extent (width) as those areas bounded by existing levees
or, in areas without levees, 91.4 meters (300 feet) of riparian zone
adjacent to each side of the middle Rio Grande. We request data and
comments from the public and all interested parties on all aspects of
this proposed rule, including data on economic and other relevant
impacts of the designation and the two areas that are not proposed as
critical habitat. A draft economic analysis, which examines primarily
economic impacts of this proposed rule, has been prepared and is also
available for review and comments. This publication also provides
notice of the availability of the draft economic analysis and the draft
EIS for this proposed rule. We invite all interested parties to submit
comments on these draft documents and this proposed rule.
DATES: Comments. We will consider all comments on the proposed rule,
draft economic analysis, and the draft EIS received from interested
parties by September 4, 2002.
Public Hearings. We will also hold two public hearings to receive
comments from the public. The public hearings will be held in Socorro
and Albuquerque, New Mexico, on June 25 and 26, respectively.
ADDRESSES: 1. Send your comments on this proposed rule, the draft
economic analysis, and draft EIS to the New Mexico Ecological Services
Field Office, 2105 Osuna Road NE, Albuquerque, NM, 87113. Written
comments may also be sent by facsimile to (505) 346-2542 or through the
Internet to [email protected]. You may also hand-deliver written
comments to our New Mexico Ecological Services Field Office, at the
above address. You may obtain copies of the proposed rule, the draft
economic analysis, or the draft EIS from the above address or by
calling 505/346-2525. All documents are also available from our website
at http://ifw2es.fws.gov/Library/.
2. Comments and materials received, as well as supporting
documentation used in the preparation of this proposed rule, will be
available for public inspection, by appointment, during normal business
hours at the New Mexico Ecological Services Field Office (see address
above).
3. We will hold public hearings in Socorro, NM, on June 25, 2002;
and in Albuquerque, NM, on June 26, 2002 at the following locations:
Socorro, NM: New Mexico Institute for Mining and
Technology, Macey Center, 801 Leroy Place, Socorro, New Mexico, on June
25, 2002, from 6 to 9 p.m.
Albuquerque, NM: Indian Pueblo Cultural Center, 2401 12th
Street NW, Albuquerque, New Mexico, on June 26, 2002, from 6 to 9 p.m.
FOR FURTHER INFORMATION CONTACT: Joy Nicholopoulos, Field Supervisor,
New Mexico Ecological Services Field Office (see ADDRESSES above);
phone: 505-346-2525.
SUPPLEMENTARY INFORMATION:
Background
The Rio Grande silvery minnow is one of seven species in the genus
Hybognathus found in the United States (Pflieger 1980). The species was
first described by Girard (1856) from specimens taken from the Rio
Grande near Fort Brown, Cameron County, TX. It is a stout silvery
minnow with moderately small eyes and a small, slightly oblique mouth.
Adults may reach 90 millimeters (mm) (3.5 inches (in)) in total length
(Sublette et al. 1990). Its dorsal fin is distinctly pointed with the
front of it located slightly closer to the tip of the snout than to the
base of the tail. The fish is silver with emerald reflections. Its
belly is silvery white, fins are plain, and barbels are absent
(Sublette et al. 1990).
This species was historically one of the most abundant and
widespread fishes in the Rio Grande Basin, occurring from
Espa[ntilde]ola, NM, to the Gulf of Mexico (Bestgen and Platania 1991).
It was also found in the Pecos River, a major tributary of the Rio
Grande, from Santa Rosa, NM, downstream to its confluence with the Rio
Grande (Pflieger 1980). The silvery minnow is completely extirpated
from the Pecos River and from the Rio Grande downstream of Elephant
Butte Reservoir and upstream of Cochiti Reservoir (Bestgen and Platania
1991). The current distribution of the silvery minnow is limited to the
Rio Grande between Cochiti Dam and Elephant Butte Reservoir. Throughout
much of its historic range, decline of the silvery minnow has been
attributed to modification of the flow regime (hydrological pattern of
flows that vary seasonally in magnitude and duration, depending on
annual precipitation patterns such as runoff from snowmelt) and channel
drying because of impoundments, water diversion for agriculture, stream
channelization, and perhaps both interactions with non-native fish and
decreasing water quality (Cook et al. 1992; Bestgen and Platania 1991,
Service 1999; Buhl 2001).
It is important to note that much of the species' life history
information detailed below comes from studies conducted within the
middle Rio Grande, the current range of the minnow. Nevertheless, we
believe that our determinations for other areas outside of the middle
Rio Grande, but within the historical range of the silvery minnow, are
consistent with the data collected to date on the species' ecological
requirements (e.g., Service 1999).
The role of the plains minnow (Hybognathus placitus) in the decline
and extirpation of the silvery minnow from the Pecos River is
uncertain; however, the establishment of the plains minnow coincided
with the disappearance of the silvery minnow (Bestgen and Platania
1991; Cook et al. 1992). It is believed the non-native plains minnow
was introduced into the Pecos drainage prior to 1964 (Cook et al.
1992), and was probably the result of the release of ``bait minnows''
that were collected from the Arkansas River drainage. It is unclear,
however, if populations of the native silvery minnow were depleted
prior to the introduction of the plains minnow, or if the reduction and
extirpation of the silvery minnow was a consequence of the interactions
of the two species (C. Hoagstrom, U.S. Fish and Wildlife Service, pers.
comm. 2001). One theory is that the plains minnow may be more tolerant
of modified habitats and,
[[Page 39207]]
therefore, was able to replace the silvery minnow in the degraded
reaches of the Pecos River. Nevertheless, the plains minnow has
experienced population declines within its native range from highly
variable water levels, unstable streambeds, and fluctuating water
temperatures (Cross et al. 1985 cited in Taylor and Miller 1990).
Although the interactions (e.g., hybridization or competition) between
the silvery minnow and the introduced plains minnow are believed by
some to be one of the primary causes for the extirpation of the silvery
minnow in the Pecos River, this hypothesis is unsubstantiated (Hatch et
al. 1985; Bestgen et al. 1989; Cook et al. 1992). Currently, New Mexico
State University is conducting research on the plains minnow and
silvery minnow to determine if the two species hybridize. Preliminary
results of this research should be available in summer 2002. It is
important to note that, within its native range, the plains minnow is
sympatric (occurs at the same localities) with other species of
Hybognathus. However, they are segregated ecologically (i.e., the
plains minnow is found in the main river channel where the substrate is
predominantly sand, whereas the western silvery minnow (Hybognathus
argyritis) predominates backwaters and protected areas with little to
no current and sand or silt substrate) (Pflieger 1997). Consequently,
if the silvery minnow and plains minnow do not hybridize, they may be
ecologically segregated and able to co-exist.
The plains minnow and silvery minnow appear to have little in the
way of behavioral or physiological isolating mechanisms and may
hybridize (Cook et al. 1992); yet the combined effects of habitat
degradation (i.e., modification of the flow regime, channel drying,
water diversion, and stream channelization) may be a more likely
explanation for the silvery minnow's extirpation from the Pecos River
(Bestgen and Platania 1991; C. Hoagstrom, pers. comm. 2001). We
acknowledge that there are no conclusive data to substantiate any
reasons for extirpation of the silvery minnow from the Pecos River.
The silvery minnow has also been extirpated from the lower Rio
Grande, including the Big Bend National Park area (Hubbs et al. 1977;
Bestgen and Platania 1991). Reasons for the species' extirpation in the
lower Rio Grande are also uncertain. The last documented collection of
a silvery minnow in the Big Bend area was 1961, but reexamination of
that specimen revealed it was a plains minnow (Bestgen and Propst
1996). Therefore, the last silvery minnow from the lower Rio Grande was
apparently collected in the late 1950s (Trevino-Robinson 1959; Hubbs et
al. 1977; Edwards and Contreras-Balderas 1991).
Decline of the species in the middle Rio Grande probably began in
1916 when the gates at Elephant Butte Dam were closed. Construction of
the dam signaled the beginning of an era of mainstem Rio Grande dam
construction that resulted in five major mainstem dams within the
silvery minnow's historic range (Shupe and Williams 1988). These dams
allowed manipulation and diversion of the flow of the river. Often this
manipulation severely altered the flow regime and likely precipitated
the decline of the silvery minnow (Bestgen and Platania 1991).
Concurrent with construction of the mainstem dams was an increase in
the abundance of non-native fish as these species were stocked into the
reservoirs created by the dams (e.g., Cochiti Reservoir) (Sublette et
al. 1990). Once established, these species often completely replaced
the native fish fauna (Propst et al. 1987; Propst 1999).
Development of agriculture and the growth of cities within the
historic range of the silvery minnow resulted in a decrease in the
quality of river water through municipal and agricultural run-off
(i.e., sewage and pesticides) that may have also adversely affected the
range and distribution of the silvery minnow. Historically there were
four other small native fish species (speckled chub (Macrohybopsis
aestivalis); Rio Grande shiner (Notropis jemezanus); phantom shiner
(Notropis orca); and Rio Grande bluntnose shiner (Notropis simus
simus)) within the middle Rio Grande that had similar reproductive
attributes, but these species are now either extinct or extirpated
(Platania 1991). The silvery minnow is a pelagic spawning species; i.e.
its eggs flow in the water column. The silvery minnow is the only
surviving small native pelagic spawning minnow in the middle Rio Grande
and its range has been reduced to only 5 percent of its historic
extent. Although the silvery minnow is a hearty fish, capable of
withstanding many of the natural stresses of the desert aquatic
environment, the majority of the individual silvery minnows live only
one year (Bestgen and Platania 1991). Thus, a successful annual spawn
is key to the survival of the species (Platania and Hoagstrom 1996;
Service 1999; Dudley and Platania 2001). The silvery minnow's range has
been so greatly restricted, the species is extremely vulnerable to a
single catastrophic event, such as a prolonged period of low or no flow
(i.e., the loss of all surface water) (59 FR 36988; Dudley and Platania
2001).
The various life history stages of the silvery minnow require
shallow waters with a sandy and silty substrate that is generally
associated with a meandering river that includes sidebars, oxbows, and
backwaters (C. Hoagstrom, pers. comm, 2001; Bestgen and Platania 1991;
Platania 1991). However, physical modifications to the Rio Grande over
the last century--including the construction of dams, levees, and
channelization of the mainstem--have altered much of the habitat that
is necessary for the species to persist (Service 1999). Channelization
has straightened and shortened mainstem river reaches; increased the
velocity of the current; and altered riparian vegetation, instream
cover, and substrate composition (U.S. Bureau of Reclamation (BOR)
2001a).
In the middle Rio Grande, the spring runoff coincides with and may
trigger the silvery minnow's spawn (Platania and Hoagstrom 1996;
Service 1999; Dudley and Platania 2001). The semi-buoyant (floating)
eggs that are produced drift downstream in the water column (Smith
1999; Dudley and Platania 2001) (see ``Primary Constituent Elements''
section of this proposed rule for further information on spawning).
However, it is believed that diversion dams act as instream barriers
and prevent silvery minnows from movement upstream after hatching
(Service 2001b; Dudley and Platania 2001; 2002). In fact, the continued
downstream displacement and decline of the silvery minnow in the middle
Rio Grande is well documented (Dudley and Platania 2001).
During the irrigation season (approximately March 1 to October 31
of each year) in the middle Rio Grande, silvery minnow often become
stranded in the diversion channels (or irrigation ditches), where they
are unlikely to survive (Smith 1999, Lang and Altenbach 1994). For
example, when the irrigation water in the diversion channels is used on
agricultural fields, the possibility for survival of silvery minnows in
the irrigation return flows (excess irrigation water that flows from
agricultural fields and is eventually returned to the river) is low,
because they perish in canals due to unsuitable habitat, dewatering, or
predation (Lang and Altenbach 1994). Unscreened diversion dams also
entrain (trap) silvery minnow fry (fish that have recently emerged from
eggs) and semi-buoyant eggs (Smith 1998; 1999). However, some
irrigation water is returned to the river via irrigation wasteways in
the reach of the middle Rio Grande from the Isleta Diversion
[[Page 39208]]
Dam to the San Acacia Diversion Dam (Isleta reach), which helps sustain
flow in certain segments of this reach. Nevertheless, we do not believe
these riverside drains offer suitable refugia or are useful for
recovery of the silvery minnow.
In the middle Rio Grande, perhaps even more problematic for the
silvery minnow are drought years during the irrigation season when
there may be little supplemental water (water that is used to augment
river flows) available and when most or all of the water in the middle
Rio Grande may be diverted into the irrigation channels (e.g., see
Dudley and Platania 2001) or otherwise consumed. Compounding this
problem is stream bed aggradation (i.e., the river bottom is rising due
to sedimentation) below San Acacia, NM, where the bed of the river is
now perched above the bed of the low flow conveyance channel (LFCC),
which is immediately adjacent and parallel to the river channel.
Because of this physical configuration, waters in the mainstem of the
river are drained from the river bed into the LFCC. The LFCC parallels
the Rio Grande for approximately 121 kilometers (km) (75 miles (mi))
and was designed to expedite delivery of water to Elephant Butte
Reservoir, pursuant to the Rio Grande Compact of 1939. The LFCC
diverted water from the Rio Grande from 1959 to 1985. The LFCC was
built to more efficiently deliver water to Elephant Butte Reservoir
during low-flow conditions and has the capacity to take approximately
2,000 cubic feet per second (cfs) of the river's flow, via gravity. If
natural river flow is 2,000 cfs or less, the LFCC can dewater the Rio
Grande from its heading at the San Acacia Diversion Dam south to
Elephant Butte Reservoir.
However, the LFCC has not been fully operational since 1985 because
of outfall problems (e.g., stream bed aggradation) at Elephant Butte
Reservoir. Even without water diversion into the LFCC, seepage from the
river to the LFCC is occurring and causing some loss of surface flows
in the river channel (BOR 2001a). In effect, water is drained from the
Rio Grande into the LFCC and conveyed to Elephant Butte Reservoir,
thereby resulting in water losses in the reach from the San Acacia
Diversion Dam to Elephant Butte Reservoir (San Acacia reach). During
some years this can result in prolonged periods of low or no flow.
It is believed that, historically, the silvery minnow was able to
withstand periods of drought primarily by retreating to pools and
backwater refugia, and swimming upstream to repopulate upstream
habitats (e.g., Deacon and Minckley 1974, J. Smith, U.S. Fish and
Wildlife Service, pers. comm. 2001). It is also believed that after
prolonged periods of low or no flow the silvery minnow may have been
able to repopulate downstream habitat the following year by the drift
of eggs from upstream populations (Platania 1995). However, when the
present-day middle Rio Grande dries and dams prevent upstream movement
of the silvery minnow, they can become trapped in dewatered reaches and
often die in isolated pools before the river becomes wetted again. The
inability of the population to find adequate refugia during prolonged
periods of low or no flow and to repopulate extirpated reaches creates
a very unstable population (Service 2001b). In some isolated pools,
Smith and Hoagstrom (1997) and Smith (1999) documented complete
mortality of silvery minnows in the middle Rio Grande in both 1996 and
1997 during prolonged periods of low or no flow. These studies
documented both the relative size of the isolated pool (i.e., estimated
surface area and maximum depth) in relation to pool longevity (i.e.,
number of days the isolated pool existed) and the fish community within
isolated pools. For example, isolated pools found during these
conditions typically only lasted for about 48 hours before drying up
completely (Smith 1999). Those isolated pools that persisted longer
than 48 hours lost greater than 81 percent of their estimated surface
area and greater than 26 percent of their maximum depth within 48
hours. Moreover, isolated pools receive no surface inflow; water
temperatures increase; dissolved oxygen decreases; and depending on
location, size, and duration of the prolonged periods of low or no
flow, will usually result in the death of all fish (Tramer 1977;
Mundahl 1990; Platania 1993b; Ostrand and Marks 2000; Ostrand and Wilde
2001). Therefore, when periods of low or no flow are longlasting (over
48 hours), complete mortality of silvery minnows in isolated pools can
be expected.
Formation of isolated pools also increases the risk of predation of
silvery minnows in drying habitats. Predators; primarily fish and
birds, have been observed in high numbers in the middle Rio Grande,
consuming fish in drying, isolated pools, where the fish become
concentrated and are more vulnerable to predation (J. Smith, pers.
comm. 2001).
The potential for prolonged periods of low or no flow on the middle
Rio Grande becomes particularly significant for the silvery minnow
below the San Acacia Diversion Dam, where approximately 95 percent of
the only extant population lives. For example, in the river reach above
(north of) the San Acacia Diversion Dam, return flows from irrigation
and other activities are routed back into the mainstem of the river. At
times, this can provide a fairly consistent flow in particular
stretches of the Isleta reach. However, at the San Acacia Diversion
Dam, once diversions are made (i.e., to irrigation canals, as well as
seepage losses to the LFCC) the return flows continue in off-river
channels (with a few exceptions at Brown's Arroyo and the 10-mile
outfall of the LFCC) until they enter Elephant Butte Reservoir. Thus,
unlike in the Isleta reach, the silvery minnow does not receive the
benefit of irrigation return flows in the San Acacia reach.
Although we determine that a river reach in the lower Rio Grande in
Big Bend National Park downstream of the park boundary to the Terrell/
Val Verde County line, Texas, and a river reach in the middle Pecos
River, from Sumner Dam to Brantley Dam in De Baca, Chaves, and Eddy
Counties, New Mexico, are essential to the conservation of the silvery
minnow, these areas are not proposed for critical habitat designation
because of our preliminary analysis under section 4(b)(2) (see
``Exclusions Under Section 4(b)(2) of the Act'' section of this rule).
The current proposal only includes the middle Rio Grande (Cochiti Dam
to Elephant Butte Dam) in New Mexico, and no other reaches within the
historical range of the silvery minnow. Therefore, we are only
proposing to designate the river reaches currently occupied by the
silvery minnow. This proposal is analyzed as the preferred alternative
in the draft Environmental Impact Statement (EIS), pursuant to the
National Environmental Policy Act (NEPA), which the Service was
required to prepare under the court order from the United States
District Court for the District of New Mexico, in Middle Rio Grande
Conservancy District v. Babbitt, Civ. Nos. 99-870, 99-872, 99-1445M/RLP
(Consolidated). The two reaches referenced above (i.e., middle Pecos
River and lower Rio Grande) are also analyzed in the draft EIS. The
Service must follow the procedures required by the Act, NEPA, and the
Administrative Procedure Act. Therefore, we seek public comment on all
reaches identified in this proposed rule as essential, including
whether any of these or other areas should be excluded from the final
designation pursuant to Section 4(b)(2). As required by law, we will
consider all comments received on this proposed rule, the draft EIS,
and the
[[Page 39209]]
draft economic analysis before making a final determination.
In accordance with the Recovery Plan, we have initiated a captive
propagation program for the silvery minnow (Service 1999). We currently
have silvery minnows housed at: (1) The Service's Dexter National Fish
Hatchery and Technology Center; (2) the Service's Mora National Fish
Hatchery and Technology Center; (3) the City of Albuquerque's
Biological Park; (4) the U.S. Geological Survey Biological Resources
Division's Yankton Laboratory; and (5) the New Mexico State University
(J. Brooks, pers. comm., 2001). Progeny of these fish are being used to
augment the middle Rio Grande silvery minnow population, but could also
be used in future augmentation or reestablishment programs for the
silvery minnow in other river reaches (J. Remshardt, New Mexico Fishery
Resources Office, pers. comm. 2001). We have also salvaged and
transplanted silvery minnows within the middle Rio Grande in recent
years (Service 1996, 1998, 1999, 2000, 2001). For example,
approximately 220,000 silvery minnow larvae and adults have been
released (i.e., stockings from captive bred fish or translocated from
downstream reaches) since May 1996 (J. Remshardt, U.S. Fish and
Wildlife Service, pers. comm. 2001). Effectiveness of these releases is
currently being investigated and will be useful for evaluating future
efforts to repatriate the species.
If this proposed rule is finalized, section 7(a)(2) of the Act
would require that Federal agencies ensure that actions they fund,
authorize, or carry out are not likely to result in the ``destruction
or adverse modification'' of critical habitat. In our regulations at 50
CFR 402.02, we define destruction or adverse modification as ``direct
or indirect alteration that appreciably diminishes the value of
critical habitat for both the survival and recovery of a listed
species. Such alterations include, but are not limited to, alterations
adversely modifying any of those physical or biological features that
were the basis for determining the habitat to be critical.'' Section 4
of the Act requires us to consider economic and other relevant impacts
of specifying any particular area as critical habitat.
Our practice is to make comments that we receive on this
rulemaking, including names and home addresses of the respondents,
available for public review during normal business hours. Individual
respondents may request that we withhold their home address from the
rulemaking record, which we will honor to the extent allowable by
Federal law.
Previous Federal Action
We proposed to list the silvery minnow as an endangered species
with critical habitat on March 1, 1993 (58 FR 11821). The comment
period, originally scheduled to close on April 30, 1993, was extended
to August 25, 1993 (58 FR 19220; April 13, 1993). This extension
allowed us to conduct public hearings and to receive additional public
comments. Public hearings were held in Albuquerque and Socorro, NM, on
the evenings of June 2 and 3, 1993, respectively. After a review of all
comments received in response to the proposed rule, we published the
final rule to list the silvery minnow as endangered on July 20, 1994
(59 FR 36988).
Section 4(a)(3) of the Act requires that the Secretary, to the
maximum extent prudent and determinable, designate critical habitat at
the time a species is listed as endangered or threatened. Our
regulations (50 CFR 424.12(a)(2)) state that critical habitat is not
determinable if information sufficient to perform required analyses of
the impacts of the designation is lacking or if the biological needs of
the species are not sufficiently well known to permit identification of
an area as critical habitat. At the time the silvery minnow was listed,
we found that critical habitat was not determinable because there was
insufficient information to perform the required analyses of the
impacts of the designation.
We contracted for an economic analysis of the proposed critical
habitat designation in September 1994 and a draft analysis was prepared
and provided to us on February 29, 1996. The draft document was then
provided to all interested parties on April 26, 1996. That mailing
included 164 individuals and agencies, all affected Pueblos in the
valley, all county commissions within the occupied range of the
species, and an additional 54 individuals who had attended the public
hearings on the proposed listing and who had requested that they be
included on our mailing list, particularly for the economic analysis.
At that time, we notified the public that, because of a moratorium on
final listing actions and determinations of critical habitat imposed by
Public Law 104-6, no work would be conducted on the analysis or on the
final decision concerning critical habitat. However, we solicited
comments from the public and agencies on the document for use when such
work resumed.
On April 26, 1996, the moratorium was lifted. Following the waiver
of the moratorium, we reactivated the listing program that had been
shut down for over a year and faced a backlog of 243 proposed species
listings. In order to address that workload, we published, on May 16,
1996, our Listing Priority Guidance for the remainder of Fiscal Year
1996 (61 FR 24722). That guidance identified the designation of
critical habitat as the lowest priority upon which we could expend
limited funding and staff resources. Subsequent revisions of the
guidance for Fiscal Years 1997 (December 5, 1996; 61 FR 64475) and for
1998/1999 (May 8, 1998; 63 FR 25502) retained critical habitat as the
lowest priority for the listing program within the Service. Thus, no
work resumed on the economic analysis due the low priority assigned to
critical habitat designations.
On February 22, 1999, in Forest Guardians v. Babbitt, Civ. No. 97-
0453 JC/DIS, the United States District Court for the District of New
Mexico ordered us to publish a final determination with regard to
critical habitat for the silvery minnow within 30 days. The deadline
was subsequently extended by the court to June 23, 1999. On July 6,
1999, we published a final designation of critical habitat for the
silvery minnow (64 FR 36274), pursuant to the court order.
On November 21, 2000, the United States District Court for the
District of New Mexico, in Middle Rio Grande Conservancy District v.
Babbitt, Civ. Nos. 99-870, 99-872, 99-1445M/RLP (Consolidated), set
aside the July 9, 1999, critical habitat designation and ordered us to
issue both an EIS and a new proposed rule designating critical habitat
for the silvery minnow. This proposed rule and the draft EIS are being
issued pursuant to that court order.
On April 5, 2001, we mailed approximately 500 pre-proposal
notification letters to the six Middle Rio Grande Indian Pueblos
(Cochiti, Santo Domingo, San Felipe, Santa Ana, Sandia, and Isleta),
various governmental agencies, interested individuals, and the New
Mexico Congressional delegation. The letter informed them of our intent
to prepare an EIS for the proposed designation of critical habitat for
the silvery minnow and announced public scoping meetings pursuant to
NEPA. On April 17, 23, 24, and 27, 2001, we held public scoping
meetings in Albuquerque and Carlsbad, NM, Fort Stockton, TX, and
Socorro, NM, respectively. We solicited oral and written comments and
input. We were particularly interested in obtaining additional
information on the status of the species or information concerning
threats to the species. The comment period closed June 5, 2001. We
received
[[Page 39210]]
approximately 40 comments during the EIS scoping process. During April
2001, we contracted with Industrial Economics Incorporated for an
economic analysis and the Institute of Public Law at the University of
New Mexico School of Law for an EIS on the proposed critical habitat
designation. Following the closing of the scoping comment period, we
outlined possible alternatives for the EIS. We held a meeting on
September 12, 2001, to solicit input on the possible alternatives from
the Rio Grande Silvery Minnow Recovery Team (Recovery Team) and other
invited participants including individuals from the Carlsbad Irrigation
District, Fort Sumner Irrigation District, the States of New Mexico and
Texas, and potentially affected Pueblos and Tribes. Following this
meeting, we sent letters to the Recovery Team and other invited
participants, including Tribal entities, and resource agencies in New
Mexico and Texas, to solicit any additional information--particularly
biological, cultural, social, or economic data--that may be pertinent
to the economic analysis or EIS. We received 10 comments from our
requests for additional information. The information provided in the
comment letters was fully considered in developing the alternatives
that were analyzed in the draft EIS, which contains this proposed rule
as our preferred alternative. We made these comments part of the
administrative record for this rulemaking.
Recovery Plan
Restoring an endangered or threatened species to the point where it
is recovered is a primary goal of the Service's endangered species
program. To help guide the recovery effort, we prepare recovery plans
for most of the listed species native to the United States. Recovery
plans describe actions considered necessary for conservation of the
species, establish criteria for downlisting or delisting them, and
estimate time and cost for implementing the recovery measures needed.
Although a recovery plan is not a regulatory document (i.e., recovery
plans are advisory documents because there are no specific protections,
prohibitions, or requirements afforded to a species based solely on a
recovery plan), the information contained in the Rio Grande Silvery
Minnow Recovery Plan (Recovery Plan) was considered in developing this
proposed critical habitat designation.
On July 1, 1994, the Recovery Team was established by the Service
pursuant to section 4(f)(2) of the Act and our cooperative policy on
recovery plan participation, a policy intended to involve stakeholders
in recovery planning (July 1, 1994; 59 FR 34272). Stakeholder
involvement in the development of recovery plans helps minimize the
social and economic impacts that could be associated with recovery of
endangered species. Numerous individuals, agencies, and affected
parties were involved in the development of the Recovery Plan or
otherwise provided assistance and review (Service 1999). On July 8,
1999, we finalized the Recovery Plan (Service 1999), pursuant to
section 4(f) of the Act.
The Recovery Plan recommends recovery goals for the silvery minnow,
as well as procedures to better understand the biology of the species.
The primary goals of the Recovery Plan are to: (1) Stabilize and
enhance populations of silvery minnow and its habitat in the middle Rio
Grande valley; and (2) reestablish the silvery minnow in at least two
other areas of its historical range (Service 1999). The reasons for
determining that these areas were necessary for recovery include: (1)
Consideration of the biology of the species (i.e., few silvery minnows
live more than 12 to 14 months, indicating the age 1 fish (e.g., all
fish born in 2000 that remain alive in 2001 would be age 1 fish) are
almost entirely responsible for perpetuation of the species); (2) the
factors in each reach that may inhibit or enhance reestablishment and
security of the species vary among areas; and (3) it is unlikely that
any single event would simultaneously eliminate the silvery minnow from
three geographic areas (Service 1999).
We have continued working with the Recovery Team since the Recovery
Plan was finalized. We believe this proposed critical habitat
designation and our conservation strategy (see ``Exclusions Under
Section 4(b)(2) of the Act'' section below) are consistent with the
Recovery Plan (Service 1999). The purpose of the Recovery Plan is to
outline the research and data collection activities that will identify
measures to ensure the conservation of the silvery minnow in the wild
and to provide a roadmap that leads to the protection of habitat
essential to its recovery. Therefore, we also believe this proposed
critical habitat designation and our conservation strategy are
consistent with the recommendations of Recovery Team members.
Nevertheless, we will request that peer reviewers who are familiar with
this species review the proposed rule.
The term ``conservation,'' as defined in section 3(3) of the Act
and in 50 CFR 424.02(c), means ``to use and the use of all methods and
procedures which are necessary to bring any endangered species or
threatened species to the point at which the measures provided pursuant
to this Act are no longer necessary'' (i.e., the species is recovered
and removed from the list of endangered and threatened species). It is
important to note that we utilized the recommendations in the Recovery
Plan, consistent with this definition of conservation, to conclude that
the middle Rio Grande proposed critical habitat unit and the middle
Pecos River from Sumner Dam to Brantley Dam, NM (middle Pecos River),
and the lower Rio Grande from the upstream boundary of Big Bend
National Park downstream through the area designated as a wild and
scenic river to the Terrell/Val Verde County line, TX (lower Rio
Grande) are ``essential to the conservation of'' the silvery minnow.
Although the middle Pecos River and the lower Rio Grande are not
proposed as critical habitat units, we believe they are important for
the recovery of the silvery minnow. Thus, we concur with the Recovery
Plan that reestablishment of the silvery minnow within additional
geographically distinct areas is necessary to ensure the minnow's
survival and recovery (Service 1999). However, recovery is not achieved
by designating critical habitat. The Act provides for other mechanisms
that will provide for reestablishment of the minnow outside of the
middle Rio Grande and the eventual recovery of the silvery minnow. We
are not proposing critical habitat designation for the area on the
middle Pecos River or the lower Rio Grande; we are proposing to
designate only the middle Rio Grande as critical habitat. Our
conservation strategy for this species and our rationale is discussed
in the ``Exclusions Under Section 4(b)(2) of the Act'' section of this
rule below.
Exclusions Under Section 4(b)(2) of the Act
Section 4(b)(2) of the Act requires us to base critical habitat
designations on the best scientific and commercial data available,
after taking into consideration the economic and any other relevant
impact of specifying any particular area as critical habitat. We may
exclude areas from a critical habitat designation when the benefits of
exclusion outweigh the benefits of designation, provided the exclusion
will not result in the extinction of the species. Our preliminary
analysis of the following two areas: (1) The river reach in the middle
Pecos River, NM, from Sumner Dam to Brantley Dam in De Baca, Chaves,
and Eddy Counties, NM; and (2)
[[Page 39211]]
the river reach in the lower Rio Grande in Big Bend National Park
downstream of the National Park boundary to the Terrell/Val Verde
County line, TX, finds that the benefits of excluding these areas from
the designation of critical habitat outweigh the benefits of including
them. Therefore, we are not proposing these areas as critical habitat.
As indicated in the ``Public Comments Solicited'' section of this
rule, we are seeking comments on whether these areas should be
designated as critical habitat. In making a final determination, we
will consider all comments we receive on this proposed rule, the draft
EIS, and the draft economic analysis.
(1) Benefits of Inclusion
The benefits of inclusion of the river reach in the middle Pecos
River, NM, from Sumner Dam to Brantley Dam in De Baca, Chaves, and Eddy
Counties, NM, would result from the requirement under section 7 of the
Act that Federal agencies consult with us to ensure that any proposed
actions do not destroy or adversely modify critical habitat.
Historically, no consultations have occurred on the Pecos River for the
silvery minnow since the area is not occupied. However, while critical
habitat designation could provide some benefit to the silvery minnow,
in fact, consultations are already occurring for another listed fish
with similar requirements. The Pecos bluntnose shiner (Notropis simus
pecosensis) was federally listed in 1987 and portions of the Pecos
River are designated as critical habitat for the Pecos bluntnose shiner
(52 FR 5295). As stated in the ``Criteria for Identifying Proposed
Critical Habitat Units'' section of this rule, these fish species
belong to the same guild of broadcast spawners with semi-buoyant eggs
and also spawn during high flow events with eggs and larvae being
distributed downstream (Bestgen et al. 1989). Therefore, flow regime
operations in this reach that benefit the Pecos bluntnose shiner also
provide benefits to habitat of the silvery minnow. We also believe that
the primary constituent elements for the Pecos bluntnose shiner
critical habitat are compatible with the proposed primary constituent
elements for the silvery minnow. Thus, we find that little additional
benefit through section 7 would occur as a result of the overlap
between habitat suitable for the silvery minnow and the Pecos bluntnose
shiner listing and critical habitat designation.
In Sierra Club v. Fish and Wildlife Service, 245 F.3d 434 (5th Cir.
2001), the Fifth Circuit Court of Appeals stated that the
identification of habitat essential to the conservation of the species
can provide informational benefits to the public, State, and local
governments; scientific organizations; and Federal agencies. The court
also noted that heightened public awareness of the plight of listed
species and its habitat may facilitate conservation efforts. We agree
with these findings; however, we believe that there would be little
additional informational benefit gained from including the middle Pecos
River because the final rule will identify all areas that are essential
to the conservation of the silvery minnow, regardless of whether all of
these areas are included in the regulatory designation. Consequently,
we believe that the informational benefits will be provided to the
middle Pecos River, regardless of whether this reach is designated as
critical habitat.
The draft economic analysis recognizes that while consultations
regarding the Pecos will occur without a silvery minnow critical
habitat designation, those consultations would not consider the silvery
minnow. However, due to the similar life history requirements of these
species, we do not anticipate that the outcomes of such consultations
would be altered. We recognize, as does the draft economic analysis,
that the middle Pecos River area (as described above) covers about
twice the length of the area designated for the Pecos bluntnose shiner.
Historically, two formal consultations and two informal consultations
occurred annually for the Pecos bluntnose shiner. The draft economic
analysis assumes that twice as many consultations would occur if this
area were designated as critical habitat for the silvery minnow, since
the area would be doubled in size. However, the draft economic analysis
also recognizes that this is likely an overstatement of the actual
increase in consultations because consultations frequently occur on
projects located outside of Pecos bluntnose shiner critical habitat,
due to the interdependent nature of the river system and the presence
of the species. Consequently, we do not believe that designating
critical habitat within this river reach would provide additional
benefits for the silvery minnow, because currently the activities that
occur outside of critical habitat designated for the Pecos bluntnose
shiner are also being consulted upon. We find little benefit to
including this river reach in the proposed critical habitat for the
silvery minnow due to the presence of the Pecos bluntnose shiner and
its designated critical habitat, in the absence of the silvery minnow.
Current and ongoing activities for the Pecos bluntnose shiner are
compatible with those of the silvery minnow such that reestablishment
of the silvery minnow in this stretch of river should not be precluded
in the future. Thus, we determine that any additional benefit from a
designation of critical habitat in this river reach does not outweigh
the benefit of excluding this area, as discussed below in the
``Benefits of Exclusion'' section.
The benefits of inclusion of the river reach in the lower Rio
Grande in Big Bend National Park downstream of the park boundary to the
Terrell/Val Verde County line, TX, would also result from the
requirement under section 7 that Federal agencies consult with us to
ensure that any proposed actions do not destroy or adversely modify
critical habitat. However, as indicated in the draft economic analysis,
we anticipate very little consultation activity within this area. The
draft economic analysis (section 6.3.3) estimates that over the next 20
years there would be a total of 12 formal consultations and 6 informal
consultations. The only Federal actions that we are aware of within the
stream reach of the lower Rio Grande downstream of Big Bend National
Park is the Big Bend National Park oversight and permitting authority
for float trips, scientific research permits, environmental education,
and law enforcement (R. Skiles, Big Bend National Park, pers. comm.
2001). Therefore, unless there are other types of Federal permitting or
authorization within this area, private and State-owned lands would not
be affected. Additional activities that were used to estimate the
numbers of consultations for this area include: National Park
management activities (e.g., pesticide application and fishing
regulations), U.S. International Boundary and Water Commission channel
maintenance activities, U.S. Fish and Wildlife Service (e.g., fire
management plans, fish stocking), and Environmental Protection Agency,
National Pollution Discharge Elimination System permitting for the
Predsidio or Lajitas wastewater treatment facility. We find sufficient
regulatory and protective conservation measures in place and believe
there would be little benefit to a designation in this reach since this
area is protected and managed by the National Park Service and the
number of consultations expected to occur in this area are relatively
low.
As above, we believe that heightened public awareness of a listed
species and its habitat may facilitate conservation efforts.
Nevertheless, we believe that there would be little additional
[[Page 39212]]
informational benefit gained from including the lower Rio Grande within
designated critical habitat for the silvery minnow because we have
identified in this proposed rule, and will identify in the final
designation, those areas that we believe are essential to the
conservation of the species. For these reasons, we determine that any
additional benefit of designation of critical habitat in this river
reach does not outweigh the benefit of excluding this area, as
discussed below.
(2) Benefits of Exclusion
As discussed in the ``Recovery Plan'' section of this rule, the
primary goals of the silvery minnow Recovery Plan are to: (1) Stabilize
and enhance populations of the silvery minnow and its habitat in the
middle Rio Grande valley; and (2) reestablish the silvery minnow in at
least two other areas of its historical range (Service 1999). We
believe that the best way to achieve the second recovery goal will be
to use the authorities under section 10(j) of the Act. Consequently, we
have developed a conservation strategy that we believe is consistent
with the species' Recovery Plan. The conservation strategy is to
reestablish the silvery minnow, under section 10(j) of the Act, within
areas of its historical range, possibly including the river reach in
the middle Pecos River and the river reach in the lower Rio Grande
(both are described above). Since the silvery minnow is extirpated from
these areas and natural repopulation is not possible without human
assistance, use of a 10(j) rule is the appropriate tool to achieve this
recovery objective. Nevertheless, any future recovery efforts,
including repatriation of the species to areas of its historical range
must be conducted in accordance with NEPA and the Act. An overview of
the process to establish an experimental population under section 10(j)
of the Act is described below.
Section 10(j) of the Act enables us to designate certain
populations of federally listed species that are released into the wild
as ``experimental.'' The circumstances under which this designation can
be applied are: (1) The population is geographically separate from non-
experimental populations of the same species (e.g., the population is
reintroduced outside the species' current range but within its probable
historical range); and (2) we determine that the release will further
the conservation of the species. Section 10(j) is designed to increase
our flexibility in managing an experimental population by allowing us
to treat the population as threatened, regardless of the species'
status elsewhere in its range. Threatened status gives us more
discretion in developing and implementing management programs and
special regulations for a population and allows us to develop any
regulations we consider necessary to provide for the conservation of a
threatened species. In situations where we have experimental
populations, certain section 9 prohibitions (e.g., harm, harass,
capture) that apply to endangered and threatened species may no longer
apply, and a special rule can be developed that contains the
prohibitions and exceptions necessary and appropriate to conserve that
species. This flexibility allows us to manage the experimental
population in a manner that will ensure that current and future land,
water, or air uses and activities will not be unnecessarily restricted
and the population can be managed for recovery purposes.
When we designate a population as experimental, section 10(j) of
the Act requires that we determine whether that population is either
essential or nonessential to the continued existence of the species,
based on the best available information. Nonessential experimental
populations located outside National Wildlife Refuge System or National
Park System lands are treated, for the purposes of section 7 of the
Act, as if they are proposed for listing. Thus, for nonessential
experimental populations, only two provisions of section 7 would apply
outside National Wildlife Refuge System and National Park System lands:
section 7(a)(1), which requires all Federal agencies to use their
authorities to conserve listed species, and section 7(a)(4), which
requires Federal agencies to informally confer with the Service on
actions that are likely to jeopardize the continued existence of a
proposed species. Section 7(a)(2) of the Act, which requires Federal
agencies to ensure that their activities are not likely to jeopardize
the continued existence of a listed species, would not apply except on
National Wildlife Refuge System and National Park System lands.
Experimental populations determined to be ``essential'' to the survival
of the species would remain subject to the consultation provisions of
section 7(a)(2) of the Act.
In order to establish an experimental population we must issue a
proposed regulation and consider public comments on the proposed rule
prior to publishing a final regulation. In addition, we must comply
with NEPA. Also, our regulations require that, to the extent
practicable, a regulation issued under section 10(j) of the Act
represent an agreement between the Service, the affected State and
Federal agencies, and persons holding any interest in land that may be
affected by the establishment of the experimental population (see 50
CFR 17.81(d)).
The flexibility gained by establishment of a nonessential
experimental population through section 10(j) would be of little value
if there is a designation of critical habitat that overlaps it. This is
because Federal agencies would still be required to consult with us on
any actions that may adversely modify critical habitat. In effect, the
flexibility gained from section 10(j) would be rendered useless by the
designation of critical habitat. In fact, section 10(j)(2)(C)(ii)(B) of
the Act states that critical habitat shall not be designated under the
Act for any experimental population determined to be not essential to
the continued existence of a species.
The second goal of the Recovery Plan is to reestablish the silvery
minnow in areas of its historic range. We strongly believe that in
order to achieve recovery for the silvery minnow we would need the
flexibility provided for in section 10(j) of the Act to help ensure the
success of reestablishing the minnow in the middle Pecos River and
lower Rio Grande areas. Use of section 10(j) is meant to encourage
local cooperation through management flexibility. Critical habitat is
often viewed negatively by the public since it is not well understood
and there are many misconceptions about how it affects private
landowners. It is important for recovery of this species that we have
the support of the public when we move towards meeting the second
recovery goal. It is critical to the recovery of the silvery minnow
that we reestablish the species in areas outside of its current
occupied range. The current population of silvery minnow in the middle
Rio Grande is in an imperiled state making it extremely important that
reestablishment into other portions of its historical range occur.
Nonessential experimental populations located within the National
Park System are treated, for purposes of section 7 of the Act, as if
they are listed as threatened (50 CFR 17.83(b)). Moreover, a
nonessential experimental population established in the river reach in
the lower Rio Grande downstream of the Big Bend National Park boundary
(i.e., within the reach designated as a wild and scenic river) to the
Terrell/Val Verde County line, TX, would also be treated, for purposes
of section 7, as a threatened species because this area is a component
of the national wild and scenic rivers system that is administered by
the Secretary of the Interior through
[[Page 39213]]
the National Park Service and is considered part of the National Park
System (16 USC 1281(c)). These lands downstream of Big Bend National
Park are owned by the State of Texas (Black Gap Wildlife Management
Area) and approximately 12 to 15 private landowners. The National Park
Service's management authority in the wild and scenic river designation
currently extends 0.25 mi from the ordinary high water mark. For the
past two years, Big Bend National Park has been working on a management
plan for the ``outstanding remarkable values of the Rio Grande wild and
scenic river'' (F. Deckert, Big Bend National Park, pers. comm. 2002).
The development of the river management plan has involved stakeholders,
including private landowners and the State of Texas. Throughout the
stakeholder-based planning process, the Park has built trust among
diverse and competing interests by encouraging open dialogue regarding
various river management issues. If critical habitat were designated in
this river reach, the introduction of additional Federal influence
could jeopardize the trust and spirit of cooperation that has been
established over the last several years (F. Deckert, pers. comm.,
2002). The designation of critical habitat would be expected to
adversely impact our, and possibly the Park's, working relationship
with the State of Texas and private landowners, and we believe that
Federal regulation through critical habitat designation would be viewed
as an unwarranted and unwanted intrusion. Based on recent conversations
with the National Park Service, their plan and draft EIS are expected
to be completed in 2002, and finalized in 2003. We do not want to
impede the development of a river management plan, which will likely
provide for the management of this river reach consistent with the
recovery needs of the silvery minnow. We believe this area has the
greatest potential for repatriating the species within an area of its
historical range and believe this river reach also has the greatest
potential for developing an experimental population under section 10(j)
of the Act. In order for an experimental population to be successful,
the support of local stakeholders--including the National Park Service,
the State of Texas, private landowners, and other potentially affected
entities--is crucial. In light of this and the fact that the river
management plan will soon be completed, we find that there would be
significant benefits to excluding this river reach from designation of
critical habitat.
On the middle Pecos River, we acknowledge that the New Mexico
Interstate Stream Commission (NMISC) has been actively acquiring and
leasing water rights to meet the State's delivery obligations to Texas
as specified in the Pecos River Compact and pursuant to an Amended
Decree entered by the U.S. Supreme Court. For example, between 1991 and
1999, $27.8 million was spent on the Pecos River water rights
acquisition program. New Mexico faced a shortfall in its Pecos River
Compact delivery obligations for the year 2001 and the possibility of
priority administration, in which the State Engineer would order junior
water rights holders not to use water. Given the tight water situation
and the Compact delivery obligations, we believe that the flexibility
of section 10(j) would be especially appropriate in the middle Pecos.
Economic costs associated with endangered species management and
critical habitat designation for the silvery minnow are discussed in
the draft economic analysis. There are a variety of current and
potential future costs associated with the ongoing water management and
water reallocation on the middle Pecos River. The draft economic
analysis and DEIS discuss and analyze these costs. We used the draft
economic analysis and DEIS to make our preliminary determinations on
the benefits of including or excluding areas from the proposed
designation of critical habitat. Consequently, we invite comments on
the economic and other relevant impacts of all of the areas we have
determined are essential for the conservation of the silvery minnow.
In summary, we believe that the benefits of excluding the middle
Pecos River and lower Rio Grande outweighs the benefits of their
inclusion as critical habitat. Including these areas may result in some
benefit through additional consultations with Federal agencies whose
activities may affect critical habitat. However, overall this benefit
is minimal due to the presence of the Pecos bluntnose shiner and its
critical habitat in the middle Pecos River and the minimal number of
estimated future consultations that are expected to occur within Big
Bend National Park and the wild and scenic river designation that
extends beyond the Park's boundaries. On the other hand, an exclusion
will greatly benefit the overall recovery of the minnow by allowing us
to move forward using the flexibility and greater public acceptance of
section 10(j) of the Act to reestablish minnows in other portions of
its historical range where it no longer occurs. This is likely the most
important step in reaching recovery of this species and we believe that
section 10(j), as opposed to a critical habitat designation, is the
best tool to achieve this objective. Thus, we believe that an exclusion
of these two areas outweighs any benefits that could be realized
through a designation of critical habitat and we have not proposed
these two areas for critical habitat designation.
The Pecos River and lower Rio Grande reaches were historically
occupied but are currently unoccupied by the silvery minnow (Hubbs
1940; Trevino-Robinson 1959; Hubbs et al. 1977; Bestgen and Platania
1991). The silvery minnow occupies less than five percent of its
historic range and the likelihood of extinction from a catastrophic
event is high because of its limited range (Hoagstrom and Brooks 2000,
Service 1999). However, if critical habitat were designated in the
middle Pecos River or lower Rio Grande, the likelihood of extinction of
the species from the occupied reach of the middle Rio Grande would not
decrease because critical habitat designation is not a process to
reestablish additional populations within areas outside of the current
known distribution. We believe that the exclusion of the river reaches
of the middle Pecos River and the lower Rio Grande will not lead to the
extinction of the species.
Exclusions Under Section 3(5)(A) Definition
Section 3(5) of the Act defines critical habitat, in part, as areas
within the geographical area occupied by the species ``on which are
found those physical and biological features (I) essential to the
conservation of the species and (II) which may require special
management considerations and protection.'' As noted above, special
management considerations or protection is a term that originates in
the definition of critical habitat. Additional special management is
not required if adequate management or protection is already in place.
Adequate special management considerations or protection is provided by
a legally operative plan or agreement that addresses the maintenance
and improvement of the primary constituent elements important to the
species and manages for the long-term conservation of the species. We
use the following three criteria to determine if a plan provides
adequate special management or protection: (1) A current plan or
agreement must be complete and provide sufficient conservation benefit
to the species; (2) the plan or agreement must provide assurances that
the
[[Page 39214]]
conservation management strategies will be implemented; and (3) the
plan or agreement must provide assurances that the conservation
management strategies will be effective (i.e., provide for periodic
monitoring and revisions as necessary). If all of these criteria are
met, then the area covered under the plan would no longer meet the
definition of critical habitat. If any management plans are submitted
during the open comment period, we will consider whether these plans
provide adequate special management or protection for the species. We
will use this information in determining which, if any, river reaches
or portions of river reaches within the middle Rio Grande should not be
included in the final designation of critical habitat for the silvery
minnow.
Proposed Critical Habitat
Critical habitat is defined in section 3(5)(A) of the Act as--(i)
the specific areas within the geographic area occupied by a species, at
the time it is listed in accordance with the Act, on which are found
those physical or biological features (I) essential to the conservation
of the species and (II) that may require special management
considerations or protection; and (ii) specific areas outside the
geographic area occupied by a species at the time it is listed, upon a
determination that such areas are essential for the conservation of the
species. ``Conservation,'' as defined by the Act, means the use of all
methods and procedures that are necessary to bring an endangered or a
threatened species to the point at which listing under the Act is no
longer necessary.
Section 4(b)(2) of the Act requires that we base critical habitat
designation on the best scientific and commercial data available,
taking into consideration the economic impact, and any other relevant
impact, of specifying any particular area as critical habitat. We may
exclude areas from critical habitat designation if we determine that
the benefits of exclusion outweigh the benefits of including the areas
as critical habitat, provided the exclusion will not result in the
extinction of the species.
Designation of critical habitat helps focus conservation activities
by identifying areas that are essential to the conservation of the
species and alerting the public and land management agencies to the
importance of an area to conservation. Within areas currently occupied
by the species, critical habitat also identifies areas that may require
special management or protection. Critical habitat receives protection
from destruction or adverse modification through required consultation
under section 7 of the Act with regard to actions carried out, funded,
or authorized by a Federal agency. Where no such Federal agency action
is involved, critical habitat designation has no bearing on private
landowners, State, or Tribal activities. Aside from the added
protection provided under section 7, the Act does not provide other
forms of protection to lands designated as critical habitat.
Designating critical habitat does not, in itself, lead to recovery
of a listed species. Designation does not create a management plan,
establish numerical population goals, prescribe specific management
actions (inside or outside of critical habitat), or directly affect
areas not designated as critical habitat. Specific management
recommendations for areas designated as critical habitat are most
appropriately addressed in recovery, conservation, and management
plans, and through section 7 consultations and section 10 permits. We
recognize that designation of critical habitat may not include all of
the habitat areas that may eventually be determined to be necessary for
the recovery of the species. For these reasons, critical habitat
designations do not signal that habitat outside the designation is
unimportant or may not be required for recovery.
Areas outside the critical habitat designation will continue to be
subject to conservation actions that may be implemented under section
7(a)(1), the regulatory protections afforded by the section 7(a)(2)
jeopardy standard, and the section 9 take prohibition. Federally funded
or assisted projects affecting listed species outside their designated
critical habitat areas may still result in jeopardy findings in some
cases. Similarly, critical habitat designations made on the basis of
the best available information at the time of designation will not
control the direction and substance of future recovery plans, habitat
conservation plans under section 10 of the Act, or other species
conservation planning efforts if new information available to these
planning efforts calls for a different outcome.
Methods
In determining areas that are essential to conserve the silvery
minnow, we used the best scientific and commercial data available. This
included data from research and survey observations published in peer-
reviewed articles, recovery criteria outlined in the Recovery Plan
(Service 1999), data collected from reports submitted by biologists
holding section 10(a)(1)(A) recovery permits, and comments received on
the previous proposed and final rule, draft economic analysis, and
environmental assessment. This proposed rule constitutes our best
assessment of areas needed for the conservation of the silvery minnow.
We must make this determination based on the information available at
this time, and we are not allowed to delay our decision until all
information about the species and its habitat are known, nor are we
required to conduct further surveys or scientific studies on our own.
Southwest Center for Biological Diversity v. Babbitt, 215 F.3d 58 (D.C.
Cir. 2000). We have emphasized areas known to be occupied by the
silvery minnow and described other stream reaches that were identified
in the Recovery Plan and we believe are important for possible
repatriation and recovery (Service 1999).
Primary Constituent Elements
In accordance with section 3(5)(A)(i) of the Act and regulations at
50 CFR 424.12, in determining which areas to propose as critical
habitat, we are required to base critical habitat designations on the
best scientific and commercial data available and to consider those
physical and biological features (primary constituent elements) that
are essential to the conservation of the species and, within areas
currently occupied by the species, that may require special management
considerations or protection. These include, but are not limited to:
space for individual and population growth, and for normal behavior;
food, water, or other nutritional or physiological requirements; cover
or shelter; sites for breeding, reproduction, or rearing of offspring;
and habitats that are protected from disturbance or are representative
of the historical geographical and ecological distributions of a
species.
Diverse habitats are used by the various life-history stages of the
silvery minnow. The following discussion summarizes the biological
requirements of the silvery minnow relevant to identifying the primary
constituent elements of its critical habitat.
The silvery minnow historically inhabited the portions of the wide,
shallow rivers and larger streams of the Rio Grande basin,
predominantly the Rio Grande and the Pecos River (Bestgen and Platania
1991). Adults were common in shallow and braided runs over sand
substrate, and almost never occurred in habitats with bottoms of gravel
or cobble, while young-of-year fish (less than 1 year old) occupy
shallow, low-velocity backwaters with sand-silt substrates (Dudley and
Platania 1997; Platania and Dudley
[[Page 39215]]
1997; Platania 1991; Remshardt et al. 2001). Young-of-year silvery
minnows are infrequently found at the same time in the same habitat as
adults. Stream reaches dominated by straight, narrow, incised (deep)
channels with rapid flows are not typically occupied by the silvery
minnow (Bestgen and Platania 1991).
The habitats most often occupied by silvery minnow were
characterized by low (<20 cm) to moderate depths (31 to 40 cm), little
(<10 cm/s) to moderate (11 to 30 cm/s) water velocity, and silt and
sand substrata (Dudley and Platania 1997; Remshardt et al. 2001). It is
believed that silvery minnow select debris piles, pools, and
backwaters, as habitat with main channel runs generally being avoided
(Dudley and Platania 1997).
The silvery minnow is believed to be a generalized forager, feeding
upon items suspended in the water column and items lying on the
substrate (e.g., plankton, algae, diatoms) (Sublette et al. 1990;
Dudley and Platania 1997; Service 1999). The silvery minnow's elongated
and coiled gastrointestinal tract suggests that detritus (partially
decomposed plant or animal matter), including sand and silt, is scraped
from the river bottom (Sublette et al. 1990). Other species of
Hybognathus have similar food habits, consuming rich organic ooze and
detritus found in silt or mud substrates (Pflieger 1997).
The silvery minnow is a pelagic spawner, with each female capable
of producing an average of 3,000 semi-buoyant, non-adhesive eggs during
a spawning event (Platania 1995; Platania and Altenbach 1998). The
collection of eggs in the middle of May, late May, early June, and late
June suggest a contracted spawning period in response to a spring
runoff or spike (increase in flow that occurs when winter snows melt)
(Service 1999; BOR 2001a). However, the peak of egg production appears
to occur in mid-May (Smith 1998, 1999). If the spring spike occurs at
the wrong time or is reduced, then silvery minnow reproduction could be
impacted. It is unknown if the silvery minnow spawns multiple times
during the summer, although this behavior has been documented in other
species of Hybognathus in other drainages (Lehtinen and Layzer 1988,
Taylor and Miller 1990).
Platania (1995, 2000) found that early development and hatching of
eggs is correlated with water temperature. Silvery minnow eggs raised
in 30 deg.C water hatched in about 24 hours, while eggs reared in
20 deg.C water hatched within 50 hours. Eggs were 1.6 mm (0.06 in) in
size upon fertilization, but quickly swelled to 3 mm (0.12 in).
Recently hatched larval fish are about 3.7 mm (0.15 in) in standard
length and grow about 0.15 mm (0.005 in) in size per day during the
larval stages. Eggs and larvae remain in the drift for 3 to 5 days, and
may be transported from 216 to 359 km (134 to 223 mi) downstream
depending on river flows and habitat conditions (e.g., debris piles,
low velocity backwaters, etc.) (Platania and Altenbach 1998). About
three days after hatching, the larvae begin moving to low velocity
habitats where food (mainly phytoplankton and zooplankton) is abundant
and predators are scarce. Because eggs and larvae can be swept
downstream, where recruitment (individuals added to the breeding
population) of fish may be poor in the current degraded condition of
the middle Rio Grande (e.g., channelization, banks stabilization, levee
construction, disruption of natural processes throughout the
floodplain, etc.), adequate stream length appears to be an important
determinant of reproductive success.
Platania (1995) indicated that the downstream transport of eggs and
larvae of the silvery minnow over long distances may have been,
historically, beneficial to the survival of their populations. This
behavior could have promoted recolonization of reaches impacted during
periods of natural drought (Platania 1995). Alternatively, in a natural
functioning river system (e.g., a natural, unregulated flow regime), a
variety of low-velocity refugia (e.g., oxbows, backwaters, etc.) would
have been available for silvery minnow and lengthy downstream drift of
eggs and larvae may not have been common (J. Brooks, U.S. Fish and
Wildlife Service pers. comm., 2001). Currently, the release of floating
silvery minnow eggs may replenish downstream reaches, but the presence
of the diversion dams (Angostura, Isleta, and San Acacia Diversion
Dams) prevents recolonization of upstream habitats (Platania 1995). As
reaches are depleted upstream, and diversion structures prevent
upstream movements, population decline of the species within stream
reaches may occur through loss of connectivity (i.e., preventing
upstream movement of fish). Silvery minnow, eggs, and larvae are also
transported downstream to Elephant Butte Reservoir, where it is
believed that survival of these fish is highly unlikely because of poor
habitat, and, even more important, because of predation from reservoir
fishes (Service 2001b). The population center (i.e., the stream reach
that contains the majority of adult silvery minnows) is believed to
have moved farther downstream over the last several years (Dudley and
Platania 2001; 2002). For example, in 1997, it was estimated that 70
percent of the silvery minnow population was found in the reach below
San Acacia Diversion Dam (Dudley and Platania 1997). Moreover, during
surveys in 1999, over 95 percent of the silvery minnows captured
occurred downstream of San Acacia Diversion Dam (Dudley and Platania
1999a, Smith and Jackson 2000). Probable reasons for this distribution
include: (1) The spawning of buoyant eggs during the spring and early
summer high flows, resulting in downstream transport of eggs and larval
fish; (2) diversion dams that restrict or preclude the movement of fish
into upstream reaches; and (3) reduction in the amount of available
habitat due to the current degraded condition of some areas within the
middle Rio Grande (e.g., channelization, streambed degradation,
reduction in off-channel habitat, and the general narrowing and
incising of the stream channel) (Platania 1998; Lagassee 1981; BOR
2001).
Most Great Plains streams are highly variable environments. Fish in
these systems (e.g., the Rio Grande) are subjected to extremes in water
temperatures, flow regimes, and overall water quality conditions (e.g.,
quantity of dissolved oxygen). Native fish in these streams often
exhibit life history strategies and microhabitat preferences that
enabled them to cope with these natural conditions. For example,
Matthews and Maness (1979) reported that the synergistic (combined)
effects of high temperature, low oxygen, and other stressors probably
limit fishes in streams of the Great Plains.
The silvery minnow evolved in a highly variable ecosystem, and is
likely more tolerant of elevated temperatures and low dissolved oxygen
concentrations for short periods than other non-native species.
Although little is known about the upper tolerance limits of the
silvery minnow, when water quality conditions degrade, stress
increases, and fish generally die (e.g., see Matthews and Maness 1979;
Ostrand and Wilde 2001). Generally, it is believed that during periods
of low flow or no flow, Great Plains fishes seek refugia in large
isolated pools, backwater areas, or adjoining tributaries (Deacon and
Minckley 1974; Matthews and Maness 1979). Fish in these refugia strive
to survive until suitable flow conditions return and these areas
reconnect with the main river channel. This pattern of retraction and
recolonization of occupied areas in response to flow and other habitat
[[Page 39216]]
conditions is typical of fishes that endure harsh conditions of Great
Plains rivers and streams (Deacon and Minckley 1974; Matthews and
Maness 1979).
Localized reductions in abundance are not typically a concern where
sufficient numbers of the species survive, because stream reaches can
be recolonized when conditions improve. However, habitat conditions
such as oxbows, backwaters, or other refugia that were historically
present on the Rio Grande and Pecos River and were a component of
natural population fluctuations (e.g., extirpation and recolonization)
have been dramatically altered or lost (e.g., Bestgen and Platania
1991; Hoagstrom 2000; BOR 2001a, 2001b). Over the past several decades,
the extent of areas in the Rio Grande and Pecos River that periodically
lost flow has increased due to human alterations of the watersheds and
stream channels and diversion of the streamflows (Service 1994).
Variation in stream flow (i.e., flow regime) strongly affects some
stream fish (Schlosser 1985). For example, juvenile recruitment (that
portion of the young-of-the-year fish that survive to adults and
reproduce) of some stream fish is highly influenced by stable flow
regimes (Schlosser 1985; Hoagstrom 2000). When sufficient flows persist
and other habitat needs are met, then recruitment into the population
is high. Silvery minnows and other Great Plains or desert fishes cannot
currently survive when conditions lead to prolonged periods of low or
no flow of long stretches of river (Hubbs 1974; Hoagstrom 2000). Fish
mortality likely begins from degraded water quality (e.g., increasing
temperatures, p.H., and decreasing dissolved oxygen) and loss of refuge
habitat prior to prolonged periods of low or no flow (J. Brooks, pers.
comm 2001; Ostrand and Wilde 2001). For instance, a reduction of stream
flow reduces the amount of water available to protect against
temperature oscillations, and high temperatures from reduced water flow
frequently kill fish before prolonged periods of no flow occurs (Hubbs
1990).
It is also possible that fish may subsequently die from living
under sub-optimal conditions or that their spawning activities may be
significantly disrupted (Hubbs 1974; Platania 1993b). Such conditions
are in part responsible for the current, precarious status of the
silvery minnow. For example, management of water releases from
reservoirs, evaporation, diversion dams, and irrigation water
deliveries have resulted in dewatered habitat--causing direct mortality
and isolated pools that cause silvery minnow mortality due to poor
water quality (low dissolved oxygen, high water temperatures) and
predation from other fish and predators (e.g., birds, raccoons etc.).
Portions of the middle Rio Grande were dewatered in 1996 to 2001
(Service 2001b; J. Smith, pers. comm. 2001). In 1996, about 58 km (34
mi) out of the 90 km (56 mi) from the San Acacia Diversion Dam to
Elephant Butte Reservoir was dewatered. In 1997, water flows ceased at
the south boundary of the Bosque del Apache National Wildlife Refuge,
resulting in dewatering 22.5 km (14 mi) of silvery minnow habitat. In
1998, the Rio Grande was discontinuous within the Bosque del Apache
National Wildlife Refuge, dewatering about 32 km (20 mi) of habitat. In
1999, flows ceased about one mile upstream of the Bosque del Apache
National Wildlife Refuge northern boundary, dewatering about 39 km (24
mi) of habitat. A similar event occurred in 2000, only not to the
extent of the 1999 drying. In 2001, approximately 14 combined km (9 mi)
of river dried, within the Bosque del Apache National Wildlife Refuge
and south of San Marcial (Smith 2001). Because of recurring prolonged
periods of low or no flow through multiple years, the status of the
silvery minnow has declined (Dudley and Platania 2001; 2002).
We believe it is possible to manage the middle Rio Grande and Pecos
River to avoid prolonged periods of low or no flow and provide
sufficient flowing water during critical time periods, such as from May
to October (Service 2001a, 2001b). For example, in a recent biological
opinion we issued on the effects of actions associated with the U.S.
Bureau of Reclamation's, U.S. Army Corps of Engineers'', and Non-
Federal Entities' discretionary actions related to water management on
the middle Rio Grande, NM, provided, among other elements of a
reasonable and prudent alternative:
river flow from Cochiti Dam to Elephant Butte Reservoir from October
31 to April 30 of each year, with a target flow of 50 cfs at the San
Marcial Floodway gage. Flows will not drop below 40 cfs. From May 1
to June 15 of each year, provide a minimum flow of 50 cfs at the San
Marcial Floodway gage. From June 16 to July 1 of each year, ramp
down the flow to achieve 50 cfs over San Acacia Diversion Dam
(Service 2001b).
A similar biological opinion on the effects on the Pecos bluntnose
shiner of actions associated with the U.S. Bureau of Reclamation's
discretionary actions related to water management on the Pecos River,
in New Mexico, provided for target flows of 35 cfs at the Acme Gage
(Service 2001a). We believe that by providing target flows, it may be
possible to intensively manage and closely monitor the water in middle
Rio Grande and Pecos River. For example, this was the case during the
2001 irrigation season on the middle Rio Grande in which the continued
existence of the silvery minnow was not jeopardized (i.e., the
implementation of the elements of the reasonable and prudent
alternative) (Service 2001b).
The primary constituent elements identified below provide a
qualitative description of those physical and biological features
necessary to ensure the conservation of the silvery minnow. We did not
identify quantitative estimates of specific minimum thresholds (e.g.,
minimum flows or depths), because we believe these estimates vary
seasonally and annually, and by stream reach within the proposed
critical habitat unit. Thus, we believe these thresholds are
appropriately enumerated through section 7 consultations (e.g., see
Service 2001b), which can be more easily changed if new information
reveals effects to critical habitat in a manner or extent not
previously considered (see 50 CFR 402.16(b)). We acknowledge that if
thresholds were established as part of a critical habitat designation,
they could be revised if new data became available (50 CFR 424.12(g));
however, the process of new rulemaking can take years (see 50 CFR
424.17), as opposed to months to reinitiate and complete a formal
consultation (see 50 CFR 402.14). Formal consultation provides an up-
to-date biological status of the species or critical habitat (i.e.,
environmental baseline) which is used to evaluate a proposed action
during formal consultations. Consequently, we believe it is more
prudent to pursue the establishment of specific thresholds through
formal consultation.
This proposed rule does not explicitly state what might be included
as special management for a particular river reach within the middle
Rio Grande. We anticipate that special management actions will likely
be developed as part of the section 7 consultation process. Special
management might entail a suite of actions including: re-establishment
of hydrologic connectivity within the floodplain, widening the river
channel, or placement of woody debris or boulders within the river
channel (J. Smith, pers. comm., 2001).
It is important to note that some areas within the middle Rio
Grande proposed critical habitat unit have the potential for periods of
low or no flow under certain conditions (e.g., see discussion above on
middle Rio Grande). We recognize that the proposed critical
[[Page 39217]]
habitat designation specifically includes some areas that have lost
flow periodically (Middle Rio Grande Conservancy District 1999;
Scurlock and Johnson 2001; D. Coleman, U.S. Fish and Wildlife Service,
pers. comm., 2001). It is difficult to describe the existing conditions
for the river reach below San Acacia Diversion Dam on the middle Rio
Grande. It is our belief that this stretch of river is likely to
experience periods of low or no flow under certain conditions. However,
it is important to note that we are not able to predict with certainty
which areas within the middle Rio Grande will experience these
conditions. We nevertheless believe this area is essential to the
conservation of the silvery minnow because it likely serves as
connecting corridors for fish movements between areas of sufficient
flowing water (e.g., see Deacon and Minckley 1974; Eberle et al. 1993).
Additionally, we believe this area is essential for the natural channel
geomorphology (the topography of the river channel) to maintain or re-
create habitat, such as pools, by removing or redistributing sediment
during high flow events (e.g., see Simpson et al. 1982; Middle Rio
Grande Biological Interagency Team 1993). Therefore, we believe that
the inclusion of an area that has the potential for periods of low or
no flow as proposed critical habitat will ensure the long-term survival
and recovery of silvery minnow. As such, we believe that the primary
constituent elements as described in this proposed rule provide for a
flow regime that allows for short periods of low or no flow. However,
it is difficult to describe the existing conditions of this area (see
above) and to define the primary constituent elements to reflect such a
flow regime. Thus, we are soliciting comments or information related to
the proposed designation of critical habitat in this area that may
experience periods of no or low flow, and in particular the primary
constituent elements and how they relate to the existing conditions
(e.g., flow regime).
If this proposed rule is finalized, Federal agencies with
discretion over actions related to water management that affect
critical habitat will be required to consider critical habitat and
possibly enter into consultation under section 7 of the Act. These
consultations will evaluate whether any Federal discretionary actions
destroy or adversely modify critical habitat to the extent that the
action appreciably diminishes the value of the critical habitat for the
survival and recovery of the species. The adverse modification analysis
will likely evaluate whether the adverse effect of prolonged periods of
low or no flow is of sufficient magnitude (e.g., length of river) and
duration that it would appreciably diminish the value of the critical
habitat unit for the survival and recovery of the silvery minnow. For
example, the effect of prolonged periods of low or no flow on the
habitat quality (e.g., depth of pools, water temperature, pool size,
etc.) and the extent of fish mortality is related to the duration of
the event (Bestgen and Platania 1991). All of these factors will be
analyzed under section 7 of the Act, if they are part of an action
proposed by a Federal agency. Additionally, any Federal agency whose
actions influence water quantity or quality in a way that may affect
proposed critical habitat or the silvery minnow must enter into section
7 consultation with us. Still, these consultations cannot result in
biological opinions that require actions that are outside an action
agency's legal authority and jurisdiction (50 CFR 402.02).
We determined the primary constituent elements of critical habitat
for the silvery minnow based on studies on their habitat and population
biology including, but not limited to: Bestgen and Platania 1991;
Service 1999; Dudley and Platania 1997; 2001; 2002; Platania and
Altenbach 1998; Platania 1991, 2000; Service 2001; Smith 1998, 1999;
Hoagstrom 2000; Remshardt et al. 2001. These primary constituent
elements include:
1. A hydrologic regime that provides sufficient flowing water with
low to moderate currents capable of forming and maintaining a diversity
of aquatic habitats, such as, but not limited to: backwaters (a body of
water connected to the main channel, but with no appreciable flow),
shallow side channels, pools (that portion of the river that is deep
with relatively little velocity compared to the rest of the channel),
eddies (a pool with water moving opposite to that in the river
channel), and runs (flowing water in the river channel without
obstructions) of varying depth and velocity which are necessary for
each of the particular silvery minnow life-history stages; e.g., the
silvery minnow requires habitat with sufficient flows from early spring
(March) to early summer (June) to trigger spawning, flows in the summer
(June) and fall (October) that do not increase prolonged periods of low
or no flow; and a relatively constant winter flow (November to
February), in appropriate seasons;
2. The presence of low velocity habitat (including eddies created
by debris piles, pools, or backwaters, or other refuge habitat (e.g.,
connected oxbows or braided channels)) within unimpounded stretches of
flowing water of sufficient length (i.e., river miles) that provide a
variation of habitats with a wide range of depth and velocities;
3. Substrates of predominantly sand or silt; and
4. Water of sufficient quality to maintain natural, daily, and
seasonally variable water temperatures in the approximate range of
greater than 1 deg.C (35 deg.F) and less than 30 deg.C (85 deg.F) and
reduce degraded water quality conditions (decreased dissolved oxygen,
increased pH, etc.).
We determined that these proposed primary constituent elements of
critical habitat provide for the physiological, behavioral, and
ecological requirements of the silvery minnow. The first primary
constituent element provides water of sufficient flows to reduce the
formation of isolated pools. We conclude this element is essential to
the conservation of the silvery minnow because the species cannot
withstand permanent drying (loss of surface flow) of long stretches of
river. Water is a necessary component for all silvery minnow life-
history stages and provides for hydrologic connectivity to facilitate
fish movement. The second primary constituent element provides habitat
necessary for development and hatching of eggs and the survival of the
silvery minnow from larvae to adult. Low velocity habitat provides
food, shelter, and sites for reproduction, and are essential for the
survival and reproduction of silvery minnow. The third primary
constituent element provides appropriate silt and sand substrates
(Dudley and Platania 1997; Remshardt et al. 2001), which we and other
scientists conclude are important in creating and maintaining
appropriate habitat and life requisites (e.g., food and cover). The
final primary constituent element provides protection from degraded
water quality conditions. We conclude that when water quality
conditions degrade (e.g., increasing water temperatures, pH, decreasing
dissolved oxygen, etc.), silvery minnows will likely be injured or die.
Criteria for Identifying Proposed Critical Habitat
The primary objective in designating critical habitat is to
identify areas that are considered essential for the conservation of
the species, and to highlight specific areas where management
considerations should be given highest priority. In proposing critical
habitat for the silvery minnow, we have reviewed the overall approach
[[Page 39218]]
to the conservation of the silvery minnow undertaken by the local,
State, Tribal, and Federal agencies operating within the species'
historical range since the species' listing in 1994, and the previous
proposed (58 FR 11821) and final critical habitat rules (64 FR 36274).
We have also outlined our conservation strategy to eventually recover
the species (see ``Exclusions Under Section 4(b)(2) of the Act''
section above).
We also considered the features and steps necessary for recovery
and habitat requirements described in the Recovery Plan (Service 1999),
and information provided by our Fishery Resources Office in New Mexico,
and other biologists, as well as utilized our own expertise. We also
reviewed the biological opinion issued June 29, 2001, to the BOR and
U.S. Army Corps of Engineers (Corps) for impacts to the silvery minnow
from water operations in the middle Rio Grande (Service 2001b), the
biological opinion issued to the BOR for discretionary actions related
to water management on the Pecos River, in New Mexico (Service 2001a),
and reviewed available information that pertains to the habitat
requirements of this species, including material received during the
initial public comment period on the proposed listing and designation,
the information received following the provision of the draft economic
analysis to the public on April 26, 1996, the comments and information
provided during the 30-day comment period opened on April 7, 1999,
including the public hearing, and the comments and information received
during the 60-day comment period opened on April 5, 2001, for the
notice of intent to prepare an EIS and public scoping meetings held on
April 17, 23, 24, and 27, 2001 (April 7, 1999; 64 FR 16890).
Since the listing of the silvery minnow in 1994 (59 FR 36988), no
progress has been made toward reestablishing this species within
unoccupied areas (e.g., stream reaches on the middle Pecos, lower Rio
Grande, etc.). Because the silvery minnow has been extirpated from
these areas, Federal agencies have not consulted with us on how their
discretionary actions may affect the silvery minnow. We conclude these
areas (e.g., stream reaches on the middle Pecos and the lower Rio
Grande) are essential to the conservation of the minnow, but we have
not proposed them for designation of critical habitat (see discussion
above).
For these reasons, this proposed critical habitat designation
differs from the final critical habitat designation we made in 1999 (64
FR 36274), and which was subsequently set aside by court order. The
differences also reflect the best scientific and commercial information
analyzed in the context of the final Recovery Plan (see ``Recovery
Plan'' discussion above) and our conservation strategy for this
species. Although we could have proposed two additional critical
habitat units to respond to the Recovery Plan's recommendation that
additional areas are required to achieve recovery (Service 1999) (see
``Recovery Plan'' discussion above), we believe that the inclusion of
these areas could hinder our future conservation strategy (see
``Exclusions Under Section 4(b)(2) of the Act'' section above) and
actually impede recovery of the silvery minnow.
Recovery requires protection and enhancement of existing
populations and reestablishment of populations in suitable areas of
historical range. The Recovery Plan identifies, ``the necessity of
reestablishing silvery minnow in portions of its historical range
outside of the middle Rio Grande in New Mexico.'' The Recovery Plan
identified potential areas for reestablishment of silvery minnow in
certain stream reaches of the Rio Grande and Pecos River. The Recovery
Plan also recommended a thorough analysis of the reestablishment
potential of specific river reaches within the historical range of the
silvery minnow.
Therefore, we have determined that one of the most important goals
to be achieved toward the conservation of this species is the
establishment of secure, self-reproducing populations in areas outside
of the middle Rio Grande, but within the species' historical range
(Service 1999). Thus, we have outlined our conservation strategy for
the silvery minnow (see ``Exclusions Under Section 4(b)(2) of the Act''
section above). Because the species occupies less than five percent of
its historical range and the likelihood of extinction from a
catastrophic event is greatly increased (Hoagstrom and Brooks 2000,
Service 1999), we believe that additional populations should be
established within certain unoccupied reaches (i.e., areas outside of
the current known distribution). Nevertheless, any future recovery
efforts, including repatriation of the species to areas of its
historical range must be conducted in accordance with NEPA and the Act.
The recent trend in the status of the silvery minnow has been
characterized by dramatic declines in numbers and range despite the
fact that this species evolved in rapidly fluctuating, harsh
environments. Moreover, none of the threats affecting the silvery
minnow have been eliminated since the fish was listed (59 FR 36988),
and through the summer of 2000, its status declined (Dudley and
Platania 2001). Although the 2001 population levels of silvery minnow
in the middle Rio Grande were higher than those recorded in 2000, the
known silvery minnow population within the middle Rio Grande has become
fragmented and isolated and is vulnerable to those natural or manmade
factors that might further reduce population size (Dudley and Platania
2001; 2002). Because there have been low spring peak flows in the Rio
Grande in some recent years (e.g., such as in 2000), and a related
decrease in spawning success of the silvery minnow, the population size
of silvery minnow declined through the summer of 2000, but catch rates
in June 2001 were higher than those observed in 2000 (Dudley and
Platania 2001; 2002). We conclude the species' vulnerability to
catastrophic events, such as prolonged periods of low or no flow, have
increased since the species was listed as endangered in 1994 (59 FR
36988).
It is widely recognized that major efforts to repatriate the
silvery minnow to large reaches of its historical habitat in the Rio
Grande and Pecos River will not likely occur without either natural or
induced changes in the river, including changes affecting the existing
fish community, habitat restoration, and coordinated water management
(e.g., see Service 1999). Nevertheless, we conclude that conservation
and recovery of the silvery minnow requires habitat conditions that
will facilitate population expansion or repatriation. As an example, we
are currently involved in developing several efforts to assist in the
conservation and recovery of the silvery minnow and other imperiled
species (e.g., Federal and non-Federal efforts to create a middle Rio
Grande Endangered Species Act Collaborative Program). Any future
habitat restoration efforts conducted by us or other Federal agencies
within the species' historical habitat will be analyzed through NEPA
and will be conducted in accordance with the pertinent sections of the
Act and Federal rulemaking procedures.
Habitat alteration and loss, and non-native competition, predation,
and other effects are inextricably intertwined and have contributed
substantially to the endangered status of the silvery minnow (Service
1999; Dudley and Platania 2001). Furthermore, habitat alteration has
been a significant contributor to non-native fish invasion,
competition, and adverse effects. In turn, non-native species have
likely contributed significantly to the inability of native fish, such
as the silvery minnow, to persist in altered environments (Hubbs
[[Page 39219]]
1990; Propst 1999). However, non-native fish species may have the
potential to be removed or reduced to acceptable levels using a variety
of control or management techniques. For example, the New Mexico State
Game Commission recently passed a regulation limiting the species that
can be used as baitfish in the Pecos River (New Mexico Department of
Game and Fish 2000). As part of this proposed rule (see ``Public
Comments Solicited'' section below) we are seeking further information
regarding the role of unoccupied stream reaches within the historical
range of the silvery minnow, including those reaches with non-native
fish species (e.g., plains minnow) present or those reaches that have
the potential for low or no flow events. We are particularly interested
in assistance on how to describe the existing habitat (e.g., flow)
conditions for the river reach below San Acacia Diversion Dam on the
middle Rio Grande.
It is important to note that the mere presence of non-native
aquatic species does not eliminate an area from being considered for
designation as critical habitat. For example, the relationship between
the introduction of the plains minnow and extirpation of the silvery
minnow is unclear (see discussion above). Although the Recovery Plan
suggested that the plains minnow would be the primary limiting factor
precluding successful reestablishment of the silvery minnow to the
Pecos River (Service 1999), we have little data from which to draw firm
conclusions for the extirpation of the silvery minnow from the Pecos
River. We recognize that any efforts to reestablish the silvery minnow
to unoccupied stream reaches must fully analyze and consider a variety
of habitat management techniques, including the control or management
of non-native fish. Consequently, we invite comments or information
relating to the status of the plains minnow in the Pecos River and this
area not being proposed as critical habitat. We are especially
interested in observations of related species of Hybognathus and any
behavioral or reproductive mechanisms that might provide for ecological
separation in areas where two or more species of Hybognathus co-occur.
Portions of the Pecos River include designated critical habitat for
the Pecos bluntnose shiner (52 FR 5295). The Pecos bluntnose shiner
critical habitat includes a 103 km (64 mi) reach of the Pecos River
extending from a point 16 km (10 mi) south of Fort Sumner, NM
downstream to the De Baca and Chaves County line and a 60 km (37 mi)
reach from near Hagerman, NM, to near Artesia, NM (52 FR 5295). There
are current protections in place for the Pecos bluntnose shiner in the
river reach from Sumner to Brantley Reservoirs on the Pecos river;
consequently, we believe that the designation of critical habitat would
provide little additional benefit for the silvery minnow above the
current jeopardy and adverse modifications standards for the Pecos
bluntnose shiner (see ``Exclusions Under Section 4(b)(2) of the Act''
section above).
The Pecos bluntnose shiner inhabits main-channel habitats with
sandy substrates, low velocity flows, and at depths from 17 to 41 cm (7
to 16 in) (Hatch et al. 1985). Adult Pecos bluntnose shiners use main-
channel habitats, with larger individuals found mainly in more rapidly
flowing water (greater than 40 cm/sec, 1.25 ft/sec), but preferences
for particular depths were not found (Hoagstrom et al. 1995). Young of
the year use the upstream reaches between Sumner and Brantley
Reservoirs, which provide shallow, low velocity habitat. These reaches
also maintain such habitat at high (bankfull) discharge, providing
refugia from swift, deep water. Pecos bluntnose shiner and related
mainstream cyprinids (e.g., silvery minnow) are adapted to exploit
features of Great Plains rivers (Hoagstrom 2000). These fish species
belong to the same guild of broadcast spawners with semi-buoyant eggs
and also spawn during high flow events in the Pecos River, with eggs
and larvae being distributed downstream to colonize new areas (Bestgen
et al. 1989). The habitat features used by the Pecos bluntnose shiner
are largely affected by ongoing Sumner Dam operations (e.g., block
releases). Nevertheless, any flow regime operations in this reach that
benefit the Pecos bluntnose shiner, would also benefit the silvery
minnow. We believe they could both occupy the same river reach in the
future with little to no interspecific competition, in part, because
these species historically co-existed (Bestgen and Platania 1991), and
microhabitat partitioning has been documented for related species of
southwestern fish (Matthews and Hill 1980). Therefore, we believe that
the primary constituent elements for the Pecos bluntnose shiner
critical habitat (e.g., clean permanent water; a main river channel
habitat with sandy substrate; and a low velocity flow (52 FR 5295)) are
compatible with our conservation strategy for repatriating the silvery
minnow. We invite comments or information relating to the current
protections under the Act for the Pecos bluntnose shiner and our
exclusion of this area from the designation of critical habitat for the
silvery minnow.
Lateral Extent of Critical Habitat
The proposed critical habitat designation defines the lateral
extent as those areas bounded by existing levees or in areas without
levees the lateral extent of critical habitat is proposed to be defined
as 91.4 meters (300 feet) of riparian zone adjacent to each side of the
middle Rio Grande. Thus, the lateral extent of proposed critical
habitat does not include areas adjacent to the existing levees but
within the 300-foot lateral width outside the existing levees (i.e.,
these areas are not proposed as critical habitat, even though they may
be within the 300-foot lateral width). If this proposed rule is
finalized, critical habitat will not remove existing levees. We
recognize that these areas can be important for the overall health of
river ecosystems, but these areas have almost no potential for
containing the primary constituent elements because they are protected
from the levees and are rarely inundated by water. Therefore, they are
not included in the proposed designation because we conclude they are
not essential to the conservation of the silvery minnow. Nevertheless,
these and other areas outside the critical habitat designation will
continue to be subject to conservation actions that may be implemented
under section 7(a)(1) of the Act and to the regulatory protections
afforded by the section 7(a)(2) of the Act jeopardy standard and the
section 9 of the Act take prohibition.
For each stream reach within the middle Rio Grande, the up- and
downstream-boundaries are described below. Proposed critical habitat
includes the stream channels within the identified stream reaches and
areas within these reaches potentially inundated during high flow
events. Critical habitat includes the area of bankfull width plus 300
feet on either side of the banks. The bankfull width is the width of
the stream or river at bankfull discharge, i.e., the flow at which
water begins to leave the channel and move into the floodplain (Rosgen
1996). Bankfull discharge, while a function of the size of the stream,
is a fairly consistent feature related to the formation, maintenance,
and dimensions of the stream channel (Rosgen 1996). This 300-foot width
defines the lateral extent of those areas we believe are essential to
the species' conservation. Although the silvery minnow cannot be found
in these areas when they are dry, they likely provided backwater
habitat and were sometimes flooded (Middle Rio Grande Biological
Interagency Team 1993), suggesting
[[Page 39220]]
these areas may provide habitat during high-water periods. As discussed
in this section, we determined that the areas within the 300-foot
lateral width are essential to the conservation of the silvery minnow.
We determined the 300-foot lateral extent for several reasons.
First, the implementing regulations of the Act require that critical
habitat be defined by reference points and lines as found on standard
topographic maps of the area (50 CFR 424.12). Although we considered
using the 100-year floodplain, as defined by the Federal Emergency
Management Agency (FEMA), we found that it was not included on standard
topographic maps, and the information was not readily available from
FEMA or from the Corps for the areas we are proposing to designate. We
suspect this is related to the remoteness of various stream reaches. We
could not find specific aerial photos, maps, or geographic information
systems coverages that accurately delineated vegetation type along the
proposed critical habitat unit. If this information were available, we
could have refined the extent of the lateral width, specific to various
river reaches. Therefore, we selected the 300-foot lateral extent,
rather than some other delineation, for three biological reasons: (1)
The biological integrity and natural dynamics of the river system are
maintained within this area (i.e., the floodplain and its riparian
vegetation provide space for natural flooding patterns and latitude for
necessary natural channel adjustments to maintain appropriate channel
morphology and geometry, store water for slow release to maintain base
flows, provide protected side channels and other protected areas for
larval and juvenile silvery minnow, allow the river to meander within
its main channel in response to large flow events, and recreate the
mosaic of habitats necessary for the survival and recovery of the
silvery minnow); (2) conservation of the adjacent riparian area also
helps provide essential nutrient recharge and protection from sediment
and pollutants, which contributes to successful spawning and
recruitment of silvery minnows; and (3) vegetated lateral zones are
widely recognized as providing a variety of aquatic habitat functions
and values (e.g., aquatic habitat for fish and other aquatic organisms,
moderation of water temperature changes, and detritus for aquatic food
webs) and help improve or maintain local water quality (65 FR 12897;
Middle Rio Grande Biological Interagency Team 1993). We invite comments
or information relating to the 300-foot lateral width of this proposed
designation of critical habitat.
This proposed critical habitat designation takes into account the
naturally dynamic nature of riverine systems and recognizes that
floodplains (including riparian areas) are an integral part of the
stream ecosystem. For example, riparian areas are seasonally flooded
habitats (i.e., wetlands) that are major contributors to a variety of
vital functions within the associated stream channel (Federal
Interagency Stream Restoration Working Group 1998, Brinson et al.
1981). They are responsible for energy and nutrient cycling, filtering
runoff, absorbing and gradually releasing floodwaters, recharging
groundwater, maintaining streamflows, protecting stream banks from
erosion, and providing shade and cover for fish and other aquatic
species. Healthy riparian areas help ensure water courses maintain the
habitat components essential to aquatic species (e.g., see U.S.D.A.
Forest Service 1979; Middle Rio Grande Biological Interagency Team
1993; Briggs 1996), including the silvery minnow. Habitat quality
within the mainstem river channels in the historical range of the
silvery minnow is intrinsically related to the character of the
floodplain and the associated tributaries, side channels, and backwater
habitats that contribute to the key habitat features (e.g., substrate,
water quality, and water quantity) in the middle Rio Grande (Middle Rio
Grande Biological Interagency Team 1993). Among other things, the
floodplain provides space for natural flooding patterns and latitude
for necessary natural channel adjustments to maintain channel
morphology and geometry. We believe a relatively intact riparian area,
along with periodic flooding in a relatively natural pattern, is
important in maintaining the stream conditions necessary for long-term
survival and recovery of the silvery minnow.
Human activities that occur outside the river channel can have a
demonstrable effect on physical and biological features of aquatic
habitats. However, not all of the activities that occur within a
floodplain will have an adverse impact on the silvery minnow or its
habitat. Thus, in determining the lateral extent of critical habitat
along riverine systems, we must consider the definition of critical
habitat under the Act. That is, critical habitat must be determined to
be essential to a species' conservation and, within areas currently
occupied by the species, must be in need of special management
considerations or protection.
We do not believe that the entire floodplain is essential to the
conservation of the species, and we are not proposing to designate the
entire floodplain as critical habitat. However, conservation of the
river channel alone is not sufficient to ensure the survival and
recovery of the silvery minnow. For the reasons discussed above, we
believe the riparian corridors adjacent to the river channel provide an
important function for the protection and maintenance of the primary
constituent elements and are essential to the conservation of the
species.
The lateral extent (width) of riparian corridors fluctuates
considerably on the Rio Grande. The appropriate width for riparian
protection has been the subject of several studies (Castelle et al.
1994). Most Federal and State agencies generally consider a zone 23 to
46 meters (m) (75.4 to 150.9 feet (ft)) wide on each side of a stream
to be adequate to help improve or maintain local water quality (Natural
Resource Conservation Service 1998, Moring et al. 1993, Lynch et al.
1985), although lateral widths as wide as 152 m (500 ft) have been
recommended for achieving flood attenuation benefits (Corps 1999). In
most instances, however, these riparian areas are primarily intended to
reduce (i.e. protect) detrimental impacts to the stream from sources
outside the river channel (e.g., agricultural runoff). Generally, we
believe a lateral distance of 91.4 m (300 ft) on each side of the
stream beyond the bankfull width to be appropriate for the protection
of riparian and wetland habitat and the natural processes involved in
the maintenance and improvement of water quality (e.g., see Middle Rio
Grande Biological Interagency Team 1993). We believe this lateral width
will help ensure the protection of one or more primary constituent
elements (e.g., water quality) of the critical habitat. Thus, within
the area proposed for critical habitat designation on the middle Rio
Grande, we conclude that the 300-foot lateral width is essential to the
conservation of the species.
We did not map critical habitat in sufficient detail to exclude all
developed areas and other lands unlikely to contain primary constituent
elements essential for silvery minnow conservation. Some developed
lands within the 300-foot lateral extent are not considered critical
habitat because they either do not contain the primary constituent
elements or they are not essential to the conservation of the silvery
minnow. Lands located within the exterior boundaries of the proposed
critical habitat designation, but not considered critical habitat
include:
[[Page 39221]]
existing paved roads, bridges, parking lots, dikes, levees, diversion
structures, railroad tracks, railroad trestles, water diversion canals
outside of natural stream channels, active gravel pits, cultivated
agricultural land, and residential, commercial, and industrial
developments. These developed areas do not contain any of the primary
constituent elements and do not provide habitat or biological features
essential to the conservation of the silvery minnow, and generally will
not contribute to the species' recovery. However, some activities in
these areas like activities in other areas not included within the
designation (if Federally funded, authorized, or carried out) may
affect the primary constituent elements of the proposed critical
habitat and, therefore, may be affected by the critical habitat
designation, as discussed later in this proposed rule.
Reach-by-Reach Analysis
We conducted a reach-by-reach analysis of the entire known
historical range of the silvery minnow to evaluate and select stream
reaches that require special management or protection, or are essential
to the conservation of the species. As identified in the Recovery Plan
(see ``Recovery Plan'' discussion above), important factors we
considered in determining whether areas were essential to the
conservation of the species include presence of other members of the
reproductive guild (e.g. pelagic spawners, species with semibuoyant
eggs, etc.), habitat suitability (e.g., appropriate substrate), water
quality, and presence of non-natives (competitors, predators, other
species of Hybognathus, etc.). These important factors were evaluated
in conjunction with the variable flow regime of each reach. Each of the
stream reaches, to some extent, has a varying flow regime. However, the
fact that a river reach may at times experience a prolonged period of
low or no flow as a result of a varying flow regime does not preclude
the area from being considered essential to the conservation of the
species and, further, being proposed as critical habitat. Based on our
reach-by-reach analysis, we have determined which reaches are essential
for the conservation of the species.
We are proposing to designate the middle Rio Grande as a critical
habitat unit. This unit contains all of the primary constituent
elements during some or all of the year (see the ``Regulation
Promulgation'' section of this rule for exact descriptions of
boundaries of the proposed critical habitat unit). We conclude that the
proposed critical habitat unit can provide for the physiological,
behavioral, and ecological requirements of the silvery minnow. The
proposed critical habitat unit is within the middle Rio Grande from
immediately downstream of Cochiti Reservoir to the Elephant Butte
Reservoir Dam, including the tributary Jemez River from Jemez Canyon
Reservoir to its confluence with the Rio Grande. Although we determined
that other areas are essential to the conservation of the silvery
minnow (i.e., the middle Pecos River from immediately downstream of
Sumner Dam to Brantley Dam, NM; and the lower Rio Grande from the
upstream boundary of Big Bend National Park to Terrell/Val Verde County
line, TX), these areas are not proposed as critical habitat. A
description of each stream reach within the silvery minnow's historical
range is provided below. We also provide our reasons for determining
whether each reach is essential to the conservation of the species and
whether we are proposing or not proposing critical habitat for each of
the identified reaches. We conclude that we can secure the long-term
survival and recovery of this species with the establishment of future
experimental populations under section 10(j) of the Act, along with the
proposed critical habitat unit in the middle Rio Grande.
The historical range of the species in the Rio Grande is from
Espa[ntilde]ola, NM, to the Gulf of Mexico, and, in the Pecos River (a
major tributary of the Rio Grande) from Santa Rosa, NM, downstream to
its confluence with the Rio Grande (Pflieger 1980; Bestgen and Platania
1991). We separated the historical range of the silvery minnow into 12
stream reaches that include: (1) Upstream of Cochiti Reservoir to the
confluence of the Rio Chama and Rio Grande, New Mexico; (2) Middle Rio
Grande from Cochiti Reservoir downstream to the Elephant Butte Dam,
including the Jemez River immediately downstream of Jemez Canyon
Reservoir to the confluence of the Rio Grande; (3) Downstream of
Elephant Butte Dam to the Caballo Dam, New Mexico; (4) downstream of
Caballo Dam, New Mexico, to the American Dam, Texas; (5) downstream of
American Reservoir, to the upstream boundary of Big Bend National Park,
Texas; (6) the upstream boundary of Big Bend National Park to the
southern boundary of the wild and scenic river designation at Terrell/
Val Verde County line, Texas; (7) the Terrell/Val Verde County line,
Texas to the Amistad Dam, Texas; (8) downstream of Amistad Dam to the
Falcon Dam, Texas; (9) downstream of the Falcon Dam to the Gulf of
Mexico, Texas, (10) Pecos river from Santa Rosa Reservoir to Sumner
Dam, Guadalupe County, New Mexico, (11) Sumner Dam to the Brantley Dam,
NM; (12) Brantley Dam, NM to the Red Bluff Dam, TX; and (13) Red Bluff
Dam to the confluence of the Rio Grande, TX. Each of these reaches are
analyzed below.
1. Upstream of Cochiti Reservoir to the confluence of the Rio Chama
and Rio Grande, Rio Arriba, Sante Fe, and Sandoval Counties, NM.
Currently, this reach is dominated by cool water, which is not
considered suitable for the silvery minnow (Platania and Altenbach
1998). The majority of this reach is bounded by canyons, with substrate
dominated by gravel, cobble, and boulder (Service 1999). The flow
regime is also highly variable seasonally because of irrigation and
other agricultural needs, and recreational and municipal uses. This
river reach is highly manipulated by releases from El Vado and Abiquiu
Reservoirs (J. Smith, pers. comm. 2001). Furthermore, silvery minnow
populations may have been historically low for some areas of this
reach, supporting only small outlier populations (Bestgen and Platania
1991). Currently, this reach is dominated by cool or cold water
species, which have almost completely replaced the native fish species
(Service 1999). For these reasons, we conclude that habitat for silvery
minnow within this stream reach is generally degraded and unsuitable,
and is not essential to the conservation of the silvery minnow.
Therefore, this stream reach is not proposed as critical habitat.
2. Middle Rio Grande from Cochiti Reservoir downstream to the
Elephant Butte Dam, including the Jemez River immediately downstream of
Jemez Canyon Reservoir to the confluence of the Rio Grande, Sandoval,
Bernalillo, Valencia, and Socorro Counties, NM. The middle Rio Grande
is currently occupied, and the status of the silvery minnow within this
segment is unstable (Bestgen and Platania 1991; Dudley and Platania
1999; Platania and Dudley 2001; 2002). This area currently contains the
primary constituent elements (described above) during all or a part of
the year and is considered suitable habitat for the silvery minnow, as
shown by the presence of the silvery minnow within this reach. The
river reaches in the proposed critical habitat unit are degraded from
lack of floodplain connectivity, non-native vegetation, stabilized
banks (e.g., jetty jacks), streambed aggradation, and decreasing
channel width, increasing depths, and increasing velocities (BOR 2001a;
Service 2001b). Thus,
[[Page 39222]]
conservation of the silvery minnow requires stabilizing populations
within the middle Rio Grande, including special management
considerations or protections (e.g., habitat management and/or
restoration).
The middle Rio Grande is essential to the conservation of the
silvery minnow (see discussion below), and therefore we propose the
following reaches as a critical habitat unit. This proposed critical
habitat unit does not include the ephemeral or perennial irrigation
canals and ditches, including the LFCC (i.e., downstream of the
southern boundary of Bosque del Apache National Wildlife Refuge to the
headwaters of Elephant Butte Reservoir) that are adjacent to a portion
of the stream reach within the middle Rio Grande because these areas do
not offer suitable refugia and are not useful for recovery of the
silvery minnow. The stream reaches in the proposed middle Rio Grande
critical habitat unit include (see the Regulation Promulgation section
of this rule for exact descriptions of boundaries of this proposed
critical habitat unit):
a. Jemez Canyon Reach--8 km ( 5 mile) of river immediately
downstream of Jemez Canyon Reservoir to the confluence of the Rio
Grande. This reach of river is manipulated by releases from Jemez
Canyon Reservoir. Releases from this reservoir are determined by
downstream needs and flood events occurring in the Jemez River. Silvery
minnows historically occupied this reach of the Jemez River and have
recently been collected there (Sublette et al. 1990; Corps 2001). The
water within this reach is continuous to the confluence with Rio Grande
and currently contains the primary constituent elements (described
above) during all or a part of the year. Although this reach currently
provides suitable habitat for the silvery minnow, we believe that it is
important to ensure that special management actions are implemented
within this stream reach. We also conclude that this area is essential
to the conservation and contains the primary constituent elements for
the silvery minnow. This area is essential because the additional loss
of any habitat that is currently occupied could increase the likelihood
of extinction (Hoagstrom and Brooks 2000, Service 1999). Moreover, if
the species or habitat were severely impacted within this reach, the
continued existence of silvery minnows in downstream reaches would be
affected (i.e., the extirpation of fish within this reach would create
a very unstable population within the downstream reaches). Thus, we
propose this section of the Jemez River as critical habitat for the
silvery minnow.
b. Cochiti Reservoir Dam to Angostura Diversion Dam (Cochiti
Reach)--34 km (21 mile) of river immediately downstream of Cochiti
Reservoir to the Angostura Diversion Dam. This reach is somewhat
braided and is dominated by clear water releases from Cochiti
Reservoir. Since Cochiti Reservoir was filled, the downstream substrate
has changed from a course sand to a gravel substrate (Baird 2001).
Silvery minnows were collected immediately downstream of Cochiti Dam in
1988 (Platania 1993). Although the Cochiti reach has not been monitored
since the mid-1990s (Platania 1995), it is believed that silvery minnow
may still be present within this reach, but reduced in abundance. For
example, silvery minnows were documented near the Angostura Diversion
Dam in 2001 (Platania and Dudley 2001; 2002; Service 2001c). In this
reach, water releases from Cochiti Reservoir have scoured sand from the
stream channel and reduced the downstream temperatures (Bestgen and
Platania 1991; Platania 1991; 59 FR 36988; Service 1999; Hoagstrom
2000). These effects (e.g., low water temperatures) may inhibit or
prevent reproduction among Rio Grande Basin Cyprinids (Platania and
Altenbach 1998), but it is unknown if water temperatures have affected
silvery minnow reproduction within this reach. Although reservoirs can
modify river flows and habitat (e.g., the downstream river reaches have
increased in depth and water velocity) (Hoagstrom 2000), we believe
this river reach is essential to the conservation of the silvery minnow
because we believe it is still occupied by the species and contributes
to its survival in downstream reaches (i.e., the eggs and larvae of the
silvery minnow drift in the water column and may be transported
downstream depending on river flows and habitat conditions). We
reviewed aerial photographs from 1997, and have determined that the
river through this reach is braided in areas and contains many side
channels. We also spoke with the Corps and conclude there is a high
potential to increase the amount of suitable habitat (e.g., debris
piles, low velocity backwaters, side channels, etc.) within the entire
reach, but particularly in the proximity of the confluences of Galisteo
Creek and the Rio Grande and the Sante Fe River and the Rio Grande (D.
Kreiner, U.S. Army Corps of Engineers, pers. comm. 2001). Thus, we
conclude special management in this reach is needed. We conclude that
this area contains suitable habitat for the silvery minnow and contains
the primary constituent elements (described above) during all or a part
of the year. Therefore, this reach is proposed as critical habitat.
c. Angostura Diversion Dam to Isleta Diversion Dam (Angostura
Reach)--61 km (38 mile) of river immediately downstream of the
Angostura Diversion Dam to the Isleta Diversion Dam. Silvery minnows
and suitable habitat are still present throughout this reach of the
river, although their abundance appears to be low (Dudley and Platania
2001; 2002). This reach is relatively wide 183 m (600 ft) and the
substrate is mostly course sand to gravel (Baird 2001). The river bank
within this reach is dominated by bank stabilization (e.g., jetty
jacks), which has led to the floodplain being predominantly
disconnected from the river. Bank stabilization devices and other flood
control operations (e.g., channelization) have led to flows that seldom
exceed channel capacity, such that the river dynamics which likely
provided backwater habitat for the silvery minnow no longer function
naturally. These river processes historically shaped and reshaped the
river, constantly redefining the physical habitat and complexity of the
river. Historical large flow events allowed the river to meander,
thereby creating and maintaining the mosaic of habitats necessary for
the survival of the silvery minnow and other native fish (Middle Rio
Grande Biological Interagency Team 1993). We conclude that the creation
and maintenance of these habitats is essential to the conservation of
the silvery minnow. We believe that special management is necessary in
this and other downstream reaches within the middle Rio Grande to
create and maintain the habitat complexity (e.g., backwater areas,
braided channels, etc.) that was historically present, but may not
currently present, in these river reaches. This reach currently
contains the primary constituent elements (described above) during all
or a part of the year. Thus, we propose this reach as critical habitat.
d. Isleta Diversion Dam to San Acacia Diversion Dam (Isleta Reach)-
-90 km (56 mi) of river immediately downstream of the Isleta Diversion
Dam to the San Acacia Diversion Dam. The river bank within this reach
is also dominated by bank stabilization (e.g., jetty jacks), and the
floodplain is predominantly disconnected from the river. The substrate
is mostly sand and silt and there are many permanent islands within the
river channel (J. Smith, pers. comm. 2001). This reach provides
continuous water flow in most years with infrequent periods of low or
[[Page 39223]]
no flow (Service 2001b). Nevertheless, flows vary markedly in
magnitude, from high spring to low summer flows. The variable flow
regime is a result of irrigation demand, irrigation returns (e.g.,
augmented flow), precipitation, temperature, and sediment transport.
This reach also contains numerous arroyos and small tributaries that
provide water and sediment during rainstorm events, which may
periodically augment river flows (Service 2001b; J. Smith, pers. comm.
2001). Silvery minnows and suitable habitat are still present
throughout this reach of the river; however, abundance appears to be
low (Dudley and Platania 2001; 2002). Nevertheless, we conclude that
this area is essential to the conservation of the silvery minnow
because the additional loss of any habitat that is currently occupied
could increase the likelihood of extinction (Hoagstrom and Brooks 2000,
Service 1999). Similarly, if the species or habitat were severely
impacted within this reach, the continued existence of silvery minnows
in downstream reaches would be affected (i.e., the extirpation of fish
within this reach would create a very unstable population within the
downstream reaches). This reach currently contains the primary
constituent elements (described above) during all or a part of the
year. We believe that special management is necessary within this reach
to create and maintain the habitat complexity (e.g., backwater areas,
debris piles, meandering river, etc.) that was historically, but may
not currently be associated with this reach. Thus, we propose this
reach as critical habitat.
e. San Acacia Diversion Dam to the Elephant Butte Dam (San Acacia
Reach)--147 km (92 mi) of river immediately downstream of the San
Acacia Diversion Dam to the Elephant Butte Dam. We selected Elephant
Butte Dam as the boundary of the proposed critical habitat because it
is a stationary structure. Nevertheless, the area inundated by the
reservoir does not provide those physical or biological features
essential to the conservation of the species and is specifically
excluded from the proposed critical habitat. We define the reservoir as
that part of the body of water impounded by Elephant Butte Dam where
the storage waters are lentic (relatively still waters) and not part of
the lotic (flowing water) river channel.
The channel width within this reach varies from approximately 15 m
(50 ft) to approximately 198 m (650 ft). The substrate is mostly sand
and silt. The flow regime within this reach was historically, and is
currently, highly variable. In fact, this stretch may not have provided
continuous flow in some years prior to the 1900s (Middle Rio Grande
Conservancy District 1999; Scurlock and Johnson 2001). As described
above, we are soliciting comments or information relating to the
proposed designation of critical habitat in this reach, which may
experience periods of no or low flow.
Currently, the river channel has been highly modified by water
depletions from agricultural and municipal use, dams and water
diversion structures, bank stabilization, and the infrastructure for
water delivery (e.g., irrigation ditches). These modifications have led
to the loss of sediment, channel drying, separation of the river from
the floodplain, and changes in river dynamics and resulting channel
morphology. Consequently, this reach requires special management
considerations similar to those discussed above. This reach currently
contains the primary constituent elements (described above) during all
or a part of the year. Although the silvery minnow continues to be
widespread within this reach with higher abundance than the Angostura
or Isleta reaches (Dudley and Platania 2001; 2002), the variable flow
regime and modifications to the river have increased the potential for
short and long-term impacts not only to the silvery minnow, but also to
its habitat. Thus, we determine that this area is essential to the
conservation of the species and in need of special management
considerations or protections; we propose this reach as critical
habitat.
3. Downstream of Elephant Butte Reservoir to the Caballo Dam,
Sierra County, NM. This short 26-km (16-mile) reach is highly
channelized with widely variable flow regimes. Construction of Elephant
Butte and Caballo Reservoirs in 1916 and 1938, respectively, severely
altered the flows and habitat within this reach (Bestgen and Platania
1991). The silvery minnow has not been documented within this reach
since 1944 (Service 1999). This river reach is currently highly
channelized to expedite water deliveries and very few native fish
remain (Propst et al. 1987; International Boundary and Water Commission
2001). This reach is subject to prolonged periods of low or no flow and
there is no spring runoff spike (Service 1999). Altered flow regimes
will continue to affect habitat quality in this reach and it does not
contain suitable habitat for the silvery minnow. The stream length in
this reach is inadequate (e.g., less than 134 to 223 mi) to ensure the
survival of downstream drift of eggs and larvae and recruitment of
adults (Platania and Altenbach 1998). We conclude this area is not
essential to the conservation of the species. Therefore, this river
reach is not proposed as critical habitat.
4. Downstream of Caballo Dam to American Reservoir Dam, Sierra and
Do[ntilde]a Ana, Counties, NM and El Paso, County, TX. This
approximately 176-km (110 mile) reach has a highly regulated flow
regime from releases of water stored in Caballo Reservoir. This reach
is also highly canalized with winter flows near zero in the upper
portions and does not contain suitable habitat for the silvery minnow
(Service 1999; IBWC 2001a). Silvery minnow have not been reported from
this reach since 1944 (Bestgen and Platania 1991, Service 1999). The
reach is currently inhabited by many non-native fish species (IBWC
2001a). Due to lack of suitable habitat, diminished and highly
regulated flow (IBWC 2001a), this reach of river no longer contains
suitable habitat for the silvery minnow and is not essential to the
conservation of the silvery minnow. Thus, this reach is not proposed as
critical habitat.
5. Downstream of American Reservoir to the upstream boundary of Big
Bend National Park, El Paso, Hudspeth, and Presidio, Counties, TX.
Portions of this reach, primarily upstream of Presido, TX, are
continually dewatered, especially between Fort Quitman and Presidio
(Hubbs et al. 1977; Department of Interior 1998). River flow is
augmented downstream of Presido by waters flowing from the Rio Conchos.
The near-continuous input of municipal waste has led to a deterioration
of water quality, with corresponding changes to the ichthyofauna (fish
species assemblage within a region) (Hubbs et al. 1977; Bestgen and
Platania 1988; IBWC 1994; El-Hage and Moulton 1998a). Flows in this
reach consist of a blend of raw river water; treated municipal waste
from El Paso, TX; untreated municipal water from Juarez, Mexico;
irrigation return flow; and the occasional floodwater (Texas Water
Development Board 2001). For example, water temperature patterns can be
elevated and oxygen levels decreased by the input of various pollutants
(e.g., nitrogen, phosphorus) (Texas Water Development Board 2001; IBWC
2001b). Water quality is believed to improve farther downstream of the
confluence of the Rio Conchos and Rio Grande. The development of
agriculture and population growth of this area has resulted in a
decrease of water quantity and quality, which has had a significant
impact on the range and distribution of many fish species within this
reach
[[Page 39224]]
(IBWC 1994; El-Hage and Moulton 1998a). There are no current or museum
records of silvery minnow from this reach (Service 1999). Because of
dewatering upstream and the degraded water quality, we believe this
reach of river would never provide suitable habitat for the silvery
minnow. Thus, this river reach is not essential to the conservation of
the silvery minnow and is not proposed as critical habitat.
6. The upstream boundary of Big Bend National Park (3.2 km, 2 mi
downstream of Lajitas), Brewster County, to the southern boundary of
the wild and scenic river designation at Terrell/Val Verde County line,
TX. This approximately 368-km (230-mile) reach of the lower Rio Grande
was historically occupied but is currently unoccupied by the silvery
minnow (Hubbs 1940; Trevino-Robinson 1959; Hubbs et al. 1977; Bestgen
and Platania 1991). The continuing presence of members of the pelagic
spawning guild (e.g., speckled chub and Rio Grande shiner) are evidence
that the lower Rio Grande through Big Bend National Park area may
support reestablishment of silvery minnow (Platania 1990; IBWC 1994).
Moreover, water quality, compared to the reach upstream of the Park, is
greatly improved in this reach from the many freshwater springs within
Big Bend National Park (MacKay 1993; R. Skiles, pers. comm. 2001; IBWC
1994). This area is protected and managed by the National Park Service
and the river currently supports a relatively stable hydrologic regime
(R. Skiles, pers. comm. 2001). The National Park Service's management
authority in the wild and scenic river designation currently extends
0.25 mi from the ordinary high water mark. Thus, the area designated as
a wild and scenic river outside of Big Bend National Park is currently
managed by the National Park Service under their authorities and is
considered part of the National Park Service System. As discussed
above, we have determined that recovery of the silvery minnow requires
reestablishing populations outside of the middle Rio Grande (see
``Recovery Plan'' discussion above), and should include areas within
the lower Rio Grande. Because the silvery minnow has been extirpated
from this reach, Federal agencies have determined their actions will
not adversely affect the silvery minnow and therefore have not
consulted with the Service under section 7(a)(2) on their actions
related to this reach. We believe it is important to ensure that the
assistance of Federal agencies, the State of Texas resource agencies,
and non-Federal entities in future recovery actions (e.g., the
establishment of an experimental population) are not compromised.
Although Big Bend National Park expressed support for a critical
habitat designation for the silvery minnow within the National Park,
they also indicated that if areas outside the National Park, but within
the wild and scenic river were included, their attempts at developing a
river management plan could be compromised (F. Deckert, Big Bend
National Park, pers. comm.).
We have determined that this reach is essential to the conservation
of the silvery minnow. However, our conservation strategy for the
silvery minnow is to establish populations within its historical range
under section 10(j) of the Act, and this could include all or portions
of this stream reach. We believe that this area will contribute to the
recovery of the silvery minnow, but have not proposed this stream reach
for designation of critical habitat. As indicated in the ``Public
Comments Solicited'' section of this rule we are seeking comments on
whether this reach should or should not be designated as critical
habitat based upon the factors discussed in this proposed rule and any
other relevant information that you believe should be considered in our
analysis. We are also soliciting comments on the applicability of an
experimental population under section 10(j) of the Act to provide for
conservation and recovery of the silvery minnow within this reach of
its historical range.
7. The Terrell/Val Verde County line, TX to the Amistad Dam, TX.
This short reach is highly influenced by the Amistad Dam at its
terminus. It is also believed that introduced fish played a role in the
extirpation of silvery minnow in this reach (Bestgen and Platania
1991). Water quality conditions within this reach are generally
degraded, and are also a concern for this reach, particularly during
low-flow conditions (Texas Water Development Board 2001; Texas Natural
Resource Conservation Commission 1996). For all these reasons, we do
not believe that this river reach is essential to the conservation of
the silvery minnow; therefore, it is not proposed as critical habitat.
8. Downstream of the Amistad Dam to the Falcon Dam, Val Verde,
Kinney, Maverick, Web, Zapata, and Starr Counties, TX. This reach does
provide continuous base flows ranging between 500 and 3000 cfs (Service
1999), but the reach is highly urbanized and has many instream barriers
(e.g., earthen dams) at Maverick, Eagle Pass, and Indio that would
prevent movements of silvery minnow. Water quality is also a potential
concern for this reach, particularly during low-flow conditions (Texas
Water Development Board 2001; Texas Natural Resource Conservation
Commission 1996). This reach is heavily channelized with little to no
stream braiding and, in areas inappropriate substrate (e.g., cobble).
There is no suitable habitat for the silvery minnow within this reach,
and the species was last recorded here in the 1950s (Service 1999). The
fish community within this reach is dominated by warm water non-native
predators (Platania 1990; Service 1999). Because this reach does not
have suitable habitat for the silvery minnow and water quality during
variable flow conditions is a concern, this reach of river is not
essential to the conservation of the silvery minnow and is not proposed
as critical habitat.
9. Downstream of Falcon Reservoir to the Gulf of Mexico, Starr,
Hildago, and Cameron, Counties, TX. The silvery minnow historically
occupied this reach of river (Service 1999). In fact, the type locality
(the location from which the species was originally described) for the
species is Brownsville, TX (Hubbs and Ortenburger 1929). However, the
last collection of the silvery minnow occurred in 1961 just downstream
of Falcon Reservoir (Bestgen and Platania 1991). This flow regime of
this reach of the Rio Grande is highly influenced by releases from
Falcon Reservoir. Most of the tributary inflow is controlled or
influenced by small impoundments off the main channel of the river. The
lower portion of this reach is often dewatered with the river flow
stopping before the confluence with the Gulf of Mexico (IBWC 2001b).
The fish community in this reach of the Rio Grande has had a
significant shift toward estuarine (a mixture of fresh and salt water)
type species (IBWC 1994; Contreras-B. and Lozano-V.1994). There has
also been a significant loss of the native fish fauna in the Mexican
tributaries in the last several decades (Hubbs et al. 1977 Almada-
Villela 1990; Platania 1990), apparently from poor water quality (e.g.,
see Texas Water Development Board 2001; Texas Natural Resource
Conservation Commission 1996). Finally, invasive weeds (e.g., hydrilla
and hyacinth) have clogged many areas of this reach and have reduced
the amount of dissolved oxygen in the water (IBWC 2001b). Because this
reach does not have suitable habitat, there appears to be little
benefit in trying to intensively managing the flow regime in this reach
of river. For these reasons, this reach is not considered essential to
[[Page 39225]]
the conservation of the silvery minnow and is not proposed as critical
habitat.
10. Pecos River from Santa Rosa Reservoir to Sumner Dam, Guadalupe
County, NM. This reach is approximately 89 km (55 mi) and is typified
by wide fluctuations in flow regimes from upstream releases from Santa
Rosa Reservoir (Hoagstrom 2000). Within this reach there is one
diversion at Puerto del Luna, NM. The silvery minnow has not been
collected within this reach since 1939 (Bestgen and Platania 1991;
Service 1999). The habitat in this reach is not suitable for the
silvery minnow because much of the surrounding topography is composed
of steep cliffs and canyons (Hoagstrom 2000). Canyon habitat does not
provide suitable habitat (e.g., shallow, braided, streams with sandy
substrates) for the silvery minnow (Bestgen and Platania 1991; Dudley
and Platania 1997; Remshardt et al. 2001). Due to the short length of
this reach, fluctuations in the flow regime, and the absence of
suitable habitat for the silvery, this reach of river is not essential
to the conservation of the silvery minnow and is not proposed as
critical habitat.
11. Middle Pecos Reach--approximately 345 km (214 mi) of river
immediately downstream of Sumner Reservoir to the Brantley Reservoir
Dam in De Baca, Chaves, and Eddy Counties, NM. The Pecos River was
historically occupied but is currently unoccupied by the silvery minnow
(Bestgen and Platania 1991). In fact, the silvery minnow was once one
of the most common fish species present between Sumner and Avalon
Reservoir (the area currently inundated by Brantley Reservoir) (Bestgen
and Platania 1991). The Pecos River can support a relatively stable
hydrologic regime between Sumner and Brantley Reservoirs, and, until
summer 2001, this stretch maintained continuous flow for about the last
10 years (D. Coleman, pers. comm. 2001). For example, groundwater
seepage areas and base flow supplementation from Sumner Dam bypasses
can offer a degree of stability for the river flow, especially during
low flow periods (Hatch et al. 1985; Service 2001). Still, segments of
this river reach were dewatered for at least 5 days during summer 2001
(D. Coleman, pers. comm. 2001). Although springs and irrigation return
flows maintain water flow in the lower portions of this river reach
during times when no water is being released from Sumner Dam, periods
of low discharge or intermittency have the potential to impact much of
the suitable habitat within portions of this reach (Service 2001).
After the construction of Sumner Dam, major channel incision
occurred during the 1949 to 1980 period, accompanied by salt cedar
proliferation along the river banks (Hoagstrom 2000). High velocity
flows within the incised (deep) river channel have the ability to
displace eggs from pelagic spawners such as the silvery minnow. This
channel incision also reduced the areas of low velocity habitat within
this river reach (Hoagstrom 2000). Recently lengthy reservoir releases
such as those that occurred in 1988 (36 days) and in 1989 (56 days),
have been shortened to about 10 days, which has benefitted species such
as the Pecos bluntnose shiner (Service 2001). Nevertheless, historical
block releases of water from Sumner Reservoir have modified river flows
and habitat (e.g., the downstream river reaches have increased in depth
and water velocity) (Hoagstrom 2000).
The recovery of the silvery minnow requires reestablishing
populations outside of the middle Rio Grande (Service 1999). We believe
that repatriation is required outside of the area presently occupied by
the species (i.e., the middle Rio Grande) to ensure the recovery of the
silvery minnow (50 CFR 424.12(e)) (see ``Recovery Plan'' discussion
above). We recognize that habitat within this river reach is degraded,
but believe this reach within the middle Pecos River may provide one of
the most promising areas for conducting recovery efforts because we
believe it still contains habitat suitable for the silvery minnow
(Hoagstrom 2000). For example, the continuing presence of members of
the pelagic spawning guild (e.g., speckled chub, Rio Grande shiner,
Pecos bluntnose shiner) is evidence that this reach of the Pecos River
contains habitat suitable for the silvery minnow and may support
reestablishment of the species (Hoagstrom 2000).
Federal agencies have not consulted with us on how their actions
will affect the silvery minnow, because the species no longer occurs
within the Pecos River (D. Coleman, pers. comm. 2001). Because habitat
suitable for the silvery minnow is still present within this river
reach, we find that this stream reach is essential to the conservation
of the species. Although we have determined that this reach is
essential to the conservation of the silvery minnow, we have not
proposed this area for designation of critical habitat (see
``Exclusions Under Section 4(b)(2) of the Act'' section above). Our
conservation strategy is to develop, through Federal rulemaking
procedures, one or more experimental populations within the historical
range of the silvery minnow. We believe this river reach may provide a
suitable area for an experimental population. Consequently, we are
soliciting comments on the applicability of an experimental population
under section 10(j) of the Act to provide for conservation and recovery
of the silvery minnow in areas of currently suitable habitat within its
historical range.
12. Downstream of Brantley Reservoir, Eddy County, NM to Red Bluff
Reservoir, Loving and Reeves Counties, Texas. This reach is short, with
a highly variable flow regime that is dependent on agricultural demand.
This reach is also highly segmented with small closely placed
impoundments (e.g., permanent and temporary diversion dams) that pond
water, impede fish movements, and would not allow for adequate stream
length (e.g., 134 to 223 mi) to ensure the survival of downstream drift
of eggs and larvae and recruitment of adults (Platania and Altenbach
1998). Additionally, agricultural and oil field pollution and permian
salts (i.e., brine) are added to the river in this reach, decreasing
the water quality to levels that likely would not support the silvery
minnow (Campbell 1959; Larson 1994). Silvery minnow was historically
uncommon within this reach; only 14 specimens from two collections are
known (Bestgen and Platania 1991). Due to the short length of this
reach, fluctuations in the flow regime, degraded water quality, and the
absence of suitable habitat for the silvery minnow, it is not
considered essential to the conservation of the silvery minnow and is
not proposed as critical habitat.
13. Downstream of Red Bluff Reservoir to the confluence with Rio
Grande, Loving, Reeves, Pecos, Ward, Crane, Crockett, and Terrell
Counties, TX. Historically silvery minnows occurred in this reach,
though their exact distribution and abundance is unclear (Campell
1958,Trevino-Robinson 1959, James and De La Cruz 1989, Linam and
Kleinsasser 1996, Garrett 1997, Service 1999). For example, Bestgen and
Platania (1991) suggest silvery minnows may have been uncommon within
this reach because of pond habitat and high water salinity. However,
this area may not have been well surveyed when the silvery minnow was
still extant in the Pecos River (D. Propst, New Mexico Game and Fish,
pers. comm. 2001). Still, sampling the middle and lower parts of this
river reach has been historically difficult because of dense
vegetation, steep canyon banks, and lack of public access (Campbell
1959). The upper segment of this reach can be characterized as devoid
of suitable habitat, and has a
[[Page 39226]]
highly variable flow regime from release of water from Red Bluff
Reservoir for agricultural use. Indeed, many freshwater springs that
historically augmented the Pecos River throughout this reach have
recently been diminished or gone dry (Campbell 1959; Brune 1981 cited
in Hoagstrom 2000; Barker et al. 1994; El-Hage and Moulton 1998b; ).
The water quality in this upper portion is also poor and dominated by
high salinity (generally exceeding 5 parts per thousand) (Hiss 1970;
Hubbs 1990; Linam and Kleinsasser 1996; Miyamoto et al. 1995; El-Hage
and Moulton 1998b). Additionally, algal blooms (Prymnesium parvum) have
essentially eliminated all the fishes throughout from Malaga, NM, to
Amistad Dam, TX (James and De la Cruz 1989; Hubbs 1990; Rhodes and
Hubbs 1992). The river channel is also somewhat incised and dominated
by non-native vegetation in parts (Koidin 2000; Harman 1999; IBWC
2001b). Agricultural needs diminish south of Girvin, TX, and water
quality conditions (e.g., salinity) generally begin to improve
downstream from the confluence of Independence Creek to Amistad Dam
(Hubbs 1990; Linam and Kleinsasser 1996). This improvement could result
from the freshwater springs within the lower 160 km (100 mi) stretch of
this reach. Nevertheless, gaging records from the lower segment
indicate that there is virtually no flow during drought conditions
(Texas Water Development Board 2001) and water quality (e.g., total
dissolved solids) at Shumla Bend, just upstream of Amistad Reservoir,
would be expected to have a deleterious effect on aquatic life (IBWC
1994). We did not include this reach because the current or potential
suitability for the silvery minnow is unknown; detailed habitat studies
have not been conducted in this reach. Moreover, it is believed that
this area contains a network of steep canyons, with rock and course
gravel substrate (Campbell 1959; Texas Parks and Wildlife 1999). Canyon
habitat reduces stream channel width, which decreases sinuosity and
meandering, and creates deep channels that do not provide suitable
habitat (e.g., shallow, braided, streams with sandy substrates)
(Bestgen and Platania 1991; Dudley and Platania 1997; Remshardt et al.
2001). Additionally, the presence of algal blooms will continue to
affect water quality in this reach. For these reasons, we do not
believe that this reach is essential to the conservation of the
species. It is unknown whether this reach contains or has the potential
to develop the primary constituent elements. Although portions of this
river reach may contain fresh water (i.e., salinity less than 1 part
per thousand), we suspect that much of this stream reach may never
provide suitable habitat for the silvery minnow, and it is not proposed
as critical habitat.
Land Ownership
The proposed critical habitat for the silvery minnow encompasses
stream reaches where the species has been collected in the recent past
and where it is currently known to exist. Proposed critical habitat for
the silvery minnow includes both the active river channel and the area
of bankfull width plus 300 feet on either side of the banks, except in
areas narrowed by existing levees.
Ownership of the river channel and the lateral width along the bank
is unclear in the middle Rio Grande proposed critical habitat unit.
However, most of the land in the middle Rio Grande valley that abuts
critical habitat is within the administrative boundaries of the Middle
Rio Grande Conservancy District. The Middle Rio Grande Conservancy
District is a political subdivision of the State of New Mexico which
provides for irrigation, flood control, and drainage of the Middle Rio
Grande valley in New Mexico, from Cochiti Dam downstream 150 mi (285
km) to the northern boundary of the Bosque del Apache National Wildlife
Refuge. Within these 150 miles are also the lands of the communities of
Algodones, Bernalillo, Rio Rancho, Corrales, Albuquerque, Los Lunas,
Belen, Socorro, and a number of smaller incorporated and unincorporated
communities. Other landowners, sovereign entities, and managers
include: The Pueblos of Cochiti, Santo Domingo, San Felipe, Santa Ana,
Sandia, and Isleta; the BOR; the Service; the U.S. Bureau of Land
Management (BLM); New Mexico State Parks Division; New Mexico
Department of Game and Fish; New Mexico State Lands Department; and the
Corps. Approximately 86 river km (45 mi) of our proposed critical
habitat run through Pueblo lands including: Cochiti, Santo Domingo, San
Felipe, Santa Ana, Sandia, and Isleta.
Effect of Critical Habitat Designation
Section 7 Consultation
Section 7(a)(2) of the Act requires Federal agencies, including the
Service, to ensure that actions they fund, authorize, or carry out do
not destroy or adversely modify critical habitat to the extent that the
action appreciably diminishes the value of the critical habitat for the
survival and recovery of the species. Individuals, organizations,
States, Indian Pueblos and Tribes, local governments, and other non-
Federal entities are affected by the designation of critical habitat
only if their actions occur on Federal lands, require a Federal permit,
license, or other authorization, or involve Federal funding.
Activities on Federal lands that may affect the silvery minnow or
its proposed critical habitat will require section 7 consultation.
Actions on private, State, or Indian Pueblo and Tribal lands receiving
funding or requiring a permit from a Federal agency also will be
subject to the section 7 consultation process if the action may affect
proposed critical habitat. Federal actions not affecting the species or
its proposed critical habitat, as well as actions on non-Federal lands
that are not federally funded or permitted, will not require section 7
consultation. Regulations implementing this interagency cooperation
provision of the Act are codified at 50 CFR part 402.
Section 7(a)(4) of the Act require Federal agencies to confer with
us on any action that is likely to jeopardize the continued existence
of a proposed species or to result in destruction or adverse
modification of proposed critical habitat. Conference reports provide
conservation recommendations to assist the agency in eliminating
conflicts that may be caused by the proposed action. The conservation
recommendations in a conference report are advisory.
We may issue a formal conference report if requested by a Federal
agency. Formal conference reports on proposed critical habitat contain
a biological opinion that is prepared according to 50 CFR 402.14, as if
critical habitat were designated. We may adopt the formal conference
report as a biological opinion if the critical habitat is designated,
if no significant new information or changes in the action alter the
content of the opinion (see 50 CFR 402.10(d)).
Regulations at 50 CFR 402.16 also require Federal agencies to
reinitiate consultation in instances where we have already reviewed an
action for its effects on a listed species if critical habitat is
subsequently designated. Consequently, some Federal agencies may
request reinitiation of consultation or conferencing with us on actions
for which formal consultation has been completed, if those actions may
affect designated critical habitat or adversely modify or destroy
proposed critical habitat.
When we issue a biological opinion concluding that a project is
likely to
[[Page 39227]]
result in jeopardy or the destruction or adverse modification of
critical habitat, we also provide reasonable and prudent alternatives
to the project, if any are identifiable. Reasonable and prudent
alternatives are defined at 50 CFR 402.02 as alternative actions
identified during consultation that can be implemented in a manner
consistent with the intended purpose of the action, that are consistent
with the scope of the Federal agency's legal authority and
jurisdiction, that are economically and technologically feasible, and
that the Director of the Service believes would avoid the likelihood of
jeopardizing the continued existence of listed species or result in the
destruction or adverse modification of critical habitat. Reasonable and
prudent alternatives can vary from slight project modifications to
extensive redesign or relocation of the project. Costs associated with
implementing a reasonable and prudent alternative are similarly
variable.
Section 4(b)(8) of the Act requires us to describe in any proposed
or final regulation that designates critical habitat a description and
evaluation of those activities involving a Federal action that may
adversely modify such habitat or that may be affected by such
designation. When determining whether any of these activities may
adversely modify critical habitat, we will analyze the effects of the
action in relation to the designated critical habitat unit (Service and
National Marine Fisheries Service 1998). Therefore, the analysis (i.e.,
the determination whether an action destroys or adversely modifies
critical habitat) conducted through consultation or conferencing should
evaluate whether that loss, when added to the environmental baseline,
is likely to appreciably diminish the capability of the critical
habitat unit to satisfy essential requirements of the species. In other
words, activities that may destroy or adversely modify critical habitat
include those that alter the primary constituent elements (defined
above) to an extent that the value of the critical habitat unit for
both the survival and recovery of the silvery minnow is appreciably
reduced (50 CFR 402.02).
A number of Federal agencies or departments fund, authorize, or
carry out actions that may affect the silvery minnow and proposed
critical habitat. We have reviewed and continue to review numerous
activities proposed within the range of the silvery minnow that are
currently the subject of formal or informal section 7 consultations. A
wide range of Federal activities have the potential to destroy or
adversely modify critical habitat of the silvery minnow. These
activities may include land and water management actions of Federal
agencies (e.g., Corps, BOR, Service, and the Bureau of Indian Affairs)
and related or similar actions of other federally regulated projects
(e.g., road and bridge construction activities by the Federal Highway
Administration; dredge and fill projects, sand and gravel mining, and
bank stabilization activities conducted or authorized by the Corps;
construction, maintenance, and operation of diversion structures;
management of the conveyance channel; and levee and dike construction
and maintenance by the BOR; and, National Pollutant Discharge
Elimination System permits authorized by the Environmental Protection
Agency). These types of activities have already been examined under
consultation with us upon listing the species as endangered and in our
previous designation of critical habitat. We expect that the same types
of activities will be reviewed in section 7 consultation if critical
habitat is again designated. However, there is some potential for an
increase in the number of proposed actions we review under section 7 of
the Act from actions proposed in areas that are contained within the
300-foot lateral width. We believe that we currently review most
actions (e.g., indirect effects) that could affect silvery minnow
through section 7 that occur in this lateral width, but acknowledge
that an explicit boundary could result in a slight increase in
consultations.
Activities that we are likely to review under section 7 of the Act
include, but are not limited to:
1. Significantly and detrimentally altering the river flow or the
natural flow regime of any of the proposed river reaches in the middle
Rio Grande. Possible actions would include groundwater pumping,
impoundment, and water diversion with a Federal nexus (i.e., activities
that are authorized, funded, or carried out by a Federal agency). We
note that such flow reductions that result from actions affecting
tributaries of the designated stream reaches may also destroy or
adversely modify critical habitat.
2. Significantly and detrimentally altering the characteristics of
the 300-foot lateral width (e.g., parts of the floodplain) in the
middle Rio Grande critical habitat unit. Possible actions would include
vegetation manipulation, timber harvest, road construction and
maintenance, prescribed fire, livestock grazing, off-road vehicle use,
powerline or pipeline construction and repair, mining, and urban and
suburban development with a Federal nexus.
3. Significantly and detrimentally altering the channel morphology
(e.g., depth, velocity, etc.) of any of the stream reaches within the
proposed designation. Possible actions would include channelization,
impoundment, road and bridge construction, deprivation of substrate
source, reduction of available floodplain, removal of gravel or
floodplain terrace materials, reduction in stream flow, and excessive
sedimentation from mining, livestock grazing, road construction, timber
harvest, off-road vehicle use, and other watershed and floodplain
disturbances with a Federal nexus.
4. Significantly and detrimentally altering the water quality
within the proposed designation. Possible actions with a Federal nexus
would include release of chemical or biological pollutants into the
surface water or connected groundwater at a point source or by
dispersed release (non-point).
5. Introducing, spreading, or augmenting non-native aquatic species
within the proposed designation. Possible actions with a Federal nexus
would include fish stocking for sport, aesthetics, biological control,
or other purposes; use of live bait fish; aquaculture; construction and
operation of canals; and interbasin water transfers.
Not all of the identified activities are necessarily of current
concern within the middle Rio Grande; however, they do indicate the
potential types of activities that will require consultation in the
future and, therefore, that may be affected by the proposed designation
of critical habitat. We do not expect that the proposed designation of
critical habitat will result in a significant regulatory burden above
that already in place due to the presence of the listed species.
However, areas included within the 300-foot lateral width of the
proposed designation that are not currently occupied by the species may
result in an additional regulatory burden when there is a Federal nexus
(Federal funding, authorization, or permit).
As discussed previously, Federal actions that are found likely to
destroy or adversely modify critical habitat may often be modified,
through development of reasonable and prudent alternatives, in ways
that will remove the likelihood of destruction or adverse modification
of critical habitat. Such project modifications may include such things
as adjustment in timing of projects to avoid sensitive periods for the
species and its habitat; replanting of riparian vegetation;
minimization of work and vehicle use in the main river channel or the
300-foot lateral width; restriction of
[[Page 39228]]
riparian and upland vegetation clearing in the 300-foot lateral width;
fencing to exclude livestock and limit recreational use; use of
alternative livestock management techniques; avoidance of pollution;
minimization of ground disturbance in the 300-foot lateral width; use
of alternative material sources; storage of equipment and staging of
operations outside the 300-foot lateral width; use of sediment
barriers; access restrictions; and use of best management practices to
minimize erosion.
The silvery minnow does not need a large quantity of water to
survive but it does need a sufficient amount of flowing water to reduce
prolonged periods of low or no flow and minimize the formation of
isolated pools. The identification of primary constituent elements for
the silvery minnow is not intended to create a high-velocity, deep
flowing river, with a bank-to-bank flow. The silvery minnow does not
require such habitat characteristics. Instead, the silvery minnow
requires habitat with sufficient flows through the irrigation season to
avoid prolonged periods of low or no flow; additionally, a spike in
flow in the late spring or early summer to trigger spawning, and a
relatively constant winter flow are also required.
If you have questions regarding whether specific activities will
likely constitute destruction or adverse modification of proposed
critical habitat, contact the Field Supervisor, New Mexico Ecological
Services Field Office (see ADDRESSES section). If you would like copies
of the regulations on listed wildlife or have questions about
prohibitions and permits, contact the U.S. Fish and Wildlife Service,
Division of Endangered Species, P.O. Box 1306, Albuquerque, New Mexico
87103 (telephone 505-248-6920; facsimile 505-248-6788).
Economic Analysis
Section 4(b)(2) of the Act requires that we designate critical
habitat on the basis of the best scientific and commercial information
available and consider the economic and other relevant impacts of
designating a particular area as critical habitat. We based this
proposed rule on the best available scientific information, including
the recommendations in the Recovery Plan (Service 1999). We will
further utilize the draft and final economic analyses and our analysis
of other relevant impacts, and consider all comments and information
submitted during the public hearing and comment period, to make a final
critical habitat designation. We may exclude areas from the final
designation upon a final determination that the benefits of such
exclusions outweigh the benefits of specifying such areas as critical
habitat. In accordance with section 4(b)(2) of the Act we cannot
exclude areas from critical habitat when their exclusion will result in
the extinction of the species. We have prepared a draft economic
analysis that is available for public review and comment during the
comment period for this proposed rule. Send your requests for copies of
the draft economic analysis to the New Mexico Ecological Services Field
Office (see ADDRESSES section).
American Indian Tribal Rights, Federal-Tribal Trust Responsibilities,
and the Endangered Species Act
In accordance with the Presidential Memorandum of April 29, 1994,
we believe that, to the maximum extent possible, Indian Pueblos and
Tribes should be the governmental entities to manage their lands and
tribal trust resources. To this end, we support tribal measures that
preclude the need for Federal conservation regulations. We provide
technical assistance to Indian Pueblos and Tribes who ask for
assistance in developing and expanding tribal programs for the
management of healthy ecosystems so that Federal conservation
regulations, such as designation of critical habitat, on tribal lands
are unnecessary.
The Presidential Memorandum of April 29, 1994, also requires us to
consult with the Indian Pueblos and Tribes on matters that affect them,
and section 4(b)(2) of the Act requires us to gather information
regarding the designation of critical habitat and the effects thereof
from all relevant sources, including Indian Pueblos and Tribes.
Recognizing a government-to-government relationship with Indian Pueblos
and Tribes and our Federal trust responsibility, we have and will
continue to consult with the Indian Pueblos and Tribes that might be
affected by the designation of critical habitat.
We will make every effort to consult with the affected Indian
Pueblos and Tribes during the comment period for this proposed rule to
gain information on: (1) possible effects if critical habitat were
designated on Tribal lands; and (2) possible effects on tribal
resources resulting from the proposed designation of critical habitat
on non-tribal lands. We will meet with each potentially affected Pueblo
or Tribe to ensure that government-to-government consultation on
proposed critical habitat issues occurs in a timely manner.
Designation of Critical Habitat on Tribal Lands
Section 3(5) of the Act defines critical habitat, in part, as areas
within the geographical area occupied by the species ``on which are
found those physical and biological features (I) essential to the
conservation of the species and (II) which may require special
management considerations and protection.'' We included lands of the
Indian Pueblos of Cochiti, Santo Domingo, San Felipe, Santa Ana,
Sandia, and Isleta in this proposed designation of critical habitat for
the silvery minnow.
As provided under section 4(b)(2) of the Act, we are soliciting
information on the possible economic and other impacts of critical
habitat designation, and we will continue to work with the Indian
Pueblos and Tribes in developing voluntary measures adequate to
conserve silvery minnow on tribal lands. If any of these Indian Pueblos
and Tribes submit management plans, we will consider whether these
plans provide adequate special management or protection for the
species, and we will further weigh the benefits of including these
areas versus the benefits of excluding these areas under section
4(b)(2) of the Act. We will use this information in determining which,
if any, tribal lands should be excluded in the final designation of
critical habitat for the silvery minnow.
Effects on Tribal Trust Resources From Critical Habitat Designation on
Non-Tribal Lands
We do not anticipate that the proposal of critical habitat on non-
tribal lands will result in any impact on tribal trust resources or the
exercise of tribal rights. However, in complying with our tribal trust
responsibilities, we must communicate with all Indian Pueblos and
Tribes potentially affected by the designation. Therefore, we are
soliciting information from the Indian Pueblos and Tribes and will
arrange meetings with them during the comment period on potential
effects to them or their resources that may result from critical
habitat designation. We sent preproposal letters to all affected Indian
Pueblos including Cochiti, Santo Domingo, San Felipe, Santa Ana,
Sandia, Isleta, and San Juan, and solicited additional information from
them regarding biological, cultural, social, or economic data that were
pertinent to the EIS process. We will continue to provide assistance to
and cooperate with Indian Pueblos and Tribes that potentially could be
affected
[[Page 39229]]
by this proposed critical habitat designation at their request.
Public Comments Solicited
We intend to make any final action resulting from this proposed
rule to be as accurate and as effective as possible. Therefore, we are
soliciting comments or suggestions from the public, other concerned
governmental agencies, the scientific community, industry, or any other
interested party concerning this proposed rule. We particularly seek
comments concerning:
1. The reasons why any habitat should or should not be determined
to be critical habitat as provided by section 4 of the Act, including
whether the benefits of excluding areas will outweigh the benefits of
including areas as critical habitat. Specifically we ask if there is
adequate special management and protection in place on any lands
included in this proposed rule to allow us not to designate these lands
as critical habitat. We also seek information concerning New Mexico or
Texas State water rights issues (e.g., Rio Grande Compact delivery
obligations) and how designation of critical habitat might affect these
uses. We also request assistance in describing the existing conditions
for the river reach below San Acacia Diversion Dam on the middle Rio
Grande. For these and other areas that have the potential for low or no
flow events, we are soliciting comments or information relating to the
proposed designation of critical habitat that includes areas that may
experience these conditions. In addition, we are seeking comments on
the primary constituent elements and how they relate to the existing
conditions (i.e., flow regime) in the middle Rio Grande.
2. We ask whether areas or river reaches suggested in the Recovery
Plan for potential reestablishment of the silvery minnow, which are not
included in this proposed rule, should be designated as critical
habitat. We are further soliciting information or comments concerning
our conservation strategy for the silvery minnow. We believe that, in
particular, the development of one or more experimental populations
provides a conservation benefit for the silvery minnow that outweighs
the conservation benefit of designating areas as critical habitat.
Depending on public comments, information, or data received, we will
evaluate whether the areas we have determined are essential for the
conservation of the silvery minnow (i.e., the river reach of the middle
Pecos and lower Rio Grande in Big Bend National Park and downstream to
the Terrell/Val Verde County line) should be designated as critical
habitat, and critical habitat could be revised as appropriate.
3. Specific information on the amount and distribution of silvery
minnow habitat, and what habitat is essential to the conservation of
the species and why;
4. Land use practices and current or planned activities in the
subject areas, including comments or information relating to the 300-
foot lateral width, and their possible impacts on proposed critical
habitat;
5. Any foreseeable economic or other impacts resulting from the
proposed designation of critical habitat including, in particular, any
impacts on small entities or families; and
6. Economic and other values associated with designating critical
habitat for the silvery minnow, such as those derived from
nonconsumptive uses (e.g., hiking, camping, birding, enhanced watershed
protection, increased soil retention, ``existence values,'' and
reductions in administrative costs).
We are also seeking additional information about the silvery
minnow's status and would like information on any of the following:
1. The location of silvery minnow populations;
2. Any additional information about the silvery minnow's range,
distribution, and population sizes; and
3. Any current or planned activities (i.e., threats or recovery
actions) in or near areas occupied by the silvery minnow.
Clarity of the Rule
Executive Order 12866 requires each agency to write regulations and
notices that are easy to understand. We invite your comments on how to
make this proposed rule easier to understand including answers to
questions such as the following: (1) Are the requirements in the
document clearly stated? (2) Does the proposed rule contain technical
language or jargon that interferes with the clarity? (3) Does the
format of the proposed rule (grouping and order of sections, use of
headings, paragraphing, etc.) aid or reduce its clarity? (4) Is the
description of the proposed rule in the ``Supplementary Information''
section of the preamble helpful in understanding the document? (5) What
else could we do to make the proposed rule easier to understand? Send a
copy of any written comments about how we could make this rule easier
to understand to: Office of Regulatory Affairs, Department of the
Interior, Room 7229, 1849 C Street NW., Washington, DC 20240.
Our practice is to make comments that we receive on this
rulemaking, including names and home addresses of respondents,
available for public review during regular business hours. Individual
respondents may request that we withhold their home address from the
rulemaking record, which we will honor to the extent allowable by
Federal law. In some circumstances, we would withhold from the
rulemaking record a respondent's identity, as allowable by Federal law.
If you wish for us to withhold your name and/or address, you must state
this prominently at the beginning of your comment. However, we will not
consider anonymous comments. We will make all submissions from
organizations or businesses, including individuals identifying
themselves as representatives or officials of organizations or
businesses, available for public inspection in their entirety.
Peer Review
In accordance with our policy published on July 1, 1994 (59 FR
34270), we will seek the expert opinions of at least three appropriate
and independent specialists regarding this proposed rule. The purpose
of such review is to ensure listing decisions are based on
scientifically sound data, assumptions, and analyses. We will send
copies of this proposed rule immediately following publication in the
Federal Register to these peer reviewers. We will invite these peer
reviewers to comment, during the public comment period, on the specific
assumptions and conclusions regarding the proposed designation of
critical habitat.
We will consider all comments and information received during the
comment period on this proposed rule during preparation of a final
rulemaking. Accordingly, the final decision may differ from this
proposed rule. It is important to note that we have not proposed
critical habitat designation for two areas that we have determined are
essential for the conservation of the silvery minnow (i.e., the river
reach of the middle Pecos and lower Rio Grande in Big Bend National
Park and downstream to the Terrell/Val Verde County line). We believe
that our conservation strategy of developing one or more experimental
populations outweighs the benefits that would be provided to the
silvery minnow by including these areas within a designation of
critical habitat. However, depending on public comments, information,
or data received, we will evaluate whether these areas within the
silvery minnow's historical range should be designated as critical
habitat,
[[Page 39230]]
and critical habitat could be revised as appropriate.
Public Hearings
The Act provides for one or more public hearings on this proposed
rule, if requested. Given the high likelihood of multiple requests we
have scheduled two public hearings. We will hold public hearings in
Socorro, New Mexico, on June 25, 2002; and in Albuquerque, NM, on June
26, 2002 (see ADDRESSES section for times and locations). Announcements
for the public hearings will be made in local newspapers.
Written comments submitted during the comment period receive equal
consideration with those comments presented at a public hearing.
Required Determinations
Regulatory Planning and Review
In accordance with Executive Order 12866, this document is a
significant rule and has been reviewed by the Office of Management and
Budget (OMB), under Executive Order 12866.
1. We have prepared a draft economic analysis to assist us in
considering whether areas should be excluded pursuant to section
4(b)(2) of the Act. The draft analysis indicates that this rule will
not have an annual economic effect of $100 million or more or adversely
affect an economic sector, productivity, jobs, the environment, or
other units of government. Under the Act, critical habitat may not be
destroyed or adversely modified by a Federal agency action; the Act
does not impose any restrictions related to critical habitat on non-
Federal persons unless they are conducting activities funded or
otherwise sponsored or permitted by a Federal agency.
2. As discussed above, Federal agencies would be required to ensure
that their actions do not destroy or adversely modify designated
critical habitat of the silvery minnow. Because of the potential for
impacts on other Federal agencies activities, we will review this
proposed action for any inconsistencies with other Federal agency
actions.
3. We believe that this rule, if finalized, will not materially
affect entitlements, grants, user fees, loan programs, or the rights
and obligations of their recipients, except those involving Federal
agencies which would be required to ensure that their activities do not
destroy or adversely modify designated critical habitat. As discussed
above, we do not anticipate that the adverse modification prohibition
(from critical habitat designation) will have any significant economic
effects such that it will have an annual economic effect of $100
million or more.
4. OMB has determined that the critical habitat portion of this
rule will raise novel legal or policy issues and, as a result, this
rule has undergone OMB review. The proposed rule follows the
requirements for proposing critical habitat contained in the Act.
Regulatory Flexibility Act (5 U.S.C. 601 et seq.)
Under the Regulatory Flexibility Act (as amended by the Small
Business Regulatory Enforcement Fairness Act (SBREFA) of 1996; 5 U.S.C.
804(2)), whenever a Federal agency is required to publish a notice of
rulemaking for any proposed or final rule, it must prepare and make
available for public comment a regulatory flexibility analysis that
describes the effect of the rule on small entities (i.e., small
businesses, small organizations, and small government jurisdictions).
However, no regulatory flexibility analysis is required if the head of
an agency certifies that the rule will not have a significant economic
impact on a substantial number of small entities. SBREFA amended the
Regulatory Flexibility Act to require Federal agencies to provide a
statement of the factual basis for certifying that a rule will not have
a significant economic impact on a substantial number of small
entities. We are certifying that the rule will not have a significant
effect on a substantial number of small entities. The following
discussion explains our rationale.
The economic analysis determined whether this proposed critical
habitat designation potentially affects a ``substantial number'' of
small entities in counties supporting proposed critical habitat areas.
It also quantifies the probable number of small businesses that
experience a ``significant effect.'' While SBREFA does not explicitly
define either ``substantial number'' or ``significant effect,'' the
Small Business Administration (SBA) and other Federal agencies have
interpreted these terms to represent an impact on 20 percent or more of
the small entities in any industry and an effect equal to three percent
or more of a business' annual sales.
Based on the past consultation history for the silvery minnow,
wastewater discharges from municipal treatment plants are the primary
activities anticipated to be affected by the designation of critical
habitat that could affect small businesses. To be conservative, (i.e.,
more likely to overstate impacts than understate them), the economic
analysis assumes that a unique company will undertake each of the
projected consultations in a given year, and so the number of
businesses affected is equal to the total annual number of
consultations (both formal and informal).
First, the number of small businesses affected is estimated. As
shown in Exhibit 1 below, the following calculations yield this
estimate:
Estimate the number of businesses within the study area
affected by section 7 implementation annually (assumed to be equal to
the number of annual consultations);
Calculate the percent of businesses in the affected
industry that are likely to be small;
Calculate the number of affected small businesses in the
affected industry;
Calculate the percent of small businesses likely to be
affected by critical habitat.
Exhibit 1.--Estimated Annual Number of Small Businesses Affected by
Critical Habitat Designation: The ``Substantial'' Test
------------------------------------------------------------------------
Sanitary services SIC
Industry name 4959
------------------------------------------------------------------------
Annual number of affected businesses in industry:
By formal consultation....................... 0.13
(Equal to number of annual consultations): 1
By informal consultation..................... 0.75
Total number of all businesses in industry within 6
study area.
Number of small businesses in industry within 6
study area.
Percent of businesses that are small (Number of 100%
small businesses)/(Total Number of businesses).
[[Page 39231]]
Annual number of small businesses affected 0.88
(Number affected businesses) * (Percent of small
businesses).
Annual percentage of small businesses affected 15%
(Number of small businesses affected)/(Total
number of small businesses); 20
percent is substantial.
------------------------------------------------------------------------
1 Note that because these values represent the probability that small
businesses will be affected during a one-year time period,
calculations may result in fractions of businesses. This is an
acceptable result, as these values represent the probability that
small businesses will be affected.
This calculation reflects conservative assumptions and nonetheless
yields an estimate that is still far less than the 20 percent threshold
that would be considered ``substantial.'' As a result, this analysis
concludes that a significant economic impact on a substantial number of
small entities will not result from the designation of critical habitat
for the silvery minnow. Nevertheless, an estimate of the number of
small businesses that will experience effects at a significant level is
provided below.
Costs of critical habitat designation to small businesses consist
primarily of the cost of participating in section 7 consultations and
the cost of project modifications. To calculate the likelihood that a
small business will experience a significant effect from critical
habitat designation for the silvery minnow, the following calculations
were made:
Calculate the per-business cost. This consists of the unit
cost to a third party of participating in a section 7 consultation
(formal or informal) and the unit cost of associated project
modifications. To be conservative, the economic analysis uses the high-
end estimate for each cost.
Determine the amount of annual sales that a company would
need to have for this per-business cost to constitute a ``significant
effect.'' This is calculated by dividing the per-business cost by the
three percent ``significance'' threshold value.
Estimate the likelihood that small businesses in the study
area will have annual sales equal to or less than the threshold amount
calculated above. This is estimated using national statistics on the
distribution of sales within industries.
Based on the probability that a single business may
experience significant effects, calculate the expected value of the
number of businesses likely to experience a significant effect.
Calculate the percent of businesses in the study area
within the affected industry that are likely to be affected
significantly.
Calculations for costs associated with designating critical habitat
for the silvery minnow are provided in Exhibit 2 below.
Exhibit 2.--Estimated Annual Effects on Small Businesses: The
``Significant Effect'' Test
------------------------------------------------------------------------
Sanitary services SIC 4959
----------------------------------------
Formal
Industry consultations with Informal
project consultations
modifications
------------------------------------------------------------------------
Annual Number of Small 0.13............... 0.75
Businesses Affected (From
Exhibit 8-1).
Per-Business Cost.............. $34,100............ $2,900
Level of Annual Sales Below $1,136,667......... $96,667
Which Effects Would Be
Significant (Per-Business Cost/
3%).
Probability That Per-Business 48%................ 3%
Cost Is Greater Than 3% of
Sales for Small Business \1\.
Probable Annual Number of Small 0.06............... 0.02
Businesses Experiencing
Significant Effects (Number
Small Businesses)*
(Probability of Significant
Effect).
Total Annual Number of Small 0.08
Businesses Bearing Significant
Costs in Industry.
Total Annual Percentage of 1.4%
Small Businesses Bearing
Significant Costs in Industry.
------------------------------------------------------------------------
\1\ This probability is calculated based on national industry statistics
obtained from the Robert Morris Associated Annual Statement of
Studies: 2001-2002, which provides data on the distribution of annual
sales in an industry within the following ranges: $0-1 million, $1-3
million, $3-5 million, $5-10, $10-25 million, and $25+ million. This
analysis uses the ranges that fall within the SBA definition of small
businesses (i.e., for industries in which small businesses have sales
of less than $5.0 million, it uses $0-1 million, $1-3 million, and $3-
5 million) to estimate a distribution of sales for small businesses.
It then calculates the probability that small businesses have sales
below the threshold value using the following components: (1) All
small businesses (expressed as a percentage of all small businesses)
in ranges whose upper limits fall below the threshold value experience
the costs as significant; (2) for the range in which the threshold
value falls, the percentage of companies in the bin that fall below
the threshold value is calculated as [(threshold value-range minimum)/
(bin maximum-range minimum)] x percent of small businesses captured in
range. This percentage is added to the percentage of small businesses
captured in each of the lower ranges to reach the total probability
that small businesses have sales below the threshold value. Note that
in instances in which the threshold value exceeds the definition of
small businesses (i.e., the threshold value is $10 million and the
definition of small businesses is sales less than $5.0 million), all
small businesses experience the effects as significant.
Because the costs associated with designating critical habitat for
the silvery minnow are likely to be significant for less than one small
businesses per year (approximately one percent of the small businesses
in the sanitary services industry) in the affected counties, the
economic analysis concludes that a significant economic impact on a
substantial number of small entities will not result from the
designation of critical habitat for the silvery minnow. This would be
true even if all of the effects of section 7 consultation on these
activities were attributed solely to the critical habitat designation.
[[Page 39232]]
Executive Order 13211
On May 18, 2001, the President issued an Executive Order (E.O.
13211) on regulations that significantly affect energy supply,
distribution, and use. Executive Order 13211 requires agencies to
prepare Statements of Energy Effects when undertaking certain actions.
We have a very good consultation history for silvery minnow; thus, we
can describe the kinds of actions that have undergone consultations.
Within the middle Rio Grande proposed critical habitat unit, the BLM
has the highest likelihood of any Federal agency to undergo section 7
consultation for actions relating to energy supply, distribution, or
use. However, since 1994, the BLM has not conducted any consultations
for resource management plans that related to energy supply,
distribution, or use. We do not anticipate the development of oil and
gas leases within the area we are proposing to designate as critical
habitat (J. Smith, pers. comm. 2001). Nevertheless, if we were to
consult on a proposed BLM energy-related action, the outcome of that
consultation likely would not differ from the BLM's policy of not
allowing oil and gas development within the 100-year floodplain. For
these reasons, we do not anticipate, this rule will be a significant
regulatory action under Executive Order 12866, and it is not expected
to significantly affect energy supplies, distribution, or use.
Therefore, this action is not a significant energy action and no
Statement of Energy Effects is required.
Unfunded Mandates Reform Act (2 U.S.C. 1501 et seq.)
In accordance with the Unfunded Mandates Reform Act (2 U.S.C. 1501
et seq.):
1. This rule will not ``significantly or uniquely'' affect small
governments. A Small Government Agency Plan is not required. Small
governments will be affected only to the extent that any of their
actions involving Federal funding or authorization must not destroy or
adversely modify the critical habitat or take the species under section
9.
2. This rule will not produce a Federal mandate of $100 million or
greater in any year (i.e., it is not a ``significant regulatory
action'' under the Unfunded Mandates Reform Act).
Takings
In accordance with Executive Order 12630 (``Government Actions and
Interference with Constitutionally Protected Private Property
Rights''), we have analyzed the potential takings implications of the
proposed listing and designation of critical habitat for the silvery
minnow. The takings implications assessment concludes that this
proposed rule does not pose significant takings implications. A copy of
this assessment is available by contacting the New Mexico Ecological
Services Field Office (see ADDRESSES section).
Based on the above assessment, the Service finds that this proposed
rule designating critical habitat for the silvery minnow does not pose
significant takings implications.
Federalism
In accordance with Executive Order 13132, we have considered
whether this rule has significant Federalism effects and have
determined that a Federalism assessment is not required. In keeping
with Department of the Interior policy, we requested information from
and coordinated development of this proposed rule with appropriate
resource agencies in New Mexico and Texas (i.e., during the EIS scoping
period). We will continue to coordinate any future designation of
critical habitat for the silvery minnow with the appropriate agencies.
We do not anticipate that this regulation will intrude on State
policy or administration, change the role of the Federal or State
government, or affect fiscal capacity. For example, we have conducted
one formal consultation with the Corps and BOR, and a non-Federal
agency (e.g., Middle Rio Grande Conservancy District) over actions
related to water operations on the middle Rio Grande (Service 2001b).
Although this consultation was conducted after critical habitat
designation for the silvery minnow was removed pursuant to court order,
we do not believe that this designation of critical habitat will have
significant Federalism effects. For example, in the recent formal
section 7 consultation, the Middle Rio Grande Conservancy District's
regulatory burden requirement was only affected to the extent that they
were acting as the United States' agent over the operation and
maintenance of facilities. If this critical habitat designation is
finalized, Federal agencies also must ensure, through section 7
consultation with us, that their activities do not destroy or adversely
modify designated critical habitat. Nevertheless, we do not anticipate
that the amount of supplemental instream flow, provided by past
consultations (e.g., Service 2001b), will increase because an area is
designated as critical habitat. This rule also will not change the
appropriation of water rights within the area proposed to be designated
as critical habitat. For these reasons, we do not anticipate that the
designation of critical habitat will change State policy or
administration, change the role of the Federal or State government, or
affect fiscal capacity.
Within the 300-foot lateral width, designation of critical habitat
could trigger additional review of Federal activities under section 7
of the Act, and may result in additional requirements on Federal
activities to avoid destroying or adversely modifying critical habitat.
Any action that lacked Federal involvement would not be affected by the
critical habitat designation. Should a Federally funded, permitted, or
implemented project be proposed that may affect designated critical
habitat, we will work with the Federal action agency and any applicant,
through section 7 consultation, to identify ways to implement the
proposed project while minimizing or avoiding any adverse effect to the
species or critical habitat. In our experience, the vast majority of
such projects can be successfully implemented with at most minor
changes that avoid significant economic impacts to project proponents.
The designation may have some benefit to these governments in that
the areas essential to the conservation of the species would be clearly
defined, and the primary constituent elements of the habitat necessary
to the survival of the species would be identified. While this
definition and identification does not alter where and what Federally
sponsored activities may occur, it may assist these local governments
in long-range planning (rather than waiting for case-by-case section 7
consultations to occur).
Civil Justice Reform
In accordance with Executive Order 12988, the Office of the
Solicitor has determined that this rule would not unduly burden the
judicial system and would meet the requirements of sections 3(a) and
3(b)(2) of the Order. We propose to designate critical habitat in
accordance with the provisions of the Act. The rule uses standard
property descriptions and identifies the primary constituent elements
within the designated areas to assist the public in understanding the
habitat needs of the silvery minnow.
Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.)
This rule does not contain any new collections of information that
require approval by the Office of Management and Budget (OMB) under 44
U.S.C. 3501 et seq. This rule will not impose new
[[Page 39233]]
record-keeping or reporting requirements on State or local governments,
individuals, businesses, or organizations. An agency may not conduct or
sponsor, and a person is not required to respond to, a collection of
information unless they display a currently valid OMB control number.
National Environmental Policy Act
It is our position that, outside the Tenth Circuit, we do not need
to prepare environmental analyses as defined by the NEPA in connection
with designating critical habitat under the Endangered Species Act of
1973, as amended. We published a notice outlining our reasons for this
determination in the Federal Register on October 25, 1983 (48 FR
49244). This assertion was upheld in the Ninth Circuit Douglas County
v. Babbitt, 48 F.3d 1495 (9th Cir. 1995), cert. denied, 116 S. Ct. 698
(1996). However, when the range of the species includes States within
the Tenth Circuit, such as that of the silvery minnow, pursuant to the
Tenth Circuit ruling in Catron County Board of Commissioners v. U.S.
Fish and Wildlife Service, 75 F.3d 1429 (10th Cir. 1996), we will
undertake a NEPA analysis for critical habitat designation.
Additionally, on November 21, 2000, the United States District Court
for the District of New Mexico, in Middle Rio Grande Conservancy
District v. Babbitt, Civ. Nos. 99-870, 99-872 and 99-1445M/RLP
(Consolidated) set aside the July 9, 1999, critical habitat designation
and ordered us to issue within 120 days both an EIS and a new proposed
rule designating critical habitat for the silvery minnow. We have
prepared the draft EIS pursuant to that court order.
Government-to-Government Relationship With Indian Pueblos and Tribes
In accordance with the Secretarial Order 3206, ``American Indian
Tribal Rights, Federal-Tribal Trust Responsibilities, and the
Endangered Species Act'' (June 5, 1997), the President's memorandum of
April 29, 1994, ``Government-to-Government Relations with Native
American Tribal Governments'' (59 FR 22951), Executive Order 13175, and
the Department of the Interior's requirement at 512 DM 2, we understand
that recognized Federal Indian Pueblos and Tribes must be related to on
a Government-to-Government basis. Therefore, we are soliciting
information from the Indian Pueblos and Tribes and will arrange
meetings with them during the comment period on potential effects to
them or their resources that may result from critical habitat
designation.
References Cited
A complete list of all references cited in this proposed rule is
available upon request from the New Mexico Ecological Services Field
Office (see ADDRESSES section).
Authors
The primary authors of this notice are the New Mexico Field Office
staff (see ADDRESSES section).
List of Subjects in 50 CFR Part 17
Endangered and threatened species, Exports, Imports, Reporting and
record-keeping requirements, Transportation.
Proposed Regulation Promulgation
Accordingly, we propose to amend part 17, subchapter B of chapter
I, title 50 of the Code of Federal Regulations as set forth below:
PART 17--[AMENDED]
1. The authority citation for part 17 continues to read as follows:
Authority: 16 U.S.C. 1361-1407; 16 U.S.C. 1531-1544; 16 U.S.C.
4201-4245; Pub. L. 99-625, 100 Stat. 3500; unless otherwise noted.
2. Amend Sec. 17.95(e) by revising critical habitat for the Rio
Grande silvery minnow (Hybognathus amarus), to read as follows.
Sec. 17.95 Critical habitat--fish and wildlife.
* * * * *
(e) Fishes. * * *
Rio Grande Silvery Minnow (Hybognathus amarus)
(1) Proposed critical habitat is depicted for Socorro, Valencia,
Bernalillo, and Sandoval, Counties, New Mexico; on the map and as
described below.
(2) For each river reach proposed, the up- and downstream
boundaries are described below. Proposed critical habitat includes
the stream channels within the identified river reaches and areas
within these reaches included within the existing levees, or if no
levees are present, then within a lateral distance of 91.4 m (300
ft) on each side of the river width at bankfull discharge. Bankfull
discharge is the flow at which water begins to leave the channel and
move into the floodplain.
(3) Within these areas the primary constituent elements include,
but are not limited to, those habitat components that are essential
for the primary biological needs of foraging, sheltering, and
reproduction. These elements include the following:
(i) A hydrologic regime that provides sufficient flowing water
with low to moderate currents capable of forming and maintaining a
diversity of aquatic habitats, such as, but not limited to:
backwaters (a body of water connected to the main channel, but with
no appreciable flow), shallow side channels, pools (that portion of
the river that is deep with relatively little velocity compared to
the rest of the channel), eddies (a pool with water moving opposite
to that in the river channel), and runs (flowing water in the river
channel without obstructions) of varying depth and velocity
necessary for each of the particular silvery minnow life-history
stages in appropriate seasons (e.g., the silvery minnow requires
habitat with sufficient flows from early spring (March) to early
summer (June) to trigger spawning, flows in the summer (June) and
fall (October) that do not increase prolonged periods of low or no
flow, and a relatively constant winter flow (November to February));
(ii) The presence of eddies created by debris piles, pools, or
backwaters, or other refuge habitat (e.g., connected oxbows or
braided channels) within unimpounded stretches of flowing water of
sufficient length (i.e., river miles) that provide a variation of
habitats with a wide range of depth and velocities;
(iii) Substrates of predominantly sand or silt; and
(iv) Water of sufficient quality to maintain natural, daily, and
seasonally variable water temperatures in the approximate range of
greater than 1 deg.C (35 deg.F) and less than 30 deg.C (85
deg.F) and reduce degraded conditions (decreased dissolved oxygen,
increased p.H., etc.).
(4) Proposed critical habitat is depicted on the following map
for the Middle Rio Grande, which includes the area from Cochiti
Reservoir downstream to the Elephant Butte Dam, Sandoval,
Bernalillo, Valencia, and Socorro Counties, New Mexico. The stream
reaches in the middle Rio Grande include:
(i) Jemez Canyon Reach--8 km ( 5 mile) of river immediately
downstream of Jemez Canyon Reservoir to the confluence of the Rio
Grande;
(ii) Cochiti Diversion Dam to Angostura Diversion Dam (Cochiti
Reach)--34 km (21 mile) of river immediately downstream of Cochiti
Reservoir to the Angostura Diversion Dam;
(iii) Angostura Diversion Dam to Isleta Diversion Dam (Angostura
Reach)--61 km (38 mile) of river immediately downstream of the
Angostura Diversion Dam to the Isleta Diversion Dam;
(iv) Isleta Diversion Dam to San Acacia Diversion Dam (Isleta
Reach)--90 km (56 mi) of river immediately downstream of the Isleta
Diversion Dam to the San Acacia Diversion Dam; and
(v) San Acacia Diversion Dam to the Elephant Butte Dam (San
Acacia Reach)-147 km (92 mi) of river immediately downstream of the
San Acacia Diversion Dam to the Elephant Butte Dam.
(vi) Map Follows:
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(5) This designation does not include the ephemeral or perennial
irrigation canals and ditches outside of natural stream channels,
including the low flow conveyance channel that is adjacent to a
portion of the stream reach within the middle Rio Grande (i.e.,
downstream of the southern boundary of Bosque del Apache National
Wildlife Refuge to the Elephant Butte Dam).
(6) The area inundated by Elephant Butte Reservoir does not
provide those physical or biological features essential to the
conservation of the species and is specifically excluded by
definition from the proposed critical habitat. We define the
reservoir as that part of the body of water impounded by the dam
where the storage waters are lentic (relatively still waters) and
not part of the lotic (flowing water) river channel.
(7) Lands located within the exterior boundaries of the proposed
critical habitat designation (i.e., within the existing levees, or
if no levees are present, then within a lateral distance of 91.4 m
(300 ft) on each side of the stream width at bankfull discharge),
but that are not considered critical habitat and are therefore
excluded by definition, include existing paved roads; bridges;
parking lots; dikes; levees; diversion structures; railroad tracks;
railroad trestles; active gravel pits; cultivated agricultural land;
and residential, commercial, and industrial developments.
* * * * *
Dated: May 23, 2002
Craig Manson,
Assistant Secretary for Fish and Wildlife and Parks.
[FR Doc. 02-14141 Filed 6-5-02; 8:45 am]
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