[Federal Register Volume 72, Number 124 (Thursday, June 28, 2007)]
[Proposed Rules]
[Pages 35388-35393]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-12564]
-----------------------------------------------------------------------
DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
50 CFR Parts 223 and 224
[Docket No. 070613193-7194-01; I.D. 121903C]
Endangered and Threatened Wildlife and Plants; Finding on Whether
to List Eastern Oyster as a Threatened or Endangered Species
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
[[Page 35389]]
ACTION: Notice of a listing determination and availability of a status
review document.
-----------------------------------------------------------------------
SUMMARY: The eastern oyster biological review team (BRT) has prepared
an Endangered Species Act (ESA) status review report for the eastern
oyster (Crassostrea virginica) and submitted it to NMFS. After
reviewing the best available scientific and commercial information, we
(NMFS) have determined that listing the eastern oyster as threatened or
endangered under the ESA is not warranted at this time.
DATES: This finding is effective on June 28, 2007.
ADDRESSES: The eastern oyster status review report and list of
references are available by submitting a request to the Assistant
Regional Administrator, Protected Resources Division, Northeast Region,
NMFS, One Blackburn Drive, Gloucester, MA 01930. The status review
report and other reference materials regarding this determination can
also be obtained via the Internet at: http://www.nero.noaa.gov/prot_res/CandidateSpeciesProgram/index.html.
FOR FURTHER INFORMATION CONTACT: Kim Damon-Randall, NMFS, Northeast
Region (978) 281-9300 x6535 or Marta Nammack, NMFS, Office of Protected
Resources (301) 713-1401.
SUPPLEMENTARY INFORMATION:
Background
On January 11, 2005, we received a petition from Mr. Wolf-Dieter
Busch (the petitioner), Ecosystem Initiatives Advisory Services, to
list eastern oyster (Crassostrea virginica) as threatened or endangered
under the ESA. After reviewing the information contained in the
petition and that which was readily available to us, we determined that
there was sufficient information to indicate that the petitioned action
may be warranted. On May 18, 2005, we published a positive 90-day
finding in the Federal Register, which initiated the status review
process.
On October 19, 2005, we received a letter from the petitioner dated
October 13, 2005, requesting the recall of the eastern oyster petition.
In his letter, the petitioner indicated that his request to withdraw
the petition was due to the public and industry's confusion over the
petition and listing process. He noted the significant concerns of some
that the species may be listed as endangered and thereby, create severe
restrictions and regulations for this resource. He also expressed
concern that, given the timeline of the review, NMFS may not have
enough information to determine if eastern oyster subspecies exist. He
concluded that he hoped that we would continue with the review as he
considers the status review report to be a comprehensive resource which
will be of great value in focusing restoration activities for this
resource.
We accepted this request and as a result, ceased the evaluation of
the petition. However, a considerable amount of effort had been
expended by the BRT at the point at which the withdrawal of the
petition occurred. Also, the completed status review report is the most
timely and comprehensive resource document for this species. As such,
we determined that because the report is a useful tool in guiding
future management decisions, the BRT would complete its report. We also
decided to complete our evaluation of the status of the species under
the ESA as stated in the Federal Register notice announcing the 90-day
finding on the petition (70 FR 28510).
As part of the full evaluation of the status of the species under
the ESA, we requested that the Center for Independent Experts provide
three independent consultants to serve as peer reviewers. These
reviewers were tasked with reading and reviewing the status review
report and providing a written summary of their comments. Specifically,
they were asked to address the following (at a minimum): (1) Are
species and/or subspecies delineations supported by the information
presented?; (2) Does the report include and cite the best scientific
and commercial information available on the species and threats to it
and its habitat?; (3) Are the scientific conclusions sound and derived
logically from the results?; (4) Where available, are opposing
scientific studies or theories acknowledged and discussed? The peer
reviewers completed their task in October 2006 and specifically found
that the status review report contained the best scientific and
commercial information available.
Biology and Life History of the Eastern Oyster
The eastern oyster occurs naturally in a great diversity of
habitats along the western Atlantic Ocean from the Canadian Maritime
Provinces to the Gulf of Mexico, Panama, and the Caribbean Islands
(Carlton and Mann, 1996; Abbott, 1974; MacKenzie, 1997a; Jenkins et
al., 1997; FAO, 1978). The eastern oyster has been transplanted outside
of its natural range and now may be found in western Canada, western
United States, western Mexico, Hawaii, Fiji, Tonga, Japan, Mauritius-
Indian Ocean, and possibly England (Ruesink et al., 2005).
The eastern oyster is protandric, as individuals first mature as
males then typically change to female later in life, and there is also
evidence suggesting that the process is reversible later in life
(Thompson et al., 1996). Oysters may change sex in response to
environmental, nutritional, and/or physiological stresses, or sex
determination may be influenced by the sex and proximity of nearby
oysters (Tranter, 1958, cited by Thompson et al., 1996; Bahr and
Hillman, 1967; Davis and Hillman, 1971; Ford et al., 1990; Needler,
1932; Burkenroad, 1931; Smith, 1949; and Menzel, 1951, all cited by
Thompson et al., 1996). Estimates of fecundity range from 2 to 115
million eggs per female, depending on size and geographic location
(Galtsoff, 1930, 1964; Davis and Chanley, 1956; Cox, 1988; Cox and
Mann, 1992; all cited in Thompson et al., 1996).
Spawning is initiated by a combination of factors including water
temperature, salinity, and physiochemical interactions (Galtsoff, 1964;
and Loosanoff, 1953, cited by Berrigan et al., 1991; Hayes and Menzel,
1981; Hofstetter, 1977, 1983). Spawning is seasonal (summer) throughout
the mid- to northern Atlantic portions of the species' range. In
southern waters, spawning occurs in all but the coldest months
(Berrigan et al., 1991). Conditions generally required for spawning
include water temperatures at or above 20 C and salinity higher than 10
parts per thousand (ppt).
After fertilization, oysters develop through several free-swimming
larval stages before attaching to a hard substrate and becoming
sessile. The mechanisms for larval dispersal and recruitment are still
unclear (Epifanio, 1988). Larval dispersal is generally explained by
``passive'' transport induced by physical factors, by an ``active''
process involving larval swimming, or by a combination of both
(Deskshenieks et al., 1996). The first larval stage (trochophore) is
formed 4 to 6 hours following fertilization and lasts approximately 1
to 2 days. The trochophore larva does not feed, but subsequent larval
stages (veliger) are planktotrophic, feeding on small plants and
animals (Kennedy, 1996). Veliger stages, lasting up to 2 months
(Hopkins, 1931), include several morphological changes to the larvae
resulting in fully developed larvae possessing a well-developed foot.
As oyster larvae become competent to settle they must locate a
suitable substrate upon which to attach. Larvae may exhibit exploratory
behavior in
[[Page 35390]]
locating a suitable substrate upon which to settle (Burke, 1983, as
cited in Kennedy, 1996). Both environmental and internal cues are used
in determining when and where veliger larvae will settle (Kennedy,
1996). Settlement is a behavioral response that can be repeated or
reversed and is followed by metamorphosis, which results in
morphological changes and is permanent (Kennedy, 1996). There is
evidence that suggests metamorphosis is triggered by salinity and by
chemicals given off by live oysters and bio-films on other suitable
substrates (Hidu and Haskin, 1971; Keck et al., 1971; Kennedy, 1996).
Temperature, salinity, and food availability greatly influence
oyster growth, and, therefore, growth rates vary seasonally, with
maximum growth occurring during the summer and fall. Eastern oysters
have been reported to survive freezing temperatures in shallow-water
habitats and after being exposed to temperatures in excess of 45[deg] C
in intertidal areas (Galtsoff, 1964; Shumway, 1996). However, exposures
to temperatures above approximately 35[deg] C will adversely affect
pumping rate and thereby, feeding (Loosanoff, 1958; and Galtsoff, 1928,
as cited by Shumway, 1996). Oysters can tolerate salinities from 0 to
42 ppt, although growth rates are affected by lower salinities (Quast
et al., 1988; Shumway, 1996).
Oysters are filter feeders, feeding primarily on phytoplankton and
suspended detritus (Langdon and Newell, 1996). Crassostrea virginica
are capable of adjusting feeding rates depending on the size, type, and
composition of the available food source (Baldwin, 1995; Baldwin and
Newell, 1995a, 1995b, as cited in Kennedy, 1996).
The eastern oyster plays an important ecological role in the
environment in which it inhabits. Self sustaining oyster populations
form reefs that: (1) contribute to trophic dynamics by promoting
species diversity; (2) provide structural integrity that supports
community stability, enhances habitat values, and affects water
circulation and flow patterns; and (3) perform ecological services
which improve water quality and recycle nutrients.
Abundance
Abundance of the eastern oyster is known to have varied or declined
in many estuaries in which it was previously known to be abundant. In
some estuaries, abundance has declined due to one or more of the
stressors discussed below. Some populations have declined dramatically
(e.g., the Hudson-Raritan Estuary). However, even in these locations,
with effort, oysters can be found. The eastern oyster can be found as
isolated individuals or clusters even in unlikely urbanized places,
such as the Hackensack River, Arthur Kill, Harlem River, East River and
the Bronx River (Steimle, 2005). However, these isolated survivors may
currently exist at the thinnest of margins even though habitat quality
has measurably improved and is currently suitable for good growth, as
evidenced by oyster culturist results in this estuary complex.
The persistence of oysters in isolated areas at low abundance for
perhaps decades, is not uncommon. Some local populations are now too
widely dispersed to support enough successful spawning-fertilization
and recruitment for natural repopulation (Pers. Comm. Luckenbach,
2005). The low abundance situation of the Hudson-Raritan area may exist
in other urbanized estuaries where oyster population surveys have not
been done for decades. Some shellfish surveys were conducted without
proper oyster sampling gear and focus because the oyster was not
considered part of a useful or manageable fishery resource any more.
Also, local management agencies may not want to publicize the existence
of oysters in some areas to avoid potential public health consequences
because of bacterially contaminated water.
According to the BRT, the notable decline of the oyster abundance
distributions from estimated historic abundance distribution levels
seems to be most prevalent in the more urbanized northeast, e.g.,
Chesapeake Bay, the Hudson-Raritan Estuary, southern Long Island NY,
and some New England estuaries. However, most of the data to document
this decline comes from fishery-dependent sources, which is somewhat
controlled by socio-economic, not ecological, factors (MacKenzie,
1996). This information base may not present an accurate picture of the
abundance and status of oyster populations in many areas. Based upon
numerous southern Atlantic/Gulf Coast state reports, the oyster
distribution abundances south of Chesapeake Bay seem relatively stable,
despite occasional major disturbances, such as hurricanes (Marsh, 2004;
Perret, 2005).
Consideration as a ``Species'' Under the ESA
Under the ESA, the term ``species'' refers to ``a species,
subspecies of fish or wildlife or plants, and any distinct population
segment of any species of vertebrate fish or wildlife which interbreeds
when mature.'' Distinct population segments of the eastern oyster
cannot be listed under the ESA because it is an invertebrate. The term
``subspecies,'' while identified as a term in the ESA's definition of
``species,'' is not itself defined in the ESA. As a matter of science,
however, subspecies delineations may rely on discernable morphological,
behavioral, genetic, or physiological differences.
Due to extreme morphological plasticity, C. virginica has not yet
been examined with the goal of identifying morphological differences
between populations. However, in 1951, Loosanoff and Nomejko recognized
the existence of physiological races along the latitudinal range of C.
virginica. Since that time, most physiological differences have been
found to be related to differences in environmental conditions. Whether
additional physiological or morphological studies would be informative
is questionable, as any differences between Gulf and Atlantic
populations are more likely to be due to local environmental conditions
rather than genetic differences (Gaffney, 1996).
Populations of C. virginica were initially found to be homogenous
in allozyme frequencies across a large portion of the species range. An
early allozyme study by Buroker (1983) provided evidence of a uniform
population from Cape Cod to Corpus Christi using 32 allozyme loci which
exhibited estimated genetic similarities among populations of 99
percent. Several recent genetic studies have been undertaken to better
understand the population structure of C. virginica, and these studies
have found strong patterns of differentiation on the basis of different
sequencing data. Studies indicate two separate populations, one within
the Atlantic region and one within the Gulf of Mexico, with an
intermediate zone between these populations found on the eastern coast
of Florida in the general area of Cape Canaveral. Crassostrea virginica
is not the only western Atlantic species with a notable genetic
transition from the temperate Atlantic to subtropical Gulf regions.
Similar genetic patterns of population subdivision between Atlantic and
Gulf populations can be found in a wide variety of coastal and marine
species (Avise, 1992; 2000). Also, a genetically distinct population of
C. virginica was found in the Laguna Madre area of Texas by different
studies that have included samples from this general area (Groue and
Lester, 1982; Buroker, 1983; Hedgecock and Okazaki, 1984; King et al.,
1994). Genetic differentiation of the Laguna Madre
[[Page 35391]]
eastern oyster population may be due to adaptation to hypersaline
conditions (up to 35 ppt) created by low levels of precipitation and
lack of river inflow, as well as selection or genetic drift due to
isolation from oyster populations further north (King et al., 1994).
Although the aforementioned studies indicate Atlantic/Gulf
population structure, other studies have agreed with Buroker's
conclusion of a panmictic population. MacDonald et al. (1996) found a
lack of genetic structure among six anonymous nuclear DNA loci from
oysters in Panacea, FL, and Charleston, SC. In 1998, Hare and Avise
(1992) looked at oysters from Massachusetts to Louisiana and found no
population structure at three nuclear loci.
Each peer reviewer was individually asked whether species/
subspecies delineations existed for the eastern oyster as a matter of
scientific fact. Two of the three felt that the existing information
was not sufficient to definitively establish eastern oyster subspecies.
The remaining reviewer felt that the available genetic information
indicates that the Gulf and Atlantic populations of eastern oyster are
``at a stage of incipient speciation and should probably be considered
subspecies.'' The peer reviewers and the members of the BRT all agree
that it is difficult to define and delineate subspecies under normal
scientific definitions of the terms.
In summation, subspecies delineations often rely on discernable
morphological, behavioral, or physiological differences. However, these
differences are not readily apparent in an invertebrate species such as
the eastern oyster. Thus, a subspecies delineation for the eastern
oyster would have to rely predominantly on the available genetic data,
which have provided mixed results. Because the data needed to support a
subspecies delineation are inconclusive, we examined the listing
potential for the eastern oyster both as a separate subspecies and as a
single biological unit. Ultimately, we determined that in either case,
the species/subspecies determination would not impact or alter the
final listing determination. Accordingly, we note the genetic
differences but do not make a subspecies delineation based on the
present facts.
Species/Subspecies Status
The process for determining whether a species (as defined above)
should be listed is based upon the best available scientific and
commercial information. We must list a species if it is endangered or
threatened because of any of the following ESA section 4(a)(1) factors:
(a) The present or threatened destruction, modification, or curtailment
of its habitat or range; (b) overutilization for commercial,
recreational, scientific, or educational purposes; (c) disease or
predation; (d) inadequacy of existing regulatory mechanisms; and (e)
other natural or manmade factors affecting the continued existence of
the species. These factors are considered in the following sections.
The Present or Threatened Destruction, Modification, or Curtailment of
its Habitat or Range
There are few data available regarding historic and current oyster
reef acreage estimates, and available fisheries dependent and
independent data are limited. In order to gather additional data to
assess the status of the species, the BRT conducted a telephone survey
of state resource managers and oyster experts. Respondents were asked
to provide the following information for each estuary within their
region/area: historic and current oyster acreage estimates; harvest
rates and regulations; the sustainability of oyster populations with
and without restoration; recruitment; and the primary stressors facing
oyster populations. The survey indicated that the eastern oyster is
widely distributed throughout its range and is currently present in all
but one of the 71 estuaries represented. This wide distribution is
beneficial in many ways in that it provides evidence of the species'
resiliency and adaptability and makes the species less susceptible to
extinction from a localized catastrophic event (e.g., a hurricane or
oil spill). We, therefore, concluded that the one estuary without
oysters, the upper Laguna Madre region, does not represent a large
portion of the vast geographic range of the species/subspecies and is
considered minor in terms of the biological significance to the species
or hypothetical subspecies.
The BRT reported that the eastern oyster displays a wide range of
survival strategies as it is both a colonizer and an ecosystem engineer
and has high reproductive potential. The species' ability to adapt to a
wide range of environmental conditions (e.g., tolerance for low
dissolved oxygen and wide ranges in salinity and temperature) makes it
resilient. The eastern oyster inhabits a naturally-variable
environment, and evidence suggests that past local extirpations and
colonizations have been common over geological time. Crassostrea
virginica is broadly distributed in the western North Atlantic, and its
distribution has not changed as threats have increased over time. This
is significant because range contraction is often used as an indicator
of a problem in many widely distributed marine species. While
separating the species into the two potential subspecies reduces the
range of each of the subspecies (as compared to the full species),
Atlantic and Gulf Coast oyster populations are still widespread,
occupying areas from Maine to eastern Florida and western Florida to
Texas, respectively. Based on the available data, we concluded that
oyster abundance throughout these areas is sufficient to sustain these
populations and prevent extinction. While the survey indicated some
habitat within the range of the eastern oyster has been degraded or
lost, we were able to conclude based upon the available information,
including the survey, that the species' ability to adapt to various
environmental conditions and its vast geographic range results in
habitat degradation being a minimal threat that will not affect the
species/subspecies' continued existence.
Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
Information from the survey indicated that oyster harvests are at
or near recent record low levels along the majority of the U.S.
Atlantic coast; however, responding resource managers and independent
experts considered overutilization (overharvesting) to currently be a
minor threat to oyster populations. According to the BRT, areas along
the Atlantic coast south of Cape Lookout and through the Gulf of Mexico
appear to have avoided some of the extremely heavy historic utilization
experienced by the area from Pamlico Sound to Long Island Sound.
Harvest parameters in the Gulf of Mexico are currently less restrictive
than those in the mid-Atlantic area, but oyster populations there
appear to be effectively managed and monitored so that harvest impacts
are not substantial (Marsh, 2004). Eastern oyster resources from
Pamlico Sound to Long Island Sound appear to have suffered from long-
term overutilization. State managers in this region have attempted to
protect public oyster stocks by conducting stock assessments, setting
conservative harvest quotas, lowering daily catch limits, limiting
harmful gear use, and reducing harvest seasons. Attempts to restore
oyster populations and rebuild the resource through general cultch
planting, reef rebuilding, and oyster sanctuaries/reserves are also
becoming common management tools in
[[Page 35392]]
this region. In the survey, overharvesting is listed as occurring only
in seven estuaries out of the 71 estuaries assessed. These seven
estuaries represent a limited portion of the large geographic range of
the species/subspecies, and overutilization in these areas represents a
localized issue. Recreational harvest and harvest for scientific
purposes were not identified as significant stressors to the eastern
oyster. Long-term overutilization in many areas of the eastern oyster's
range was a significant contributing factor to the species' historical
decline. However, survey respondents no longer consider this to be a
significant threat to the eastern oyster in the majority of the
species/subspecies' range. Thus, we conclude that overutilization is
not a significant ongoing threat that affects the continued existence
of the eastern oyster species/subspecies.
Disease or Predation
There are several predators on various life stages of the eastern
oyster, including boring sponges and clams, mud worms, carnivorous
gastropods, ctenophores, and a number of fish species. However, most of
these predators exist as natural associations in the oyster reef
community and, in general, most oysters in the population survive.
Thus, these associations do not seem to be having an effect at the
population level. The eastern oyster is affected primarily by two
diseases - DERMO (a parasitic disease caused by the protozoan Perkinsus
marinus) (Levine, 1978 = Dermocystidium marinum; Mackin et al., 1950 =
Layirinthomyxa marina; Quick and Mackin, 1971) and MSX (another
parasitic disease caused by the protozoan Haplosporidium
nelsoni)(Haskin et al., 1966). The BRT reported that both of these
diseases are capable of causing significant oyster mortalities.
However, oysters infected by DERMO have the opportunity to spawn the
first summer, and others may be able to spawn a second or third time
before succumbing to an infection. With MSX, the salinity must be above
15 ppt to sustain an infection. Thus, infections during drought years
are more prevalent. As drought conditions wane, survivors and their
progeny may reproduce to re-establish oyster populations. During the
wetter years that occurred during the 1970s, there was significant
recovery of oyster populations that had been devastated during the
1950-1960 MSX epizootic in both Delaware and Chesapeake Bays. Oyster
recovery management programs have concentrated on moderate to lower
salinity areas that are less likely to support the development of
oyster diseases. Research has been ongoing for several years to develop
oysters that are disease tolerant. Also, resource managers help to
control the spread of DERMO by controlling/preventing the
transplantation of infected oysters to areas not currently infected by
the disease. Based on the available information, we conclude that while
both predation and disease may have effects on localized populations,
impacts to the entire species/subspecies vary both spatially and
temporally, allowing some affected populations to recover and sustain
the species/subspecies. Thus, we conclude that neither disease nor
predation are significant threats that affect the continued existence
of the eastern oyster species/subspecies.
Inadequacy of Existing Regulatory Mechanisms
The BRT indicated that regulatory mechanisms for eastern oyster are
most logically defined as habitat resource protection (preventative
measures), fishery-specific, and conservation/replenishment based. The
eastern oyster is not a federally managed species. As such, each state
is responsible for controlling harvest, protecting habitat, and
conserving or replenishing oyster populations. This results in many
different types of regulations to protect oysters throughout their
range.
Habitat measures are those defined at the Federal, state, or local
level designed to protect aquatic resources (including benthic reef
habitat and water quality) from various direct or indirect development
impacts (e.g., impacts of channel dredging, onshore development, point-
source runoff, etc.). Harvest measures are those intended to control or
regulate the commercial or recreational catch of the species, and may
or may not be resource conservation based. Conservation/replenishment
measures are those intended to ensure the continuance of the fishery or
habitat resource through various measures including setting aside no-
harvest areas, requiring culling of shell during harvest, setting up
programs to return shells from harvested product back to reef areas, or
natural seed movement programs intended to support either habitat or
fishery restoration.
State shellfish control agencies are responsible for managing
shellfish harvesting areas for public health protection, which may
result in permanent or temporary closures due to the presence of toxic
algal blooms, elevated fecal coliforms and/or Vibrio spp., or chemical
contamination. According to the Environmental Protection Agency (http://www.epa.gov/maia/html/es-condition.html), shellfishing was prohibited
from 3 percent (3,660,000 acres, or 1,481,149 hectares) of the
classified shellfish areas in the estuaries in the mid-Atlantic in
2006, restricted in 5 percent (179,000 acres, or 72,438 hectares), and
conditionally closed in 2 percent (67,000 acres, or 27,113 hectares).
Similar closures occur in the Northeast, Southeast, and Gulf of Mexico,
varying spatially and temporally. These restrictions may have the
ancillary benefit of protecting some populations in chronically
contaminated areas from harvest.
Restoration and enhancement efforts for fisheries and conservation
are occurring throughout the species' range, but are more common in the
north and mid-Atlantic. According to the survey responses, in estuaries
where restoration and enhancement efforts are occurring they are
considered necessary to sustain populations in roughly half the
estuaries in the mid- and south Atlantic regions (presumably, to
support commercially viable populations). In the North Atlantic
(specifically, Connecticut and Rhode Island) and the Gulf of Mexico,
restoration and enhancement efforts are not necessary to sustain
biologically viable populations but are considered important to
maintaining a fishery and conserving ecosystem services. Many
restoration efforts throughout the species' range have been ongoing for
many years and have proven successful in maintaining oyster
populations. Due to the longevity and success of many of these efforts,
they are expected to continue into the future. Consequently, measures
to regulate the eastern oyster have been determined to be adequate.
Thus, we conclude that the inadequacy of existing regulatory mechanisms
is not a significant threat that affects the continued existence of the
eastern oyster species/subspecies.
Other Natural or Manmade Factors Affecting the Continued Existence of
the Species
Finally, hurricanes, harmful algal blooms, and non-native
introductions have been identified as other possible factors affecting
the eastern oyster throughout its range. However, none of these
stressors are thought to have a significant impact throughout all or a
significant portion of the range of either the eastern oyster species
or hypothetical subspecies. Thus, we conclude that there are no other
natural or manmade factors considered to be significant threats that
affect the
[[Page 35393]]
continued existence of the eastern oyster species/subspecies.
Summary and Synthesis of Analysis of the Factors Identified in ESA
Section 4(a)(1)
While eastern oyster abundance has declined from historic highs,
especially in the northern portion of the species' range, the eastern
oyster is still present in all areas throughout its historic
distribution. According to the survey results, even at the low
abundance levels in some areas, recruitment is sufficient to maintain
the viability of eastern oyster populations throughout the species'
range except in a portion of the mid-Atlantic (e.g., Long Island Sound,
Peconic Bay, Hudson Raritan Estuary). This area represents a small
portion of the large geographic range of the species and/or
hypothetical subspecies and would not be expected to significantly
impact or impede larval transport and exchange to and from more
productive areas to the north or south. The area also represents a
minor percentage of the overall potential oyster biomass and of the
total spawning potential of the species/hypothetical subspecies. We
conclude that recruitment in other portions of the range is more than
sufficient to maintain the continued existence of the species and/or
hypothetical subspecies.
In all cases, the analysis of all five factors indicate that the
continued existence of the species or hypothetical subspecies is not at
risk now or in the foreseeable future. While threats that may be
significant at a regional or local level to the species exist, we do
not consider any to be overwhelmingly dominant or advancing at a
significant rate which would result in the species or hypothetical
subspecies becoming threatened or endangered.
Listing Determination
The ESA defines an endangered species as any species in danger of
extinction throughout all or a significant portion of its range, and a
threatened species as any species likely to become an endangered
species within the foreseeable future throughout all or a significant
portion of its range. Section 4(b)(1) of the ESA requires that the
listing determination be based solely on the best scientific and
commercial data available, after conducting a review of the status of
the species and after taking into account those efforts, if any, that
are being made to protect such species. After reviewing the best
available scientific and commercial information for the eastern oyster,
we have determined that neither the species nor the potential
subspecies warrants listing as threatened or endangered at this time.
While listing the species or hypothetical subspecies under the ESA
is not warranted at this time, the BRT and the peer reviewers
identified specific research and/or monitoring needs that are
considered very important to the long-term conservation and
preservation of the eastern oyster. These include the following:
fishery independent surveys (quantitative stock assessments for the
entire range); effective population size estimates; monitoring of the
effectiveness of conservation/restoration efforts; additional genetic
analyses to determine population structure with a focus on local or
regional adaptations; research on proximity-recruitment relationship;
research on effects of combined and chronic stresses including changes
due to climate change; continued research on disease susceptibility and
development of selectively bred disease tolerant strains; emerging role
of endocrine disrupting pollutants; delineation of oyster habitat;
compatibility of existing information; continued ecological risk
associated with other oyster or other alien species introductions;
control and abatement of threats from all sources; developmentof a
standard monitoring protocol on a local or regional level; and research
on the effects of changes in coastal development and demographics.
Authority: 16 U.S.C. 1531 et seq.
Dated: June 22, 2007.
Samuel D. Rauch III,
Deputy Assistant Administrator for Regulatory Programs, National Marine
Fisheries Service.
[FR Doc. E7-12564 Filed 6-27-07; 8:45 am]
BILLING CODE 3510-22-S