[Federal Register Volume 75, Number 193 (Wednesday, October 6, 2010)]
[Proposed Rules]
[Pages 61904-61929]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-24461]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
50 CFR Part 224
RIN 0648-XN50
[Docket No. 090219208-9210-01]
Endangered and Threatened Wildlife and Plants; Proposed Listings
for Two Distinct Population Segments of Atlantic Sturgeon (Acipenser
oxyrinchus oxyrinchus) in the Southeast
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Proposed rule; request for comments.
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SUMMARY: In 2007, a Status Review Team (SRT) consisting of Federal
biologists from NMFS, U.S. Geological Survey (USGS), and U.S. Fish and
Wildlife Service (USFWS) completed a status review report on Atlantic
sturgeon (Acipenser oxyrinchus oxyrinchus) in the United States. We,
NMFS, have reviewed this status review report and all other best
available information to determine if listing Atlantic sturgeon under
the Endangered Species Act (ESA) as either threatened or endangered is
warranted. The SRT recommended that Atlantic sturgeon in the United
States be divided into the following five distinct population segments
(DPSs): Gulf of Maine; New York Bight; Chesapeake Bay; Carolina; and
South Atlantic, and we agree with this DPS structure. After reviewing
the available information on the Carolina and South Atlantic DPSs, the
two DPSs located within the NMFS Southeast Region, we have determined
that listing these two DPSs as endangered is warranted. Therefore, we
propose to list these two DPSs as endangered under the ESA. We have
published a separate listing determination for the DPSs within the NMFS
Northeast Region in today's Federal Register.
DATES: Comments on this proposed rule must be received by January 4,
2011. At least one public hearing will be held in a central location
for each DPS; notice of the location(s) and time(s) of the hearing(s)
will be subsequently published in the Federal Register not less than 15
days before the hearing is held.
ADDRESSES: You may submit comments, identified by the XRIN 0648-XN50,
by any of the following methods:
Electronic Submissions: Submit all electronic public
comments via the Federal eRulemaking Portal http//www.regulations.gov.
Follow the instructions for submitting comments.
Mail or hand-delivery: Assistant Regional Administrator
for Protected Resources, NMFS, Southeast Regional Office, 263 13th
Avenue South, St. Petersburg, FL 33701.
Facsimile (fax) to: 727-824-5309.
Instructions: All comments received are considered part of the
public record and will generally be posted to http://www.regulations.gov. All Personal Identifying Information (i.e., name,
address, etc.) voluntarily submitted may be publicly accessible. Do not
submit Confidential Business Information or otherwise sensitive or
protected information. We will accept anonymous comments (enter ``n/a''
in the required fields if you wish to remain anonymous). Please provide
electronic attachments using Microsoft Word, Excel, WordPerfect, or
Adobe PDF file formats only. This proposed rule, the list of
references, and the status review report are also available
electronically at the NMFS Web site at http://sero.nmfs.noaa.gov/pr/sturgeon.htm.
FOR FURTHER INFORMATION CONTACT: Kelly Shotts, NMFS, Southeast Regional
Office (727) 824-5312 or Marta Nammack, NMFS, Office of Protected
Resources (301) 713-1401.
SUPPLEMENTARY INFORMATION:
Public Comments Solicited
We intend that any final action resulting from this proposal will
be as accurate as possible and informed by the best available
scientific and commercial information. Therefore, we request comments
or information 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 abundance of Atlantic sturgeon in the various river systems
in the Carolina and South Atlantic DPSs;
(2) The mixing of fish from different DPSs in parts of their
ranges, particularly in the marine environment;
(3) Information concerning the viability of and/or threats to
Atlantic sturgeon in the Carolina and South Atlantic DPSs; and
(4) Efforts being made to protect Atlantic sturgeon in the Carolina
and South Atlantic DPSs.
Public Hearings
One public hearing will be held in a central location for each DPS.
We will schedule the public hearings on this proposal and announce the
dates, times, and locations of those hearings, as well as how to obtain
reasonable accommodations for disabilities, in the Federal Register and
local newspapers at least 15 days before the first hearing.
Background
Initiation of the Status Review
We first identified Atlantic sturgeon as a candidate species in
1991. On June 2, 1997, NMFS and USFWS (collectively, the Services)
received a petition from the Biodiversity Legal Foundation requesting
that we list Atlantic sturgeon in the United States, where it continues
to exist, as threatened or endangered and designate critical habitat
within a reasonable period of time following the listing. A notice was
published in the Federal Register on October 17, 1997, stating that the
Services had determined substantial information existed indicating the
petitioned action may be warranted (62 FR 54018). In 1998, after
completing a comprehensive status review, the Services published a 12-
month determination in the Federal Register announcing that listing was
not warranted at that time (63 FR 50187; September 21, 1998). We
retained Atlantic sturgeon on the candidate species list (and
subsequently transferred it to the Species of Concern List (69 FR
19975; April 15, 2004)). Concurrently, the Atlantic States Marine
Fisheries Commission (ASMFC) completed Amendment 1 to the 1990 Atlantic
Sturgeon Fishery Management Plan (FMP) that imposed a 20- to 40-year
moratorium on all Atlantic sturgeon fisheries until the Atlantic Coast
spawning stocks could be restored to a level where 20 subsequent year
classes of adult females were protected (ASMFC, 1998). In 1999,
pursuant to section 804(b) of the Atlantic Coastal Fisheries
Cooperative Management Act (ACFCMA) (16 U.S.C. 5101 et seq.), we
followed this action by closing the Exclusive Economic Zone (EEZ) to
Atlantic sturgeon retention. In 2003, we sponsored a workshop in
Raleigh, North Carolina, with USFWS and ASMFC entitled, ``The Status
and Management of Atlantic Sturgeon,'' to discuss the status of
sturgeon along the Atlantic Coast and determine what obstacles, if any,
were impeding their recovery (Kahnle et al., 2005). The workshop
revealed mixed results in regards to the status of Atlantic sturgeon
populations, despite the coastwide fishing
[[Page 61905]]
moratorium. Some populations seemed to be recovering while others were
declining. Bycatch and habitat degradation were noted as possible
causes for continued population declines.
Based on the information gathered from the 2003 workshop on
Atlantic sturgeon, we decided that a new review of Atlantic sturgeon
status was needed to determine if listing as threatened or endangered
under the ESA was warranted. The SRT, consisting of four NMFS, four
USFWS, and three USGS biologists prepared a draft status review report.
The draft report was then reviewed and supplemented by eight state and
regional experts who provided their individual expert opinions on the
scientific facts contained in the report and provided additional
information to ensure the report provided the best available data.
Lastly, the report was peer reviewed by six experts from academia. A
Notice of Availability of the final status review report was published
in the Federal Register on April 3, 2007 (72 FR 15865). On October 6,
2009, we received a petition from the Natural Resources Defense Council
to list Atlantic sturgeon as endangered under the ESA. As an
alternative, the petitioner requested that the species be delineated
and listed as the five DPSs described in the 2007 Atlantic sturgeon
status review report (ASSRT, 2007): Gulf of Maine, New York Bight,
Chesapeake Bay, Carolina, and South Atlantic DPSs, with the Gulf of
Maine and South Atlantic DPSs listed as threatened, and the remaining
three DPSs listed as endangered. The petitioner also requested that
critical habitat be designated for Atlantic sturgeon under the ESA. We
published a Notice of 90-Day Finding on January 6, 2010 (75 FR 838),
stating that the petition presented substantial scientific or
commercial information indicating that the petitioned actions may be
warranted.
Listing Species Under the Endangered Species Act
We are responsible for determining whether Atlantic sturgeon are
threatened or endangered under the ESA (16 U.S.C. 1531 et seq.) To be
considered for listing under the ESA, a group of organisms must
constitute a ``species,'' which is defined in section 3 of the ESA to
include ``any subspecies of fish or wildlife or plants, and any
distinct population segment of any species of vertebrate fish or
wildlife which interbreeds when mature.'' On February 7, 1996, the
Services adopted a policy describing what constitutes a DPS of a
taxonomic species (61 FR 4722). The joint DPS policy identified two
elements that must be considered when identifying a DPS: (1) The
discreteness of the population segment in relation to the remainder of
the species (or subspecies) to which it belongs; and (2) the
significance of the population segment to the remainder of the species
(or subspecies) to which it belongs. As stated in the joint DPS policy,
Congress expressed its expectation that the Services would exercise
authority with regard to DPSs sparingly and only when the biological
evidence indicates such action is warranted.
Section 3 of the ESA defines an endangered species as ``any species
which is in danger of extinction throughout all or a significant
portion of its range'' and a threatened species as one ``which is
likely to become an endangered species within the foreseeable future
throughout all or a significant portion of its range.'' The statute
requires us to determine whether any species is endangered or
threatened as a result of any one or a combination of the following
five 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) the inadequacy of existing regulatory
mechanisms; or (E) other natural or manmade factors affecting its
continued existence (section 4(a)(1)(A)(E)). Section 4(b)(1)(A) of the
ESA requires us to make listing determinations 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 efforts being
made to protect the species. Accordingly, we have followed a stepwise
approach in making our listing determination for Atlantic sturgeon.
Considering biological evidence, such as the separation between river
populations during spawning and the possibility of multiple distinct
interbreeding Atlantic sturgeon populations, we evaluated whether
Atlantic sturgeon population segments met the DPS Policy criteria. We
then determined the status of each DPS (each ``species'') and
identified the factors and threats contributing to their status per
section 4(a)(1) of the ESA. Finally, we assessed efforts being made to
protect the species, determining if these efforts are adequate to
mitigate impacts and threats to the species' status. We evaluated
ongoing conservation efforts using the criteria outlined in the Policy
for Evaluating Conservation Efforts (PECE; 68 FR 15100; March 28, 2003)
to determine their certainties of implementation and effectiveness.
We reviewed the status review report, its cited references and peer
review comments, and information that has become available since the
status review report was finalized in 2007. Thus, we believe this
proposed rule is based on the best available scientific and commercial
information. Much of the information discussed below on Atlantic
sturgeon biology, distribution, historical abundance and threats is
attributable to the status review report. However, we have
independently applied the statutory provisions of the ESA, our
regulations regarding listing determinations, and our policy on
identification of distinct population segments, in making the proposed
listing determinations.
Taxonomy and Life History
There are two subspecies of Atlantic sturgeon--the Gulf sturgeon
(Acipenser oxyrinchus desotoi) and the Atlantic sturgeon (Acipenser
oxyrinchus oxyrinchus). Historically, the Gulf sturgeon occurred from
the Mississippi River east to Tampa Bay. Its present range extends from
Lake Pontchartrain and the Pearl River system in Louisiana and
Mississippi east to the Suwannee River in Florida. The Gulf sturgeon
was listed as threatened under the ESA in 1991. The finding in this
proposed rule addresses the subspecies Acipenser oxyrinchus oxyrinchus
(referred to as Atlantic sturgeon), which is distributed along the
eastern coast of North America. Historically, sightings have been
reported from Hamilton Inlet, Labrador, south to the St. Johns River,
Florida. Occurrences south of the St. Johns River, Florida, and in
Labrador may have always been rare.
Atlantic sturgeon is a long-lived, late-maturing, estuarine-
dependent, anadromous species. Atlantic sturgeon may live up to 60
years, reach lengths up to 14 feet (ft; 4.27 meters (m)), and weigh
over 800 pounds (lbs; 363 kilograms (kg)). They are distinguished by
armor-like plates and a long protruding snout that is ventrally
located, with four barbels crossing in front. Sturgeon are omnivorous
benthic (bottom) feeders and filter quantities of mud along with their
food. Adult sturgeon diets include mollusks, gastropods, amphipods,
isopods, and fish. Juvenile sturgeon feed on aquatic insects and other
invertebrates (ASSRT, 2007).
Vital parameters of Atlantic sturgeon populations show clinal
variation with faster growth and earlier age at maturation in more
southern systems, though not all data sets conform to this
[[Page 61906]]
trend. Atlantic sturgeon mature between the ages of 5 and 19 years in
South Carolina (Smith et al., 1982), between 11 and 21 years in the
Hudson River (Young et al., 1988), and between 22 and 34 years in the
St. Lawrence River (Scott and Crossman, 1973). Atlantic sturgeon likely
do not spawn every year. Multiple studies have shown that spawning
intervals range from 1 to 5 years for males (Smith, 1985; Collins et
al., 2000; Caron et al., 2002) and 2 to 5 years for females (Vladykov
and Greeley, 1963; Van Eenennaam et al., 1996; Stevenson and Secor,
1999). Fecundity of Atlantic sturgeon has been correlated with age and
body size, with egg production ranging from 400,000 to 8 million eggs
per year (Smith et al., 1982; Van Eenennaam and Doroshov, 1998;
Dadswell, 2006). The average age at which 50 percent of maximum
lifetime egg production is achieved is estimated to be 29 years,
approximately 3 to 10 times longer than for other bony fish species
examined (Boreman, 1997).
Spawning adults migrate upriver in the spring, which occurs during
February and March in southern systems, April and May in mid-Atlantic
systems, and May and July in Canadian systems (Murawski and Pacheco,
1977; Smith, 1985; Bain, 1997; Smith and Clugston, 1997; Caron et al.,
2002). In some southern rivers, a fall spawning migration may also
occur (Rogers and Weber, 1995; Weber and Jennings, 1996; Moser et al.,
1998). Spawning is believed to occur in flowing water between the salt
front and fall line of large rivers, where optimal flows are 18 to 30
inches (in) per second (46 to 76 centimeters (cm) per second) and
depths are 36 to 89 ft (11 to 27 m) (Borodin, 1925; Leland, 1968; Scott
and Crossman, 1973; Crance, 1987; Bain et al., 2000). The fall line is
the boundary between an upland region of continental bedrock and an
alluvial coastal plain, sometimes characterized by waterfalls or
rapids. Sturgeon eggs are highly adhesive and are deposited on the
bottom substrate, usually on hard surfaces (e.g., cobble) (Gilbert,
1989; Smith and Clugston, 1997). Hatching occurs approximately 94 to
140 hours after egg deposition at corresponding temperatures of 68.0 to
64.4 degrees Fahrenheit (20 to 18 degrees Celsius). The newly emerged
larvae assume a demersal existence (Smith et al., 1980). The yolksac
larval stage is completed in about 8 to 12 days, during which time the
larvae move downstream to rearing grounds (Kynard and Horgan, 2002).
During the first half of their migration downstream, movement is
limited to night. During the day, larvae use benthic structure (e.g.,
gravel matrix) as refugia (Kynard and Horgan, 2002). During the latter
half of migration, when larvae are more fully developed, movement to
rearing grounds occurs both day and night. Juvenile sturgeon continue
to move further downstream into brackish waters and eventually become
residents in estuarine waters for months to years.
Recovery of depleted populations is an inherently slow process for
a late-maturing species such as Atlantic sturgeon. Their late age at
maturity provides more opportunities for individuals to be removed from
the population before reproducing. However, a long life-span also
allows multiple opportunities to contribute to future generations
provided the appropriate spawning habitat and conditions are available.
Distribution and Abundance
Historically, Atlantic sturgeon were present in approximately 38
rivers throughout their range, of which 35 rivers have been confirmed
to have had a historical spawning population. More recently, presence
has been documented in 36 rivers with spawning taking place in at least
18 rivers. Spawning has been confirmed in the St. Lawrence, Annapolis,
St. John, Kennebec, Hudson, Delaware, James, Roanoke, Tar-Pamlico, Cape
Fear, Waccamaw, Great Pee Dee, Combahee, Edisto, Savannah, Ogeechee,
Altamaha, and Satilla rivers. Rivers with possible, but unconfirmed,
spawning populations include the St. Croix, Penobscot, Androscoggin,
Sheepscot, York, Neuse, Santee and Cooper Rivers; spawning may occur in
the Santee and/or the Cooper Rivers, but it may not result in
successful recruitment.
Historical records from the 1700s and 1800s document large numbers
of sturgeon in many rivers along the Atlantic Coast. Atlantic sturgeon
underwent significant range-wide declines from historical abundance
levels due to overfishing in the late 1800s, as discussed more fully
below. Sturgeon stocks were further impacted through environmental
degradation, especially due to habitat loss and reduced water quality
from the construction of dams in the early to mid-1900s. The species
persisted in many rivers, though at greatly reduced levels (1 to 5
percent of their earliest recorded numbers), and commercial fisheries
were active in many rivers during all or some of the years 1962 to
1997. Many of these contemporary fisheries resulted in continued
overfishing, which prompted ASMFC to impose the Atlantic sturgeon
fishing moratorium in 1998 and NMFS to close the EEZ to Atlantic
sturgeon retention in 1999.
Abundance estimates of Atlantic sturgeon are currently only
available for the Hudson (NY) and Altamaha (GA) rivers, where adult
spawning populations are estimated to be approximately 870 and 343 fish
per year, respectively (Kahnle et al., 2007; Schueller and Peterson,
2006). Surveys from other rivers in the species' U.S. range are more
qualitative, primarily focusing on documentation of multiple year
classes and reproduction, as well as the presence of very large adults
and gravid females, in the river systems. In the Southeast Region,
spawning has been confirmed in 11 rivers (Roanoke, Tar-Pamlico, Cape
Fear, Waccamaw, Great Pee Dee, Combahee, Edisto, Savannah, Ogeechee,
Altamaha, and Satilla rivers), with possible spawning occurring in 3
additional river (the Neuse, Santee and Cooper Rivers). Based on a
comprehensive review of the available data, the literature, and
information provided by local, state, and Federal fishery management
personnel, the Altamaha River is believed to have the largest
population in the Southeast (ASSRT, 2007). The larger size of this
population relative to the other river populations in the Southeast is
likely due to the absence of dams, the lack of heavy development in the
watershed, and relatively good water quality, as Atlantic sturgeon
populations in the other rivers in the Southeast have been affected by
one or more of these factors. Trammel net surveys, as well as
independent monitoring of incidental take in the American shad fishery,
suggest that the Altamaha population is neither increasing nor
decreasing. Though abundance estimates are not available for the other
river populations, because the Altamaha spawning population is the
largest, we believe a conservative estimate of the other spawning
populations in the Southeast Region is no more than 300 adults spawning
per year.
Historically, Atlantic sturgeon were abundant in most North
Carolina coastal rivers and estuaries, with the largest fisheries
occurring in the Roanoke River/Albemarle Sound system and in the Cape
Fear River (Kahnle et al., 1998). Historical landings records from the
late 1800s indicated that Atlantic sturgeon were very abundant within
Albemarle Sound (approximately 135,600 lbs or 61,500 kg landed per
year). Abundance estimates derived from these historical landings
records indicated that between 7,200 and 10,500 adult females were
present within North Carolina prior to 1890 (Armstrong and
[[Page 61907]]
Hightower, 2002; Secor, 2002). The North Carolina Division of Marine
Fisheries (NCDMF) has conducted the Albemarle Sound Independent Gill
Net Survey (IGNS), initially designed to target striped bass, since
1990. During that time, 842 young-of-the-year (YOY) and subadult
sturgeon have been captured. Incidental take of Atlantic sturgeon in
the IGNS, as well as multiple observations of YOY from the Albemarle
Sound and Roanoke River, provide evidence that spawning continues, and
catch records indicate that this population seemed to be increasing
until 2000, when recruitment began to decline. Catch records and
observations from other river systems in North Carolina exist (e.g.,
Hoff, 1980, Oakley, 2003, in the Tar and Neuse rivers; Moser et al.,
1998, and Williams and Lankford, 2003, in the Cape Fear River) and
provide evidence for spawning, but based on the relatively low numbers
of fish caught, it is difficult to determine whether the populations in
those systems are declining, rebounding, or remaining static. Also,
large survey captures during a single year are difficult to interpret.
For instance, abundance of Atlantic sturgeon below Lock and Dam
1 in the Cape Fear River seemed to have increased dramatically
during the 1990-1997 surveys (Moser et al., 1998) as the catch per unit
effort (CPUE) of Atlantic sturgeon was up to eight times greater during
1997 than in the earlier survey years. Since 1997, Atlantic sturgeon
CPUE doubled between the years of 1997 and 2003 (Williams and Lankford,
2003). However, it is unknown whether this is an actual population
increase reflecting the effects of North Carolina's ban on Atlantic
sturgeon fishing that began in 1991, or whether the results were skewed
by one outlier year. There was a large increase observed in 2002,
though the estimates were similar among all other years of the 1997 to
2003 study.
Atlantic sturgeon were likely present in many South Carolina river/
estuary systems historically, but it is not known where spawning
occurred. Secor (2002) estimated that 8,000 spawning females were
likely present prior to 1890, based on U.S. Fish Commission landing
records. Since the 1800s, however, populations have declined
dramatically (Collins and Smith, 1997). Recorded landings of Atlantic
sturgeon in South Carolina peaked at 481,050 lbs (218,200 kg) in 1897,
but 5 years later, only 93,920 lbs (42,600 kg) were reported landed
(Smith et al., 1984). Landings remained depressed throughout the 1900s,
with between 4,410 and 99,210 lbs (2,000 and 45,000 kg) of Atlantic
sturgeon reported annually between 1958 and 1982 (Smith et al., 1984).
During the last two decades, Atlantic sturgeon have been observed in
most South Carolina coastal rivers, although it is not known if all
rivers support a spawning population (Collins and Smith, 1997). Recent
sampling for shortnose sturgeon (Acipenser brevirostrum) conducted in
Winyah Bay captured two subadult Atlantic sturgeon in 2004. Captures of
age-1 juveniles from the Waccamaw River during the early 1980s suggest
that a reproducing population of Atlantic sturgeon may persist in that
river, although the fish could have been from the nearby Great Pee Dee
River (Collins and Smith, 1997). Until recently, there was no evidence
that Atlantic sturgeon spawned in the Great Pee Dee River, although
subadults were frequently captured and large adults were often observed
by fishers. However, a fishery survey conducted by Progress Energy
Carolinas Incorporated captured a running ripe male in October 2003 and
observed other large sturgeon, perhaps revealing a fall spawning run
(ASSRT, 2007). There are no data available regarding the presence of
YOY or spawning adult Atlantic sturgeon in the Sampit River, although
it did historically support a population and is thought to serve as a
nursery ground for local stocks (ASMFC, 2009).
The Santee-Cooper system had some of the highest historical
landings of Atlantic sturgeon in the Southeast. Data from the U.S. Fish
Commission shows that greater than 220,460 lbs (100,000 kg) of Atlantic
sturgeon were landed in 1890 (Secor, 2002). The capture of 151
subadults, including age-1 juveniles, in the Santee River in 1997
suggests that an Atlantic sturgeon population still exists in this
river (Collins and Smith, 1997). The status review report documents
that three adult Atlantic sturgeon carcasses were found above the
Wilson and Pinopolis dams in Lake Moultrie (a Santee-Cooper reservoir)
during the 1990s, and also states that there is little information
regarding a land-locked population existing above the dams. There is no
effective fish passage for sturgeon on the Santee and Cooper Rivers,
and the lowest dams on these rivers are well below the fall line, thus
limiting the amount of freshwater spawning and developmental habitat
for fish below the dams. In 2007, an Atlantic sturgeon entered the lock
at the St. Stephens dam; it was physically removed and translocated
downstream into the Santee River (A. Crosby, SCDNR, pers. comm.) In
2004, 15 subadult Atlantic sturgeon were captured in shortnose sturgeon
surveys in the Santee River estuary. The previous winter, four juvenile
(YOY and subadults) Atlantic sturgeon were captured from the Santee
(one fish) and Cooper (three fish) rivers. These data support previous
hypotheses that a fall spawning run occurs within this system, similar
to that observed in other southern river systems. However, the status
review report notes that SCDNR biologists have some doubt whether
smaller sturgeon from the Santee-Cooper are resident YOY, as flood
waters from the Pee-Dee or Waccamaw Rivers could have transported these
YOY to the Santee-Cooper system via Winyah Bay and the Intracoastal
Waterway (McCord, 2004). Resident YOY could, however, be evidence of a
spawning population above the dams, as is the case with shortnose
sturgeon (S. Bolden, pers. comm.).
From 1994 to 2001, over 3,000 juveniles have been collected in the
Ashepoo-Combahee-Edisto Rivers (ACE) Basin, including 1,331 YOY
sturgeon (Collins and Smith, 1997; ASSRT, 2007). Sampling for adults
began in 1997, with two adult sturgeon captured in the first year of
the survey, including one gravid female captured in the Edisto River
and one running ripe male captured in the Combahee River. The running
ripe male in the Combahee River was recaptured one week later in the
Edisto River, which suggests that the three rivers that make up the ACE
Basin may support a single population that spawns in at least two of
the rivers. In 1998, an additional 39 spawning adults were captured
(ASSRT, 2007). These captures show that a current spawning population
exists in the ACE Basin, as both YOY and spawning adults are regularly
captured.
The Ashley River, along with the Cooper River, drains into
Charleston Bay; only shortnose sturgeon have been sampled in these
rivers. While the Ashley River historically supported an Atlantic
sturgeon spawning population, it is unknown whether the population
still exists. There has been little or no scientific sampling for
Atlantic sturgeon in the Broad/Coosawatchie River. One fish of unknown
size was reported from a small directed fishery during 1981 to 1982
(Smith and Dingley, 1984).
Prior to the collapse of the fishery in the late 1800s, the
sturgeon fishery was the third largest fishery in Georgia. Secor (2002)
estimated from U.S. Fish Commission landing reports that approximately
11,000 spawning females were likely present prior to 1890. The sturgeon
fishery was mainly centered on the Altamaha River, and in more recent
years, peak landings were recorded in
[[Page 61908]]
1982 (13,000 lbs, 5,900 kg). Based on juvenile presence and abundance,
the Altamaha River currently supports one of the healthier Atlantic
sturgeon populations in the southeast (ASSRT, 2007). Atlantic sturgeon
are also present in the Ogeechee River; however, the absence of age-1
fish during some years and the unbalanced age structure suggests that
the population is highly stressed (Rogers and Weber, 1995). Sampling
results indicate that the Atlantic sturgeon population in the Satilla
River is also highly stressed (Rogers and Weber, 1995). Only four
spawning adults or YOY, which were used for genetic analysis (Ong et
al., 1996), have been collected from this river since 1995. In Georgia,
Atlantic sturgeon are believed to spawn in the Savannah, Ogeechee,
Altamaha, and Satilla rivers. The Savannah River supports a reproducing
population of Atlantic sturgeon (Collins and Smith, 1997). According to
NOAA's National Ocean Service, 70 Atlantic sturgeon have been captured
since 1999 (ASSRT, 2007). Twenty-two of these fish have been YOY. A
running ripe male was captured at the base of the dam at Augusta during
the late summer of 1997, which supports the hypothesis that spawning
occurs there in the fall.
Reproducing Atlantic sturgeon populations are no longer believed to
exist south of the Satilla River in Georgia. Recent sampling of the St.
Marys River failed to locate any sturgeon, which suggests that the
spawning population may be extirpated (Rogers et al., 1994; NMFS 2009).
In January 2010, 12 sturgeon, believed to be Atlantics, were captured
at the mouth of the St. Marys during relocation trawling associated
with a dredging project (J. Wilcox, Florida Fish and Wildlife
Conservation Commission, Pers. Comm.), the first capture of Atlantics
in the St. Marys in decades. However, because they were not YOY or
adults captured upstream, these trawl-captured sturgeon do not provide
new evidence of a spawning population in the St. Marys. There have been
reports of Atlantic sturgeon tagged in the Edisto River (South
Carolina) being recaptured in the St. Johns River, indicating this
river may serve as a nursery ground; however, there are no data to
support the existence of a current spawning population (i.e., YOY or
running ripe adults) in the St. Johns (Rogers and Weber, 1995; Kahnle
et al., 1998).
Identification of Distinct Population Segments
The ESA's definition of ``species'' includes ``any subspecies of
fish or wildlife or plants, and any distinct population segment of any
species of vertebrate fish or wildlife which interbreeds when mature.''
The high degree of reproductive isolation of Atlantic sturgeon (i.e.,
homing to their natal rivers for spawning) (ASSRT, 2007; Wirgin et al.,
2000; King et al., 2001; Waldman et al., 2002), as well as the
ecological uniqueness of those riverine spawning habitats, the genetic
diversity amongst subpopulations, and the differences in life history
characteristics, provide evidence that discrete reproducing populations
of Atlantic sturgeon exist, which led the Services to evaluate
application of the DPS policy in its 2007 status review. To determine
whether any populations qualify as DPSs, we evaluated populations
pursuant to the joint DPS policy, and considered: (1) The discreteness
of any Atlantic sturgeon population segment in relation to the
remainder of the subspecies to which it belongs; and (2) the
significance of any Atlantic sturgeon population segment to the
remainder of the subspecies to which it belongs.
Discreteness
The joint DPS policy states that a population of a vertebrate
species may be considered discrete if it satisfies either one of the
following conditions: (1) It is markedly separated from other
populations of the same taxon as a consequence of physical,
physiological, ecological, or behavioral factors (quantitative measures
of genetic or morphological discontinuity may provide evidence of this
separation) or (2) it is delimited by international governmental
boundaries within which differences in control of exploitation,
management of habitat, conservation status, or regulatory mechanisms
exist that are significant in light of Section 4(a)(1)(D) of the ESA.
Atlantic sturgeon throughout their range exhibit ecological
separation during spawning that has resulted in multiple genetically
distinct interbreeding population segments. Tagging studies and genetic
analyses provide the evidence of this ecological separation (Wirgin et
al., 2000; King et al., 2001; Waldman et al., 2002; ASSRT, 2007;
Grunwald et al., 2008). As previously discussed, though adult and
subadult Atlantic sturgeon originating from different rivers mix in the
marine environment (Stein et al., 2004a), the vast majority of Atlantic
sturgeon return to their natal rivers to spawn, with some studies
showing one or two individuals per generation spawning outside their
natal river system (Wirgin et al., 2000; King et al., 2001; Waldman et
al., 2002). In addition, spawning in the various river systems occurs
at different times, with spawning occurring earliest in southern
systems and occurring as much as 5 months later in the northernmost
river systems (Murawski and Pacheco, 1977; Smith, 1985; Rogers and
Weber, 1995; Weber and Jennings, 1996; Bain, 1997; Smith and Clugston,
1997; Moser et al., 1998; Caron et al., 2002). Therefore, the
ecological separation of the interbreeding units of Atlantic sturgeon
results primarily from spatial separation (i.e., very few fish spawning
outside their natal river systems), as well as temporal separation
(spawning populations becoming active at different times along a
continuum from north to south).
Genetic analyses of mitochondrial DNA (mtDNA), which is maternally
inherited, and nuclear DNA (nDNA), which reflects the genetics of both
parents, provides evidence of the separation amongst Atlantic sturgeon
populations in different rivers (Bowen and Avise, 1990; Ong et al.,
1996; Waldman et al., 1996a; Waldman et al., 1996b; Waldman and Wirgin,
1998; Waldman et al., 2002; King et al., 2001; Wirgin et al., 2002;
Wirgin et al., 2005; Wirgin and King, 2006; Grunwald et al., 2008).
Overall, these studies consistently found Atlantic sturgeon to be
genetically diverse, and offered that between seven and ten Atlantic
sturgeon population groupings can be statistically differentiated
range-wide (King et al., 2001; Waldman et al., 2002; Wirgin et al.,
2002; Wirgin et al., 2005; ASSRT, 2007 (Tables 4 and 5); Grunwald et
al., 2008).
Given a number of key differences amongst the studies (e.g., the
analytical and/or statistical methods used, the number of rivers
sampled, and whether samples from subadults were included), it is not
unexpected that each reached a different conclusion as to the number of
Atlantic sturgeon population groupings. Wirgin and King (2006) refined
the genetic analyses for Atlantic sturgeon to address such differences
in prior studies. Most notably, they increased sample sizes from
multiple rivers and limited the samples analyzed to those collected
from YOY and mature adults (greater than 130 cm total length) to ensure
that the fish originated from the river in which it was sampled. The
results of the refined analysis by Wirgin and King (2006) are presented
in the status review report (ASSRT, 2007; e.g., Table 6 and Figure 17);
both the mtDNA haplotype and nDNA allelic frequencies analyzed by
Wirgin and King (2006) indicated that Atlantic sturgeon river
populations are genetically differentiated. The results of the mtDNA
analysis used for the status review
[[Page 61909]]
report were also subsequently published by Grunwald et al. (2008). In
comparison to the mtDNA analyses of the status review report, Grunwald
et al. (2008) used additional samples, some from fish in the size range
(less than 130 cm) excluded by Wirgin and King because they were
smaller than those considered to be mature adults. Nevertheless, the
results were qualitatively the same and demonstrated that each of the
12 sampled Atlantic sturgeon populations could be genetically
differentiated (Grunwald et al., 2008).
Genetic distances and statistical analyses (bootstrap values and
assignment test values) were used to investigate significant
relationships among, and differences between, Atlantic sturgeon river
populations (ASSRT, 2007; Table 6 and Figures 16-18). Overall, the
genetic markers used in this analysis resulted in an average accuracy
of only 88 percent for determining a sturgeon's natal river origin, but
an average accuracy of 94 percent for correctly classifying it to one
of five groups of populations (Kennebec River, Hudson River, James
River, Albemarle Sound, and Savannah/Ogeechee/Altamaha Rivers) when
using microsatellite data collected only from YOY and adults (ASSRT,
2007; Table 6). A phylogenetic tree (a neighbor joining tree) was
produced from only YOY and adult samples (to reduce the likelihood of
including strays from other populations) using the microsatellite
analysis (ASSRT, 2007; Figure 17). Bootstrap values (which measure how
consistently the data support the tree structure) for this tree were
high (equal to or greater than 87 percent, and all but one over 90
percent) (ASSRT, 2007). Regarding sturgeon from southeast rivers, this
analysis resulted in a range of 60 to 92 percent accuracy in
determining a sturgeon's natal river origin, but 92 and 96 percent
accuracy in correctly classifying a sturgeon from four sampled river
populations (the Albemarle Sound, Savannah, Ogeechee, and Altamaha
River populations) to two groupings of river populations (Albemarle
Sound and Savannah/Ogeechee/Altamaha Rivers). These two groupings
exhibited clear separation from northern populations and from each
other.
Genetic samples for YOY and spawning adults were not available for
river populations originating between the Albemarle Sound and the other
three rivers. However, nDNA from an expanded dataset that included
juvenile Atlantic sturgeon was used to produce a neighbor-joining tree
with bootstrap values (ASSRT, 2007; Figure 18). This dataset included
additional samples from the Santee-Cooper, Waccamaw, and Edisto
populations in the Southeast. Atlantic sturgeon river populations also
grouped into five population segments in this analysis. Atlantic
sturgeon from the Santee-Cooper system grouped with the Albemarle Sound
population, while the other two river populations grouped with the
Savannah/Ogeechee/Altamaha River population segment. With the exception
of the Waccamaw River population, all river populations sampled within
each population segment along the entire East Coast were geographically
adjacent. The Waccamaw River population grouped with the Edisto/
Savannah/Ogeechee/Altamaha River population segment, even though it is
geographically located between Albemarle Sound and the Santee and
Cooper Rivers. However, we attributed this to the small sample size (21
fish) from the Waccamaw River. From the seven Southeast river
populations included in the analysis, we determined that river
populations from the ACE Basin southward grouped together and that
river populations between the Santee-Cooper system and Albemarle Sound
(Roanoke River) grouped together.
The higher accuracy in identifying Atlantic sturgeon to one of two
population groupings (Albemarle Sound/Santee-Cooper Rivers and
Ogeechee/Savannah/Altamaha/Edisto Rivers) compared to their natal
rivers supports the fact that these multiple-river population segments
are discrete from each other.
We have considered the information on Atlantic sturgeon population
structuring provided in the status review report and Grunwald et al.
(2008). The nDNA analyses described in the status review report provide
additional genetics information, and include chord distances and
bootstrap values to support the findings for population structuring of
Atlantic sturgeon within the United States. Therefore, based on genetic
differences observed between certain river populations and the
assumption that adjacent river populations are more likely to breed
with one another than river populations from rivers that are not
adjacent to each other, five discrete Atlantic sturgeon population
segments in the United States meet the DPS Policy's Discreteness
criterion, with two located in the Southeast: (1) The ``Carolina''
population segment, which includes Atlantic sturgeon originating from
the Roanoke, Tar/Pamlico, Cape Fear, Waccamaw, Pee Dee, and Santee-
Cooper Rivers, and (2) the ``South Atlantic'' population segment, which
includes Atlantic sturgeon originating from the ACE Basin (Ashepoo,
Combahee, and Edisto rivers), Savannah, Ogeechee, Altamaha, and Satilla
Rivers.
Significance
When the discreteness criterion is met for a potential DPS, as it
is for the Carolina and South Atlantic population segments in the
Southeast identified above, the second element that must be considered
under the DPS policy is significance of each DPS to the taxon as a
whole. The DPS policy cites examples of potential considerations
indicating significance, including: (1) Persistence of the discrete
population segment in an ecological setting unusual or unique for the
taxon; (2) evidence that loss of the discrete population segment would
result in a significant gap in the range of the taxon; (3) evidence
that the DPS represents the only surviving natural occurrence of a
taxon that may be more abundant elsewhere as an introduced population
outside its historic range; or, (4) evidence that the discrete
population segment differs markedly from other populations of the
species in its genetic characteristics.
We believe that the Carolina and South Atlantic population segments
persist in ecological settings unique for the taxon. This is evidenced
by the fact that spawning habitat of each population grouping is found
in separate and distinct ecoregions that were identified by The Nature
Conservancy (TNC) based on the habitat, climate, geology, and
physiographic differences for both terrestrial and marine ecosystems
throughout the range of the Atlantic sturgeon along the Atlantic coast
(Figure 1). TNC descriptions do not include detailed information on the
chemical properties of the rivers within each ecoregion, but include an
analysis of bedrock and surficial geology type because it relates to
water chemistry, hydrologic regime, and substrate. It is well
established that waters have different chemical properties (i.e.,
identities) depending on the geology of where the waters originate.
Riverine spawning habitat of the Carolina population segment occurs
within the Mid-Atlantic Coastal Plain ecoregion, which is described as
consisting of bottomland hardwood forests, swamps, and some of the
world's most active coastal dunes, sounds, and estuaries. Natural
fires, floods, and storms are so dominant in this region that the
landscape changes very quickly. Rivers routinely change their courses
and emerge from their banks. The TNC lists the most
[[Page 61910]]
significant threats (sources of biological and ecological stress) in
the region as: global climate change and rising sea-level; altered
surface hydrology and landform alteration (e.g., flood-control and
hydroelectric dams, inter-basin transfers of water, drainage ditches,
breached levees, artificial levees, dredged inlets and river channels,
beach renourishment, and spoil deposition banks and piles); a
regionally receding water table, probably resulting from both over-use
and inadequate recharge; fire suppression; land fragmentation, mainly
by highway development; land-use conversion (e.g., from forests to
timber plantations, farms, golf courses, housing developments, and
resorts); the invasion of exotic plants and animals; air and water
pollution, mainly from agricultural activities including concentrated
animal feed operations; and over-harvesting and poaching of species.
Many of the Carolina population segment's spawning rivers, located in
the Mid-Coastal Plain, originate in areas of marl. Waters draining
calcareous, impervious surface materials such as marl are likely to be
alkaline, dominated by surface run-off, have little groundwater
connection, and be seasonally ephemeral.
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The riverine spawning habitat of the South Atlantic population
segment occurs within the South Atlantic Coastal Plain ecoregion. TNC
describes the South Atlantic Coastal Plain ecoregion as fall-line
sandhills to rolling longleaf pine uplands to wet pine flatwoods; from
small streams to large river systems to rich estuaries; from isolated
depression wetlands to Carolina bays to the Okefenokee Swamp. Other
ecological systems in the ecoregion include maritime forests on barrier
islands, pitcher plant seepage bogs and Altamaha grit (sandstone)
outcrops. The primary threats to biological diversity in the South
Atlantic Coastal Plain listed
[[Page 61912]]
by TNC are intensive silvicultural practices, including conversion of
natural forests to highly managed pine monocultures and the clear-
cutting of bottomland hardwood forests. Changes in water quality and
quantity, caused by hydrologic alterations (impoundments, groundwater
withdrawal, and ditching), and point and nonpoint pollution, are
threatening the aquatic systems. Development is a growing threat,
especially in coastal areas. Agricultural conversion, fire regime
alteration, and the introduction of nonnative species are additional
threats to the ecoregion's diversity. The South Atlantic DPS' spawning
rivers, located in the South Atlantic Coastal Plain, are primarily of
two types: brownwater (with headwaters north of the Fall Line, silt-
laden) and blackwater (with headwaters in the coastal plain, stained by
tannic acids).
Therefore, the ecoregion delineations support that the physical and
chemical properties of the Atlantic sturgeon spawning rivers utilized
by the Carolina and South Atlantic DPSs are unique to each population
segment. Since reproductive isolation accounts for the discreteness of
each population segment, the Carolina and South Atlantic population
segments of Atlantic sturgeon are ``significant'' as defined in the DPS
policy given that the spawning rivers for each population segment occur
in a unique ecological setting.
The loss of either the Carolina or the South Atlantic population
segments of Atlantic sturgeon would create a significant gap in the
range of the taxon. The loss of the Carolina population segment would
result in a 475-mile (764-kilometer (km)) gap between the northern
population segments and the South Atlantic population segment. The loss
of the South Atlantic population segment would truncate the southern
range of Atlantic sturgeon by greater than 150 miles (241 km). Though
Atlantic sturgeon travel great distances in the marine environment and
may use multiple river systems for foraging and nursery habitat, the
range occupied by the Carolina and South Atlantic population segments
would likely not be recolonized by a new, viable spawning population if
either population segment was lost. Based on genetic analyses showing
that fewer than two individuals per generation spawn outside their
natal rivers (Secor and Waldman, 1999), we do not expect Atlantic
sturgeon that originate from other population segments to re-colonize
extirpated systems and establish new spawning populations, except
perhaps over a long time frame (i.e., many Atlantic sturgeon
generations). Therefore, the loss of either the Carolina or South
Atlantic population segments would result in a significant gap in the
range of Atlantic sturgeon over a long time frame, and negatively
impact the species as a whole because the loss of either population
segment would constitute an important loss of genetic diversity for the
Atlantic sturgeon.
The information presented above describes: (1) Persistence of the
Carolina and South Atlantic population segments in ecological settings
that are unique for the Atlantic sturgeon as a whole; and (2) evidence
that loss of either population segment would result in a significant
gap in the range of the taxon. Based on this information, we concur
with the SRT's conclusion that the Carolina and South Atlantic
population segments meet the discreteness and significance criteria
outlined in the DPS policy. We hereafter refer to these DPSs as the
Carolina and South Atlantic DPSs. Figure 2 shows the riverine and U.S.
marine ranges of the Carolina and South Atlantic DPSs.
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[[Page 61913]]
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Conservation Status
We will now consider the conservation status of the two DPSs in the
Southeast Region's jurisdiction, the Carolina and South Atlantic DPSs,
in relation to the ESA's standards for listing. We will determine
whether each DPS meets the definition of ``endangered'' or
``threatened'' as defined in section 3 of the ESA, and whether that
status is a result of one or a combination of the factors listed under
section 4(a)(1) of the ESA. An endangered species is ``any species
which is in danger of extinction throughout all or a significant
portion of its range'' and a threatened species is one ``which is
likely to become an endangered species within the foreseeable future
throughout all or a significant portion of its range.''
[[Page 61914]]
The abundance of Atlantic sturgeon has decreased dramatically
within the last 150 years. A major fishery for Atlantic sturgeon
developed in 1870 when a caviar market was established (Smith and
Clugston, 1997). Record landings in the U.S. were reported in 1890,
with over 7,385,000 lbs (3,350,000 kg) of Atlantic sturgeon landed from
coastal rivers along the entire Atlantic Coast (Smith and Clugston,
1997; Secor and Waldman, 1999). Ten years after peak landings, the
fishery collapsed in 1901, when less than 10 percent (650,365 lbs,
295,000 kg) of the U.S. 1890 peak landings were reported. The landings
continued to decline coastwide, reaching about 5 percent of the peak in
1920. During the 1950s, the remaining U.S. fishery switched to
targeting sturgeon for flesh, rather than caviar, and coastwide
landings remained between 1 and 5 percent of the 1890 peak levels until
the Atlantic sturgeon fishery was closed by ASMFC in 1998.
The Carolina DPS includes all Atlantic sturgeon that spawn in the
watersheds from the Roanoke River, Virginia, southward along the
southern Virginia, North Carolina, and South Carolina coastal areas to
the Cooper River. The marine range of Atlantic sturgeon from the
Carolina DPS extends from the Bay of Fundy, Canada, to the Saint Johns
River, Florida. While Atlantic sturgeon exhibit a high degree of
spawning fidelity to their natal rivers, multiple riverine, estuarine,
and marine habitats may serve various life (e.g., nursery, foraging,
and migration) functions. Rivers known to have current spawning
populations within the range of this DPS include the Roanoke, Tar-
Pamlico, Cape Fear, Waccamaw, and Pee Dee Rivers. There may also be
spawning populations in the Neuse, Santee and Cooper Rivers, though it
is uncertain at this time. Historically, both the Sampit and Ashley
Rivers were documented to have spawning populations at one time.
However, the spawning population in the Sampit River is believed to be
extirpated and the current status of the spawning population in the
Ashley River is unknown. Both rivers may be used as nursery habitat by
young Atlantic sturgeon originating from other spawning populations.
This represents our current knowledge of the river systems utilized by
the Carolina DPS for specific life functions, such as spawning, nursery
habitat, and foraging. However, fish from the Carolina DPS likely use
other river systems than those listed here for their specific life
functions. The Carolina DPS also includes Atlantic sturgeon held in
captivity (e.g., aquaria, hatcheries, and scientific institutions) and
which are identified as fish belonging to the Carolina DPS based on
genetics analyses, previously applied tags, previously applied marks,
or documentation to verify that the fish originated from (hatched in) a
river within the range of the Carolina DPS, or is the progeny of any
fish that originated from a river within the range of the Carolina DPS.
NMFS has no records of Atlantic sturgeon from the Carolina DPS being
held in captivity.
Historical landings data indicate that between 7,000 and 10,500
adult female Atlantic sturgeon were present in North Carolina prior to
1890 (Armstrong and Hightower, 2002; Secor, 2002). Secor (2002)
estimates that 8,000 adult females were present in South Carolina
during that same timeframe. Prior reductions from the commercial
fishery and ongoing threats have drastically reduced the numbers of
Atlantic sturgeon within the Carolina DPS. Currently, the Atlantic
sturgeon spawning population in at least one river system within the
Carolina DPS has been extirpated, with a potential extirpation in an
additional system. The abundance of the remaining river populations
within the DPS, each estimated to have fewer than 300 spawning adults,
is estimated to be less than 3 percent of what it was historically
(ASSRT, 2007). Though directed fishing and possession of Atlantic
sturgeon is no longer legal, the Carolina DPS continues to face threats
such as habitat alteration and bycatch. The presence of dams has
resulted in the loss of over 60 percent of the historical sturgeon
habitat on the Cape Fear River and in the Santee-Cooper system. This
has resulted in the loss of important spawning and juvenile
developmental habitat and has reduced the quality of the remaining
habitat by affecting water quality parameters (such as depth,
temperature, velocity, and dissolved oxygen) that are important to
sturgeon.
The South Atlantic DPS includes all Atlantic sturgeon that spawn in
the watersheds of the ACE Basin in South Carolina to the St. Johns
River, Florida. The marine range of Atlantic sturgeon from the South
Atlantic DPS extends from the Bay of Fundy, Canada, to the Saint Johns
River, Florida. While Atlantic sturgeon exhibit a high degree of
spawning fidelity to their natal rivers, multiple riverine, estuarine,
and marine habitats may serve various life (e.g., nursery, foraging,
and migration) functions. Rivers known to have current spawning
populations within this DPS include the Combahee, Edisto, Savannah,
Ogeechee, Altamaha, and Satilla Rivers. Historically, both the Broad-
Coosawatchie and St. Marys Rivers were documented to have spawning
populations at one time; there is also evidence that spawning may have
occurred in the St. Johns River or one of its tributaries. However, the
spawning population in the St. Marys River, as well as any historical
spawning population present in the St. Johns, is believed to be
extirpated, and the status of the spawning population in the Broad-
Coosawatchie is unknown. Both the St. Marys and St. Johns Rivers are
used as nursery habitat by young Atlantic sturgeon originating from
other spawning populations. The use of the Broad-Coosawatchie by
sturgeon from other spawning populations is unknown at this time. The
presence of historical and current spawning populations in the Ashepoo
River has not been documented; however, this river may currently be
used for nursery habitat by young Atlantic sturgeon originating from
other spawning populations. This represents our current knowledge of
the river systems utilized by the South Atlantic DPS for specific life
functions, such as spawning, nursery habitat, and foraging. However,
fish from the South Atlantic DPS likely use other river systems than
those listed here for their specific life functions. The South Atlantic
DPS also includes Atlantic sturgeon held in captivity (e.g., aquaria,
hatcheries, and scientific institutions) and which are identified as
fish belonging to the South Atlantic DPS based on genetics analyses,
previously applied tags, previously applied marks, or documentation to
verify that the fish originated from (hatched in) a river within the
range of the South Atlantic DPS, or is the progeny of any fish that
originated from a river within the range of the South Atlantic DPS. Ten
Atlantic sturgeon taken from the Altamaha River are currently being
held at the Bears Bluff National Fish Hatchery in Warm Springs,
Georgia, though it is not certain whether those fish were spawned in
the Altamaha or were migrants from another river system. NMFS has no
other records of Atlantic sturgeon from the South Atlantic DPS being
held in captivity.
Secor (2002) estimated that 8,000 spawning female Atlantic sturgeon
were present in South Carolina. Historically, the population of
spawning female Atlantic sturgeon in Georgia was estimated at 11,000
fish per year prior to 1890 (Secor, 2002). Prior reductions from the
commercial fishery and ongoing threats have drastically reduced
[[Page 61915]]
the numbers of Atlantic sturgeon within the South Atlantic DPS.
Currently, the Atlantic sturgeon spawning population in one (possibly
two) river systems within the South Atlantic DPS have been extirpated.
The Altamaha River, with an estimated 343 spawning adults per year, is
suspected to be less than 6 percent of its historical abundance,
extrapolated from the 1890s commercial landings; the abundance of the
remaining river populations within the DPS, each estimated to have
fewer than 300 spawning adults, is estimated to be less than 1 percent
of what it was historically (ASSRT, 2007). While the directed fishery
that originally drastically reduced the numbers of Atlantic sturgeon
has been closed, other impacts have contributed to their low population
numbers, may have contributed to the extirpation of some spawning
populations, and are likely inhibiting recovery of extant river
populations. Historically, Atlantic sturgeon likely accessed all parts
of the St. Johns River, as American shad were reported as far upstream
as Lake Poinsett (reviewed in McBride, 2000). However, the construction
of Kirkpatrick Dam (originally Rodman Dam) at river mile (RM) 95 (river
km (RKM) 153) restricted migration to potential spawning and juvenile
developmental habitat upstream. Approximately 63 percent of historical
sturgeon habitat is believed to be blocked due to the dam (ASSRT,
2007), and there is no longer a spawning population in the St. Johns
River.
Small numbers of individuals resulting from drastic reductions in
populations, such as occurred with Atlantic sturgeon due to the
commercial fishery, can remove the buffer against natural demographic
and environmental variability provided by large populations (Berry,
1971; Shaffer, 1981; Soule, 1980). Though the Carolina and South
Atlantic DPSs, made up of multiple river populations of Atlantic
sturgeon, were determined to be genetically discrete, interbreeding
population units, the vast majority of Atlantic sturgeon return to
their natal rivers to spawn, with fewer than two migrants per
generation spawning outside their natal system (Wirgin et al., 2000;
King et al., 2001; Waldman et al., 2002). Therefore, it is important to
look at each riverine spawning population within each DPS when
considering the effects of a small population size on the extinction
risk for the DPS. Though there is no absolute population size above
which populations are ``safe'' and below which they face an
unacceptable risk of extinction (Gilpin and Soule, 1986; Soule and
Simberloff, 1986; Ewens et al., 1987; Goodman, 1987; Simberloff, 1988;
Thomas, 1990), some have argued that ``rules of thumb'' can and should
be applied (Soule, 1987; Thompson, 1991). Salwasser et al. (1984)
prescribe a minimum viable population size of at least 1,000 adults.
Belovsky (1987) indicates that a minimum viable population in the range
of 1,000 to 10,000 adults should be sufficient for a mid-sized
vertebrate species. Soule (1987) suggests that minimum viable
population sizes for vertebrate species should be in the ``low
thousands'' or higher. Thomas (1990) offers a population size of 5,500
as ``a useful goal,'' but suggests that where uncertainty is extreme
``we should usually aim for population sizes from several thousand to
ten thousand.'' In a NOAA Technical Memorandum ``Determining Minimum
Viable Populations under the ESA,'' Thompson (1991) states the ``50/
500'' rule of thumb initially advanced by Franklin (1980) and Soule
(1980) comes the closest of any to attaining ``magic number'' status.
Franklin (1980) has suggested that, simply to maintain short-term
fitness (i.e., prevent serious in-breeding and its deleterious
effects), the minimum effective population size should be around 50. He
further recommended that, to maintain sufficient genetic variability
for adaptation to changing environmental conditions, the minimum
effective population size should be around 500. Soule (1980) has
pointed out that, above and beyond preserving short-term fitness and
genetic adaptability, long-term evolutionary potential (at the species
level) may well require a number of substantially larger populations.
It is important to note that the 50/500 rule is cast in terms of
effective population size, a concept introduced by Wright (1931). The
effective population size refers to an ideal population of breeding
individuals produced each generation by random union of an equal number
of male and female gametes randomly drawn from the previous generation.
To the extent that this ideal is violated in nature, the effective
population size is generally smaller than the overall number of mature
individuals in the population. It is not possible to calculate the
effective population sizes of the riverine spawning populations in the
Carolina or the South Atlantic DPS. However, even under ideal
circumstances where the effective population size is equal to the
overall numbers of adults, the spawning populations are all believed to
be smaller than the 500 recommended by Thompson (1991) to maintain
sufficient genetic variability for adaptation to changing environmental
conditions, and certainly smaller than the 1,000 to 10,000 recommended
by other authors. It is not known if certain riverine populations are
at an abundance smaller than the minimum effective population size of
50 that would prevent serious in-breeding (Thompson, 1991). Moreover,
in some rivers, spawning by Atlantic sturgeon may not be contributing
to population growth because of lack of suitable habitat and other
stressors on juvenile survival and development.
The concept of a viable population able to adapt to changing
environmental conditions is critical to Atlantic sturgeon, and the low
population numbers of every river population in the Carolina and South
Atlantic DPSs put them in danger of extinction throughout their ranges;
none of the populations are large or stable enough to provide with any
level of certainty for continued existence of Atlantic sturgeon in this
part of its range. While the directed fishery that originally
drastically reduced the numbers of Atlantic sturgeon has been closed,
recovery of depleted populations is an inherently slow process for a
late-maturing species such as Atlantic sturgeon, and they continue to
face a variety of other threats that contribute to their risk of
extinction. Their late age at maturity provides more opportunities for
individual Atlantic sturgeon to be removed from the population before
reproducing. While a long life-span also allows multiple opportunities
to contribute to future generations, it also increases the timeframe
over which exposure to the multitude of threats facing the Carolina and
South Atlantic DPS can occur. These threats include the loss,
reduction, and degradation of habitat resulting from dams, dredging,
and changes in water quality parameters (such as depth, temperature,
velocity, and dissolved oxygen). Even with a moratorium on directed
fisheries, bycatch is a threat to both the Carolina and South Atlantic
DPSs. Fisheries known to incidentally catch Atlantic sturgeon occur
throughout the marine range of the species and in some riverine waters
as well. Because Atlantic sturgeon mix extensively in marine waters and
may use multiple river systems for spawning, foraging, and other life
functions, they are subject to being caught in multiple fisheries
throughout their range. In addition to direct mortality, stress or
injury to Atlantic sturgeon taken as bycatch but released alive may
result in increased susceptibility to other threats, such as
[[Page 61916]]
poor water quality (e.g., exposure to toxins). This may result in
reduced ability to perform major life functions, such as foraging and
spawning, or even post-capture mortality. While some of the threats to
the Carolina and South Atlantic DPS have been ameliorated or reduced
due to the existing regulatory mechanisms, such as the moratorium on
directed fisheries for Atlantic sturgeon, bycatch is currently not
being addressed through existing mechanisms. Further, water quality
continues to be a problem even with existing controls on some pollution
sources and water withdrawal, and dams continue to curtail and modify
habitat, even with the Federal Power Act.
We have reviewed the status review report, as well as other
available literature and information, and have consulted with
scientists and fishery resource managers familiar with Atlantic
sturgeon in the Carolina and South Atlantic DPSs. After reviewing the
best scientific and commercial information available, we find that both
the Carolina and South Atlantic DPSs are in danger of extinction
throughout their ranges and thus meet the ESA's definition of an
endangered species. Atlantic sturgeon populations declined
precipitously decades ago due to directed commercial fishing. The
failure of Atlantic sturgeon numbers within the Carolina and South
Atlantic DPSs to rebound even after the moratorium on directed fishing
was established in 1998 indicates that impacts and threats from limits
on habitat for spawning and development, habitat alteration, and
bycatch are responsible for the risk of extinction faced by both DPSs.
In addition, the persistence of these impacts and threats points to the
inadequacy of existing regulatory mechanisms to address and reduce
habitat alterations and bycatch. We will address the threats of habitat
alteration, bycatch, and the inadequacy of regulatory mechanisms and
their contributions to the endangered statuses of the Carolina and
South Atlantic DPSs in detail in the following sections of this
proposed rule.
Analysis of Section 4(a)(1) Factors' Effects on the Species
The ESA requires us to determine whether any species is endangered
or threatened because of any of the following factors: (A) Present or
threatened destruction, modification, or curtailment of habitat or
range; (B) overutilization for commercial, recreational, scientific, or
educational purposes; (C) disease or predation; (D) inadequacy of
existing regulatory mechanisms; or (E) other natural or manmade factors
affecting its continued existence. Listing determinations are made
solely on the best scientific and commercial data available and after
taking into account any efforts being made by any state or foreign
nation to protect the species. The SRT examined each of the
aforementioned five factors for their impacts on the Atlantic sturgeon
DPSs. The following is a summary of its relevant findings, any
additional information that has become available since the status
review report was published, and the conclusions that we have made
based on the available information.
A. Present or Threatened Destruction, Modification, or Curtailment of
the Species' Habitat or Range
Habitat alterations considered by the SRT that affect the status of
sturgeon populations include: dam and tidal turbine construction and
operation; dredging, disposal, and blasting; and water quality
modifications, such as changes in levels of DO, water temperature, and
contaminants. Atlantic sturgeon, like all anadromous fish, are
vulnerable to a host of habitat impacts because they use rivers,
estuaries, bays, and the ocean at various points of their life. In
addition to the habitat alterations considered by the SRT, other
emerging threats to habitat considered in this section are drought,
intra- and inter-state water allocation issues, and climate change.
These threats have the potential to further exacerbate habitat
modifications evaluated by the SRT. Because they were not evaluated in
the status review report, they are considered in more detail in this
section. In this section, we summarize the threats for each DPS that we
believe represent a present or threatened destruction, modification or
curtailment of the DPS's habitat or range and are contributing to the
endangered status of both DPSs.
Dams
Dams are a threat to the Carolina and South Atlantic DPS that
contributes to their endangered status by curtailing the extent of
available habitat, as well as modifying sturgeon habitat downstream
through a reduction in water quality. As noted in the status review
report, dams for hydropower generation, flood control, and navigation
adversely affect Atlantic sturgeon habitat by impeding access to
spawning, developmental and foraging habitat, modifying free-flowing
rivers to reservoirs, physically damaging fish on upstream and
downstream migrations, and altering water quality in the remaining
downstream portions of spawning and nursery habitat. Attempts to
minimize the impacts of dams using measures such as fish passage have
not proven beneficial to Atlantic sturgeon, as they do not regularly
use existing fish passage devices, which are generally designed to pass
pelagic fish. To date, only four Atlantic sturgeon have been documented
to have passed via a fish lift (three at the St. Stephens fish lift in
South Carolina and one at the Holyoke Dam in Massachusetts), as these
passage facilities are not designed to accommodate adult-sized
sturgeon. While there has not been a large loss of Atlantic sturgeon
habitat throughout the entire species' range due to the presence of
dams, individual riverine systems have been severely impacted by dams,
as access to large portions of historical sturgeon spawning and
juvenile developmental habitat has been eliminated or restricted. The
SRT used GIS tools and dam location data collected by Oakley (2003) as
reference points for river kilometer measurements to map historical
rivers in which Atlantic sturgeon spawned. This information was then
used to determine the number of kilometers of available habitat. Within
the Carolina and South Atlantic DPSs, the Cape Fear, Santee-Cooper, and
St. Johns River systems have lost greater than 60 percent of the
habitat historically used for spawning and juvenile development.
The Cape Fear River has three locks and dams (constructed from 1915
to 1935) between Wilmington and Fayetteville that are located below the
fall line; two additional dams, Buckhorn and B. Everette Jordan, are
located above the fall line. Atlantic sturgeon movement is blocked at
the first lock and dam located in Riegelwood, North Carolina, which was
constructed in 1915. Pelagic species can pass over the three locks and
dams during high water, but the benthic Atlantic sturgeon is not known
to pass over these three locks/dams. No Atlantic sturgeon have been
captured upstream of Lock and Dam 1 despite extensive sampling
efforts (Moser et al., 1998). Exact historical spawning locations are
unknown in the Cape Fear River, but Atlantic sturgeon spawning is
generally believed to occur in flowing water between the salt front and
fall line of large rivers (Borodin, 1925; Leland, 1968; Scott and
Crossman, 1973; Crance, 1987; Bain et al., 2000). Therefore, sturgeon
researchers judge the fall line to be the likely upper limit of
spawning habitat. Using the fall line as a guide, only 36 percent of
the historical habitat is available to Atlantic sturgeon. In some
years, the salt water interface reaches the first lock and dam;
therefore, spawning adults in the Cape Fear River either do not spawn
in such
[[Page 61917]]
years or spawn in the major tributaries of the Cape Fear River (i.e.,
Black River or Northeast Cape Fear Rivers) that are not obstructed by
dams.
The Santee-Cooper Hydroelectric Project is located in the coastal
plain of the Santee Basin on the Santee and Cooper Rivers, South
Carolina. The project was finished in 1942 and includes Lake Marion,
which is impounded by the Santee Dam (Wilson Dam) on the Santee River
at RM 87 (RKM 140), and Lake Moultrie, which is impounded by the
Pinopolis Dam on the Cooper River at RM 48 (RKM 77). Using the fall
line as the upper region of spawning habitat, it is estimated that only
38 percent of the historical habitat is available to Atlantic sturgeon
today. Although fish lifts operate at the Pinopolis and St. Stephens
Dams during the spring, observations of sturgeon in the lifts are
extremely rare (traditional fish passage designs are not typically
successful for sturgeon). There is no record of an adult Atlantic
sturgeon being lifted, although three dead Atlantic sturgeon were
observed in Lake Marion between 1995 and 1997, and in 2007, an Atlantic
sturgeon entered the St. Stephens fishway and was physically removed
and translocated downstream into the Santee River (A. Crosby, SCDNR,
Pers. Comm.)
In addition to blocking access to habitat, dams can degrade
spawning, nursery, and foraging habitat downstream by reducing water
quality. Flow, water temperature, and oxygen levels in the Roanoke
River are affected by the Kerr Dam and the Gaston Dam/Roanoke Rapids
facilities, which engage in peaking operations. Riverine water flow has
already been modified by the dam operators during the striped bass
spawning season to simulate natural flow patterns; these modifications
undoubtedly benefit Atlantic sturgeon. Regardless of the temporary
modifications, lower water temperatures resulting from the hypolimnetic
discharge from Kerr Dam have caused temporal shifts in the spawning
peaks for both American shad and striped bass and likely have had the
same impact for other diadromous species, including Atlantic sturgeon
(ASSRT, 2007). High flows from Kerr Dam during the summer are coupled
with high ambient temperatures and an influx of swamp water with low
DO, creating a large, hypoxic plume within the river. Fish kills have
been documented to occur during this time (ASSRT, 2007), and sturgeon
are more highly sensitive to low DO (less than 5 milligrams per liter
(mg/L)) than other fish species (Niklitschek and Secor, 2009a, 2009b).
Low DO in combination with high temperature is particularly problematic
for Atlantic sturgeon, and studies have shown that juvenile Atlantic
sturgeon experience lethal and sublethal (metabolic, growth, feeding)
effects as DO drops and temperatures rise (Niklitschek and Secor,
2009a, 2009b; Niklitschek and Secor, 2005; Secor and Gunderson, 1998).
Therefore, it is likely that dam operations are negatively affecting
Atlantic sturgeon nursery habitat in the lower Roanoke River.
Dredging
Dredging is a present threat to both the Carolina and South
Atlantic DPSs and is contributing to their endangered status by
modifying the quality and availability of Atlantic sturgeon habitat.
Riverine, nearshore, and offshore areas are often dredged to support
commercial shipping and recreational boating, construction of
infrastructure, and marine mining. Environmental impacts of dredging
include the direct removal/burial of organisms; turbidity/siltation
effects; contaminant resuspension; noise/disturbance; alterations to
hydrodynamic regime and physical habitat; and actual loss of riparian
habitat (Chytalo, 1996; Winger et al., 2000). According to Smith and
Clugston (1997), dredging and filling impact important habitat features
of Atlantic sturgeon as they disturb benthic fauna, eliminate deep
holes, and alter rock substrates. To reduce the impacts of dredging on
anadromous fish species, most of the Atlantic states impose work
restrictions during sensitive time periods (spawning, migration,
feeding) when anadromous fish are present. NMFS also imposes seasonal
restrictions to protect shortnose sturgeon populations (where present)
through Section 7 consultations that may have the added benefit of
protecting Atlantic sturgeon where the two species co-occur. Within the
Carolina DPS, dredging operations (including the blasting of rock) on
the lower Cape Fear River, Brunswick River, and port facilities at the
U.S. Army's Sunny Point Military Ocean Terminal and Port of Wilmington
are extensive. To protect diadromous fish, restrictions are placed on
dredging to avoid sensitive seasons and locations, such as potential
spawning habitat (February 1 through June 30) and suspected nursery
grounds (April 1 through September 30). However, while the restrictions
prevent dredging from occurring when Atlantic sturgeon are expected to
be present, the effects of dredging on Atlantic sturgeon habitat remain
long after the dredging has been completed. Moser and Ross (1995) found
that some of the winter holding sites favored by sturgeon in the lower
Cape Fear River estuary also support very high levels of benthic
infauna and may be important feeding stations. Repeated dredging in the
Cape Fear River can modify sturgeon habitat through the removal or
burial of benthic infauna in feeding grounds and creation of unsuitable
substrate in spawning grounds (ASSRT, 2007). Similar habitat
modifications are occurring in the Cooper River, which flows into
Charleston Harbor, one of the busiest ports on the Atlantic Coast, and
is dredged regularly. The river channel is maintained by dredging all
the way to the Pinopolis Dam. No seasonal restrictions are placed on
dredging in the Cooper River, potentially interrupting spawning
activities (ASSRT, 2007).
In the South Atlantic DPS, maintenance dredging in Atlantic
sturgeon nursery habitat in the Savannah River is frequent, and
substantial channel deepening took place in 1994. The Georgia Ports
Authority is seeking to expand its port facility on the Savannah River.
Within the 1999 Water Resources Development Act, Congress authorized
the deepening of the Savannah Navigation Channel from the current depth
of -42 to -48 ft (-12.8 to -14.6 m) mean low water. Hydrodynamic and
water quality models have been developed to predict changes in water
quality across depth and throughout the channel. The channel deepening
is predicted to alter overall water quality (e.g., salinity and DO),
creating inhospitable foraging/resting habitat in the lower Savannah
River for sturgeon. The lower Savannah River is heavily industrialized
and serves as a major shipping port. Nursery habitat in the lower river
has been heavily impacted by diminished water quality and
channelization. Reduced DO levels and upriver movement of the salt
wedge are predicted to result from channel deepening. Sturgeon are
highly sensitive to low DO, more so than other fish species
(Niklitschek and Secor, 2009a, 2009b). Because Atlantic sturgeon spawn
above the interface between fresh water and salt water, the upriver
movement of the salt wedge will curtail the extent of Atlantic sturgeon
habitat in the Savannah River. Dredging also commonly occurs within the
St. Johns River and has been linked to the reduction in submerged
aquatic vegetation where Atlantic sturgeon likely forage (Jordan,
2002). Though there is currently no resident spawning population in the
St. Johns, it still provides nursery habitat for juvenile Atlantic
sturgeon in the South Atlantic DPS (NMFS and USFWS, 1998). Over 60
[[Page 61918]]
percent of the historical sturgeon habitat in the St. Johns River has
already been curtailed by the presence of a dam, and dredging modifies
the quality of the remaining nursery habitat in the river.
Water Quality
Degraded water quality is a present threat to the Carolina and
South Atlantic DPSs and is contributing to their endangered status by
modifying and curtailing the extent of available habitat for spawning
and nursery areas. Atlantic sturgeon rely on a variety of water quality
parameters to successfully carry out their life functions. Low DO and
the presence of contaminants modify the quality of Atlantic sturgeon
habitat and in some cases, curtail the extent of suitable habitat for
life functions. Secor (1995) noted a correlation between low abundances
of sturgeon during this century and decreasing water quality caused by
increased nutrient loading and increased spatial and temporal frequency
of hypoxic conditions. Of particular concern is the high occurrence of
low DO coupled with high temperatures in the river systems throughout
the range of the Carolina and South Atlantic DPSs. Sturgeon are more
highly sensitive to low DO than other fish species (Niklitschek and
Secor, 2009a, 2009b) and low DO in combination with high temperature is
particularly problematic for Atlantic sturgeon. Studies have shown that
juvenile Atlantic sturgeon experience lethal and sublethal (metabolic,
growth, feeding) effects as DO drops and temperatures rise (Niklitschek
and Secor, 2009a, 2009b; Niklitschek and Secor, 2005; Secor and
Gunderson, 1998). Water quality within the river systems in the range
of the Carolina and South Atlantic DPSs is also negatively impacted by
contaminants and large water withdrawals.
For the Carolina DPS, water quality in the Pamlico system,
especially in the lower Neuse River, is highly degraded (Paerl et al.,
1998; Qian et al., 2000; Glasgow et al., 2001). The entire basin has
been designated as nutrient-sensitive, and additional regulatory
controls are being implemented to improve water quality. Both the Neuse
and Pamlico portions of the estuary have been subject to seasonal
episodes of anoxia that significantly affect the quality of Atlantic
sturgeon nursery habitat. Concentrated animal feeding operations
(CAFOs) cause at least some portion of the current water quality
problems in the Pamlico watershed (Mallin and Cahoon, 2003). Farms that
produce hogs, turkeys, and chickens have proliferated throughout the
coastal portion of the basin in the last decade, with increases in both
aquatic and atmospheric deposition of nitrogenous waste products. North
Carolina passed a moratorium in 1997 limiting additional hog operations
and is conducting a study of measures to address the problem; the
moratorium was renewed in 1999 and 2003. Water quality in the Cape Fear
River is poor for aquatic life, due largely to industrial development
and use, including the Port of Wilmington and numerous industrial
point-source discharges. Development of CAFOs in the coastal portion of
the Cape Fear River basin has been especially heavy (most concentrated
operations of CAFOs occur in the Cape Fear River drainage within North
Carolina) and contributes to both atmospheric and aquatic inputs of
nitrogenous contamination, possibly causing DO levels to regularly fall
below the 5 mg/L state standard (Mallin and Cahoon, 2003). In recent
years, fish kills have been observed, usually as a result of blackwater
swamps (with low DO) being flushed after heavy rainfall.
Industrialization also threatens the habitat of the Carolina DPS.
Paper and steel mills in the Winyah Bay system, which includes the
Waccamaw, Pee Dee, and Sampit rivers, have impacted water quality.
Riverine sediment samples contain high levels of various toxins
including dioxins (NMFS and USFWS, 1998). Though the effects of these
contaminants on Atlantic sturgeon are unknown, Atlantic sturgeon are
particularly susceptible to impacts from contaminated sediments due to
their benthic foraging behavior and long-life span, and effects from
these compounds on fish include production of acute lesions, growth
retardation, and reproductive impairment (Cooper, 1989; Sinderman,
1994). It should be noted that the effect of multiple contaminants or
mixtures of compounds at sublethal levels on fish has not been
adequately studied. Atlantic sturgeon use marine, estuarine, and
freshwater habitats and are in direct contact through water, diet, or
dermal exposure with multiple contaminants throughout their range.
Habitat utilized by the South Atlantic DPS in the Savannah River
has also been modified by mercury contamination (ASSRT, 2007). While
water quality in the Altamaha River is good at this time, the drainage
basin is dominated by silviculture and agriculture, with two paper
mills and over two dozen other industries or municipalities discharging
effluent into the river. Nitrogen and phosphorus concentrations are
increasing, and eutrophication and loss of thermal refugia are growing
concerns for the South Atlantic DPS. In the Ogeechee River, the primary
source of pollution results from non-point sources, which results in
nutrient-loading and decreases in DO. These problems result from the
cumulative effect of activities of many individual landowners or
managers. The Ogeechee River Basin Watershed Protection Plan developed
by the Georgia Environmental Protection Division (GAEPD, 2001b) states
that because there are so many small sources of non-point loading
spread throughout the watershed, non-point sources of pollution cannot
effectively be controlled by state agency permitting and enforcement,
even where regulatory authority exists. The increases in nutrients and
resulting decreases in DO are coupled with increases in water
temperature resulting from clearing of the riparian canopy and
increased paved surface areas. Downstream sturgeon nursery habitat is
compromised during hot, dry summers when water flow is minimal, and
non-point sources of hypoxic waters have a greater impact on the system
as potential thermal refugia are lost when the aquifer is lowered.
Since 1986, average summer DO levels in the Ogeechee have dropped to
approximately 4 mg/L (GAEPD, 2001b). Low DO (less than 5 mg/L), most
likely due to non-point sources, was a common occurrence observed
during 1998 and 1999 water quality surveys (GAEPD, 2002) in the Satilla
River, which serves as both spawning and nursery habitat for sturgeon
in the South Atlantic DPS. The extirpation of the Atlantic sturgeon
spawning population in the St. Marys River is believed to have been
caused by reduced DO levels during the summer in the nursery habitat,
probably due to eutrophication from non-point source pollution (ASSRT,
2007). Both the St. Marys and St. Johns Rivers continue to be used as
nursery habitat by Atlantic sturgeon in the South Atlantic DPS;
however, low DO is a common occurrence during the summer months when
water temperatures rise. At times, it is so severe in the St. Marys
that it completely eliminates juvenile nursery habitat during the
summer (D. Peterson, UGA, Pers. Comm.).
Water allocation issues are a growing threat in the Southeast and
exacerbate existing water quality problems. Taking water from one basin
and transferring it to another fundamentally and irreversibly alters
natural water flows in both the originating and receiving basins, which
can affect DO levels, temperature, and the ability of the basin of
origin to assimilate pollutants
[[Page 61919]]
(Georgia Water Coalition, 2006). Water allocation issues increasingly
threaten to exacerbate the present threat of degraded water quality on
the endangered status of the Carolina DPS. Even with its generous
natural supply of water, North Carolina is experiencing problems where
somewhat limited natural availability of water is coupled with high
demand or competition among water users. Some of these emerging
pressure points are the Central Coastal Plain, where the Cretaceous
aquifers have a relatively slow recharge rate; the headwater areas of
the Piedmont river basins, where streamflows are greatly reduced during
dry weather; and some areas near the coast and on the Outer Banks,
where the natural availability of fresh water is limited (NCDENR,
2001a). Interbasin water transfers are increasingly being looked at to
deal with the inadequate water availability. In 1993, the North
Carolina Legislature adopted the Regulation of Surface Water Transfers
Act (G.S. Sec. 143-215.22I). This law regulates large surface water
transfers between river basins by requiring a certificate from the
North Carolina Environmental Management Commission. The act has been
modified several times since it was first adopted, most recently in
2007 when G.S. Sec. 143-215.22I was repealed and replaced with G.S.
Sec. 143-215.22L. A transfer certificate is required for a new
transfer of 2 million gallons per day (mgd) (7,600 m\3\pd) or more and
for an increase in an existing transfer by 25 percent or more (if the
total including the increase is more than 2 mgd). Certificates are not
required for facilities that existed or were under construction prior
to July 1, 1993, up to the full capacity of that facility to transfer
water, regardless of the transfer amount.
The North Carolina Department of Environment and Natural Resources
reports that 20 facilities, with a combined average (not maximum) daily
transfer of 66.5 mgd (252,000 m\3\pd), were grandfathered in when G.S.
Sec. 143-215.22I was enacted (NCDENR, 2009). Since then, five
additional facilities have received certificates to withdraw up to a
combined maximum total of 167.5 mgd (634,000 m\3\pd). The most
significant certified interbasin transfer in this group is the
withdrawal of 60 mgd (227,000 m\3\pd) of water from Lake Gaston (part
of the Roanoke River Basin) by Virginia Beach, Virginia. Virginia Beach
began pumping in 1998 following a very lengthy and contested Federal
Energy Regulatory Commission (FERC) approval process, during which
North Carolina opposed the withdrawals (NCDENR, 2001b). Certificates
are pending for three facilities, totaling almost 60 mgd (227,000
m\3\pd). This includes the Kerr Lake Regional Water System (KLRWS), a
regional provider of drinking water. The KLRWS has an existing,
grandfathered, surface water transfer capacity of 10 mgd (38,000
m\3\pd). The grandfathered capacity allows the system to move water
from the Roanoke River Basin (Kerr Lake) to sub-basins of the Tar-
Pamlico River Basin. On February 18, 2009, KLRWS submitted a Notice of
Intent to Request an Interbasin Transfer Certificate to the
Environmental Management Commission. In that notice, KLRWS requested to
increase the authorized transfer from 10 mgd to 24 mgd (38,000 m\3\pd
to 91,000 m\3\pd), and to transfer 2.4 mgd (9,100 m\3\pd) from the
Roanoke River Basin to the Neuse River Basin. These transfer amounts
are based on water use projections to the year 2040.
Water allocation issues also increasingly threaten to exacerbate
the present threat of degraded water quality on the endangered status
of the South Atlantic DPS. Water allocation issues are occurring on the
Atlantic Coast of South Carolina and Georgia (Ruhl, 2003). This area is
served by five major rivers--the Savannah, Altamaha (including its two
major tributaries, the Oconee and Ocmulgee rivers), Ogeechee, Satilla,
and St. Marys Rivers. A 2006 study by the Congressional Budget Office
(CBO) reported that Georgia had the sixth highest population growth
(26.4 percent) in the nation, followed by Florida (23.5 percent) (CBO,
2006). The University of Georgia (UGA) reports that the per capita
water use in Georgia has been estimated to be 8 to 10 percent greater
than the national average, and 17 percent higher than per capita use in
neighboring states (UGA, 2002). Water shortages have already occurred
and are expected to continue due to increasing periods of drought
coupled with the rapid population growth expected in the region over
the next 50 years (Cummings et al., 2003). Two of the largest and most
rapidly expanding urban areas in the Savannah River basin, Augusta-
Richmond County and Savannah, currently utilize both ground water and
surface water for drinking water uses (GAEPD, 2001a). Surface water use
in the Savannah River basin is expected to increase in the near future,
due to a population increase in the basin. Predictions for 2050
estimate the population will increase to nearly 900,000 (GAEPD, 2001a).
It is important to note that the two water supply sources are not
independent, because ground water discharge to streams is important in
maintaining dry-weather flow. Thus, withdrawal of ground water also
results in reduction in surface water flow.
The Vogtle Electric Generating Plant consists of two nuclear
reactors and currently uses up to 64 mgd of water from the Savannah
River to generate power. In March 2008, the Southern Nuclear Operating
Company applied to the Nuclear Regulatory Commission for a license to
build two additional nuclear reactors at the plant, increasing the
potential water usage to 80 mgd. Up to 100 mgd (379,000 m\3\pd) of
Savannah River water may be withdrawn to support the growth of South
Carolina communities located outside of the Savannah River basin, such
as Greenville and Beaufort County (Spencer and Muzekari, 2002). While
Georgia has laws restricting interbasin transfers of water, South
Carolina has yet to adopt stream flow protections and does not regulate
surface water withdrawals (Rusert and Cummings, 2004). Savannah has
been withdrawing water from its coastal aquifer since the city became
established. However, Savannah has grown to the point that the aquifer
has been depleted over 100 ft (31 m) beneath the city due to growth and
increased water usage. This decrease in aquifer storage water has
resulted in salt water intrusion into the water wells used by Hilton
Head, just north of Savannah. Currently, 5 of Hilton Head's 12 wells
are unusable and the problem is expected to escalate if no action is
taken to prevent further salt water intrusion. The South Carolina team
on the Savannah River Basin Advisory Group has begun looking at
withdrawing surface water from the Savannah River to ease the aquifer
problem (State of South Carolina, 2007; Spencer and Muzekari, 2002).
New surface water withdrawal permits in the Savannah, Ogeechee, and
Altamaha Rivers pose potential threats to water quality in those rivers
(Alber and Smith, 2001). Approximately 126,500 people depend on the
Altamaha basin for water. The Ocmulgee River, a tributary of the
Altamaha, is located in North Georgia and passes through Atlanta and
Macon before joining the Altamaha River. Of the seven river basins in
Georgia, the Ocmulgee River Basin has the highest population of
1,714,722 people. The Ocmulgee River Basin is home to a diverse
industrial and attraction base, from agriculture to defense. It has the
highest agriculture production and the most agricultural water
withdrawal permits in Georgia (Fisher et al., 2003).
[[Page 61920]]
It is not known how much water is already being removed from rivers
utilized by the South Atlantic DPS for spawning and nursery habitat
because there is little information concerning actual withdrawals and
virtually no information concerning water discharges. This is
particularly the case for municipal and industrial uses because water
use permits are not required for withdrawals less than 100,000 gpd (379
m\3\pd) (Cummings et al., 2003) and discharge permits are not required
unless discharge contains selected toxic materials. Agricultural water
use permits are not quantified in any meaningful way, thus neither
water withdrawals nor return flows are measured (Fisher et al., 2003).
Large withdrawals of water (such as those for municipal use) result in
reduced water quality (altered flows, higher temperatures, and lowered
DO), and reduced water quality is already contributing to the
endangered status of the South Atlantic DPS. Therefore, water
withdrawals from the rivers in the range of the South Atlantic DPS,
which are highly likely to occur based on current water shortages and
increasing demand, threaten to exacerbate water quality problems that
are currently modifying and curtailing Atlantic sturgeon habitat in the
South Atlantic DPS.
Climate Change
Climate change threatens to exacerbate the effects of modification
and curtailment of Atlantic sturgeon habitat caused by dams, dredging,
and reduced water quality on the endangered status of the Carolina and
South Atlantic DPSs. A major advance in climate change projections is
the large number of simulations available from a broader range of
climate models, run for various emissions scenarios. The
Intergovernmental Panel on Climate Change (IPCC) reports in its
technical paper ``Climate Change and Water'' that best-estimate
projections from models indicate that decadal average warming over each
inhabited continent by 2030 (i.e., over the next 20-year period) is
insensitive to the choice of emissions scenarios and is ``very likely''
to be at least twice as large (around 0.36 degrees Fahrenheit or 0.2
degrees Celsius per decade) as the corresponding model-estimated
natural variability during the 20th century (IPCC, 2008). Continued
greenhouse gas emissions at or above current rates under non-mitigation
emissions scenarios would cause further warming and induce many changes
in the global climate system during the 21st century, with these
changes ``very likely'' to be larger than those observed during the
20th century. In addition, the IPCC expects the rate of warming to
accelerate in the coming decades. Because 20 years is equal to at least
one generation of Atlantic sturgeon (ASSRT, 2007), and possibly
multiple generations in the Southeast where Atlantic sturgeon may
mature as early as 5 years (Smith et al., 1982), the modifying effects
of climate change over the next 20 years on vital parameters of the
Carolina and South Atlantic DPS' habitat will occur on a scale relevant
to their endangered status. Researchers anticipate that the frequency
and intensity of droughts and floods will change across the nation
(CBO, 2006). The IPCC report states that the most important societal
and ecological impacts of climate change in North America stem from
changes in surface and groundwater hydrology (IPCC, 2008).
Both the Carolina and South Atlantic DPSs are within a region the
IPCC predicts will experience decreases in precipitation. Since the
status review report was completed, the Southeast experienced
approximately 3 years of drought. During this time, South Carolina
experienced drought conditions that ranged from moderate to extreme
(South Carolina State Climatology Office, 2008). From 2006 until mid-
2009, Georgia experienced the worst drought in its history. In
September 2007, many of Georgia's rivers and streams were at their
lowest levels ever recorded for the month, and new record low daily
streamflows were recorded at 15 rivers with 20 or more years of data in
Georgia (USGS, 2007). The drought worsened in September 2008. All
streams in Georgia except those originating in the extreme southern
counties were extremely low. While Georgia has periodically undergone
periods of drought--there have been 6 periods of drought lasting from 2
to 7 years since 1903 (USGS, 2000)--drought frequency appears to be
increasing (Ruhl, 2003). Abnormally low stream flows restrict access to
habitat areas, reduce thermal refugia, and exacerbate water quality
issues, such as water temperature, reduced DO, nutrient levels, and
contaminants.
The Carolina and South Atlantic DPSs are already threatened by
reduced water quality resulting from dams, inputs of nutrients,
contaminants from CAFOs, industrial activities, and non-point sources,
and interbasin transfers of water. The IPCC report projects with high
confidence that higher water temperatures and changes in extremes in
this region, including floods and droughts, will affect water quality
and exacerbate many forms of water pollution--from sediments,
nutrients, dissolved organic carbon, pathogens, pesticides, and salt,
as well as thermal pollution, with possible negative impacts on
ecosystems. In addition, sea-level rise is projected to extend areas of
salinization of groundwater and estuaries, resulting in a decrease of
freshwater availability for humans and ecosystems in coastal areas.
Some of the most populated areas of this region are low-lying, and the
threat of salt water entering into its aquifers with projected sea-
level rise is a concern (U.S. Global Research Group, 2004). Existing
water allocation issues would be exacerbated, leading to an increase in
reliance on interbasin water transfers to meet municipal water needs,
further stressing water quality. Dams, dredging, and poor water quality
have already modified and curtailed the extent of suitable habitat for
Atlantic sturgeon spawning and nursery habitat. Changes in water
availability (depth and velocities) and water quality (temperature,
salinity, DO, contaminants, etc.) in rivers and coastal waters
inhabited by Atlantic sturgeon resulting from climate change will
further modify and curtail the extent of suitable habitat for the
Carolina DPS. Effects could be especially harmful since these
populations have already been reduced to low numbers. The spawning
populations within the Carolina DPS are all estimated to number fewer
than the 500 recommended by Thompson (1991) to maintain sufficient
genetic variability for adaptation to changing environmental
conditions, and certainly smaller than the 1,000 to 10,000 recommended
by other authors (Salwasser et al., 1984; Belovsky, 1987; Soule, 1987;
Thomas, 1990).
The SRT concluded that habitat modifications due to the placement
of dams, dredging, and degraded water quality present a moderate to
moderately high threat to all river populations within the Carolina
DPS, with the exception of the Roanoke River. For the South Atlantic
DPS, the SRT concluded that dredging and water quality issues are
having a moderately low to moderate impact on the river populations. We
believe that the modification and curtailment of Atlantic sturgeon
habitat resulting from dams, dredging, and degraded water quality is
contributing to the endangered status of both the Carolina and South
Atlantic DPSs. Further, additional threats arising from water
allocation and climate change threaten to exacerbate water quality
problems already present throughout the range of both DPSs. Existing
water allocation issues will
[[Page 61921]]
likely be compounded by population growth and potentially climate
change. Climate change is also predicted to elevate water temperatures
and exacerbate nutrient-loading, pollution inputs, and lower DO, all of
which are current threats to the Carolina and South Atlantic DPSs.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
Overutilization for commercial purposes is a factor that
contributed to the historical drastic decline in Atlantic sturgeon
populations throughout the species' range. Data on the total weight of
Atlantic and shortnose sturgeon harvested were collected by each state
starting in 1880, and in the late 1800s commercial fisheries were
landing upwards of 6,800,000 lbs (3,084 kg) of sturgeon annually
(Murawski and Pacheco, 1977). By 1905, only 15 years later, this number
had dropped to 20,000 lbs (9,071 kg). The population sizes were then
further reduced by overfishing in the 1900s, when the landings
drastically fell to a total of 215 lbs (98 kg) in 1990 (Stein et al.,
2004b). The total landings recorded include shortnose sturgeon as well
as Atlantic sturgeon; however, the harvest is thought to have been
primarily Atlantic sturgeon due to the large mesh-size nets commonly
used at that time. A complete moratorium on possession of Atlantic
sturgeon has been implemented in both state and Federal waters since
1998 to eliminate the threat of directed catch and incentives to retain
Atlantic sturgeon bycatch. However, Atlantic sturgeon are taken as
bycatch in various commercial fisheries along the entire U.S. Atlantic
Coast within inland, coastal, and Federal waters. While Atlantic
sturgeon caught incidentally can no longer be legally landed, bycatch
may still be a threat if fish are injured or killed in the act of being
caught.
Based on their life history, Atlantic sturgeon are more sensitive
to fishing mortality than other coastal fish species. They are a long-
lived species, have an older age at full maturity, have lower maximum
fecundity values, with 50 percent of the lifetime egg production for
Atlantic sturgeon occurring later in life (Boreman, 1997). Boreman
(1997) looked at the relationship between fishing mortality (F) and the
corresponding percentage of the maximum lifetime egg production of an
age 1 female. The F50 is the fishing rate at which a cohort
produces 50 percent of the eggs that it would produce with no fishing
effort. Boreman calculated a sustainable fishing (bycatch) mortality
rate of 5 percent per year for adult Atlantic sturgeon based on the
F50. While many fishery models use a less conservative
target fishing level of F30 or F20, the more
conservative choice of F50 for Atlantic sturgeon is
justified by their late age at maturity and because they are periodic
spawners (Boreman, 1997).
We currently do not have all the data necessary to determine
whether the percentage of Atlantic sturgeon populations lost annually
due to bycatch mortality exceeds a sustainable rate of 5 percent per
year suggested by Boreman (1997) as we do not have abundance estimates
for the Carolina and South Atlantic DPSs and bycatch remains highly
underreported. However, bycatch is occurring throughout the range of
the Carolina and South Atlantic DPSs of Atlantic sturgeon, and the
bycatch mortality associated with the dominant fishing gear in the
Southeast is relatively high. All the spawning populations in the
Southeast Region are quite small, which means that the loss of a small
number of fish to bycatch mortality could exceed the sustainable rate
of 5 percent per year. Overutilization of Atlantic sturgeon through
commercial bycatch is presently a threat to the Carolina and South
Atlantic DPSs, and we believe it is contributing to their endangered
status.
Mortality rates of Atlantic sturgeon taken as bycatch in various
types of fishing gear range between 0 and 51 percent, with the greatest
mortality occurring in sturgeon caught by sink gillnets (Stein et al.,
2004b; ASMFC, 2007). The ASMFC Sturgeon Technical Committee (TC)
determined that bycatch losses principally occur in sink gillnet
fisheries, though there may be losses in the trawl fisheries, as well.
Atlantic sturgeon are particularly vulnerable to sink gillnets due to
their demersal nature (tendency to be at the bottom of the water
column). If the nets are not tended often enough, it can be detrimental
to the sturgeon, resulting in suffocation because their operculum or
gills can be held closed by the net. Using the NMFS ocean observer
dataset, the NEFSC estimated that bycatch mortality of sturgeon
captured in sink gillnets between 2001 and 2006 was 13.8 percent
(ASMFC, 2007). The ASMFC Sturgeon TC notes that any estimate of bycatch
from the NMFS ocean observer dataset will be an underestimate because
bycatch is under-reported in state waters and no observer coverage
exists in the South Atlantic (North Carolina to Florida) Federal
waters. In addition, bycatch mortality estimates do not account for
post-capture mortality. The 13.8 percent mortality rate for sink
gillnets estimated by the NEFSC may further underestimate the mortality
rate in sink gillnets in the Carolina and South Atlantic DPSs because
bycatch survival is greater in colder water temperatures of the north
compared to warmer southern waters occupied by these DPSs (ASSRT,
2007). Mortality of Atlantic sturgeon captured by trawls seems to be
low, with most surveys reporting 0 percent mortality. However, these
studies do not include post-capture mortality, and studies of mortality
from trawl fisheries conducted in the south, where tow times are longer
and water temperatures are higher, are very limited.
Sink gillnets and trawls are used throughout riverine, estuarine,
and marine waters in the range of the Carolina DPS to target a wide
array of finfish and shellfish. Data on Atlantic sturgeon bycatch in
Albemarle and Pamlico Sound commercial fisheries come from three
sources: (1) NCDMF independent gillnet surveys (IGNS) that were
initially designed to monitor striped bass; (2) the NCDMF Observer
Program; and (3) the NC Sea Grant Fishery Resource Grant project that
examined sturgeon bycatch in the flounder fishery (White and Armstrong,
2000). The Albemarle and Pamlico IGNS used sink and drift gillnets,
similar to those used by the shad/herring and the flounder fisheries.
Only a few fish have been captured in the Pamlico Sound gillnet survey
since 2000, although 842 Atlantic sturgeon were captured in the
Albemarle Sound between 1990 and 2005. The NCDMF Observer Program
sampled both the Albemarle and Pamlico Sound monthly from April 2004 to
December 2005. Thirty Atlantic sturgeon were observed in Albemarle
Sound, and 12 Atlantic sturgeon were observed in Pamlico Sound.
Overall, five observed mortalities (12 percent of captures) occurred in
June 2004 and April, August, January, and March 2005. No overall
bycatch estimates have been extrapolated from these observer data.
Commercial fishermen in Albemarle and Pamlico Sound and Cape Fear River
reported catches of zero to two sturgeon per fishery per year. However,
White and Armstrong (2000) reported that sturgeon bycatch in flounder
gillnets fished from 1998 to 2000 by a single fishermen in the
Albemarle Sound flounder fishery included the capture of 131 Atlantic
sturgeon. Of the 131 Atlantic sturgeon captured, no mortalities were
reported, although four individuals were noted as having minor
injuries. These data indicate that underreporting of sturgeon bycatch
is occurring in this area.
[[Page 61922]]
A sink gillnet survey conducted in the Cape Fear River by UNCW
personnel noted that 25 percent of sturgeon intercepted (22 of 88
caught) were killed. The gillnets were set one day, checked the second,
and retrieved on the third. The greatest mortality occurred during
periods of highest water temperature (Moser et al., 1998). This survey
was continued by the NCDMF, and it has reported mortality rates of 37
percent overall. Similar to earlier findings, mortality was greatest
during the summer months (June through August), averaging 49 percent
(34 of 69 sturgeon died) (ASSRT, 2007). This study has been
discontinued due to lack of funding. There are no estimates of bycatch
in fishery dependent surveys.
Winyah Bay is currently fished for American shad (Alosa
sapidissima) using both sink and drift gillnets. This fishery has an
estimated bycatch of 158 Atlantic sturgeon per year, of which 16
percent (25 fish) die and another 20 percent are injured to some
degree, although this estimate is dated (Collins et al., 1996). Shad
fishers also operate within the rivers, but neither fishing effort nor
average numbers of Atlantic sturgeon encountered are known. Poaching of
adult Atlantic sturgeon has been reported from the Winyah Bay area in
recent years. Carcasses of large females have been found with the
ovaries (caviar) removed.
The mouth of the Santee River, just south of Winyah Bay, has the
largest shad landings in the Southeast (ASSRT, 2007), likely resulting
in mortality and injury of sturgeon similar to that in the Winyah Bay
shad fishery. Upriver bycatch levels are unknown. The Cooper River also
has an active hook and line shad fishery because gillnets are
restricted (ASSRT, 2007).
The two largest commercial fisheries likely to capture Atlantic
sturgeon from the South Atlantic DPS in the state waters of South
Carolina and Georgia are the American shad gillnet and shrimp trawl
fisheries. Studies in Georgia on commercial gillnet fisheries for
American shad showed that they accounted for 52 percent of Atlantic
sturgeon bycatch and the shrimp trawl fisheries accounted for 39
percent (Collins et al., 1996). The American shad fisheries use sink
gillnets and drift gillnets. Collins et al. (1996) documented a 16
percent capture-induced mortality rate for sturgeon in the American
shad fishery.
There was a directed commercial fishery for Atlantic sturgeon in
the ACE Basin prior to the 1985 fishery closure. The commercial
sturgeon fishery operated in the lower and middle portions of both the
Combahee and Edisto rivers. Commercial shad fisheries captured some
juvenile Atlantic sturgeon, but most fishermen operate upriver from the
areas of greatest abundance during that time of year. The shrimp trawl
fishery in St. Helena Sound also captures juveniles, as evident from
tag returns (ASSRT, 2007).
Although a few commercial sturgeon fishers apparently operated in
the Port Royal river system prior to 1985, the landing of only one
Atlantic sturgeon has been recorded (Smith and Dingley, 1984). Little,
if any, shad fishing takes place in this system. It is not known
whether there is any significant bycatch in the shrimp trawl fishery in
this area.
During 1989 to 1991, the commercial shad gillnet fishery's bycatch
in the Savannah River included more endangered shortnose sturgeon than
juvenile Atlantic sturgeon. Collins et al. (1996) reported that two
commercial fishermen collected 14 Atlantic and 189 shortnose sturgeon
over the period of 1990 to 1992. It appears that abundance within the
Savannah River is extremely low, as evidenced from low bycatch and
reported captures over the last 15 years. Thus, bycatch may be a more
serious impact if abundance is low and fishing effort is high.
Bycatch in the shad fishery in the Ogeechee River is a heightened
concern because evidence suggests that this Atlantic sturgeon
population is stressed and that complete recruitment failure has
occurred in some years (ASSRT, 2007). Bycatch mortality in the
estuarine and lower river shad fishery is suspected to be high, but no
estimates of take are available (ASSRT, 2007).
Estimated annual total bycatch of Atlantic and shortnose sturgeon
in the shad gillnet fishery in the tidal portion of the Altamaha River
during 1982 and 1983 averaged 372 sturgeon (Collins et al., 1996).
Percent mortality was not determined. During a study conducted between
1986 and 1992 in the Altamaha River, 97 of 1,534 tagged juvenile
Atlantic sturgeon were recaptured primarily by shad gillnets (52
percent) and shrimp trawls (39 percent) (Collins et al., 1996).
Juvenile Atlantic sturgeon from the Altamaha are relatively abundant in
comparison to other rivers in the region, so a large percentage of the
individuals in winter mixed-stock aggregations on the shelf are likely
from this river. Most sturgeon occurring as shrimp trawl bycatch are
from mixed-stock aggregations. Using the percentages of Atlantic and
shortnose sturgeon from the 1986 to 1992 Altamaha catch data and
applying them to the 1982 and 1983 total estimated sturgeon bycatch, it
is expected that 89 percent (331 fish) of the catch consisted of
Atlantic sturgeon (ASSRT, 2007). Also, assuming a 10 percent bycatch
mortality rate for Atlantic sturgeon from drift nets (Stein et al.,
2004b), the dominant gear used in the shad gillnet fishery, it is
estimated that 33 Atlantic sturgeon would die each year from the
fishery.
Shad fishing effort is low in the Satilla River due to an
apparently depleted shad population. However, because the Atlantic
sturgeon population is depleted and highly stressed, any bycatch
mortality could have an impact on the population (ASSRT, 2007).
The SRT concluded that bycatch presents a moderate threat to the
Carolina DPS, while the threat of bycatch to the South Atlantic DPS was
characterized as moderately low in each of the populations, with the
exception of the Altamaha, where bycatch was deemed to pose a moderate
threat. Overutilization of Atlantic sturgeon from directed fishing
caused initial severe declines in Atlantic sturgeon populations in the
southeast, from which they have never rebounded. Further, we believe
continued overutilization of Atlantic sturgeon from bycatch in
commercial fisheries is an ongoing impact to the Carolina and South
Atlantic DPSs that is contributing to their endangered status. Atlantic
sturgeon are particularly vulnerable to being caught in sink gillnets;
therefore, fisheries using this type of gear account for a high
percentage of Atlantic sturgeon bycatch. Little data exist on bycatch
in the Southeast, and high levels of bycatch underreporting are
suspected. Further, total population abundances for the Carolina and
South Atlantic DPSs are not available; therefore, it is not possible to
calculate the percentages of the Carolina and South Atlantic DPSs
subject to bycatch mortality based on the available bycatch mortality
rates for individual fisheries. However, fisheries known to
incidentally catch Atlantic sturgeon occur throughout the marine range
of the species and in some riverine waters as well. Because Atlantic
sturgeon mix extensively in marine waters and may access multiple river
systems, they are subject to being caught in multiple fisheries
throughout their range. Atlantic sturgeon taken as bycatch may suffer
immediate mortality. In addition, stress or injury to Atlantic sturgeon
taken as bycatch but released alive may result in increased
susceptibility to other threats, such as poor water quality (e.g.,
exposure to toxins and low DO). This may result in reduced ability to
perform major life functions, such as foraging and spawning, or even
post-
[[Page 61923]]
capture mortality. Several of the systems in the South Atlantic DPS
(e.g., the Ogeechee and the Satilla) are stressed to the degree that
any level of bycatch could have an adverse impact on the status of the
DPS (ASSRT, 2007).
C. Disease or Predation
Very little is known about natural predators of Atlantic sturgeon.
The presence of bony scutes is likely an effective adaptation for
minimizing predation of sturgeon greater than 25 mm (Gadomski and
Parsley, 2005). Gadomski and Parsley (2005) have shown that catfish and
other species do prey on juvenile sturgeon, and concerns have been
raised regarding the potential for increased predation on juvenile
Atlantic sturgeon by introduced flathead catfish (Brown et al., 2005).
Atlantic sturgeon populations are persisting in the Cape Fear River,
North Carolina, and Altamaha River, Georgia, where flatheads have been
present for many years, at least in the absence of any directed
fisheries for Atlantic sturgeon. Thus, further research is warranted to
determine at what level, if any, flatheads and other exotic species
prey upon juvenile Atlantic sturgeon and to what extent such predation
is affecting the sturgeon populations.
While some disease organisms have been identified from wild
Atlantic sturgeon, they are unlikely to threaten the survival of the
wild populations. Disease organisms commonly occur among wild fish
populations, but under favorable environmental conditions, these
organisms are not expected to cause population-threatening epidemics.
There is concern that non-indigenous sturgeon pathogens could be
introduced, most likely through aquaculture operations. Fungal
infections and various types of bacteria have been noted to have
various effects on hatchery Atlantic sturgeon. Due to this threat of
impacts to wild populations, the ASMFC recommends requiring any
sturgeon aquaculture operation to be certified as disease-free, thereby
reducing the risk of the spread of disease from hatchery origin fish.
The aquarium industry is another possible source for transfer of non-
indigenous pathogens or non-indigenous species from one geographic area
to another, primarily through release of aquaria fish into public
waters. With millions of aquaria fish sold to individuals annually, it
is unlikely that such activity could ever be effectively regulated.
Definitive evidence that aquaria fish could be blamed for transmitting
a non-indigenous pathogen to wild fish (sturgeon) populations would be
very difficult to collect (ASSRT, 2007).
In their extinction risk analysis, the SRT ranked the threat from
disease and predation as a low risk. While information on the impacts
of disease and predation on Atlantic sturgeon is limited, there is
nothing to indicate that either of these factors is currently having
any measurable adverse impact on Atlantic sturgeon. Therefore, we
concur with the SRT, and we conclude that disease and predation are not
contributing to the endangered status of either the Carolina or the
South Atlantic DPS.
D. Inadequacy of Existing Regulatory Mechanisms
As a wide-ranging anadromous species, Atlantic sturgeon are subject
to numerous Federal (U.S. and Canadian), state and provincial, and
inter-jurisdictional laws, regulations, and agency activities. These
regulatory mechanisms are described in detail in the status review
report (see Section 3.4). We believe that the inadequacy of regulatory
mechanisms to control bycatch and the modification and curtailment of
Atlantic sturgeon habitat is contributing to the endangered status of
the Carolina and South Atlantic DPSs.
Current regulatory mechanisms have effectively removed threats from
legal, directed harvest in the United States, as well as incentives for
retention of bycatch. The ASMFC was given management authority in 1993
under the Atlantic Coastal Fisheries Cooperative Management Act
(ACFCMA) (16 U.S.C. 5101-5108), and it manages Atlantic sturgeon
through an interstate fisheries management plan (IFMP). The moratorium
prohibiting directed catch of Atlantic sturgeon was developed as an
Amendment to the IFMP. The ACFCMA, authorized under the terms of the
ASMFC Compact, as amended (Pub. L. 103-206), provides the Secretary of
Commerce with the authority to implement regulations that are
compatible to ASMFC FMPs in the Exclusive Economic Zone (EEZ) in the
absence of an approved Magnuson-Stevens FMP. In 1999, it was under this
authority that a similar moratorium was implemented for Atlantic
sturgeon in Federal waters. The Amendment includes a stock rebuilding
target of at least 20 protected mature age classes in each spawning
stock, which is to be achieved by imposing a harvest moratorium. The
Amendment requires states to monitor, assess, and annually report
Atlantic sturgeon bycatch and mortality in other fisheries. The
Amendment also requires that states annually report habitat protection
and enhancement efforts. Finally, the Amendment states that each
jurisdiction with a reproducing population should conduct juvenile
assessment surveys (including CPUE estimates, tag and release programs,
and age analysis), and states with rivers that lack a reproducing
sturgeon population(s) but support nursery habitat for migrating
juveniles should also conduct sampling.
While the ASMFC and NMFS have made significant strides in reducing
the threats from direct harvest and retention of bycatch, those threats
have not been eliminated, and continued bycatch of Atlantic sturgeon is
contributing to the endangered status of the Carolina and South
Atlantic DPSs. Although the FMP contains requirements for reporting
bycatch, fishery managers, such as the ASMFC Atlantic Sturgeon
Management Board, widely accept that Atlantic sturgeon bycatch is
underreported or not reported at all based on research and anecdotal
evidence (ASMFC, 2005; ASSRT, 2007; White and Armstrong, 2000).
Abundance estimates are available only for two river systems (the
Hudson and the Altamaha) even though the FMP states that each
jurisdiction with a reproducing population should conduct juvenile
assessment surveys (including CPUE estimates, tag and release programs,
and age analysis). While the aforementioned mechanisms have addressed
impacts to Atlantic sturgeon through directed fisheries, there are
currently no mechanisms in place to address the significant impacts and
risks posed to Atlantic sturgeon from commercial bycatch.
State and Federal agencies are actively employing a variety of
legal authorities to implement proactive restoration activities for
this species, and coordination of these efforts is being furnished
through the ASMFC. Due to existing state and Federal laws, water
quality and other habitat conditions have improved in many riverine
habitats, although many systems still have DO and toxic contaminants
issues, and habitat quality and quantity continue to be affected by
dams, dredging, and/or altering natural flow conditions.
Though statutory and regulatory mechanisms exist that authorize
reducing the impact of dams on riverine and anadromous species, such as
Atlantic sturgeon, and their habitat, these mechanisms have proven
inadequate for preventing dams from blocking access to habitat upstream
and degrading habitat downstream. Hydropower dams are regulated by the
FERC. The Federal Power Act (FPA), originally enacted in 1920, provides
for cooperation between FERC and other Federal agencies, including
resource
[[Page 61924]]
agencies, in licensing and relicensing power projects. The FPA
authorizes NMFS to recommend hydropower license conditions to protect,
mitigate damages to, and enhance anadromous fish, including related
habitat. The FPA also provides authority for NMFS to issue mandatory
fishway prescriptions. FERC licenses have a term of 30 to 50 years, so
NMFS' involvement in the licensing process to ensure the protection and
accessibility of upstream habitat, and to improve habitat degraded by
changes in water flow and quality from dam operations, only occurs
twice or thrice a century. The FPA does not apply to non-hydropower
dams, such as those operated by the Army Corps of Engineers for
navigation purposes. Even where fish passage currently exists, evidence
is rare that they effectively pass sturgeon, including Atlantic
sturgeon. As mentioned in previous sections, dams in the Southeast are
currently blocking over 60 percent of the habitat in three rivers with
historical and/or current spawning Atlantic sturgeon populations (the
Cape Fear River and Santee-Cooper System in the Carolina DPS and the
St. Johns River in the South Atlantic DPS). In addition to the loss of
important spawning and juvenile developmental habitat upstream, dam
operations reduce the quality of the remaining habitat downstream by
affecting water quality parameters (such as depth, temperature,
velocity, and DO) that are important to Atlantic sturgeon. Therefore,
the inadequacy of regulatory mechanisms to ensure safe and effective
upstream and downstream passage to Atlantic sturgeon and prevent
degradation of habitat downstream from dam operations in riverine
habitat is contributing to the endangered status of the Carolina and
South Atlantic DPSs.
Inadequacies in the regulation of water allocation also impact the
South Atlantic DPS. Data concerning consumptive water use in this
region are, at best, very limited. While extensive data exist
concerning permitted water withdrawals, there is little information
concerning actual withdrawals and virtually no information concerning
water discharges. This is particularly the case for municipal and
industrial uses because water use permits are not required for
withdrawals less than 100,000 gpd (379 m\3\pd) (Cummings et al., 2003)
and discharge permits are not required unless discharge contains
selected toxic materials. Agricultural water use permits are not
quantified in any meaningful way, thus neither water withdrawals nor
return flows are measured (Fisher et al., 2003). While several other
states have similar permitting thresholds, the majority require permits
for water withdrawals less than 100,000 gpd (379 m\3\pd) and some
require a permit for any water withdrawal. The State of Georgia allows
access to water in amounts required to satisfy the household needs of
more than 300 households without a permit (Cummings et al., 2003).
Even the most fundamental requisites for basin water planning--data
for historical, unimpaired flows in the coastal regions' rivers--simply
do not exist (Fisher et al., 2003). There are 125 river gauges in the
region's 7 river basins. However, 72 of these gauges are inactive, and
28 of the remaining 53 gauges do not provide consistent flow
information. Moreover, historical data from many gauges have gaps,
reflecting periods (sometimes extending over months) during which the
gauge was inoperative. Also, there are extensive discharge areas
between the last gauge in each river system and the point at which the
river discharges into the ocean--thus, there are potentially large
water supplies about which absolutely nothing is known (Fisher et al.,
2003).
Water quality continues to be a problem, even with existing
controls on some pollution sources. Data required to evaluate water
allocation issues are either very weak, in terms of determining the
precise amounts of water currently being used, or non-existent, in
terms of our knowledge of water supplies available for use under
historical hydrologic conditions in the region. Current regulatory
regimes are not necessarily effective in controlling water allocation
(e.g., no permit requirements for water withdrawals under 100,000 gpd
(379 m\3\pd) in Georgia and no restrictions on interbasin water
transfers in South Carolina).
In their extinction risk analysis, the SRT ranked the threat from
the inadequacy of regulatory mechanisms as moderately low to moderate.
While some of the threats to the Carolina and South Atlantic DPSs have
been ameliorated or reduced through the existing regulatory mechanisms,
such as the moratorium on directed fisheries for Atlantic sturgeon,
bycatch is currently not being addressed through existing mechanisms.
Further, water quality continues to be a problem even with existing
controls on some pollution sources and water withdrawal, and dams
continue to curtail and modify habitat, even with the Federal Power
Act.
E. Other Natural or Manmade Factors Affecting the Species' Continued
Existence
The SRT considered several manmade factors that may affect Atlantic
sturgeon, including impingement and entrainment, ship strikes, and
artificial propagation. The vast withdrawal of water from rivers that
support Atlantic sturgeon populations was considered to pose a threat
of impingement and entrainment; however, data are lacking to determine
the overall impact of this threat on sturgeon populations, as impacts
are dependent on a variety of factors (e.g., the species, time of year,
location of the intake structure, and strength of the intake current).
Multiple suspected boat/ship strikes have been reported in several
rivers. A large number of the mortalities observed in these rivers from
potential ship strikes have been of large adult Atlantic sturgeon.
Lastly, potential artificial propagation of Atlantic sturgeon was also
a concern to SRT members, as both stock enhancement programs and
commercial aquaculture can have negative impacts on a recovering
population (e.g., fish disease, escapement, outbreeding depression). In
order to circumvent these potential threats, stock enhancement programs
follow culture and stocking protocols approved by the ASMFC. Commercial
aquaculture facilities are expected to maintain disease-free facilities
and have safeguards in place to prevent escapement of sturgeon into the
wild. While in at least one instance cultured Atlantic sturgeon have
gone unaccounted for from a commercial aquaculture facility in Florida,
this is not considered to be a significant threat, as this was a rare
event. Mechanisms are in place at all facilities to prevent escapement
of sturgeon; facilities are all land based, and most are not located in
close proximity to any Atlantic sturgeon rivers.
Along the range of Atlantic sturgeon from the Carolina and South
Atlantic DPSs, most, if not all, populations are at risk of possible
entrainment or impingement in water withdrawal intakes for commercial
uses, municipal water supply facilities, and agricultural irrigation
intakes. In North Carolina, over two billion gallons of water per day
were withdrawn from the Cape Fear, Neuse, Tar, and Roanoke rivers in
1999 by agriculture and non-agricultural industries (NCDENR, 2006).
Currently, there are only three surveys that have shown the direct
impacts of water withdrawal on Atlantic sturgeon: (1) Hudson River
Utility Surveys, (2) Delaware River Salem Power Plant
[[Page 61925]]
survey, and (3) Edwin I. Hatch Nuclear Power Plant (HNP) survey. The
Edwin I. Hatch Nuclear power plant is located 11 miles north of Baxley,
Georgia. The HNP uses a closed-loop system for main condenser cooling
that withdraws from, and discharges to, the Altamaha River. Pre-
operational drift surveys were conducted and only two Acipenser sp.
larvae were collected. Entrainment samples at HNP were collected for
the years 1975, 1976, and 1980, and no Acipenser sp. were observed in
the samples (Sumner, 2004). Though most rivers have multiple intake
structures which remove millions of gallons a day during the spring and
summer months, it is believed that the migratory behavior of larval
sturgeon allows them to avoid intake structures, since migration is
active and occurs in deep water (Kynard and Horgan, 2002). Effluent
from these facilities can also affect populations, as some facilities
release heated water that acts as a thermal refuge during the winter
months, but drastic changes in water temperature have the potential to
cause mortality.
Locations that support large ports and have relatively narrow
waterways are more prone to ship strikes (e.g., Delaware, James, and
Cape Fear rivers). One ship strike per 5 years is reported for the Cape
Fear River within the Carolina DPS. Ship strikes have not been
documented in any of the rivers within the South Atlantic DPS. While it
is possible that ship strikes may have occurred that have gone
unreported or unobserved, the lack of large ship traffic on narrow
waterways within the range of the DPS may limit potential interactions.
Artificial propagation of Atlantic sturgeon for use in restoration
of extirpated populations or recovery of severely depleted wild
populations has the potential to be both a threat to the species and a
tool for recovery. Within the range of the Carolina DPS, several
attempts were made by Smith et al. (1980 and 1981) to hormonally-induce
spawning and culture Atlantic sturgeon captured in the Atlantic Ocean
off the Winyah Bay jetties. Fry were hatched in each instance, but
lived less than a year. As a result of successful spawning of Hudson
River Atlantic sturgeon from 1993 to 1998, USFWS' Northeast Fisheries
Center (NEFC) is currently rearing five year-classes of domestic fish.
These fish could potentially be used as broodstock for aquaculture
operations and stock enhancement, provided that there is no risk to
wild fish. Aquaculturists along the East Coast, including some in North
Carolina and South Carolina, have contacted the NEFC and expressed
interest in initiating commercial production of Atlantic sturgeon. In
2006, La Paz Aquaculture Group was approved by North Carolina state
resource agencies and ASMFC to produce Atlantic sturgeon for flesh and
caviar sales. However, their first year of production was halted
because remnant storms from Hurricane Katrina destroyed their fry
stock. In August 2006, ASMFC reevaluated the La Paz permit, and voted
to draft an addendum to allow La Paz to acquire Atlantic sturgeon from
multiple Canadian aquaculture companies (previously restricted to one
company), allowing them to resume Atlantic sturgeon culture. Resource
managers who reviewed the permit found the La Paz facility to pose
little threat to Atlantic sturgeon or shortnose populations due to the
facility location (far inland), use of a recirculating system, and land
application of any discharge (ASSRT, 2007).
In the range of the South Atlantic DPS, artificial propagation has
been attempted for the purposes of both restoration and commercial
profit. The St. Marys Fish Restoration Committee (SMFRC) is working
with Florida and Georgia to reestablish Atlantic sturgeon in the St.
Marys River. Efforts are currently underway to refine restoration
approaches within the system. Phase 1 of the restoration plan includes
a population and habitat assessment. Field investigations are being
funded through ESA Section 6 and coordinated through Georgia DNR. The
State of Florida has been involved in fish sampling and will continue
to explore and refine sturgeon sampling strategies. Aquatic habitat and
water quality surveillance work will continue to be accomplished by the
St. Johns River Water Management District, the Environmental Protection
Agency, Florida Department of Environmental Protection, USFWS, TNC, and
the St. Marys River Management Committee. Phase 2 of the plan would
include experimental transplanting of Atlantic sturgeon to assess
environmental factors, habitat use at different life-stages,
contaminants, migration-homing, etc. Upon approval from the ASMFC, the
SMFRC transferred 12 Atlantic sturgeon from the Altamaha River in
Georgia to the Bears Bluff National Fish Hatchery in South Carolina.
The SMFRC hopes to develop and refine captive propagation techniques
for predictable spawning and provide fish to approved researchers.
Aquaculturists in South Carolina and Florida have also contacted
the NEFC and expressed interest in initiating commercial production of
Atlantic sturgeon through use of the Hudson River broodstock. In 2001,
the Canadian Caviar Company shipped 18,000 Atlantic sturgeon sac fry to
the University of Florida. These fry were used to conduct early larval
and feeding trials. Survivors of these experiments were transferred to
four aquacultural businesses: (1) Evan's Fish Farm in Pierson, Florida;
(2) Watts Aquatics in Tampa, Florida; (3) Hi-Tech Fisheries of Florida
in Lakeland, Florida; and (4) Rokaviar in Homestead, Florida. Evan's
Fish Farm experienced a catastrophic systems failure in 2004 and
currently has five Atlantic sturgeon on its premises. The farm intends
to use these remaining sturgeon as broodstock and would like to acquire
more Atlantic sturgeon. Watts Aquatics went out of business, and the
status of the Atlantic sturgeon this farm received is unknown. Hi-Tech
Fisheries of Florida currently has around 300 Atlantic sturgeon which
have been transferred to a quarry, and the company is in the process of
evaluating stock size and health condition. Rokaviar originally
received 100 sturgeon, but due to a malfunction with the life support
systems, the company now holds only 20 Atlantic sturgeon. All of these
facilities are periodically screened for disease by a University of
Florida Institute for Food and Agricultural Science (IFAS)
veterinarian. None have reported diseases. All facilities are above the
100-year flood plain and have zero discharge, where tank culture or
quarry culture is utilized (Roberts and Huff, 2004). These facilities
may sell meat, fingerlings, and caviar in accordance with state,
Federal, and international laws.
The SRT ranked the threats from impingement/entrainment, ship
strikes, and artificial propagation as low for both DPSs, with the
exception of the threat from ship strikes as moderately low for the
Carolina DPS. We concur with these rankings and conclude that none of
these threats are contributing to the endangered status of the DPS.
Current Protective Efforts
Section 4(b)(1)(A) of the ESA requires the Secretary, when making a
listing determination for a species, to take into account those
efforts, if any, being made by any State or foreign nation to protect
the species. In judging the efficacy of existing protective efforts, we
rely on the Services' joint ``Policy for Evaluation of Conservation
Efforts When Making Listing Decisions'' (``PECE;'' 68 FR 15100; March
28, 2003). The PECE is designed to guide determinations on whether any
conservation efforts that have been recently adopted or implemented,
but not yet proven to be
[[Page 61926]]
successful, will result in recovering the species to the point at which
listing is not warranted or contribute to forming a basis for listing a
species as threatened rather than endangered. The purpose of the PECE
is to ensure consistent and adequate evaluation of future or recently
implemented conservation efforts identified in conservation agreements,
conservation plans, management plans, and similar documents when making
listing decisions. The PECE provides direction for the consideration of
such conservation efforts that have not yet been implemented, or have
been implemented but have not yet demonstrated effectiveness. The
policy is expected to facilitate the development by states and other
entities of conservation efforts that sufficiently improve a species'
status so as to make listing the species as threatened or endangered
unnecessary.
The PECE established two basic criteria: (1) The certainty that the
conservation efforts will be implemented, and (2) the certainty that
the efforts will be effective. Satisfaction of the criteria for
implementation and effectiveness establishes a given protective effort
as a candidate for consideration, but does not mean that an effort will
ultimately change the risk assessment for the species. Overall, the
PECE analysis ascertains whether the formalized conservation effort
improves the status of the species at the time a listing determination
is made.
We evaluated the current conservation efforts underway to protect
and recover Atlantic sturgeon in making our listing determination. We
determined that only the following conservation efforts warrant
consideration under the PECE for the Carolina and South Atlantic DPSs:
the 1998 ASMFC FMP and the proposal by the SMFRC to restore Atlantic
sturgeon to the St. Marys River.
The 1998 Amendment to the ASMFC Atlantic Sturgeon FMP strengthens
conservation efforts by formalizing the closure of the directed
fishery, and by banning possession of bycatch, eliminating any legal
incentive to retain Atlantic sturgeon. However, bycatch is known to
occur in several fisheries (ASMFC, 2007) and it is widely accepted that
bycatch is underreported. With respect to its effectiveness, contrary
to information available in 1998 when the Amendment was approved,
Atlantic sturgeon bycatch mortality is a major stressor affecting the
recovery of Atlantic sturgeon, despite actions taken by the states and
NMFS to prohibit directed fishing and retention of Atlantic sturgeon.
Therefore, there is considerable uncertainty that the Atlantic Sturgeon
FMP will be effective in meeting its conservation goals. In addition,
though the 1998 Amendment contains requirements for population surveys,
it is highly uncertain these will be implemented, as there are limited
resources for assessing current abundance of spawning females for each
of the DPSs and to date, abundance estimates have only been completed
for one river within the range of the two DPSs considered here. For
these reasons, there is no certainty of implementation and
effectiveness of the intended ASMFC FMP conservation effort for the
Carolina and South Atlantic DPSs of Atlantic sturgeon.
The SMFRC is working with Florida and Georgia with the intention of
reestablishing Atlantic sturgeon in the St. Marys River. Efforts are
currently underway to refine restoration approaches within the system.
As discussed in Section E, Phase 1 of the restoration plan includes a
population and habitat assessment, and Phase 2 includes experimental
transplanting of Atlantic sturgeon to assess environmental factors,
habitat use at different life-stages, contaminants, migration-homing,
etc. Atlantic sturgeon are believed to be extirpated in the St. Marys
River. This conservation effort may increase our knowledge and
understanding of Atlantic sturgeon status and habitat conditions in the
St. Marys River, as well as provide methods for restoring a population
there in the future. As previously discussed, artificial propagation of
Atlantic sturgeon for use in restoration of extirpated populations or
recovery of severely depleted wild populations has the potential to be
both a threat to the species and a tool for recovery. Because it is in
the earliest stages of planning, development, and authorization, the
feasibility of any project or the potential degree of success for this
effort is unknown. Therefore, the SMRFC efforts do not satisfy the PECE
policy's standards for certainty of implementation or effectiveness.
Conclusion
Finding for the Carolina DPS
The Carolina DPS is estimated to number less than 3 percent of its
historical population size (ASSRT, 2007). Prior to 1890, Secor (2002)
estimated there were between 7,000 and 10,000 adult females in North
Carolina and 8,000 adult females in South Carolina. Currently, there
are estimated to be less than 300 spawning adults (total of both sexes)
in each of the major river systems occupied by the DPS, whose
freshwater range occurs in the watersheds from the Roanoke River
southward along the southern Virginia, North Carolina, and South
Carolina coastal areas to the Cooper River. We have reviewed the status
review report, as well as other available literature and information,
and have consulted with scientists and fishery resource managers
familiar with the Atlantic sturgeon in the Carolina DPS. After
reviewing the best scientific and commercial information available, we
find that the Atlantic sturgeon Carolina DPS is in danger of extinction
throughout its range as a result of a combination of habitat
curtailment and alteration, overutilization in commercial fisheries,
and inadequacy of regulatory mechanisms in ameliorating these impacts
and threats, and we propose to list it as endangered.
Finding for the South Atlantic DPS
The South Atlantic DPS is estimated to number less than 6 percent
of its historical population size (ASSRT, 2007), with all river
populations except the Altamaha estimated to be less than 1 percent of
historical abundance. Prior to 1890, Secor (2002) estimated there were
8,000 adult spawning females in South Carolina and 11,000 adult
spawning females in Georgia. Currently, there are an estimated 343
spawning adults in the Altamaha and less than 300 spawning adults
(total of both sexes) in each of the other major river systems occupied
by the DPS, whose freshwater range occurs in the watersheds of the ACE
Basin in South Carolina to the St. Johns River, Florida. We have
reviewed the status review report, as well as other available
literature and information, and have consulted with scientists and
fishery resource managers familiar with the Atlantic sturgeon in the
South Atlantic DPS. After reviewing the best scientific and commercial
information available, we find that the Atlantic sturgeon South
Atlantic DPS is in danger of extinction throughout its range as a
result of a combination of habitat curtailment and alteration,
overutilization in commercial fisheries, and inadequacy of regulatory
mechanisms in ameliorating these impacts and threats, and we propose to
list it as endangered.
Role of Peer Review
In December 2004, the Office of Management and Budget (OMB) issued
a Final Information Quality Bulletin for Peer Review establishing
minimum peer review standards, a transparent process for public
disclosure of peer review planning, and opportunities for public
participation. The OMB Bulletin, implemented under the Information
[[Page 61927]]
Quality Act (Pub. L. 106-554), is intended to enhance the quality and
credibility of the Federal government's scientific information, and
applies to influential or highly influential scientific information
disseminated on or after June 16, 2005. To satisfy our requirements
under the OMB Bulletin, the Atlantic sturgeon status review report was
peer reviewed by six experts in the field, with their substantive
comments incorporated in the final status review report.
On July 1, 1994, the NMFS and USFWS published a series of policies
regarding listings under the ESA, including a policy for peer review of
scientific data (59 FR 34270). The intent of the peer review policy is
to ensure that listings are based on the best scientific and commercial
data available. Prior to a final listing, NMFS will solicit the expert
opinions of three qualified specialists selected from the academic and
scientific community, Federal and State agencies, and the private
sector on listing recommendations to ensure the best biological and
commercial information is being used in the decisionmaking process, as
well as to ensure that reviews by recognized experts are incorporated
into the review process of rulemakings developed in accordance with the
requirements of the ESA.
Effects of Listing
Conservation measures provided for species listed as endangered or
threatened under the ESA include recovery actions (16 U.S.C. 1533(f)),
critical habitat designations, Federal agency consultation requirements
(16 U.S.C. 1536), and prohibitions on taking (16 U.S.C. 1538).
Recognition of the species' plight through listing promotes
conservation actions by Federal and state agencies, private groups, and
individuals. Should the proposed listings be made final, a recovery
program would be implemented, and critical habitat may be designated.
Federal, state, and the private sectors will need to cooperate to
conserve listed Atlantic sturgeon and the ecosystems upon which they
depend.
Critical habitat is defined in section 3 of the ESA (16 U.S.C.
1532(3)) as: (1) The specific areas within the geographical area
occupied by a species, at the time it is listed in accordance with the
ESA, on which are found those physical or biological features (a)
essential to the conservation of the species and (b) that may require
special management considerations or protection; and (2) specific areas
outside the geographical 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'' means the use of all
methods and procedures needed to bring the species to the point at
which listing under the ESA is no longer necessary. Section 4(a)(3)(a)
of the ESA (16 U.S.C. 1533(a)(3)(A)) requires that, to the extent
prudent and determinable, critical habitat be designated concurrently
with the listing of a species. If we determine that it is prudent and
determinable, we will publish a proposed designation of critical
habitat for Atlantic sturgeon in a separate rule. Public input on
features and areas that may meet the definition of critical habitat for
the Carolina and South Atlantic DPSs is invited.
Identifying the DPS(s) Potentially Affected by an Action During Section
7 Consultation
The Carolina and South Atlantic DPSs are distinguished based on
genetic data and spawning locations. However, extensive mixing of the
populations occurs in coastal waters. Therefore, the distributions of
the DPSs outside of natal waters generally overlap with one another,
and with fish from Northeast river populations. This presents a
challenge in conducting ESA section 7 consultations because fish from
any DPS could potentially be affected by a proposed project. Project
location alone will likely not inform the section 7 biologist as to
which populations to consider in the analysis of a project's potential
direct and indirect effects on Atlantic sturgeon and their habitat.
This will be especially problematic for projects where take could occur
because it is critical to know which Atlantic sturgeon population(s) to
include in the jeopardy analysis. One conservative, but potentially
cumbersome, method would be to analyze the total anticipated take from
a proposed project as if all Atlantic sturgeon came from a single DPS
and repeat the jeopardy analysis for each DPS the taken individuals
could have come from. However, recently funded research may shed some
light on the composition of mixed stocks of Atlantic sturgeon, relative
to their rivers of origin, in locations along the East Coast. The
specific purpose of the study is to evaluate the vulnerability to
coastal bycatch of Hudson River Atlantic sturgeon, thought to be the
largest stock contributing to coastal aggregations from the Bay of
Fundy to Georgia. However, the mixed stock analysis will also allow
NMFS to better estimate a project's effects on different components of
a mixed stock of Atlantic sturgeon in coastal waters or estuaries other
than where they were spawned. Results from the study are expected in
February 2011. Genetic mixed stock analysis, such as proposed in this
study, requires a high degree of resolution among stocks contributing
to mixed aggregations and characterization of most potential
contributory stocks. Fortunately, almost all extant populations, at
least those with reasonable population sizes, have been characterized
in previous genetic studies, though some additional populations will be
characterized in this study. Genetic testing of mixed stocks will be
conducted in eight coastal locales in both the Northeast and Southeast
Regions. Coastal fisheries and sites were selected based on sample
availabilities, bycatch concerns, and specific biological questions
(i.e., real uncertainty as to stock origins of the coastal
aggregation). We are specifically seeking public input on the mixing of
fish from different DPSs in parts of their ranges, particularly in the
marine environment.
Identification of Those Activities That Would Constitute a Violation of
Section 9 of the ESA
On July 1, 1994, we and USFWS published a policy to identify, to
the maximum extent possible, those activities that would or would not
constitute a violation of section 9 of the ESA (59 FR 34272; July 1,
1994). The intent of this policy is to increase public awareness of the
effect of this listing on proposed and ongoing activities within the
species' range. We will identify, to the extent known at the time of
the final rule, specific activities that will not be considered likely
to result in violation of section 9, as well as activities that will be
considered likely to result in violation. Activities that we believe
could result in violation of section 9 prohibitions against ``take'' of
the Atlantic sturgeon in the Carolina and South Atlantic DPSs include,
but are not limited to, the following: (1) Bycatch associated with
commercial and recreational fisheries; (2) poaching of individuals for
meat or caviar; (3) marine vessel strikes; (4) destruction of riverine,
estuarine, and marine habitat through such activities as agricultural
and urban development, commercial activities, diversion of water for
hydropower and public consumption, and dredge and fill operations; (5)
impingement and entrainment in water control structures; (6)
unauthorized collecting or handling of the species (permits to conduct
these activities are available for purposes of scientific research or
to enhance the propagation or survival of the DPSs); (7) releasing a
captive Atlantic sturgeon into the wild; and (8) harming captive
Atlantic
[[Page 61928]]
sturgeon by, among other things, injuring or killing them through
veterinary care, research, or breeding activities outside the bounds of
normal animal husbandry practices. We believe that, based on the best
available information, the following actions will not result in a
violation of section 9: (1) Possession of Atlantic sturgeon acquired
lawfully by permit issued by NMFS pursuant to section 10 of the ESA, or
by the terms of an incidental take statement in a biological opinion
pursuant to section 7 of the ESA; (2) Federally approved projects that
involve activities such as agriculture, managed fisheries, road
construction, discharge of fill material, stream channelization, or
diversion for which consultation under section 7 of the ESA has been
completed, and when such activity is conducted in accordance with any
terms and conditions given by NMFS in an incidental take statement in a
biological opinion pursuant to section 7 of the ESA; (3) continued
possession of live Atlantic sturgeon that were in captivity or in a
controlled environment (e.g., in aquaria) at the time of this listing,
so long as the prohibitions under an ESA section 9(a)(1) are not
violated. If listed, NMFS will provide contact information for
facilities to submit information on Atlantic sturgeon in their
possession, to establish their claim of possession; and (4) provision
of care for live Atlantic sturgeon that were in captivity at the time
of this listing.
Section 9(b)(1) of the ESA provides a narrow exemption for animals
held in captivity at the time of listing: Those animals are not subject
to the import/export prohibition or to protective regulations adopted
by the Secretary, so long as the holding of the species in captivity,
before and after listing, is not in the course of a commercial
activity; however, 180 days after listing, there is a rebuttable
presumption that the exemption does not apply. Thus, in order to apply
this exemption, the burden of proof for confirming the status of
animals held in captivity prior to listing lies with the holder. The
section 9(b)(1) exemption for captive wildlife would not apply to any
progeny of the captive animals that may be produced post-listing.
References
A complete list of the references used in this proposed rule is
available upon request (see ADDRESSES).
Classification
National Environmental Policy Act
The 1982 amendments to the ESA, in section 4(b)(1)(A), restrict the
information that may be considered when assessing species for listing.
Based on this limitation of criteria for a listing decision and the
opinion in Pacific Legal Foundation v. Andrus, 675 F. 2d 825 (6th Cir.
1981), NMFS has concluded that ESA listing actions are not subject to
the environmental assessment requirements of the National Environmental
Policy Act (NEPA). (See NOAA Administrative Order 216-6.)
Executive Order 12866, Regulatory Flexibility Act and Paperwork
Reduction Act
As noted in the Conference Report on the 1982 amendments to the
ESA, economic impacts cannot be considered when assessing the status of
a species. Therefore, the economic analysis requirements of the
Regulatory Flexibility Act are not applicable to the listing process.
In addition, this proposed rule is exempt from review under Executive
Order 12866. This proposed rule does not contain a collection-of-
information requirement for the purposes of the Paperwork Reduction
Act.
Federalism
E.O. 13132 requires agencies to take into account any federalism
impacts of regulations under development. It includes specific
consultation directives for situations where a regulation will preempt
state law, or impose substantial direct compliance costs on state and
local governments (unless required by statute). Pursuant to the
Executive Order on Federalism, E.O. 13132, the Assistant Secretary for
Legislative and Intergovernmental Affairs will provide notice of the
proposed action and request comments from the governors of the states
in which the two DPSs proposed to be listed occur.
Environmental Justice
Executive Order 12898 requires that Federal actions address
environmental justice in the decision-making process. In particular,
the environmental effects of the actions should not have a
disproportionate effect on minority and low-income communities. The
proposed listing determination is not expected to have a
disproportionately high effect on minority populations or low-income
populations.
Coastal Zone Management Act (16 U.S.C. 1451 et seq.)
Section 307(c)(1) of the Federal Coastal Zone Management Act of
1972 requires that all Federal activities that affect any land or water
use or natural resource of the coastal zone be consistent with approved
state coastal zone management programs to the maximum extent
practicable. We have determined that this action is consistent to the
maximum extent practicable with the enforceable policies of approved
Coastal Zone Management Programs of each of the states within the range
of the two DPSs. Letters documenting NMFS' determination, along with
the proposed rule, will be sent to the coastal zone management program
offices in each affected state. A list of the specific state contacts
and a copy of the letters are available upon request.
List of Subjects in 50 CFR Part 224
Administrative practice and procedure, Endangered and threatened
species, Exports, Imports, Reporting and recordkeeping requirements,
Transportation.
Dated: September 24, 2010.
Eric C. Schwaab,
Assistant Administrator for Fisheries, National Marine Fisheries
Service.
For the reasons set out in the preamble, 50 CFR part 224 is
proposed to be amended as follows:
PART 224--ENDANGERED MARINE AND ANADROMOUS SPECIES
1. The authority citation for part 224 continues to read as
follows:
Authority: 16 U.S.C. 1531-1543 and 16 U.S.C. 1361 et seq.
2. In Sec. 224.101(a), amend the table by adding entries for
Atlantic Sturgeon-Carolina DPS and Atlantic Sturgeon-South Atlantic DPS
at the end of the table to read as follows:
Sec. 224.101 Enumeration of endangered marine and anadromous species.
* * * * *
[[Page 61929]]
--------------------------------------------------------------------------------------------------------------------------------------------------------
Species \1\ Citation(s) for
------------------------------------------------------------ Where listed listing Citation(s) for critical
Common name Scientific name determination(s) habitat designation(s)
--------------------------------------------------------------------------------------------------------------------------------------------------------
* * * * * * *
Atlantic Sturgeon--Carolina DPS.... Acipenser oxyrinchus The Carolina DPS includes all [INSERT FR CITATION & NA.
oxyrinchus. Atlantic sturgeon that spawn in the DATE WHEN PUBLISHED
watersheds from the Roanoke River, AS A FINAL RULE].
Virginia, southward along the
southern Virginia, North Carolina,
and South Carolina coastal areas to
the Cooper River. The marine range
of Atlantic sturgeon from the
Carolina DPS extends from the Bay
of Fundy, Canada, to the Saint
Johns River, Florida. The Carolina
DPS also includes Atlantic sturgeon
held in captivity (e.g., aquaria,
hatcheries, and scientific
institutions) and which are
identified as fish belonging to the
Carolina DPS based on genetics
analyses, previously applied tags,
previously applied marks, or
documentation to verify that the
fish originated from (hatched in) a
river within the range of the
Carolina DPS, or is the progeny of
any fish that originated from a
river within the range of the
Carolina DPS.
Atlantic Sturgeon--South Atlantic Acipenser oxyrinchus The South Atlantic DPS includes all [INSERT FR CITATION & NA.
DPS. oxyrinchus. Atlantic sturgeon that spawn in the DATE WHEN PUBLISHED
watersheds of the ACE Basin in AS A FINAL RULE].
South Carolina to the St. Johns
River, Florida. The marine range of
Atlantic sturgeon from the South
Atlantic DPS extends from the Bay
of Fundy, Canada, to the Saint
Johns River, Florida. The South
Atlantic DPS also includes Atlantic
sturgeon held in captivity (e.g.,
aquaria, hatcheries, and scientific
institutions) and which are
identified as fish belonging to the
South Atlantic DPS based on
genetics analyses, previously
applied tags, previously applied
marks, or documentation to verify
that the fish originated from
(hatched in) a river within the
range of the South Atlantic DPS, or
is the progeny of any fish that
originated from a river within the
range of the South Atlantic DPS.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Species includes taxonomic species, subspecies, distinct population segments (DPSs) (for a policy statement, see 61 FR 4722, February 7, 1996), and
evolutionarily significant units (ESUs) (for a policy statement, see 56 FR 58612, November 20, 1991).
* * * * *
[FR Doc. 2010-24461 Filed 10-5-10; 8:45 am]
BILLING CODE 3510-22-P