[Federal Register Volume 63, Number 39 (Friday, February 27, 1998)]
[Rules and Regulations]
[Pages 9967-9974]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-5193]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
50 CFR Part 226
DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
Endangered and Threatened Wildlife and Plants; Decision on
Designation of Critical Habitat for the Gulf Sturgeon
AGENCIES: National Marine Fisheries Service, National Oceanic and
Atmospheric Administration, Commerce; and Fish and Wildlife Service,
Interior.
ACTION: Notice of decision on critical habitat designation.
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SUMMARY: The National Marine Fisheries Service (NMFS) and the Fish and
Wildlife Service (FWS), collectively the Services, announce a decision
on designation of critical habitat for the Gulf sturgeon (Acipenser
oxyrinchus desotoi), a federally listed threatened species pursuant to
the Endangered Species Act of 1973, as amended. Based on lack of
benefit to the species, the Services have determined that critical
habitat designation is not prudent. This constitutes the Services' not
prudent finding for the designation of critical habitat for the Gulf
sturgeon.
DATES: The finding announced in this notice was made on February 24,
1998.
ADDRESSES: Information, comments, or questions should be submitted to
the Field Supervisor, U.S. Fish and Wildlife Service, 6620 Southpoint
Drive South, Suite 310, Jacksonville, Florida 32216; or the Regional
Director, U.S. Department of Commerce, National Marine Fisheries
Service, 9721 Executive Center Drive N., St. Petersburg, Florida 33702.
The administrative record supporting this decision is available for
public inspection, by appointment, during normal business hours at the
above addresses.
FOR FURTHER INFORMATION CONTACT: Dr. Michael M. Bentzien, Assistant
Field Supervisor, FWS, see ADDRESSES section above or telephone 904/
232-2580, extension 106; or Ms. Colleen Coogan, NMFS, see ADDRESSES
section above or telephone 813/570-5312.
SUPPLEMENTARY INFORMATION:
Background
The Gulf sturgeon (Acipenser oxyrinchus (=oxyrhynchus) desotoi),
also known as the Gulf of Mexico sturgeon, is a nearly cylindrical fish
with an extended snout, ventral mouth, chin barbels, and with the upper
lobe of the tail longer than the lower. Adults range from 1.8 to 2.4
meters (m) (6 to 8 feet (ft)) in length, with adult females larger than
males. It is a subspecies of Atlantic sturgeon, Acipenser oxyrinchus
(=oxyrhynchus), and is distinguished from Acipenser oxyrinchus
oxyrinchus, the East Coast subspecies, by its longer head, pectoral
fins, and spleen. The Gulf sturgeon is restricted to the Gulf of Mexico
and its drainages, primarily from the Mississippi River to the Suwannee
River, within the States of Louisiana, Mississippi, Alabama, and
Florida. Sporadic occurrences are known as far west as Texas (Rio
Grande), and marine waters in Florida south to Florida Bay (Wooley and
Crateau 1985, Reynolds 1993). An anadromous species, the Gulf sturgeon
migrates between fresh and salt water.
The Services' involvement with the Gulf sturgeon began with
monitoring and other studies of the Apalachicola River population by
the FWS Panama City, Florida, Fisheries Assistance Office in 1979. The
fish was included as a category 2 species in the FWS December 30, 1982
(47 FR 58454) and September 18, 1985 (50 FR 37958) vertebrate review
notices and in the January 6, 1989 (54 FR 554) animal notice of review.
Category 2 designation was given at that time to species for which
listing as threatened or endangered was possibly appropriate, but for
which additional biological information was needed to support a
proposed rule. In 1980, the FWS Jacksonville, Florida, Office
contracted a status survey report on the Gulf sturgeon (Hollowell
1980). The report concluded that the fish had been reduced to a small
population due to overfishing and habitat loss. In 1988, the Panama
City Office completed a report (Barkuloo 1988) on the conservation
status of the Gulf sturgeon, recommending that the subspecies be listed
as a threatened species pursuant to the Act. The Services jointly
proposed the Gulf sturgeon for listing as a threatened species on May
2, 1990 (55 FR 18357). In that proposed rule, the Service maintained
that designation of
[[Page 9968]]
critical habitat was not determinable due to the sturgeon's broad range
and the lack of knowledge of specific areas utilized by the subspecies.
The final rule for the Gulf sturgeon was published on September 30,
1991 (56 FR 49653). It included special rules promulgated under Section
4(d) of the Act for a threatened species, allowing taking of Gulf
sturgeon in accordance with applicable State laws, for educational and
scientific purposes, the enhancement of propagation or survival of the
species, zoological exhibition, and other conservation purposes. The
final rule found that critical habitat designation ``may be prudent but
is not now determinable.'' Further comments on the critical habitat
issue were solicited from all interested parties following listing. A
final decision on designation of critical habitat was to have been made
by May 2, 1992.
On August 11, 1994, the Sierra Club Legal Defense Fund, Inc.
(Fund), on behalf of the Orleans Audubon Society and Florida Wildlife
Federation, gave written notice of their intent to file suit against
the Department of the Interior for failure to designate critical
habitat for the Gulf sturgeon within the statutory time limits
established under the Act. The Fund filed suit (Orleans Audubon Society
v. Babbitt, Civ. No. 94-3510 (E.D. La)) following a combined meeting
and teleconference with the Service on October 11, 1994.
On August 23, 1995, the Services published a notice of decision (60
FR 43721) on critical habitat designation for the Gulf sturgeon. The
Services determined that critical habitat designation was not prudent
based on the lack of additional conservation benefit to the species.
On November 23, 1995, the above mentioned plaintiffs again gave
notice of their intent to file suit against the Departments of the
Interior and Commerce for failing to designate critical habitat for the
Gulf sturgeon. On January 31, 1996, the Court denied both the Services'
motion to dismiss the suit and the plaintiffs' motion to find the
Services in contempt. On October 28, 1997, the Court rejected the
plaintiffs' request for a Court order requiring the Services to
designate critical habitat. The plaintiffs' motion for summary judgment
was granted, with relief restricted to a remand of the matter to the
agencies for further consideration based on the best scientific
information available.
Critical Habitat Definition and Requirements
Critical habitat is defined in section 3(5)(A) of the Act as ``(i)
the specific areas within the geographic area occupied by a species * *
* on which are found those physical or biological features (I)
essential to the conservation of the species, and (II) that may require
special management considerations or protection; and (ii) specific
areas outside the geographical area occupied by a species at the time
it is listed * * * upon determination by the Secretary that such areas
are essential for the conservation of the species.'' The term
``conservation,'' as defined in Section 3(3) of the Act, means ``* * *
to use and the use of all methods and procedures which are necessary to
bring any endangered or threatened species to the point at which the
measures provided pursuant to this Act are no longer necessary,'' i.e.,
the species is recovered and can be removed from the list of endangered
and threatened species. Section 4(a)(3) of the Act requires that
critical habitat be designated at the time any species is listed as an
endangered or threatened species, to the extent prudent and
determinable. If a final regulation listing a species finds that
critical habitat is not determinable, a critical habitat designation
must be made within one additional year (within two years of the date
on which the species was proposed for listing).
Section 4(b)(2) of the Act requires the Services to consider the
economic impact of designating any particular area as critical habitat.
The Services' regulations for listing endangered and threatened species
and designating critical habitat (50 CFR 424.19) require that, in
analyzing such impacts, the Services identify any significant
activities that would either affect an area considered for designation
as critical habitat or be likely to be affected by the designation, and
after proposing the designation for such an area, consider the probable
economic and other impacts of the designation upon proposed or ongoing
activities. An area may be excluded from critical habitat if it is
determined that the economic benefits of such exclusion outweigh the
conservation benefits of including the area in critical habitat.
Exclusions may not be made if the failure to designate them as critical
habitat would result in the extinction of the species concerned. This
standard approximates the jeopardy standard of the Act, but may be less
stringent because it requires a determination that the exclusion ``* *
* will result in the extinction * * *'' rather than more probabilistic
criterion ``* * * likely to jeopardize the continued existence * * *''
of section 7(a)(2).
If no exclusions are made to critical habitat, it should (presuming
adequate biological and distributional information is available)
include all areas necessary to recover the species. If areas are
excluded from critical habitat for economic reasons, final critical
habitat designation could range from an area just under that required
for recovery to an area barely sufficient to prevent the species'
extinction, and insufficient for its recovery. In summary, while the
Act defines ``conservation'' to mean recovery of the species, section
4(b)(2) does not require the Services to designate critical habitat
sufficient for the recovery of the species if economic benefits of
excluding certain areas outweigh the conservation benefit to the
species from their inclusion.
In accordance with the definition of critical habitat provided by
section 3(5)(A)(i) of the Act, the Services' regulations (50 CFR
424.12) require the Services to consider the principal biological or
physical features that are essential to the conservation of the
species. General requirements of species include, but are not limited
to:
(1) Space for individual and population growth, and for normal
behavior;
(2) Food, water, air, light, minerals, or other nutritional or
physiological requirements;
(3) Cover or shelter;
(4) Sites for breeding, reproduction, rearing of offspring,
germination, or seed dispersal; and generally
(5) Habitats that are protected from disturbance or are
representative of the historic geographical and ecological
distributions of a species.
The regulations further require the Services to focus on principal
biological or physical constituent elements within the defined area
that are essential to the conservation of the species. Primary
constituent elements may include, but are not limited to, roost sites,
nesting grounds, spawning sites, seasonal wetland or dryland, water
quality or quantity, host species or plant pollinators, geological
formation, vegetation type, tide, and specific soil types.
The regulations state that a designation of critical habitat is not
prudent if either of the two following situations exist:
(1) The species is threatened by taking or other human activity,
and identification of critical habitat can be expected to increase the
degree of such threat to the species, or
(2) Such designation of critical habitat would not be beneficial to
the species.
Potential benefits of critical habitat designation derive from
section 7(a)(2) of the Act, which requires Federal
[[Page 9969]]
agencies, in consultation with the Service, to ensure that their
actions are not likely to jeopardize the continued existence of listed
species or to result in the destruction or adverse modification of
critical habitat of such species. Implementing regulations (50 CFR
402.14) require each Federal agency to review its actions at the
earliest possible time to determine whether any action may affect
listed species or critical habitat. If a determination is made that a
Federal action may adversely affect a listed species a formal
consultation is required. All consultations result in a finding of
whether or not the proposed action is likely to jeopardize the
continued existence of the species, and, if critical habitat is
designated, whether the action is likely to destroy or adversely modify
critical habitat.
Critical habitat, by definition, applies only to Federal agency
actions. 50 CFR 402.02 defines ``jeopardize the continued existence
of'' as meaning to engage in an action that would reasonably be
expected, directly or indirectly, to reduce appreciably the likelihood
of both the survival and recovery of a listed species in the wild by
reducing the reproduction, numbers, or distribution of that species.
``Destruction or adverse modification'' is defined as a direct or
indirect alteration that appreciably diminishes the value of critical
habitat for both the survival and recovery of a listed species. Such
alterations include, but are not limited to, alterations adversely
modifying any of those physical or biological features that were the
basis for determining the habitat to be critical. Thus, in the section
7(a)(2) consultation process, the jeopardy analysis focuses on
potential effects on the species' populations, whereas the destruction
or adverse modification analysis focuses on habitat value, specifically
on those constituent elements identified in the critical habitat
listings in 50 CFR 17.95, 17.96 (FWS), or 226 (NMFS). However, either a
jeopardy or a destruction or adverse modification biological opinion
requires the Services to find an appreciable effect on both the
species' survival and recovery.
Federal actions satisfying the standard for adverse modification
are nearly always found to also jeopardize the species concerned, and
the existence of critical habitat designation does not materially
affect the outcome of consultation. Biological opinions which conclude
that a Federal agency action is likely to adversely modify critical
habitat but is not likely to jeopardize the species for which it is
designated are extremely rare historically; none have been issued in
recent years. Such situations might involve a Federal action in
critical habitat outside of current range of the species, where the
action would not reduce the current reproduction, distribution, or
numbers of the species, but would appreciably reduce the value of
critical habitat for both survival and recovery. For some highly
endangered species whose survival and recovery in its current range was
unlikely, and which depended on the expansion of its range and numbers
into currently unoccupied habitat, the designation of unoccupied
critical habitat may in certain rare instances provide additional
protection to that afforded by the jeopardy standard. Since threatened
species such as the Gulf sturgeon are, by definition, not currently at
risk of extinction, but are rather anticipated to become so in the
foreseeable future, unoccupied critical habitat would not be
immediately required for their survival.
It should be noted also that regardless of critical habitat
designation, Federal agencies are required by section 7(a)(1) of the
Act to utilize their authorities in furtherance of the Act's purposes
by carrying out conservation (i.e., recovery) activities for listed
species. For no jeopardy (or no destruction or adverse modification)
biological opinions, the Services may provide discretionary
conservation recommendations to the consulting Federal agency to assist
them in this responsibility. Recovery plans also provide guidance on
specific tasks that Federal and other agencies can carry out to assist
in the recovery of listed species.
Ecology of the Gulf Sturgeon
The Gulf sturgeon is an anadromous species inhabiting the Gulf of
Mexico and Gulf Coast rivers from Louisiana to Florida. Adults and
subadults spend eight to nine months each year in rivers where they
spawn and three to four of the coolest months in estuaries or Gulf
waters.
Migration
In Florida, both adults and subadults begin moving from the Gulf of
Mexico into the Suwannee and Apalachicola rivers in early spring until
early May (Carr 1983, Wooley and Crateau 1985, Odenkirk 1989, Clugston
et al. 1995). River water temperatures at that time range from 16.0
deg.C to 23.0 deg.C (60.8 deg.F to 75.0 deg.F). Large females
apparently prefer migrating upstream in shallow water areas, whereas
deep water areas are preferred during downstream or post spawning
migrations. This preference does not apply to males (Huff 1975).
Downstream migration in the Apalachicola River begins in late September
when water temperatures reach about 23.0 deg.C (75.0 deg.F), and
extends into November (Wooley and Crateau 1985). During the fall
migration from fresh to salt water, Gulf sturgeon in the Apalachicola
River enter the Brothers River, a tributary located about 19.2
kilometers (km) (12.0 miles (mi)) above the Gulf of Mexico. It is
believed that the Brothers River is used as a staging area for Gulf
sturgeon to osmoregulate (adjust to changed salinity) prior to entering
the Gulf of Mexico. The sturgeon occupy a microhabitat 8.0 to 18.0 m
(26.2 to 59.0 ft) in depth with a sand and clay substrate covered with
Asiatic clams (Corbicula fluminea) and detritus (Wooley and Crateau
1985). The fish remain in the Brothers River for an average of twelve
days (Wooley and Crateau 1985, Odenkirk 1989). Very little is known
about the estuarine and neritic (shallow coastal waters) habitat use of
migrating Gulf sturgeon. Parauka (U.S. Fish and Wildlife Service 1997)
found that subadult Gulf sturgeon immigrating from the Choctawhatchee
River into the estuarine waters of Choctawhatchee Bay moved generally
along the shoreline. Water depths ranged from 2.0 to 7.0 m (6.5 to 23.0
ft) with a sand and mud substrate.
Freshwater Habitat
Foster and Clugston (1997) found that telemetered Gulf sturgeon in
the Suwannee River were frequently located close to springs throughout
the warmest period, but none were located within a spring or the
thermal plume emanating from a spring. The substrate of much of the
Suwannee River is sand and limerock, especially in those areas near
springs and spring runs. Wooley and Crateau (1985) reported that Gulf
sturgeon in the Apalachicola River utilized the area immediately
downstream from Jim Woodruff Lock and Dam (JWLD) from May through
September. The area occupied consisted of the tailrace and spillway
basin of JWLD and a large scour hole below the lock. The area consisted
of sand and gravel substrate with water depths ranging from 6.0 to 12.0
m (19.7 to 39.4 ft). Telemetry studies conducted on Gulf sturgeon in
the Choctawhatchee River found that they did not distribute themselves
uniformly throughout the river and did not occupy the deepest and
coolest water available (Potak et al. 1995). Fish remained within two
primary summer holding areas staying outside the main channel where
water velocities were less than the maximum available. Most fish were
in water depths of 1.5 to 3.0 m (4.9 to 9.9 ft) and substrates were
silt or clay. Morrow et
[[Page 9970]]
al. (in press) reported that the lower part of the West Middle River
(lower Pearl River system) was an important summer habitat for juvenile
and sub-adult Gulf sturgeon. The habitat is characterized with water
depths ranging from 9.0 to 19.0 m (29.5 to 62.3 ft) with sluggish flows
and a hard substrate of sand and gravel.
Estuarine Habitat
Mason and Clugston (1993) noted that the estuarine seagrass beds
with mud and sand substrates appear to be important winter habitats for
Gulf sturgeon where most of the feeding is thought to occur. Clugston
et al. (1995) reported that the young Gulf sturgeon in the Suwannee
River, weighing between 0.3 and 2.5 kilograms (kg) (0.7 to 5.5 pounds
(lb)), remained in the vicinity of the river mouth and estuary during
the winter and spring. Fox and Hightower (1997) captured adult Gulf
sturgeon in the early spring in Choctawhatchee Bay prior to their
migration into the Choctawhatchee River. Fish were collected in
stationary gill nets set 455.0 m (1,500 ft) from shore at depths of 2.0
to 4.0 m (6.5 to 13.0 ft). The bay at that site is about 5.5 km (3.4
mi) wide and with depths up to 6.7 m (22.0 ft). Parauka (U.S. Fish and
Wildlife Service 1997) collected 6 subadult Gulf sturgeon in the
Choctawhatchee River, equipped them with acoustic tags, and monitored
their movement in the estuary during the winter. Five of six fish
remained in the estuary the entire winter occupying nearshore habitats,
1.2 to 4.6 m (4 to 15 ft) in depth with a sand and mud substrate.
Food Habits
Mason and Clugston (1993) reported that in the spring, immigrating
subadult and adult Gulf sturgeon collected from the mouth of the
Suwannee River contained gammarid, haustoriid, and other maphipods,
polychaete and oligochaete annelids, lancelets, and brachiopods.
However, once in fresh water, these Gulf sturgeon did not eat as
evidenced by the presence of only a greenish-tinged mucus in their guts
from June through October. The stomach contents of a 79.5 kg (175 lb)
Gulf sturgeon collected in Choctawhatchee Bay during the winter
contained adult ghost and commensal shrimp (R. Head, Gulf Coast
Research Laboratory, personal communication 1997). Clugston et al.
(1995) concluded that Gulf sturgeon appear to gain weight only during
the winter and spring while in marine or estuarine waters and lose
weight during the eight to nine month period while in fresh water. Carr
(1983) reported that marked Gulf sturgeon from the Suwannee River
gained up to 30 percent of body weight in one year but showed little or
no growth when recaptured during the same season. Wooley and Crateau
(1985) noted that Gulf sturgeon 80.0 to 114.0 centimeters (cm) (31.5 to
44.9 inches (in)) long that were captured and recaptured in the
Apalachicola River during the summer period exhibited weight losses of
4 to 15 percent or 0.5 to 2.3 kg (1.1 to 5.1 lb).
River-Specific Fidelity
The results of tagging studies suggest that Gulf sturgeon exhibit a
high degree of river fidelity. From 1981 to 1993, 4,100 fish were
tagged in the Apalachicola and Suwannee rivers, with 860 fish
recaptured in the river of initial collection and only 8 sub-adults
exhibiting inter-river movement (Wooley and Crateau 1985, U.S. Fish and
Wildlife Service and Gulf States Marine Fisheries Commission 1995, Carr
et al. 1996, Foster and Clugston 1997). Foster and Clugston (1997)
noted that telemetered Gulf sturgeon in the Suwannee River returned to
the same areas as the previous summer suggesting that chemical cuing
may influence distribution. Wooley and Crateau (1985) indicate that the
results of tagging Gulf sturgeon in the Apalachicola River would
suggest the fish are genetically or behaviorally imprinted to the
chemosensory environment of their home rivers. Stabile et al. (1996)
analyzed Gulf sturgeon populations from eight drainages along the Gulf
of Mexico for genetic diversity. He noted significant differences among
Gulf sturgeon stocks and suggested that they displayed region-specific
affinities and may exhibit river-specific fidelity. Stabile et al.
(1996) identified five regional or river-specific stocks (from west to
east)--(1) Lake Ponchartrain and Pearl River, (2) Pascagoula River, (3)
Escambia and Yellow rivers, (4) Choctawhatchee River, and (5)
Apalachicola, Ochlockonee, and Suwannee rivers.
Reproduction
Gulf sturgeon are long-lived, reaching at least 42 years in age
(Huff 1975). Age at sexual maturity for females ranges from 8 to 17
years, and for males from 7 to 21 years (Huff 1975). Fertilized Gulf
sturgeon eggs were collected at 2 upriver locations on the Suwannee
River (Marchent and Shutters 1996) and 6 upriver sites on the Pea and
Choctawhatchee rivers (Fox 1997). Habitat at the egg collection sites
consisted of limestone bluffs and outcroppings, cobble, limestone
gravel and sand with water depths ranging from 1.4 to 7.9 m (4.5 to
26.0 ft). Water temperatures ranged from 18.3 deg.C to 22.0 deg.C
(65.0 deg.F to 71.6 deg.F). Chapman et al. (1993) reported that three
mature Gulf sturgeon had 458,080; 274,680; and 475,000 eggs and were
estimated to have an average fecundity of 20,652 eggs/kg (9,366 eggs/
lb).
Population
Population estimates for Gulf sturgeon in the Apalachicola River
have been conducted from 1984 to 1993. During that period, estimates of
fish exceeding 45.0 cm (17.7 in) in length ranged from 96 to 131 fish
with a mean of 115 (F. Parauka, FWS, personal communication; U.S. Fish
and Wildlife Service and Gulf States Marine Fisheries Commission 1995).
In the Suwannee River, a mark/recapture study implemented from 1986 to
1994 estimated a population of 1,504 to 3,066 for Gulf sturgeon
weighing between 3.0 and 81.0 kg (6.6 to 178.2 lb) (Carr et al. 1996).
Morrow et al. (in press) estimated that the summer population of Gulf
sturgeon in the West Middle Pearl River, 459 to 1143 mm (18 to 46 in)
in length, ranged from 67 to 124 fish.
Habitat Needs
The Gulf sturgeon requires nearshore (bays and estuaries) and
offshore (Gulf of Mexico) feeding areas, and freshwater rivers for
spawning and resting habitat. Specific habitat needs of the Gulf
sturgeon, in the context of the constituent elements discussed above,
include:
1. Migration corridors which support subspecies' distribution
throughout its primary range. Primary range for the Gulf sturgeon in
freshwater extends from the Mississippi River to the Suwannee River in
Florida (Wooley and Crateau 1985). A migration corridor is a Gulf Coast
river drainage within the primary range through which sturgeon pass
between marine and estuarine environments to freshwater spawning and
resting sites. Records of Gulf sturgeon through sightings, incidental
captures, and tagging studies have been made over the last ten years
from most major drainages and a number of smaller river systems
(Reynolds 1993, U.S. Fish and Wildlife Service and Gulf States Marine
Fisheries Commission 1995). Tagging studies in the Apalachicola and
Suwannee rivers demonstrated the high probability of recapturing fish
in the same river where they were first tagged (Wooley and Crateau
1985, Foster and Clugston 1997). A small number of sub-adult fish
exhibited inter-river movement; however, the data obtained from capture
and recapture studies suggest that Gulf sturgeon have a high degree of
river
[[Page 9971]]
fidelity. Stabile et al. (1996) noted significant genetic differences
among Gulf sturgeon stocks and suggested that they displayed region-
specific affinities and may exhibit river-specific fidelity which
further defines an essential migratory corridor. The significance of
this study to critical habitat is discussed in the section on proposed
designation.
2. Silt-free, consolidated bottom substrate composed of rock,
gravel or hard sand. This material can be the predominant benthic
substrate in some drainages, while in others it can be more patchily
distributed (U.S. Fish and Wildlife Service and Gulf States Marine
Fisheries Commission 1995). This feature is often associated with
springs, geologic outcroppings, and deep holes. Adult, sub-adult, and
juvenile Gulf sturgeon frequent such sites and these areas are thought
to be important for spawning and resting (Wooley and Crateau 1985,
Odenkirk 1989, Carr et al. 1996, Marchent and Shutters 1996, Foster and
Clugston 1997). Telemetry and tagging studies further suggest that
individuals return to the same areas of the river inhabited the
previous summer (Foster 1993, Carr et al. 1996, Foster and Clugston
1997, U.S. Fish and Wildlife Service 1989, 1990, 1991, 1992, 1993).
3. Adequate water quantity and quality for normal behavior in both
fresh and brackish environments. Normal behavior includes, but is not
limited to, migration of adult, subadult, and juvenile sturgeon; local
movement and feeding by larval and juvenile stages; and reproduction.
Natural surface and groundwater discharges influence a river's
characteristic fluctuations in volume, depth, and velocity (Torak et
al. 1993, Leitman et al. 1993). Migrating sturgeon and planktonic
larvae are adapted to conditions in their natal rivers which affect
distance traveled and survival. These demographics may be influenced by
changes in the water quantity parameters (U.S. Fish and Wildlife
Service and Gulf States Marine Fisheries Commission 1995).
Temperature, sediment load, and chemical constituents are important
water quality features. Seasonal changes in water temperature trigger
sturgeon migration into and out of rivers (Wooley and Crateau 1985).
Cooler waters associated with deep holes, springs and spring runs
appear to be important for spawning (Marchant and Shutters 1996, Smith
and Clugston 1997) and also as refugia from ambient water temperatures
during summer and fall (Carr et al. 1996). Sturgeon access to these
springs, spring runs, and deep holes may depend upon the maintenance of
stream bed elevation through the natural removal and deposition of
sediment (U.S. Army Corps of Engineers 1986). Changes in flow dynamics
resulting from surface and groundwater withdrawals for drinking and
irrigation (Torak et al. 1993, Leitman et al. 1993), and excessive
sedimentation resulting from riverbed elevation changes due to dams and
other navigation activities (U.S. Army Corps of Engineers 1986) have
impacted these sites.
Undesirable chemicals contaminating river water may enter sturgeon
through contact with water, sediment, or food sources. Bateman and Brim
(1994, 1995) found heavy metals, other inorganics, organochlorine
compounds, and polycyclic aromatic hydrocarbons in juvenile and adult
Gulf sturgeon from Florida. A variety of toxic effects to fish from
these contaminants have been demonstrated (Mayer and Mehrle 1977,
Armstrong 1979, Johnson and Finley 1980, White et al. 1983, Fox 1992).
Historical and Current Threats to the Species
Identified threats for the Gulf sturgeon include historic
overexploitation, incidental take, habitat loss and degradation,
contaminants, and potential hybridization with a non-native species,
the white sturgeon (Acipenser transmontanus), used in aquaculture.
The Gulf sturgeon historically was considered important because its
eggs and smoked flesh were valued foods, its oil was used in paints,
and the swim bladder yielded isinglass, a gelatin used in food products
and glues (Smith and Clugston 1994). The resulting demand produced an
intense and directed fishing industry. Available landing records
indicate that the principal commercial, recreational, and subsistence
fisheries were in west Florida, especially in the Apalachicola and
Suwannee rivers (Burgess 1963, Huff 1975, Swift et al. 1977, Futch
1984, Barkuloo 1988). Directed commercial harvest of Gulf sturgeon in
other Gulf states was minor or incidental. Most commercial fishing
occurred from the late 19th century until the 1970's, with peak catches
in Florida recorded around 1900. Harvest thereafter declined swiftly
and averaged around three percent of peak until the fishery collapsed
by the late 1970's. From 1972 to 1990, State regulatory agencies in
Alabama, Mississippi, Florida, and Louisiana enacted laws prohibiting
any take of Gulf sturgeon within their jurisdictional waters.
The historic decline of Gulf sturgeon populations (Barkuloo 1988)
begun by over-exploitation was later exacerbated by habitat
destruction, degradation, and inaccessibility. Water control
structures, high- and low-head dams, and sills within a number of river
drainages throughout its range prevent or severely restrict sturgeon
access to historic migration routes and spawning areas (Boschung 1976,
Murawski and Pacheco 1977, Wooley and Crateau 1985, McDowell 1988).
Dredging, spoil disposal, and other navigation maintenance may have
adversely affected Gulf sturgeon habitats through lowering of river
elevations, elimination of deep holes, and altering of rock substrates
(Carr 1983, Wooley and Crateau 1985). Cool waters emanating from
springs are believed to be important thermal refugia for sturgeon and
other anadromous fish during warm weather (see below).
S. Carr (pers. comm.) believed that cool water habitats which
appear to serve as thermal refugia during summer months may be impacted
by reduction in groundwater flows. Leitman et al. (1993) indicated that
the major spring-fed flow component of Georgia's Flint River, a major
flow contributor to the Apalachicola River during low-flow periods, has
been reduced since the early 1970's from groundwater and surface water
irrigation withdrawals. More specifically, increased groundwater
withdrawal for irrigation in southwest Georgia may result in a 30
percent reduction of discharge to streams (Hayes et al. 1983). These
actions, in conjunction with drought, may have caused the observed
reduction and cessation of water flow from several springs and spring
runs in the upper Apalachicola River. Reduction of cool water flows or
their complete loss during critical summer periods could subject
sturgeon to increased environmental stress.
Agricultural and industrial contaminants also may be affecting fish
populations. DDT and its DDD/DDE metabolites were detected in Gulf
sturgeon samples collected from Florida Gulf river drainages between
1985 to 1991 (Bateman and Brim 1994). A second organochlorine
insecticide, toxaphene, was detected in fish from the Apalachicola
River during the same study. General organochlorine effects on fish
include reproductive failure, reduced survival of young, and
physiological alterations affecting their ability to withstand stress
(White et al. 1983). DDT compounds are also known to be endocrine
disrupters (Fox 1992). Toxaphene has been shown to impair reproduction,
reduce growth in adults and juveniles, and alter collagen formation in
fry, resulting in ``broken back syndrome'' (Mayer and Mehrle
[[Page 9972]]
1977). Bateman and Brim (1994, 1995) also detected heavy metals
including arsenic, cadmium, lead, mercury, and polycyclic aromatic
hydrocarbons, the latter at levels which could adversely affect
development and survival of eggs and larval and juvenile fish.
Accidental or intentional introductions of cultured stocks and non-
endemic species, such as the white sturgeon (Acipenser transmontanus),
could also potentially harm wild Gulf sturgeon stocks. In addition to
these anthropogenic impacts, the life history of Gulf sturgeon
complicates recovery efforts. Breeding populations take years to
establish due to their advanced age at sexual maturity. The subspecies
appears to be a home stream spawner, with little if any natural
repopulation by migrants from other rivers.
Application of Critical Habitat Designation to Threats
Take of Gulf sturgeon is prohibited throughout its range by section
9 of the Act and by State laws. Critical habitat designation would
provide no benefit to the application of these prohibitions.
Habitat loss and degradation and contaminant threats are directly
related to physical and biological features essential to the
conservation of the Gulf sturgeon. Additional protection from critical
habitat designation would apply in the case of Federal actions that
were likely to destroy or adversely modify critical habitat yet not
jeopardize the continued existence of the species. The Services believe
this scenario is highly unlikely. The U.S. Army Corps of Engineers'
navigation maintenance activities, dam and water control construction
and operations, and permitting program have the potential to affect all
of the constituent elements discussed above--(1) migration corridors
could be affected by dams and possibly reduced water flow, (2) bottom
substrate could be affected by dredging or deposition of dredged
materials, and (3) water quality could be affected by increased
turbidity or changed temperature, and water quantity could be reduced.
In order to trigger an adverse modification biological opinion without
jeopardy, such effects would have to appreciably reduce the value of
designated critical habitat for both the survival and recovery of the
Gulf sturgeon without reducing its reproduction, distribution, or
numbers. Most of the Corps' activities will take place in occupied
habitat and a significant reduction in habitat value within occupied
habitat of the Gulf sturgeon will inevitably reduce its reproduction,
distribution, or numbers, thus providing the protection of the jeopardy
prohibition. Unoccupied upstream habitat will still be subject to
consultation, regardless of critical habitat designation, if a proposed
project would affect downstream occupied habitat (e.g., changed water
flows). An example would be the Flint and Chattahoochee rivers in
Georgia, where the disappearance of Gulf sturgeon occurred following
the construction of Jim Woodruff Dam and its locks in Florida in 1956.
On July 25, 1996, the FWS provided the Corps with a biological
opinion on the proposed West Pearl River Navigation Project in
Louisiana and Mississippi. The project involved dredging three river
segments. The Gulf sturgeon was one of the federally listed species
considered in the opinion. Regardless of the lack of designated
critical habitat, the FWS considered features of the Gulf sturgeon's
habitat (resuspension of sediments, spread of contaminants, turbidity
increases from increased navigation, geomorphic changes) in reaching
the decision that the project was not likely to jeopardize the
continued existence of the Gulf sturgeon. The no jeopardy finding was
based on two factors--(1) existing stable populations of the Gulf
sturgeon are found in off-project portions of the Lower Pearl River
Basin; and (2) The proposed project activities were localized and
temporary in nature.
This biological opinion demonstrates that habitat features are an
essential part of the analysis for any biological opinion under the
jeopardy standard; that is, any analysis of the effects on
reproduction, distribution, or numbers of the Gulf sturgeon would have
to consider the effects of changes to the fish's habitat. Critical
habitat designation would not have added additional protection--it
would not have been possible to arrive at a destruction of adverse
modification biological opinion because habitat value for both survival
and recovery of the species was not appreciably reduced.
Permitting under the Environmental Protection Agency's (EPA)
National Pollution Discharge Elimination System (NPDES), water quality
standards, and pesticide registration have the potential to affect
water quality for the Gulf sturgeon. Since the Gulf sturgeon inhabits
larger channel areas, the effects of any point discharge into its
habitat would likely be minimized by dilution, and the States of
Louisiana, Mississippi, Alabama, and Florida set water quality
standards that are believed to be protective of aquatic life. The
Service believes that if current Federal water quality standards under
the CWA are maintained, there will be no need to modify the State's
water quality standards to protect habitat for the Gulf sturgeon.
Pesticide registration would have to be evaluated on a case-by-case
basis. The Services believe that, for these activities to reach the
survival and recovery criteria, reproduction, distribution, or numbers
of the Gulf sturgeon would be affected and that potential threats can
be effectively addressed under the jeopardy standard.
Relation of Critical Habitat Designation to Recovery/Management
Plan
Section 4(f)(1) of the Act requires the Services to develop and
implement recovery plans for endangered and threatened species, unless
such a plan would not promote the conservation of the species.
The Services classify recovery tasks according to three priorities:
(1) Priority 1 tasks are actions that must be taken to prevent
extinction or to prevent the species from declining irreversibly in the
foreseeable future.
(2) Priority 2 tasks are actions that must be taken to prevent a
significant decline in species population, habitat quality, or some
other significant negative impact short of extinction.
(3) Priority 3 tasks are all other actions necessary to meet the
recovery objectives.
The section 7 consultation process is closely linked with recovery
through both section 7(a)(1) and 7(a)(2). Because priority 1 and 2
tasks are closely related to a species' survival and recovery, they
provide guidance on Federal activities that could result in jeopardy or
destruction or adverse modification biological opinions. Priority 3
tasks provide guidance on activities that could further the
conservation of the species, and which would be included by the
Services as conservation recommendations, pursuant to 50 CFR 402.14(j)
in biological opinions.
The Recovery/Management Plan (Plan) for the Gulf sturgeon (U.S.
Fish and Wildlife Service and Gulf States Marine Fisheries Commission,
1995) was written by a recovery/management team including
representatives from the affected States, the Services, the U.S. Army
Corps of Engineers, the Caribbean Conservation Corporation, the
University of Florida, and a commercial fisherman. The Plan was
approved by the Services and the Gulf States Marine Fisheries
Commission in September 1995. The basic objectives of the Plan are:
(1) In the short term, prevent further reductions of wild Gulf
sturgeon populations throughout the range.
(2) For recovery, establish population levels that would allow
delisting of the
[[Page 9973]]
Gulf sturgeon by management units based on river drainages.
(3) Establish, following delisting, a self-sustaining population
that could support fishing pressure within management units.
When a recovery plan has been prepared for a species it
incorporates the management actions necessary for the conservation of
the species. If the recovery tasks involve Federal actions, they are
subject to consultation under section 7 of the Act, either between the
implementing agency and the Services or, if carried out by FWS or NMFS,
within the agency.
Critical habitat designation is not included as a task in the Plan.
However, since potential benefits of critical habitat designation are
linked to recovery tasks through the section 7 consultation process,
the Services have analyzed priority 1 and 2 recovery actions (those
which are required for the survival of the Gulf sturgeon) for potential
added protection if critical habitat were designated. The analysis is
based on the assumption that loss of habitat value to the point of
affecting survival in occupied habitat will, by definition, reduce
reproduction, distribution, or numbers of the Gulf sturgeon. Critical
habitat designation, therefore, will not add protection in occupied
habitat because the definition of destruction or adverse modification
and that of jeopardy both require an effect on survival (and recovery)
of the species. The high priority tasks are summarized as follows:
----------------------------------------------------------------------------------------------------------------
Habitat value affected, not
Priority Task reproduction, numbers, or Net benefit from
distribution critical habitat?
----------------------------------------------------------------------------------------------------------------
1....................... 1.3.1 Develop and No No.
implement monitoring
techniques.
1....................... 2.5.3 Regulate accidental No No.
and intentional
introductions.
1....................... 2.1.2 Reduce or eliminate No No.
incidental mortality.
1....................... 2.4.5 Restore natural No No.
river habitats.
1....................... 2.3.1 Protect habitat with Potentially No.
existing laws or
additional laws or
incentives.
2....................... 2.1.1 Effectively enforce No No.
take prohibitions.
2....................... 1.1.1 Locate important No No.
habitats.
2....................... 1.1.2 Characterize No No.
essential habitat areas.
2....................... 1.2 Conduct life history No No.
studies.
2....................... 2.2.1 Identify No No.
contaminants.
2....................... 2.2.2 Eliminate Potentially No.
contaminants.
2....................... 2.4.6 Coordinate No No.
consistent water projects.
2....................... 2.4.1 Identify dam/lock Yes No.
sites for restoration.
2....................... 2.4.4 Minimize effects of Potentially No.
navigation projects.
2....................... 4.3 Implement projects to No No.
achieve recovery plan
objectives.
2....................... 4.2 Seek funding for No No.
recovery activities.
2....................... 2.2.4 Eliminate impacts to Potentially No.
water quality and quantity.
2....................... 2.2.5 Assess effects of No No.
groundwater pumping on
riverine habitat.
----------------------------------------------------------------------------------------------------------------
Tasks 1.3.1, 2.5.3, 2.1.2, and 2.1.1 are not habitat related and
would not benefit from critical habitat designation. Tasks 1.1.1,
1.1.2, 1.2, 2.2.1, 2.4.6, 2.4.1, 4.3, 4.2, and 2.2.5 are informational
or procedural and are, therefore, also independent of potential
critical habitat benefits.
Tasks 2.4.5 and 2.3.1 address both occupied and unoccupied habitat;
however, there is no priority 1 or 2 task in the plan requiring
additional authority for protecting unoccupied habitat. Protection of
unoccupied habitat is, therefore, essential for full recovery, but not
for survival of the Gulf sturgeon.
Under tasks 2.2.2, 2.2.4 and 2.4.4 navigation and water quality and
quantity projects in unoccupied habitat will not affect survival of the
Gulf sturgeon unless they indirectly affect its reproduction,
distribution, or numbers in occupied areas. The criterion requiring
harm to both ``survival and recovery'' is not met by projects affecting
only unoccupied habitat.
Most of the Plan tasks involve activities that affect the
reproduction, numbers, and distribution of the Gulf sturgeon, and,
therefore, for which critical habitat designation would afford no
additional protection. Tasks that would potentially receive additional
protection from the section 7 prohibition on destruction or adverse
modification of critical habitat are those that involve unoccupied
habitat, where habitat might be reduced in value without affecting
reproduction, numbers, or distribution of the Gulf sturgeon. However,
habitat related tasks in the Plan involving unoccupied habitat do not
meet the ``survival and recovery'' criterion in the definition of
destruction or adverse modification. In summary, no high priority
recovery plan actions (those which are designed to ensure survival of
the Gulf sturgeon) have been identified that would benefit from
critical habitat designation. Known or anticipated Federal agency
actions that would appreciably diminish the value of critical habitat
of the Gulf sturgeon (thereby invoking the destruction or adverse
modification standard) would also reduce appreciably the likelihood of
both the survival and recovery of the species by reducing its
reproduction, numbers, or distribution (thus triggering the jeopardy
standard). Both definitions require impairment of survival and recovery
and are functionally equivalent.
Based on the above discussion, the Services have determined that
the lack of additional conservation benefit from critical habitat
designation for this species makes such designation not prudent.
References Cited
A complete list of all references cited herein is available upon
request from the Jacksonville Field Office (see ADDRESSES section).
Authors: The primary authors of this document are Dr. Michael M.
Bentzien and Mr. Francis M. Parauka, FWS; and Ms. Colleen Coogan, NMFS
(see ADDRESSES section).
Authority: The authority for this action is the Endangered
Species Act, as amended (16 U.S.C. 1531 et seq).
[[Page 9974]]
Dated: February 20, 1998.
Jamie Rappaport Clark,
Director, Fish and Wildlife Service.
Dated: February 24, 1998.
David L. Evans,
Deputy Assistant Administrator for Fisheries, National Marine Fisheries
Service.
[FR Doc. 98-5193 Filed 2-26-98; 8:45 am]
BILLING CODE 4310-55-P
