[Federal Register Volume 63, Number 59 (Friday, March 27, 1998)]
[Proposed Rules]
[Pages 14885-14892]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-7997]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
RIN 1018-AE86
Endangered and Threatened Wildlife and Plants; Proposed Rule To
List the Devils River Minnow (Dionda diaboli) as Endangered
AGENCY: Fish and Wildlife Service, Interior.
[[Page 14886]]
ACTION: Proposed rule.
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SUMMARY: The U.S. Fish and Wildlife Service (Service) proposes to list
the Devils River minnow (Dionda diaboli) as an endangered species under
authority of the Endangered Species Act of 1973, as amended (Act). The
current range of the Devils River minnow is limited to three stream
systems in Val Verde and Kinney counties, Texas, and one drainage in
Coahuila, Mexico. The species' range has been significantly contracted
and fragmented. In addition, the numbers of Devils River minnows
collected during fish surveys has declined dramatically over the past
25 years; the species has declined from one of the most abundant fish
to one of the least abundant. Based on the current information, the
decline of the species in both distribution and abundance may be
attributed in large part to the effects of habitat loss and
modification and possibly predation by smallmouth bass (Micropterus
dolomieu), an introduced game fish. This proposal, if made final, will
implement Federal protection provided by the Act for the Devils River
minnow.
DATES: Comments from all interested parties must be received by July
27, 1998. Public hearing requests must be received by May 11, 1998.
ADDRESSES: Comments and materials concerning this proposal should be
sent to the Field Supervisor, Austin Ecological Services Field Office,
U.S. Fish and Wildlife Service, 10711 Burnet Road, Suite 200, Austin,
Texas, 78758. Comments and materials received will be available for
public inspection, by appointment, during normal business hours at the
above address.
FOR FURTHER INFORMATION CONTACT: Nathan Allan, Fish and Wildlife
Biologist (see ADDRESSES section) (telephone 512/490-0057; facsimile
512/490-0974).
SUPPLEMENTARY INFORMATION:
Background
The Devils River minnow (Dionda diaboli Hubbs and Brown) is
classified in the Cyprinidae (Minnow) family. It was first collected
from Las Moras Creek, near Brackettville, Texas, on April 14, 1951. The
species was formally described by Hubbs and Brown (1956) from specimens
collected in the Devils River; the holotype locality being Devils River
at Baker's Crossing. The species occurs with Dionda argentosa
(manantial roundnose minnow) and is also similar to Dionda episcopa
(roundnose minnow). Devils River minnow is recognized as a distinct
species by the American Fisheries Society (Robins et al. 1991) based on
morphological characteristics (Hubbs and Brown 1956), genetic markers
(Mayden et al. 1992) and chromosome differences (Gold et al. 1992).
The Devils River minnow is a small fish, with adults reaching sizes
of 25-53 millimeters (mm) (1.0-2.1 inches (in)) standard length. The
fish has a wedge-shaped caudal spot and pronounced lateral stripe with
double dashes extending through the eye to the snout but not reaching
the lower lip. The species has a narrow head with prominent dark
markings on scale pockets above the lateral line that produce a cross-
hatched appearance when viewed from the top (Hubbs and Brown 1956).
No information is available on life history characteristics,
feeding patterns, or reproductive behaviors of this species. However,
based on the extended intestinal tract, species of the genus Dionda are
considered to feed primarily on algae. Dionda episcopa have been
observed to be broadcast spawners with nonadhesive eggs that sink to
the substrate (Johnston and Page 1992).
General habitat associations for Devils River minnow have been
described as channels of fast-flowing, spring-fed waters over gravel
substrates (Harrell 1978). Although the species is closely associated
with spring systems, it most often occurs where spring flow enters a
stream, rather than in the spring outflow itself (Hubbs and Garrett
1990). The species is adapted to the hydrologic variations inherent in
desert river systems (Harrell 1978), characterized by extended droughts
and extreme flash floods (USGS 1989).
The Devils River minnow is part of a unique fish fauna in west
Texas streams where a mixture of fishes occur, including Mexican
peripherals, local endemics, and widespread North American fishes
(Hubbs 1957). About half of the native fishes of the Chihuahuan Desert
of Mexico and Texas are considered threatened by Hubbs (1990) and at
least four species have been documented to already be extinct (Miller
et al. 1989), primarily due to habitat destruction and introduced
species.
The Devils River minnow is native to tributary streams of the Rio
Grande River in Val Verde and Kinney counties, Texas, and Coahuila,
Mexico. The known historic range of the species is based on collections
from the 1950s and 1970s and includes--the Devils River from Beaver
Lake downstream to near its confluence with the Rio Grande; San Felipe
Creek from the springs in the headwaters to springs in Del Rio;
Sycamore Creek, in Kinney County; Las Moras Creek near Brackettville;
and Rio Sabinas, Rio San Carlos, and Rio Alamo from the Rio Salado
drainage in northern Mexico (Brown 1955; Hubbs and Brown 1956; Robinson
1959; Harrell 1978; Smith and Miller 1986; Garrett et al. 1992).
Despite numerous collection efforts, the species has never been
reported from the mainstem Rio Grande, the Rio Conchos drainage, or
tributary streams other than those listed above. The range of the
species prior to 1951 is unknown.
The current distribution of Devils River minnow in Texas was
described by Garrett et al. (1992). This study documented the presence
of the species in 1989 at two sites on the Devils River, two sites on
San Felipe Creek, and one site on Sycamore Creek. Garrett et al. (1992)
showed that Devils River minnow was very rare throughout its range in
1989 compared to past collections. At 24 sampling locations within the
historic range, a total of only 7 individuals were collected from 5
sites. In addition to declines in the Devils River minnow populations,
Garrett et al. (1992) also observed a general shift in community
structure toward fishes that tend to occupy quiet water or pool
habitat, conditions that are often limited in flowing spring runs. The
authors hypothesized that this shift was the result of reduced stream
flows from drought, exacerbated by human modification to stream
habitats, especially in Sycamore and Las Moras creeks.
No published information has been found on the status of the Devils
River minnow in Mexico. A review of museum records indicates the
species may now occur in only two localities in Mexico. Populations
there appear to be very depressed and face significant threats from
industrial development (Contreras and Lozano 1994; S. Contreras-B.,
University of Nuevo Leon, in litt. 1997). Throughout the region of
northern Mexico, fish species are severely threatened with habitat loss
and modification. Of an approximate 200 species that may occur in the
region, 135 are considered threatened (Williams et al. 1989; Contreras
and Lozano 1994) and 15 are thought to already be extinct (Miller et
al. 1989; Contreras and Lozano 1994).
The region of Texas where the Devils River minnow occurs is semi-
arid, receiving an average of about 46 centimeters (cm) (18 in) of
rainfall annually. Spring-fed streams of west Texas flow southerly
through rocky, limestone soils and shrubby vegetation characteristic of
desert hill country. The aquifer that sustains spring flows within
[[Page 14887]]
the range of the Devils River minnow is the Edwards-Trinity (Plateau)
Aquifer. This major aquifer produces the largest number of springs in
Texas (Brune 1975). The contributing recharge area for springs on the
Devils River and San Felipe Creek is suspected to include a large area
as far north as Sheffield in Pecos County and Eldorado in Schleicher
County, although the subsurface hydrogeomorphology of the region is not
well-defined (Brune 1981). The flow from springs tends to fluctuate
considerably, depending on the amount of rainfall, recharge, and water
in storage in the underground reservoirs. Conservation of this
groundwater supply is essential for the continued existence of the
Devils River minnow.
Areas where the Devils River minnow occurs are mostly in private
ownership. Exceptions include the Devils River State Natural Area,
owned by the Texas Parks and Wildlife Department (TPWD) (Baxter 1993),
and land adjoining portions of San Felipe Creek, owned by the City of
Del Rio (population of about 38,000). One important private holding is
the Dolan Falls Preserve, owned by The Nature Conservancy (Baxter
1993). Primary land uses are cattle, sheep, and goat ranching.
Generally, these areas are very remote with little human development,
beyond those to support ranching operations. Primary communities within
the Devils River watershed are Ozona in Crockett County and Sonora in
Sutton County (each with a population of less than 5,000), in the upper
portion of the drainage where flows in the Devils River are
intermittent. The middle and lower portions of the Devils River are
popular for recreational fishing and canoeing (Gough 1993), although
public access is limited.
The Devils River minnow is currently listed as a threatened species
by the State of Texas, the Texas Organization for Endangered Species
(Hubbs et al. 1991), and the Endangered Species Committee of the
American Fisheries Society (Williams et al. 1989).
Previous Federal Action
On August 15, 1978, the Service published a proposed rule (43 FR
36117) to list the Devils River minnow as a threatened species and to
designate critical habitat. On March 6, 1979, the Service published a
notice (44 FR 12382) to withdraw the critical habitat portion of the
proposal in order to meet requirements set forth in the Endangered
Species Act Amendments of 1978 (Public Law 95-632, 92 Stat. 3751). The
Service reproposed the designation of critical habitat for the Devils
River minnow on May 16, 1980 (45 FR 32348). A notice of public hearing
was published on July 9, 1980 (45 FR 46141), and the public hearing was
held on July 23, 1980, in Del Rio, Texas. The Service gave notice that
the listing and critical habitat proposals were withdrawn on September
30, 1980 (45 FR 64853), because the 2-year time limit on the proposal
had expired.
The Service included the Devils River minnow as a category 2
candidate species in Notices of Review published December 30, 1982 (47
FR 38454), September 18, 1985 (50 FR 37958), and January 6, 1989 (54 FR
554). Category 2 taxa were those that the Service believed may be
eligible for threatened or endangered status, but for which the
available biological information in possession of the Service was
insufficient to support listing the species. However, new information
obtained in 1989 (and later published as Garrett et al. 1992) provided
a basis for including the Devils River minnow as a category 1 candidate
in Notices of Review published November 21, 1991 (56 FR 58804), and
November 15, 1994 (59 FR 58982). Category 1 taxa were those for which
the Service had substantial biological information on hand to support
proposing to list the species as threatened or endangered.
As announced in a notice published in the February 28, 1996,
Federal Register (61 FR 7596), the designation of multiple categories
of candidates has been discontinued, and only former category 1 species
are now recognized as candidates for listing purposes. The Devils River
minnow remained a candidate species with a listing priority of 2 in
Notices of Review published February 28, 1996 (61 FR 7596), and
September 19, 1997 (62 FR 49398). The listing priority numbers for
candidate taxa range from 1 (highest priority) to 12 (lowest priority)
and are assigned by the Service based on the immediacy and magnitude of
threats, as well as taxonomic status (48 FR 43098).
Summary of Factors Affecting the Species
Section 4(a)(1) of the Act (16 U.S.C. 1531 et seq.) and regulations
(50 CFR part 424) promulgated to implement the listing provisions of
the Act set forth the procedures for adding species to the Federal
lists. A species may be determined to be an endangered or threatened
species due to one or more of the five factors described in section
4(a)(1). These factors and their application to the Devils River minnow
(Dionda diaboli) are as follows:
A. The present or threatened destruction, modification, or curtailment
of its habitat or range.
(1.) Devils River
The Devils River constitutes the largest segment of the documented
range of the Devils River minnow. Over 40 percent of the total length
of the Devils River has been lost as potential habitat, representing a
contraction of the range from the northern extent of the distribution
of the species. The Devils River from Beaver Springs to its confluence
with the Rio Grande is about 127 river-kilometers(km) (79 river-
miles(mi)) long. The lower 29 km, downstream of Big Satan Creek, is
inundated by Amistad Reservoir. The uppermost 26 km, between Pecan
Springs and Beaver Springs, can no longer be considered suitable
habitat because of the loss of permanent flows.
The most significant loss of Devils River minnow habitat occurred
on the Devils River with the impoundment of Amistad Reservoir in 1968.
Backwaters from Amistad Dam inundated the natural stream habitats
(about 29 km), transforming the area from a riverine to lake
environment. The area is no longer suitable for most native fishes,
including Devils River minnow. Before construction of Amistad Dam, two
smaller dams (Devils Lake and Wall Lake) were built in the 1920's in
this lower portion of the stream. However, spring run habitat remained
and Devils River minnow was collected there in 1953 and 1954. Amistad
Reservoir, however, inundated these springs, eliminating the natural
environment and suitable habitat for native fish. Also, the
construction of the dam created a physical barrier to fish movement
that permanently separated the Devils River population of the species
from other populations.
In addition to habitat loss in the lower Devils River due to
impoundment, habitat for the species has been lost from the lack of
permanent spring flows in the upstream portion (about 26 km) of the
river (Dietz 1955, Brune 1975, Harrell 1978). These springs
historically provided a pristine source of significant flowing water.
Brune (1981) indicates that agricultural land use practices both within
and north of the watershed may affect aquifer levels and account for a
lack of permanent flows from the northern-most springs. Heavy well
pumping from groundwater reserves for irrigation (Dietz 1955) and long
term overgrazing (that reduces recharge and enhances runoff) have been
cited as possible causes for decreased spring flows in the upper Devils
River (Brune 1981). Springs on the Devils River
[[Page 14888]]
(upstream of Pecan Springs) that no longer support permanent discharges
include Beaver, Juno, Headwater, Stein, and San Pedro springs (Brune
1981).
Continued decline of permanent discharge from springs is a
significant threat to Devils River minnow in the middle segment of the
Devils River. This threat can be the result of drought and/or human
activities that withdraw groundwater or prevent recharge. The remaining
central portion of the Devils River continues to flow naturally, and
has been referred to as one of the most pristine rivers in Texas.
Because of large groundwater reservoirs that support the remaining
spring systems, the river maintains a substantial perennial flow.
Historic stream flow analysis, however, indicates decreasing base
flows during the 1960's that were independent of precipitation levels
(suggesting human influences). Drought can further aggravate spring
flow declines (Garrett 1992). Declining trends of stream flow during
the 1950's and 1980's track a decrease in precipitation in the region,
suggesting the effects of drought (USGS 1989).
When spring flows become seasonally intermittent, fish populations
are unable to use the stream to fulfill their life history
requirements. Declines in base flow of streams also affect fish
populations by reducing the total available habitat and thereby
intensifying competitive and predatory interactions. For Devils River
minnow, decreased instream flows may lead to a population decline due
to exclusion from preferred habitats and increased mortality from
predation.
Using relative abundance as an indicator, the Devils River minnow
has decreased in the Devils River over time. The Devils River minnow
was the fifth most abundant species of 18 species collected in 1953 at
Bakers Crossing (Brown 1955); the sixth most abundant of 23 species in
the river in 1974 (Harrell 1978); and one of the least abundant of 16
species in 1989 (Garrett et al. 1992). Recent information from Cantu
and Winemiller (1997) indicates that the species was still present in
the Devils River at the confluence with Dolan Falls in 1994, but only
in low numbers (thirteenth most abundant of 27 species). The four
collections by Cantu and Winemiller (1997) were extensive surveys over
1 year at the one site near Dolan Falls. Even with this increased
effort, only 28 individuals of Devils River minnow, out of 4,470 total
fish, were documented.
New information on the distribution and abundance of Devils River
minnow in the Devils River and San Felipe Creek was obtained from
surveys conducted in November 1997 by the TPWD. No Devils River minnow
were collected from several locations on the Devils River from Pecan
Springs downstream to Finegan Springs, just above Dolan Falls (Gary
Garrett, TPWD, in litt. 1997). This indicates that, if the fish still
persists in the Devils River, it is very rare.
The drastic decline in abundance within the Devils River can best
be documented from collections at the site at Baker's Crossing. Over 60
individuals were collected there in 1953, only one was collected in
1989, and none were collected in 1997.
(2.) San Felipe Creek
San Felipe Creek constitutes the second largest segment of
remaining habitat for Devils River minnow in Texas. Devils River minnow
previously occurred in two areas on this stream. The upper area is
associated with a series of headwater springs several miles upstream of
the City of Del Rio and the lower area is associated with two large
springs in Del Rio.
In 1979, Devils River minnow made up about 2 percent of all
collections (total of 3,458 fish), and was the seventh most abundant of
16 species in the headwater springs in the upper portion of San Felipe
Creek. In 1989, no Devils River minnow were collected from this site
(Garrett et al. 1992). No known collections have been made in this area
since 1989. This area of San Felipe Creek (upstream of Del Rio) is
privately owned and no information is available to discern why the
populations of Devils River minnow in this area have significantly
declined.
In San Felipe Springs (in Del Rio) in 1989, the fish was very rare
(less than 1 percent of 1,651 fish collected, and the tenth most
abundant of 12 species collected) (Garrett et al. 1992). Data from 1997
suggest that the Devils River minnow is common in the San Felipe
Springs and the urban section of the creek (about 50 individuals were
collected for captive study) (Gary Garrett, TPWD, in litt. 1997).
The San Felipe Springs are located within the City of Del Rio and
may be threatened with future habitat changes from continued urban
development. Brune (1975) lists San Felipe Springs as one of the four
largest springs in Texas. The City draws water directly from the
springs which are the sole source of the City's municipal water supply.
The expected population growth of Del Rio is projected to be low (0.5
to 1 percent annual growth). With some water conservation measures in
place to reduce per capita water use, the City could reduce its water
consumption in coming decades. However, any future declines in spring
flows due to increased withdrawals could affect the Devils River minnow
population in this location. Presently, Amistad Reservoir is thought to
increase spring flows from San Felipe Springs because the pool
elevation of the reservoir is often higher than that of the spring
outlet. This situation places hydrostatic pressure on San Felipe
Springs through inundated spring openings within the reservoir (Brune
1981).
Water quality and contamination are constant threats to the
population in San Felipe Creek because of the urban setting. Recent
studies by the Texas Natural Resource Conservation Commission (TNRCC)
(1994) found elevated levels of nitrates, phosphates and
orthophosphates in San Felipe Creek, indicating potential water quality
problems. Land uses in the immediate area of the springs, such as
runoff from the municipal golf course near the spring, may be
contributing to these conditions. Other threats from catastrophic
events such as contaminant spills could affect the species.
Based on the current abundance of the Devils River minnow in San
Felipe Creek, it appears that existing practices that could impact the
aquatic habitat are not yet serious enough to significantly reduce the
local population. Aquatic habitat conservation measures (such as water
use conservation and water quality protection) in this section of San
Felipe Creek could help ensure survival of the species there.
(3.) Sycamore Creek
Sycamore Creek constitutes a relatively small portion of the range
of the species. There is only one published account of fishes in this
stream from one site, at the State Highway 277 crossing near the Rio
Grande River (Garrett et al. 1992), although Harrell (1980) references
the species' occurrence there. Garrett et al. (1992) found very few
individuals at this location. Sycamore Creek is an ungaged stream, and
there is little information available on habitat conditions. However,
the Devils River minnow in this stream is evidently very rare and faces
increased risks for extirpation because of the apparent small
population size. Devils River minnow in Sycamore Creek likely face
potential threats from decreasing spring and stream flows due to
groundwater withdrawals and some land use practices in the watershed.
(4.) Las Moras Creek
Las Moras Creek represents the eastern extent of the range of the
species. Although the populations there may have been restricted to the
spring
[[Page 14889]]
area in Brackettville, the number of fish in historic collections was
relatively large (54 individuals were collected in 1953) (Hubbs and
Brown 1956). The natural spring system in Brackettville that supports
Las Moras Creek is the location of the earliest collection of Devils
River minnow. The species has not been collected from these springs
since the 1950s and is believed to be extirpated from that stream,
based on several sampling efforts in the late 1970's and 1980's (Smith
and Miller 1986; Hubbs et al. 1991; Garrett et al. 1992).
Habitat for the Devils River minnow was lost when the spring was
altered by damming the outflow and removing streambank vegetation to
create a recreational swimming pool. Garrett et al. (1992) reported
that the creek smelled of chlorine, indicating that the swimming pool
may be maintained with chlorination (a toxin to fish). Garrett et al.
1992 also indicates that spring flow has been drastically reduced by
drought and diversion of water for human consumption. This combination
of habitat loss and alteration and the resulting water quality problems
appears to be the most likely cause for the apparent extirpation of the
species from Las Moras Creek.
(5.) Rio Salado
The populations of Devils River minnow in the Rio Salado Drainage
of northern Mexico represent a critical portion of the range. These
streams are southern tributaries of the Rio Grande and are
geographically distinct from the tributaries where the fish occurs in
Texas. Garrett et al. (1992) cites that the Devils River minnow occurs
in low numbers in the Rio San Carlos and Rio Sabinas. The species may
also occur in the Rio Alamo (S. Contreras-B., University of Nuevo Leon,
in litt. 1997).
The condition of aquatic habitats in the Rio Salado drainage in
Mexico is extremely poor. Contreras and Lozano (1994) report that
aquatic ecosystems in this region of Mexico face significant threats
due to groundwater and surface water withdrawals, as well as air and
water pollution. Watersheds in northern Mexico have been heavily
impacted by land uses and industrial development (S. Contreras-B.,
University of Nuevo Leon, in litt. 1997). The Rio Sabinas, in
particular, has been noted for decreasing flows; and spring systems
within Coahuila have been extensively exploited (Contreras and Lozano
1994).
(6.) Range-Wide
Habitat loss and modification throughout a significant portion of
the range of the Devils River minnow has resulted in both the
fragmentation and contraction of the range of the species. The previous
occurrences of known populations of Devils River minnow in Texas can be
grouped into nine geographic areas, primarily associated with spring
systems: five areas in the Devils River (lower Devils River, Dolan
Falls, Baker's Crossing, Pecan Springs, Juno to Beaver Lake); two areas
in San Felipe Creek (headwater springs and Del Rio); one area in
Sycamore Creek; and one area in Las Moras Creek. Of these nine areas,
the best available information indicates that a viable population may
exist only in San Felipe Creek in Del Rio. The known existence of only
one viable population located in an urban setting makes the threat of
extinction of the species within the U.S. very high. Although detailed
information is limited regarding the status of the species in Mexico,
its condition there is likely at least to be threatened.
The construction of Amistad Dam has separated the two primary
populations of Devils River minnow in Texas (Devils River and San
Felipe Creek) and assured they will be permanently isolated from one
another. This population fragmentation has significant conservation
implications (Gilpin 1987). Determining and monitoring the genetic
structure of the different Devils River minnow populations will be
needed to ensure the necessary genetic variation within and among
populations is not lost (Meffe 1986; Minckley et al. 1991).
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
Overutilization is not considered a significant threat to the
Devils River minnow. However, there is a potential for impacts should
this species be harvested as a baitfish (either commercially or non-
commercially).
C. Disease or Predation
The Devils River minnow may be affected by the presence of
introduced fishes within its range. Of special concern is the threat of
predation by smallmouth bass (Micropterus dolomieu), a game fish
introduced to Amistad Reservoir in about 1975. The smallmouth bass is
native to eastern North America but has been widely introduced as a
sport fish to reservoirs and streams outside its natural range. It is
believed smallmouth bass gained access to the upper portions of the
Devils River (upstream of Dolan Falls) in the early to mid-1980's (Gary
Garrett, TPWD, pers. comm. 1997). This species is now the dominant
predator in the fish community of the Devils River. The TPWD is
currently managing the Devils River as a trophy smallmouth bass
fishery.
The Devils River minnow evolved in the presence of native
piscivores such as channel catfish (Ictalurus punctatus) and largemouth
bass (Micropterus salmoides) and is adapted to persist with these
species. However, smallmouth bass are not native, are aggressive
predators, and are known to impact other native fish communities
(Taylor et al. 1984, Moyle 1994). The Devils River minnow falls within
the size class of small fishes that are susceptible to predation by
smallmouth bass. The scarcity of Devils River minnow in the Devils
River (where smallmouth bass are prominent) and the abundance of Devils
River minnow in San Felipe Creek (where smallmouth bass are not known
to occur) provides circumstantial evidence of the likely impacts of
this introduced predator. The establishment of smallmouth bass in San
Felipe Creek is another potential threat to that Devils River minnow
population.
The release (intentional or unintentional) of other minnows into
areas inhabited by Devils River minnow is another potential threat.
Live bait fish are commonly discarded by anglers resulting in
introductions of nonnative species. This situation has occurred in many
streams in the southwestern U.S. with considerable impacts to the
native fish community (Moyle 1994). Exotic fishes from aquariums can
also be introduced into local waters. Currently, only a small number of
introduced fishes occur within the range of the Devils River minnow,
but the potential for bait bucket introductions is high because of the
number of anglers on the Devils River. Threats to the populations of
Devils River minnow from possible introduction and establishment of
nonnative fishes include diseases, parasites, competition for food and
space, and hybridization.
D. The Inadequacy of Existing Regulatory Mechanisms
The Devils River minnow is listed as a threatened species by the
State of Texas. This provides some protection from collecting, as a
permit is required to collect listed species in Texas. However, there
is no State or local mechanism to protect habitat for the conservation
of the species. In addition, limited regulations exist to prevent
unintentional releases of exotic species by the baitfish industry and
anglers.
Limited State regulations exist that serve to protect instream
flows for surface water rights and water quality for wildlife and human
uses. However,
[[Page 14890]]
these regulations were not designed to conserve habitat for native
fishes and currently no minimum instream flows are required on streams
where Devils River minnow occur. Surface water rights along the Rio
Grande in Texas and its U.S. tributaries are administered by the State
of Texas. Groundwater withdrawals that could be affecting stream flows
within the range of the Devils River minnow are unregulated. Texas
courts have held that, with few exceptions, landowners have the right
to take all the water that can be captured under their land (right of
capture). Therefore, there is little opportunity to protect groundwater
reserves within existing regulations.
State Water Quality Standards, though primarily concerned with
protecting human health, may provide some protection to the Devils
River minnow and its habitat. The classification of the Devils River
and San Felipe Creek under the Texas Surface Water Quality Standards
requires maintenance of existing water quality. Sycamore and Las Moras
Creeks are not classified under these standards
E. Other Natural or Manmade Factors Affecting Its Continued Existence.
The destruction of habitat throughout the range of the Devils River
minnow has reduced the number of viable populations of the species,
perhaps down to as few as one. The restricted range makes the species
especially vulnerable to extinction. The Devils River minnow is
currently known to be common in only one location, San Felipe Creek in
Del Rio, and this population is threatened due to its proximity to the
urban environment.
Populations of Devils River minnow in Sycamore Creek, and possibly
the Devils River, may have so few individuals that they may no longer
constitute viable populations (Caughley and Gunn 1996). Small
populations can lead to genetic erosion through inbreeding and are more
vulnerable to loss from random natural events than larger populations
(Meffe 1986).
The overall decline in abundance of Devils River minnow is likely
the result of several cumulative factors. For example, subtle changes
in stream flows could produce small shifts in habitat use that make the
species more vulnerable to competition and predation by native
predators and nonnative smallmouth bass. In addition, long-term drought
can have a major effect on the habitat of the species, particularly
when combined with impacts of human water use. This species has adapted
to the historic natural climatic variations (such as large floods and
prolonged droughts). However, in conjunction with other threats to the
species (primarily existing habitat loss and exotic predators), a
drought could significantly increase the threat of extinction. The use
of water supplies for human needs (municipal or agricultural) serves to
worsen the effects of drought on the natural environment.
The Service has carefully assessed the best scientific and
commercial information available regarding the past, present, and
future threats faced by this species in determining to propose this
rule. Based on this evaluation, the preferred action is to list the
Devils River minnow as endangered. The species currently inhabits a
very limited range and the best scientific information available
indicates a decline in abundance throughout the range of the species.
The species is in danger of becoming extinct in the foreseeable future
throughout all or a significant portion of its range. Threatened status
would not accurately reflect the vulnerability of the species due to
its restricted range and low numbers. Critical habitat is not being
proposed for the reasons discussed below.
Critical Habitat
Critical habitat is defined in section 3 of the Act as: (i) The
specific areas within the geographical area occupied by a species, at
the time it is listed in accordance with the Act, on which are found
those physical or biological features (I) essential to the conservation
of the species and (II) that may require special management
considerations or protection and; (ii) specific areas outside the
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 Act is no longer necessary.
Section 4(a)(3) of the Act and implementing regulations (50 CFR
424.12) require that, to the maximum extent prudent and determinable,
the Secretary designate critical habitat at the time the species is
determined to be endangered or threatened. Service regulations (50 CFR
424.12(a)) state that designation of critical habitat is not prudent
when one or both of the 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.
The Service finds that the designation of critical habitat for the
Devils River minnow is not prudent due to lack of benefit. The section
7 prohibitions against adverse modification of critical habitat apply
to Federal actions only (see Available Conservation Measures section).
The watersheds in the U.S. in which the Devils River minnow occurs are
almost entirely in private ownership, and no significant Federal
actions affecting the species' habitat are likely to occur in the area.
Therefore, the designation of critical habitat would provide no benefit
to the species.
In addition, any Federal action which would cause adverse
modification of critical habitat for the Devils River Minnow likely
would also cause jeopardy. Under section 7, actions funded, authorized,
and carried out by Federal agencies may not jeopardize the continued
existence of a species or result in the destruction or adverse
modification of critical habitat. To ``jeopardize the continued
existence'' of a species is defined as an action that appreciably
reduces the likelihood of its survival and recovery. ``Destruction or
adverse modification of critical habitat'' is defined as an appreciable
reduction in the value of critical habitat for the survival and
recovery of a species. Given the imperiled status of the Devils River
minnow, it is likely that a Federal action that would destroy or
adversely modify the species' critical habitat would also jeopardize
its continued existence. Thus, prohibitions associated with critical
habitat would be duplicative and superfluous, and would, therefore,
provide no benefit to the species.
Finally, critical habitat designation can sometimes serve to
highlight areas that may be in need of special management
considerations or protection. The continued existence of the Devils
River minnow is dependent upon the efforts of the TPWD and local land
owners, and those parties are aware of the areas in need of special
management considerations or protection. For these reasons, the
designation of critical habitat for the Devils River minnow would
provide no benefit to the species beyond that conferred by listing
alone and is, therefore, not prudent.
Available Conservation Measures
Conservation measures provided to species listed as endangered or
threatened under the Act include recognition, recovery actions,
requirements for Federal protection, and prohibitions against certain
practices. Recognition through listing results in public awareness and
conservation
[[Page 14891]]
actions by Federal, State, and local agencies, private organizations,
and individuals. The Act provides for possible land acquisition and
cooperation with the States and requires that recovery actions be
carried out for all listed species.
The State of Texas is currently working on a conservation agreement
for the Devils River minnow. Because the agreement has not yet been
finalized, the Service did not consider it in determining whether to
issue this listing proposal. Should this agreement be finalized within
a reasonable period of time, and should the Service decide that it
potentially removes the need to list the species, the Service will
extend or reopen the comment period for this proposal to accept
comments on the agreement and its ability to remove the need to list
the species.
Section 7(a) of the Act, as amended, requires Federal agencies to
evaluate their actions with respect to any species that is proposed or
listed as endangered or threatened and with respect to its critical
habitat, if any is being designated. Regulations implementing these
interagency cooperation provisions of the Act are codified at 50 CFR
part 402. Section 7(a)(4) requires Federal agencies to confer with the
Service on any action that is likely to jeopardize the continued
existence of a proposed species or result in destruction or adverse
modification of proposed critical habitat. If a species is listed
subsequently, section 7(a)(2) requires Federal agencies to ensure that
activities they authorize, fund, or carry out are not likely to
jeopardize the continued existence of such a species or to destroy or
adversely modify its critical habitat, if any has been designated. If a
Federal action may affect a listed species or its critical habitat, the
responsible Federal agency must enter into consultation with the
Service.
Federal agency actions that may require conference and/or
consultation as described in the preceding paragraph include Army Corps
of Engineers review and approval of activities such as the construction
of roads, bridges, and dredging projects subject to Section 404 of the
Clean Water Act (33 U.S.C. 1344 et seq.) and Section 10 of the Rivers
and Harbors Act of 1899 (33 U.S.C. 401 et seq.) and U.S. Environmental
Protection Agency authorization of discharges under the National
Pollutant Discharge Elimination System. Other Federal agencies whose
actions could require consultation include the Department of Defense,
Natural Resources Conservation Service, the Federal Highways
Administration, and the Department of Housing and Urban Development.
The Act and its implementing regulations set forth a series of
general prohibitions and exceptions that apply to all endangered
wildlife. The prohibitions, codified at 50 CFR 17.21, in part, make it
illegal for any person subject to the jurisdiction of the U.S. to take
(includes harass, harm, pursue, hunt, shoot, wound, kill, trap,
capture, or collect; or to attempt any of these), import or export,
ship in interstate commerce in the course of commercial activity, or
sell or offer for sale in interstate or foreign commerce any listed
species. It also is illegal to possess, sell, deliver, carry,
transport, or ship any such wildlife that has been taken illegally.
Certain exceptions apply to agents of the Service and State
conservation agencies.
Permits may be issued to carry out otherwise prohibited activities
involving endangered wildlife under certain circumstances. Regulations
governing permits are codified at 50 CFR 17.22 and 17.23. Such permits
are available for scientific purposes, to enhance the propagation or
survival of the species, and/or for incidental take in the course of
otherwise lawful activities. Information collections associated with
these permits are approved under the Paperwork Reduction Act, 44 U.S.C.
3501 et seq., and assigned Office of Management and Budget clearance
number 1018-0094. For additional information concerning these permits
and associated requirements, see 50 CFR 17.22.
It is the policy of the Service (59 FR 34272) to identify to the
maximum extent practicable at the time a species is listed those
activities that would or would not constitute a violation of section 9
of the Act. The intent of this policy is to increase public awareness
of the effect of the listing on proposed and on-going activities within
a species' range. The Service believes that, based on the best
available information, the following actions will not result in a
violation of section 9:
(1) Normal livestock grazing and other standard ranching practices
which do not destroy or significantly degrade Devils River minnow
habitat.
(2) Federally-approved projects that involve activities conducted
in accordance with any reasonable and prudent measures given by the
Service in accordance with section 7 of the Act.
Activities the Service believes could potentially harm the Devils
River minnow and result in ``take'' include, but are not limited to:
(1) Unauthorized collecting or handling of the species.
(2) Any activities that may result in destruction or significant
alteration of habitat occupied by Devils River minnow including, but
not limited to, the discharge of fill material, the diversion or
alteration of spring and stream flows or withdrawal of groundwater to
the point at which habitat becomes unsuitable for the species, and the
alteration of the physical channels within the spring runs and stream
segments occupied by the species;
(3) Discharge or dumping of pollutants such as chemicals, silt,
household or industrial waste, or other material into the springs or
streams occupied by Devils River minnow or into areas that provide
access to the aquifer and where such discharge or dumping could affect
water quality in spring outflows;
(4) Herbicide, pesticide, or fertilizer application in violation of
label restrictions in or near the springs containing the species; and
(5) Introduction of certain non-native species (fish, plants, and
other) into occupied habitat of the Devils River minnow or areas
connected to these habitats.
In the descriptions of activities above, a violation of section 9
would occur if those activities occur to an extent that would result in
``take'' of Devils River minnow. Not all of the activities mentioned
above will result in violation of section 9 of the Act; only those
activities which result in ``take'' of Devils River minnow would be
considered violations of section 9. Questions regarding whether
specific activities would constitute a violation of section 9 should be
directed to the Field Supervisor, Austin Ecological Services Field
Office (see ADDRESSES section).
Requests for copies of the regulations regarding listed wildlife
and inquiries about prohibitions and permits may be addressed to U.S.
Fish and Wildlife Service, Region 2, Endangered Species Listing
Coordinator, 500 Gold Avenue SW., Room 4012, Albuquerque, New Mexico
87103-1306 (telephone 505/248-6655; facsimile 505/248-6922).
Public Comments Solicited
The Service intends that any final action resulting from this
proposal will be as accurate and as effective as possible. Therefore,
comments or suggestions from the public, other concerned governmental
agencies, the scientific community, industry, or any other interested
party concerning this rule are hereby solicited. Comments particularly
are sought concerning:
(1) Biological, commercial trade, or other relevant data concerning
any
[[Page 14892]]
threat (or lack thereof) to the Devils River minnow;
(2) The location of any additional populations of this species and
the reasons why any habitat should or should not be determined to be
critical habitat as provided by section 4 of the Act;
(3) Additional information concerning the range, distribution, and
population size of the species;
(4) Current or planned activities in the subject area and their
possible impacts on this species.
Final promulgation of the regulation on this species will take into
consideration the comments and any additional information received by
the Service, and such communication may lead to a final regulation that
differs from this proposal.
The Endangered Species Act provides for one or more public hearings
on this proposal, if requested. Requests must be received within 45
days of the date of publication of the proposal. Such requests must be
made in writing and addressed to the Field Supervisor, Austin
Ecological Services Field Office (see ADDRESSES section).
National Environmental Policy Act
The Fish and Wildlife Service has determined that an Environmental
Assessment, as defined under the authority of the National
Environmental Policy Act of 1969, need not be prepared in connection
with regulations adopted pursuant to section 4(a) of the Endangered
Species Act of 1973, as amended. A notice outlining the Service's
reasons for this determination was published in the Federal Register on
October 25, 1983 (48 FR 49244).
Required Determinations
This rule does not contain collections of information that require
approval by the Office of Management and Budget under 44 U.S.C. 3501 et
seq.
References Cited
A complete list of all references cited herein, as well as others,
is available upon request from the Austin Ecological Services Field
Office (see ADDRESSES section).
Author
The primary author of this proposed rule is Nathan Allan (see
ADDRESSES section).
List of Subjects in 50 CFR Part 17
Endangered and threatened species, Exports, Imports, Reporting and
recordkeeping requirements, Transportation.
Proposed Regulation Promulgation
Accordingly, the Service hereby proposes to amend part 17,
subchapter B of chapter I, title 50 of the Code of Federal Regulations,
as set forth below:
PART 17--[AMENDED]
1. The authority citation for part 17 continues to read as follows:
Authority: 16 U.S.C. 1361-1407; 16 U.S.C. 1531-1544; 16 U.S.C.
4201-4245; Pub. L. 99-625, 100 Stat. 3500, unless otherwise noted.
2. Amend section 17.11(h) by adding the following, in alphabetical
order under ``Fishes,'' to the List of Endangered and Threatened
Wildlife:
Sec. 17.11 Endangered and threatened wildlife.
* * * * *
(h) * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------
Species Vertebrate
-------------------------------------------------------- population where Critical Special
Historic range endangered or Status When listed habitat rules
Common name Scientific name threatened
--------------------------------------------------------------------------------------------------------------------------------------------------------
Fishes
* * * * * * *
Minnow, Devils River............. Dionda diaboli...... U.S.A. (TX), Mexico Entire............. E ........... NA NA
* * * * * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------
Dated: March 17, 1998.
Jamie Rappaport Clark,
Director, Fish and Wildlife Service.
[FR Doc. 98-7997 Filed 3-26-98; 8:45 am]
BILLING CODE 4310-55-P
