Endangered and Threatened Wildlife and Plants; Proposal To List Three Aquatic Invertebrates in Comal and Hays Counties, Texas, as Endangered

DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

RIN 1018-AD28

Endangered and Threatened Wildlife and Plants; Proposal To List

Three Aquatic Invertebrates in Comal and Hays Counties, Texas, as

Endangered

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Proposed rule.

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SUMMARY: The Fish and Wildlife Service proposes to list three aquatic

invertebrate species known only from Comal and Hays counties, Texas, as

endangered species under the Endangered Species Act of 1973, as amended

(Act). The primary threat to these species is a decrease in water

quantity and quality as a result of water withdrawal and other

activities by humans throughout the San Antonio segment of the Edwards

Aquifer. This proposal, if made final, will implement Federal

protection provided by the Act for the Peck's cave amphipod

(Stygobromus pecki), Comal Springs riffle beetle (Heterelmis

comalensis), and Comal Springs dryopid beetle (Stygoparnus comalensis).

DATES: Comments from all interested parties must be received by August

4, 1995. Public hearing requests must be received by July 20, 1995.

ADDRESSES: Comments and materials concerning this proposal should be

sent to the State Administrator, 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: Ruth Stanford, Ecologist, or Alisa

Shull, Fish and Wildlife Biologist (see ADDRESSES section) (512/490-

0057).

SUPPLEMENTARY INFORMATION:

Background

The U.S. Fish and Wildlife Service (Service) proposes to list as

endangered under the Endangered Species Act of 1973, as amended (Act)

three aquatic invertebrate animal species with a known distribution in

spring sites in Comal and Hays counties, Texas; two of the species are

subterranean. Peck's cave amphipod is known from Comal Springs and

Hueco Springs, both in Comal County. The Comal Springs riffle beetle is

known from Comal Springs and San Marcos Springs (Hays County). The

Comal Springs dryopid beetle is known from Comal Springs and Fern Bank

Springs (Hays County). The water flowing out of each of these springs

comes from the Edwards Aquifer (Balcones Fault Zone--San Antonio

Region), which extends from Hays County on the east to Kinney County on

the west. Comal Springs are located in Landa Park, which is owned and

operated by the City of New Braunfels, and on private property adjacent

to Landa Park. Hueco Springs and Fern Bank Springs are located on

private property. San Marcos Springs are located on the property of

Aquarena Springs, formerly a privately owned resort facility. Southwest

Texas State University purchased the facility in 1994. Aquarena Springs

continues to operate as a resort, but the university plans to increase

conference facilities and provide educational and interpretive displays

and to increase availability of the springs for biological and

ecological research (Billy Moore, Public Affairs Director, Southwest

Texas State University, pers. comm., 1995).

Peck's cave amphipod is a subterranean, aquatic crustacean. The

other two species are aquatic beetles. The families to which these

beetles belong live primarily in flowing, uncontaminated waters. The

Comal Springs riffle beetle is a surface species in the family Elmidae.

The Comal Springs dryopid beetle is the only known subterranean member

of the family Dryopidae.

The first recorded specimen of the amphipod Stygobromus

(=Stygonectes) pecki (Holsinger 1967) was collected by Peck at Comal

Springs in June, 1964. Reddell collected a second specimen at the same

place in May, 1965. In 1967, Holsinger named the species Stygonectes

pecki, in Peck's honor; the 1965 specimen, an adult female 10.5 mm

(about one half inch) long, served as the type specimen. Later he

included all the nominal Stygonectes species in the synonymy of the

large genus Stygobromus. The Service has used ``cave amphipod'' as a

generic common name for members of this genus, and this name was simply

translated as ``Peck's cave amphipod'' without reference to a

particular cave. Other known springs and artesian wells of the Edwards

Aquifer in central Texas have been extensively sampled for amphipod

crustaceans; a single specimen of Peck's cave amphipod was collected at

Hueco Springs by Barr in August, 1992.

Over 300 specimens of Peck's cave amphipod have been collected

since its description. Most documented specimens were netted from

crevices in rock and gravel near the orifices of the three largest

Comal Springs on the west side of Landa Park in Comal County, Texas.

Barr collected one specimen from a fourth Comal spring run on private

property adjacent to Landa Park and one specimen from Hueco Springs,

about 7 km (4 miles) north of Comal Springs (Barr 1993). However, like

all members of the exclusively subterranean genus Stygobromus, this

species is eyeless and unpigmented, indicating that its primary habitat

is a zone of permanent darkness in the underground aquifer feeding the

springs. Above ground, individuals are easy prey for predators, but

they usually take shelter in the rock and gravel crevices and may

succeed in reentering the spring orifice. Barr (1993) got most

specimens in drift nets at spring orifices and found them less often as

she moved downstream, supporting the notion that they may be easy prey

and do not likely survive for long outside the aquifer.

The Comal Springs riffle beetle is a small, aquatic beetle known

from Comal Springs and San Marcos Springs. It was first collected by

Bosse in 1976 and was described in 1988 by Bosse et al. The closest

relative of H. comalensis appears to be a species that occurs farther

to the west (Bosse et al. 1988).

Adult Comal Springs riffle beetles are about 2 mm (\1/10\ inch)

long, with females slightly larger than males. Unlike the other two

organisms proposed here, the Comal Springs riffle beetle is not a

subterranean species. It occurs in the gravel substrate and shallow

riffles in spring runs. Some riffle beetle species can fly, but the

hind wings of Heterelmis comalensis are short and almost certainly non-

functional, making the species [[Page 29538]] incapable of this mode of

dispersal (Bosse et al. 1988). The larvae have been collected with

adults in the gravel substrate of the spring headwaters and not on

submerged wood as is typical of most Heterelmis species (Brown and Barr

1988). Usual water depth in occupied habitat is 2 to 10 cm (1 to 4

inches) although the beetle may also occur in slightly deeper areas

within the spring runs. Populations are reported to reach their

greatest densities from February to April (Bosse et al. 1988). The

Comal Springs riffle beetle has been collected from spring runs 1, 2,

and 3 at Comal Springs in Landa Park, and a single specimen was

collected from San Marcos Springs 32 km (20 miles) to the northeast.

The Comal Springs dryopid beetle is a recently discovered species.

It was first collected in 1987 and described as a new genus and species

in 1992 by Barr (California State University) and Spangler (National

Museum of Natural History, Smithsonian Institution). Adult Comal

Springs dryopid beetles are about 3.0-3.7 mm (\1/8\ inch) long. They

have vestigial (non-functional) eyes and are weakly pigmented,

translucent, and thin-skinned. The species is the first stygobiontic

(subterranean aquatic) member of its family to be discovered (Brown and

Barr 1988, Barr, in litt. 1990, Barr and Spangler 1992). Collection

records for the Comal Springs dryopid beetle are primarily from spring

run 2 at Comal Springs, but they have also been collected from runs 3

and 4 at Comal Springs and from Fern Bank Springs about 32 km (20

miles) to the northeast in Hays County. Specimens have been collected

in April, May, June, July, and August. Most of the specimens have been

taken from drift nets or from inside the spring orifices. Although the

larvae of the Comal Springs dryopid beetle have been collected in drift

nets positioned over the spring openings, they are presumed to be

associated with air-filled voids inside the spring orifices since all

other known dryopid beetle larvae are terrestrial. Unlike Peck's cave

amphipod, the Comal Springs dryopid beetle does not swim, and it may

have a smaller range within the aquifer.

The exact depth and subterranean extent of the ranges of the two

subterranean species (Comal Springs dryopid beetle and Peck's cave

amphipod) are not precisely known because of a lack of methodologies

available for studying karst aquifer systems and the organisms that

inhabit such systems. The subterranean portion of this habitat may be a

single, interconnected system that provides the area necessary for the

feeding, growth, survival, and reproduction of the Comal Springs

dryopid beetle and Peck's cave amphipod, which are obligate aquatic

stygobiontic species. However, no specimens of Stygoparnus comalensis

or Stygobromus pecki have appeared in collections from 22 artesian and

pumped wells flowing from the Edwards Aquifer (Barr 1993), suggesting

that these species may be confined to small areas surrounding the

spring openings and are not distributed throughout the aquifer. Barr

(1993) also surveyed nine springs in Bexar, Comal, and Hays counties

considered most likely to provide habitat for endemic invertebrates and

found Stygoparnus comalensis only at Comal and Fern Bank springs and

Stygobromus pecki only at Comal and Hueco springs.

The low water limits for survival are not known for any of these

three invertebrate species. At least a single population of each

species survived the drought of the middle 1950's, which resulted in

cessation of flow at Comal Springs from June 13 through November 3,

1956. Hueco springs is documented to have gone dry in the past (Brune

1981; Barr 1993), and although no information is available for Fern

Bank Springs, it has probably gone dry as well given its higher

elevation (Glenn Longley, Edwards Aquifer Research and Data Center,

pers. comm., 1993). San Marcos Springs has not gone dry in recorded

history.

Although these invertebrates were not entirely extirpated by the

temporary cessation of spring flow, they may have been adversely

affected and are not expected to be able to survive long periods of

drying (up to several years in duration) that may occur in the absence

of an adequate water management plan for the Edwards Aquifer.

Stagnation of water may be a limiting condition, particularly for the

two stygobiontic invertebrates. Stagnation of water and/or drying

within the spring runs and the photic (lighted) zone of the spring

orifices would probably be limiting for the Comal Springs riffle

beetle. Natural water flow is considered important to the respiration

and therefore survival of these species. The two beetle species have a

mass of tiny, hydrophobic (unwettable) hairs on their underside where

they maintain a thin bubble of air through which gas exchange occurs

(Chapman 1982). This method of respiration loses its effectiveness as

the level of dissolved oxygen in the water decreases. A number of

aquatic insects that use dissolved oxygen rely on flowing water to

obtain oxygen from the water.

In a petition dated September 9, 1974, the Conservation Committee

of the National Speleological Society requested the Service to list

Peck's cave amphipod. The species was included in a notice of review

published on April 28, 1975 (40 FR 18476). A ``warranted but

precluded'' finding regarding several species in that petition was made

October 12, 1983, and published January 20, 1984 (49 FR 2485). The same

petition determination has been repeated for Peck's cave amphipod in

subsequent years. The species was included as a category 2 candidate in

comprehensive notices of review published May 22, 1984 (49 FR 21664),

January 6, 1989 (54 FR 554), and November 21, 1991 (56 FR 58804). In

the latest notice of review of November 15, 1994 (59 FR 58982), it was

included as a category 1 candidate.

In a petition dated June 20, 1990, and received June 21, 1990, Mr.

David Whatley, Director of the City of New Braunfels Parks and

Recreation Department, requested the Service to list five invertebrate

taxa, including Peck's cave amphipod and four insects. The Service

treated this as a second petition for the amphipod. A notice of 90-day

petition finding published April 29, 1991 (56 FR 19632) announced that

the petition had presented substantial information indicating that

listing the Comal Springs riffle beetle and the Comal Springs dryopid

beetle may be warranted, and initiated a formal status review for those

species. Taxonomic uncertainties about the Comal Springs Microcylloepus

riffle beetle and Hexagenia mayfly, also included in the June 21, 1990,

petition, led to 90-day petition findings that were negative for those

insects. The Heterelmis was recognized as a category 2 candidate in the

November 21, 1989, notice of review, and both it and the Stygoparnus

were recognized as category 1 candidates in the 1994 notice of review.

The present proposal constitutes a positive 1-year finding for the

petitions to list the Comal Springs riffle beetle, Comal Springs

dryopid beetle, and Peck's cave amphipod.

Summary of Factors Affecting the Species

Section 4(a)(1) of the Endangered Species Act (16 U.S.C. 1531 et

seq.) and regulations promulgated to implement the listing provisions

of the Act (50 CFR Part 424) 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 Peck's cave amphipod (Stygobromus pecki), Comal Springs riffle

beetle (Heterelmis comalensis), and Comal Springs dryopid

[[Page 29539]] beetle (Stygoparnus comalensis) are as follows:

A. The present or threatened destruction, modification, or

curtailment of their habitat or range. The main threat to the habitat

of these aquatic invertebrates is a reduction or loss of water of

adequate quantity and quality, due primarily to human withdrawal of

water from the Edwards Aquifer and other activities. Total withdrawal

from the San Antonio region of the Edwards Aquifer has been increasing

since at least 1934, when the total well discharge was 101,900 acre-

feet (Edwards Underground Water District 1989). In 1989, the total well

discharge was slightly more than 542,000 acre-feet (Longley 1991;

Edwards Underground Water District 1992a).

There is an integral connection between the waters in the aquifer

west of the springs and the waters serving as habitat for these species

at the springs. Water entering the Edwards Aquifer as far west as

Kinney County would eventually exit at springs were it not for

withdrawal of groundwater from wells. Water in the Edwards Aquifer

flows from west to east or northeast, and withdrawal or contamination

of water in the western part of the aquifer can have a direct effect on

the quantity and quality of water flowing toward the springs and at the

spring openings.

Prior to wells being drilled into the aquifer, the average

springflow from Comal and San Marcos springs was equal to the average

annual recharge. That is, almost all of the water entering the aquifer

eventually exited at the springs. At present, much of the recharge is

pumped out of the aquifer, and most of what is left becomes the average

springflow (Guadalupe-Blanco River Authority 1988). The amount of water

removed by wells is therefore a direct, one-for-one depletion of water

that would otherwise exit through the springs (Guadalupe-Blanco River

Authority 1988) and provide habitat for the proposed invertebrates.

The Texas Water Commission (TWC) (1989) classified the San Antonio

segment of the Edwards Aquifer as a critical area in terms of its

potential for groundwater problems related to overdrafting. The

Commission also ranked Bexar, Comal, and Hays counties among the top 23

counties in Texas for number of active groundwater public supply

systems. Human population in the region is expected to increase

(Technical Advisory Panel 1990; Edwards Underground Water District

1993), which will result in increased demand for water from the

aquifer.

The Texas Water Development Board has applied its model of the

Edwards Aquifer to determine the maximum pumping level that would allow

Comal Springs to continue to flow (Technical Advisory Panel 1990). The

Board found that during a drought similar to that of the 1950's, the

maximum pumpage that would allow spring flow at Comal Springs is about

250,000 acre-feet per year (less than half the current pumping rate).

``At this pumping level, Comal Springs could be expected to maintain

some annual flow although they may flow on an intermittent basis during

a recurrence of the drought of record'' (Technical Advisory Panel

1990). The Panel also stated that in the year 2000, if pumping

continues to grow at historical rates and a drought of record were to

occur, Comal Springs would go dry for a number of years (Technical

Advisory Panel 1990). Wanakule (1990) states: ``The present problem

facing the Edwards Aquifer is the threat of overdrafting of the annual

average recharge rate (1934-1988) of approximately 635,500 acre-feet.

McKinney and Watkins (1993) evaluated the Texas Water Development Board

model and other models and concluded that, without limiting withdrawal

to about 200,000 acre-feet per year, Comal Springs will likely go dry

for extended periods during even a minor drought. The creation of the

Edwards Aquifer Authority may help to alleviate this threat to some

degree (see Factor D for further discussion). The Edwards Aquifer

Authority is currently subject to litigation regarding violation of the

Voting Rights Act in its formation. The Texas Legislature is now

considering bills designed to bring the Authority into compliance, but

the outcome of this effort remains to be determined.

In 1984 and 1990, some of the higher-elevation Comal Springs ceased

flowing and water levels in the index well (J-17) in San Antonio

dropped to within twelve feet of the historic low of 612.5 ft that

occurred in 1956 (Wanakule 1990). Because these invertebrates require

relatively well-oxygenated water, a reduction or cessation of spring

flows, even if standing water remained around the spring orifices, may

adversely affect the species. Loss of water entirely within their

habitat would result in the extirpation of these aquatic species from

their native habitat.

In addition to a loss of water, a decrease in the water level in

the aquifer could lead to a decreased quality of water at the springs.

The Balcones Fault Zone--San Antonio Region is bounded on the south and

east by a ``bad water'' line across which the groundwater quality

abruptly deteriorates to greater than 1000 mg/l total dissolved solids

(TDS). In other words, at the bad water line, there is a transition in

groundwater from fresh to saline or brackish. Lowered water levels

resulting from groundwater pumpage or decreased recharge may result in

deterioration of water quality in the fresh water section of the

aquifer through movement of the bad water line. The Comal and San

Marcos Springs are very close to the bad water line (TWC 1989; Edwards

Underground Water District 1992b) and although the data are

inconclusive at present, these springs may be sensitive to intrusion of

saline waters at low aquifer levels. Other possible effects of reduced

springflow levels include changes in the chemical composition of the

water in the aquifer and at the springs, a decrease in current velocity

and corresponding increase in siltation, and increase in temperature

and temperature fluctuations in the aquatic habitat (McKinney and

Watkins 1993).

Another threat to the habitat of these species is the potential for

groundwater contamination. Pollutants of concern include those

associated with human sewage (particularly septic tanks), animal/

feedlot waste, agricultural chemicals (especially insecticides,

herbicides, and fertilizers) and urban runoff (including pesticides,

fertilizers, and detergents). Pipeline, highway, and railway

transportation of potentially harmful materials in the Edwards Aquifer

recharge zone and its watershed with the attendant possibility of

accidents presents a particular risk to water quality in Comal and San

Marcos springs. Comal and San Marcos springs are both located in highly

urbanized areas. Hueco Springs is located alongside River Road, which

is heavily travelled for recreation on the Guadalupe River, and may be

susceptible to road runoff and spills related to traffic. Fern Bank

Springs is in a relatively remote, rural location and its principal

vulnerability is probably to contaminants associated with leaking

septic tanks, animal/feedlot wastes, and agricultural chemicals.

Of the counties containing portions of the San Antonio segment of

the Edwards Aquifer, the potential for acute, catastrophic

contamination of the aquifer is greatest in Bexar, Hays, and Comal

counties because of the higher density of urbanization compared to the

western counties. Although spill or contamination events that could

affect water quality may occur to the west of Bexar County, dilution

and the time required for the water to reach the springs may lessen the

threat from that area. As aquifer levels decrease,

[[Page 29540]] however, dilution of contaminants moving through the

aquifer may also decrease.

The TWC reported that in 1988 within the San Antonio segment of the

Edwards Aquifer, Bexar, Hays, and Comal counties had the greatest

number of land-based oil and chemical spills in central Texas that

affect surface and/or groundwater with 28, 6, and 4 spills,

respectively (TWC 1989). As of July, 1988, Bexar County had between 26

and 50 confirmed leaking underground storage tanks, Hays County had

between 6 and 10, and Comal County had between 2 and 5 (TWC 1989),

putting these counties among the top five counties in central Texas for

confirmed underground storage tank leaks. The TWC estimates that, on

average, every leaking underground storage tank will leak about 500

gallons per year of contaminants before the leak is detected. These

tanks are considered one of the most significant sources of groundwater

contamination in the State (TWC 1989).

A TWC project, using the DRASTIC methodology/tool (Aller, et al.

1987) classified Texas aquifers statewide according to their pollution

potential. The Edwards Aquifer (Balcones Fault Zone--Austin and San

Antonio Regions) was ranked among the highest in pollution potential of

all major Texas aquifers (TWC 1989). The project's objective was to

identify areas sensitive to groundwater pollution from a contaminated

land surface. The project modelled both point source and non-point

source types of contamination. The area of particular concern is the

Edwards Aquifer recharge zone and its watershed. The TWC (1989) also

reviewed and reported on the risk to Texas aquifers from sanitary

landfills, hazardous waste disposal facilities, industrial waste and

sewage disposal wells, commercial feedlots, and graveyards.

The DRASTIC methodology may underestimate the importance of faults

and fractures, which affect the movement of groundwater and pollutants.

Faults and fractures may act as conduits and/or barriers to groundwater

flow and, in the vicinity of springs, could facilitate movement of

contaminants. The Comal Springs fault facilitates the movement of

groundwater (and potentially pollutants) towards Comal Springs. Hueco

Springs has a large local recharge component (Brune 1981) and may be

more susceptible to contamination via polluted runoff than Comal or San

Marcos Springs. Little information is available on the relative

contribution of groundwater and local recharge to the water emerging at

Fern Bank Springs, although the temporary increase in discharge seen

after storm events indicates a local recharge component (Barr 1993).

B. Overutilization for commercial, recreational, scientific or

educational purposes. No threat from overutilization of these species

is known to exist.

C. Disease or predation. While individuals of these three species

may be preyed upon by various predatory insects or fishes, no

information indicates that this is a substantial threat to any of the

three species.

D. The inadequacy of existing regulatory mechanisms. Invertebrates

are not included on the Texas Parks and Wildlife Department's (TPWD)

list of threatened and endangered species and are provided no

protection by the State. Nor do the TPWD regulations contain provisions

for protecting habitat of any listed species.

Traditionally, the State of Texas has had no authority to regulate

withdrawal of groundwater from an aquifer. In response to a lawsuit

filed against the Service by the Sierra Club (Sierra Club v. Babbitt,

formerly Sierra Club v. Lujan), the Texas State Legislature passed a

bill (S.B. 1477) authorizing the creation of the Edwards Aquifer

Authority (Authority) and granting the Authority the power to regulate

groundwater withdrawal from the Edwards Aquifer. The bill recommends

limiting groundwater withdrawal from the aquifer to 450,000 acre-feet

per year initially, then reducing it to 400,000 acre-feet per year by

January 1, 2008, based on a model developed by the TWC. One stated goal

of the bill is to provide continuous minimum springflow of at least 100

cfs at Comal and San Marcos Springs by the year 2012 to protect species

that are designated as threatened or endangered under Federal or State

law. However, some researchers have maintained that, even with such

pumping limits, flow at Comal Springs will drop below 100 cfs, and the

springs will likely go dry for extended periods in time of severe

drought and probably during minor droughts (McKinney and Watkins 1993).

The bill creating the Authority gives consideration in setting

minimum springflow requirements only to those species protected under

Federal or State law. These invertebrates would receive no

consideration under the current plan until they are listed. In

addition, Comal and San Marcos Springs are the lowest elevation springs

in which these invertebrates are found, and maintaining flow at Fern

Bank and Hueco Springs is not a stated goal of the water withdrawal

limitations. Efforts to maintain minimum springflow at Comal and San

Marcos Springs would not necessarily be sufficient to maintain flow at

Hueco and Fern Bank Springs, which lie at higher elevations.

Although creation of the Edwards Aquifer Authority and development

of regulations for limiting withdrawal of groundwater from the Edwards

Aquifer is a positive step toward protecting the Comal and San Marcos

spring ecosystems, creation of the Authority is currently a matter in

litigation regarding compliance with the Voting Rights Act. It is

uncertain if or when the Authority will be empowered to enforce the

pumping limits dictated by the legislation, and thus whether it will be

able to protect these aquatic invertebrates and other threatened and

endangered species dependent upon water from the aquifer.

The major regulations affecting water quality in the San Antonio

segment of the Edwards Aquifer are the Edwards Rules (31 Texas

Administrative Code, Chapter 313), promulgated and enforced by the TWC

(recently renamed as the Texas Natural Resource Conservation

Commission). The Edwards Rules regulate construction-related activities

on the recharge zone that may ``alter or disturb the topographic,

geologic, or existing recharge characteristics of the site'' as well as

any other activity ``which may pose a potential for contaminating the

Edwards Aquifer.'' The Edwards Rules regulate construction activities

through review of Water Pollution Abatement Plans (WPAPs). The WPAPs do

not require site-specific water quality performance standards for

developments over the recharge zone nor do they address land use or

impervious cover limitations. The WPAPs do not regulate activities in

the aquifer contributing zone and, as yet, the Edwards Rules do not

include a comprehensive plan to address the effects of cumulative

impacts on water quality in the aquifer (Edwards Underground Water

District 1993).

E. Other natural or manmade factors affecting its continued

existence. The effect of droughts in south central Texas will be much

more severe than previously was the case, due to the large increase in

groundwater withdrawals (Wanakule 1990). These species' very limited

habitat is likely to be lost through drying or decreased volume of

springflow during minor or severe drought.

At present, competition is not known to be a significant threat to

these species. However, two exotic snail species, Thiara granifera and

Thiara tuberculata are common in the spring runs and, as grazers, may

compete for food. Another exotic, the giant ramshorn

[[Page 29541]] snail (Marisa cornuarietis), is present in two of the

spring runs and may colonize the other runs at low flow levels or

through transfer by humans.

The Service has carefully assessed the best scientific and

commercial information available regarding the past, present, and

future threats faced by these species in determining to propose this

rule. Based on this evaluation the preferred action is to list the

Peck's cave amphipod (Stygobromus pecki), Comal Springs riffle beetle

(Heterelmis comalensis), and Comal Springs dryopid beetle as

endangered.

Critical Habitat

Critical habitat is defined by 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, as amended, and implementing

regulations (50 CFR 424.12) require that to the maximum extent prudent

and determinable, the Secretary designate critical habitat at the time

a species is determined to be endangered or threatened. The Service

finds that designation of critical habitat is not prudent for Peck's

cave amphipod, the Comal Springs riffle beetle, and the Comal Springs

dryopid beetle at this time. Service regulations (50 CFR 424.12(a)(1)

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 threat to the

species, or (2) such designation of critical habitat would not be

beneficial to the species.

The Service finds that designation of critical habitat for these

three species would not be prudent because it would not provide a

conservation benefit to them, and would actually be detrimental by

suggesting a misleadingly restricted view of their conservation needs.

Designation of critical habitat would not be beneficial to these

species beyond the benefits provided by listing and the subsequent

evaluation of activities under section 7 of the Act for possible

jeopardy. In the Service's section 7 regulations at 50 CFR Part 402,

the definition of ``jeopardize the continued existence of'' includes

``to reduce appreciably the likelihood of both the survival and

recovery of the listed species,'' and ``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.'' Because these species are endemic to

such highly localized areas, actions that apparently diminish water

quality and quantity at the springs would be fully evaluated for their

effects on the three species through analysis of whether the actions

would be likely to jeopardize their continued existence. Any action

that would appreciably diminish the value, in quality or quantity, of

spring flows on which they depend would also reduce appreciably the

likelihood of survival and recovery of the three species. The analysis

for possible jeopardy applied to these species would therefore be

identical to the section 7 analysis for determining adverse

modification or destruction of critical habitat; no distinction between

jeopardy and adverse modification for activities impacting the springs

on which these species depend can be made at this time. Application of

section 7 relative to critical habitat would therefore not add

measurable protection to these species beyond what is achievable

through review for jeopardy.

Designation of the springs and their immediate environment as

critical habitat would actually be detrimental to conservation efforts

for these species because it would promote the misconception that the

springs are the only areas important to their conservation.

Conservation efforts for these species must address a wide variety of

federally funded or authorized activities (summarized in the

``Available Conservation Measures'' section of this proposed rule) that

affect the quality and quantity of water available to these species

through effects on the recharge sources and aquifer that supply water

to their habitats. Nearly all of these activities will occur beyond the

immediate vicinity of the springs, and some will occur many miles away.

Designation of the springs as critical habitat would be misleading in

implying to Federal agencies whose activities may affect these species

that the Service's concern is limited only to activities taking place

at the springs occupied by the species. Designation of critical habitat

for these species would therefore not be prudent.

Available Conservation Measures

Conservation measures provided to species listed as endangered or

threatened under the Endangered Species Act include recognition,

recovery actions, requirements for Federal protection, and prohibitions

against certain practices. Recognition through listing encourages and

results in conservation actions by Federal, State, and private

agencies, groups, and individuals. The Endangered Species Act provides

for cooperation with the States and requires that recovery actions be

carried out for all listed species. The protection required of Federal

agencies and the prohibitions against taking and harm are discussed, in

part, below.

Conservation and management of the Peck's cave amphipod, Comal

Springs riffle beetle, and Comal Springs dryopid beetle are likely to

involve protection and conservation of the Edwards Aquifer and spring

flow at Comal Springs, Hueco Springs, San Marcos Springs, and Fern Bank

Springs. It is also anticipated that listing will encourage research on

critical aspects of the species' population biology.

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 this

interagency cooperation provision of the Act are codified at 50 CFR

Part 402. Section 7(a)(4) requires Federal agencies to confer

informally with the Service on any action that is likely to jeopardize

the continued existence of a proposed species. 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 species or to destroy or

adversely modify its critical habitat. If a Federal action may affect a

listed species or its critical habitat, the responsible Federal agency

must enter into formal consultation with the Service. Federal actions

that could affect the Peck's cave amphipod, Comal Springs riffle

beetle, and/or Comal Springs dryopid beetle include the funding,

authorization, and implementation of projects that would reduce the

quantity or quality of water within the San Antonio segment of the

Edwards Aquifer or otherwise significantly affect the outlets or water

output of Comal Springs in New Braunfels, Texas; San Marcos Springs in

[[Page 29542]] San Marcos, Texas; Hueco Springs in Comal County, Texas;

and Fern Bank Springs in Hays County, Texas. Examples of these types of

activities include projects that would involve withdrawal of water from

the aquifer; permits for municipal wastewater discharge; agricultural

irrigation; use of pesticides and herbicides; Environmental Protection

Agency National Pollutant Discharge Elimination System permits; section

18 exemptions under the Federal Insecticide, Fungicide, and Rodenticide

Act; and Corps of Engineers permits for stream crossings.

The Act and implementing regulations found at 50 CFR 17.21 set

forth a series of general prohibitions and exceptions that apply to all

endangered wildlife. These prohibitions, in part, make it illegal for

any person subject to the jurisdiction of the United States to take

(includes harass, harm, pursue, hunt, shoot, wound, kill, trap, or

collect; or to attempt any of these), import or export, ship in

interstate commerce in the course of a commercial activity, or sell or

offer for sale in interstate or foreign commerce any listed species. It

is also illegal to possess, sell, deliver, carry, transport, or ship

any 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 species under certain circumstances.

Regulations governing permits are 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

connection with otherwise lawful activities. It is anticipated that few

trade permits would ever be sought or issued because these species are

not known to be in trade.

It is the policy of the Service (59 FR 34272) to identify to the

maximum extent practicable at the time a species is listed or proposed

to be 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 a listing on proposed and

ongoing activities within a species' range. The Service emphasizes that

this action is a proposed listing, and that the guidelines presented

herein are for use in the event that the listing becomes final. Should

the listing become final, the discussion and outline presented here

should assist landowners and managers in avoiding violation of section

9 of the Act. The Service believes that, based on the best available

information, activities that could potentially harm the Comal

invertebrates and result in ``take'' include, but are not limited to--

(1) Collecting or handling of the species;

(2) Activities that may result in destruction or alteration of the

species' habitat (including, but not limited to withdrawal of water

from the aquifer to the point at which habitat becomes unsuitable for

the species, alteration of the physical habitat within the spring runs,

or physical alteration of the spring orifices or of the subsurface

pathways providing water to the springs);

(3) Discharge or dumping of chemicals, silt, pollutants, household

or industrial waste, or other material into the springs or into areas

that provide access to the aquifer and where such discharge or dumping

could affect water quality; or

(4) Herbicide, pesticide, or fertilizer application in or near

springs containing the species or areas that drain into the aquifer.

Careful use of pesticides in the vicinity of the springs may be

necessary in some instances.

The Service believes that a wide variety of activities would not

harm these species if undertaken in the vicinity of their habitats and

thus would not constitute taking. In general, any activity in the

contributing, recharge, or artesian zones of the Edwards aquifer that

would not have potential for cumulative or acute/catastrophic decrease

in water quality within the aquifer and would not involve use of water

from the aquifer should not harm these species. Inquiries concerning

the possible effects of specific activities should be directed to the

Service's Texas State Office (see ADDRESSES, above).

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 proposed rule are hereby solicited. Comments are

particularly sought concerning:

(1) Biological, commercial trade, or relevant data concerning any

threat (or lack thereof) to Peck's cave amphipod, the Comal Springs

riffle beetle, and Comal Springs dryopid beetle;

(2) The location of any additional populations of these 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 ranges, distributions,

and population sizes of these species;

(4) Current or planned activities in the subject area and their

possible impacts on these species; and

Final promulgation of the regulations on these species will take

into consideration the comments and any additional information received

by the Service, and such communications may lead to a final regulation

that differs from this proposal.

The Endangered Species Act provides for a public hearing 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 State Administrator, U.S. Fish and Wildlife

Service (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).

References Cited

Aller, L., T. Bennett, J.H. Lehr, R.J. Petty, and G. Hackett. 1987.

DRASTIC: a standardized system for evaluating groundwater pollution

potential using hydrogeologic settings. U.S. Environmental

Protection Agency. EPA/600/2-87/035. 622 pp.

Barr, C.B. 1993. Survey for two Edwards Aquifer invertebrates: Comal

Springs dryopid beetle Stygoparnus comalensis Barr and Spangler

(Coleoptera: Dryopidae) and Peck's cave amphipod Stygobromus pecki

Holsinger (Amphipoda: Crangonyctidae). Prepared for U.S. Fish and

Wildlife Service. 70 pp.

Barr, C.B., and P.J. Spangler. 1992. A new genus and species of

stygobiontic dryopid beetle, Stygoparnus comalensis (Coleoptera:

Dryopidae), from Comal Springs, Texas. Proc. Biol. Soc. Wash.

105(1):40-54.

Bosse, L.S., D.W. Tuff, and H.P. Brown. 1988. A new species of

Heterelmis from Texas (Coleoptera: Elmidae). Southwestern Naturalist

33(2):199-203.

Brown, H.P., and C.B. Barr. 1988. First report of stygobiontic

(subterranean) riffle beetles in North America. Program abstract for

April 22, 1988, meeting of Southwestern Association of Naturalists.

5 pp.

Brune, G. 1981. Springs of Texas, Volume 1. Branch-Smith Inc., Ft.

Worth, Texas.

Chapman, R.F., 1982. The Insects: Structure and Function. Harvard

University Press, Cambridge, MA. 919 pp.

Edwards Underground Water District. 1989. Compilation of hydrologic

data for the [[Page 29543]] Edwards Aquifer, San Antonio area,

Texas, 1988, with 1934-88 summary: Bulletin 48, 157 pp.

Edwards Underground Water District. 1992a. Report of the technical

data review panel on the water resources of the south central Texas

region. 307 pp.

Edwards Underground Water District. 1992b. Investigation of the

fresh/saline water interface in the Edwards Aquifer in New Braunfels

and San Marcos, Texas. Report 92-02. 18 pp.

Edwards Underground Water District. 1993. Urban Development on the

Edwards Aquifer Recharge Zone. Report 93-09. 40 pp.

Guadalupe-Blanco River Authority. 1988. The Edwards Aquifer:

Underground River of Texas. Guadalupe-Blanco River Authority,

Seguin, Texas. 63 pp.

Holsinger, J.R. 1967. Systematics, speciation, and distribution of

the subterranean amphipod genus Stygonectes (Gammaridae). Bull. U.S.

Nat. Mus. 259:1-176.

Longley, G. 1991. Status and trends of the Edwards (Balcones Fault

Zone) Aquifer in the San Antonio Region. pp. 4-18 In: Proceedings of

South Texas Irrigation Conference. Guy Fipps, ed. 146 pp.

McKinney, D.C., and D.W. Watkins, Jr. 1993. Management of the

Edwards Aquifer: A critical assessment. Technical Report CRWR 244.

Center for Research in Water Resources, Bureau of Engineering

Research. University of Texas at Austin. 94 pp.

Technical Advisory Panel. 1990. Technical factors in Edwards Aquifer

use and management. Prepared for Special Committee on the Edwards

Aquifer. 57 pp.

Texas Water Commission. 1989. Ground-water quality of Texas--an

overview of natural and man-affected conditions. Austin, Texas. 197

pp. and 3 plates.

Wanakule, N. 1990. Stochastic drought analysis of the Edwards

Aquifer. Edwards Aquifer Research and Data Center No. R1-90, San

Marcos, Texas. 32 pp.

Authors: The primary authors of this rule are Ruth Stanford and

Alisa Shull (see ADDRESSES section) and George Drewry, Division of

Endangered Species, U.S. Fish and Wildlife Service, 452 ARLSQ,

Washington DC 20240.

List of Subjects in 50 CFR Part 17

Endangered and threatened species, Exports, Imports, Reporting and

recordkeeping requirements, Transportation.

Proposed Regulations Promulgation

PART 17--[AMENDED]

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:

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. Section 17.11(h) is amended by adding the following, in

alphabetical order under Crustaceans and Insects, respectively, to the

List of Endangered and Threatened Wildlife to read as follows:

Sec. 17.11 Endangered and threatened wildlife.

* * * * *

(h) * * *

--------------------------------------------------------------------------------------------------------------------------------------------------------

Species Vertebrate population

---------------------------------------------------- Historic range where endangered or Status When listed Critical Special

Common name Scientific name threatened habitat rules

--------------------------------------------------------------------------------------------------------------------------------------------------------

* * * * * * *

CRUSTACEANS:

* * * * * * *

Amphipod, Peck's cave Stygobromus U.S.A. (TX)............. NA...................... E ........... NA NA

(=Stygonectes) pecki.

* * * * * * *

INSECTS:

Beetle, Comal Springs Stygoparnus comalensis.. U.S.A. (TX)............. NA...................... E ........... NA NA

dryopid.

* * * * * * *

Beetle, Comal Springs Heterelmis comalensis... U.S.A. (TX)............. NA...................... E ........... NA NA

riffle.

--------------------------------------------------------------------------------------------------------------------------------------------------------

Dated: May 23, 1995.

Mollie H. Beattie,

Director, U.S. Fish and Wildlife Service.

[FR Doc. 95-13457 Filed 6-1-95; 8:45 am]

BILLING CODE 4310-55-P