SAN MARCOS & COMAL SPRING & ASSOCIATED AQUATIC ECOSYSTEMS (REVISED ...

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SAN MARCOS & COMAL SPRING
& ASSOCIATED AQUATIC
ECOSYSTEMS (REVISED)
RECOVERY
PLAN
rI
Us.
San Marcos and Comal Springs
and
AssociatedAquatic Ecosystems
(Revised)
Recovery Plan
(Short tide: San Marcos/Comal
(Revised) Recovery Plan)
for
San Marcos Gaxnbusia (Gambusiageorgei)
Fountain Darter (Etheostomafonticola)
San Marcos Salamander (Eu~ycea nana)
Texas Wild-rice (Zizania texana)
Texas Blind Salamander (Typhiomolge rathbuni)
(Original approved: April 8, 1985)
Prepared by
The San Marcos/Comal RecoveryTeam
and
U.S. Fish and Wildlife Service
Austin Ecological Services Office
10711 Burnet Road, Suite 200
Austin, Texas 78758-4455
for
Region 2
U.S. Fish and Wildlife Service
Albuquerque, NewMexico
Approved:
Date:
February 14, 1996
United States Department ofthe Interior
FiSH ANDWThDLIFESERVICE
Eco1o~izaiSerucdFieldQ~ic
1071’. ~uxnerRe~ad. S.~ire200
~pJ~ BankBide.
A.Lstin,TexasT8753
March 22, 1996
CORRECTION SHEET FOR
SAN HARCOS/COI4A.L (REVISED) RECOVERY PLAN
The following corrections should be noted to the San MarcoS & Comal
Springs and Associated Aquatic Ecosystems (Revised) Recovery Plan
(U.S. Fish and Wildlife Service 1996):
P.iv, the literature citation should read “U.S. Fish and Wildlife
Service. 1996. not 1995.
. . . ‘,
P.7, column 2, second paragraph, line 13: “atchment” should be
“catchment”
P. 33, column 1, under “Habitat”, first paragraph: the list given
there should be numbered 1-6.
P. 34, column 1, lines 4—5: For clarification, the on the end
“—“
of line 4 is a negative number sign.
P. 59, task 2.~: for clarification, the reference to task 2.11,
actually refers to subtask 2.11 listed above task 2.3.
P. 64, column 2, line 7: the sentence beginning “Some mechanism
should read “Some mechanism for assuring adequate aquifer
“
levels and springflows is essential to assure success of this plan,
otherwise all the efforts of the involved parties could be offset
by parties who choose not to participate in the implementation of
the Aquifer Management Plan.”
P. 114, column 2, line 14: replace “without” with “which does not
impose”
p. 116, column 1, 7 lines from the bottom: “task 2.11” should read
“subtask 2.12”.
SanMarcus &ComalSprings &AssociatedAquatic Ecosystems Recovers’Plan
SAN MARCOS/COMAL
RECOVERY TEAM
Dr. RobertJ. Edwards, Leader Ms. Jackie Poole
DepartmentofBiology Texas Parks and Wildlife Department
University ofTexas-Pan American Endangered Resources Branch
Edinburg,TX 78539 3000 So. IH-35 Suite 100
Austin, TX 78704
Dr. Gary P. Garrett
Texas Parks and WildlifeDepartment Dr. Dianna D. Tupa
Heartofthe Hills ResearchStation 11102 D-K Ranch Rd.
Junction StarRoute Box 62 Austin, TX 78759
Ingram,TX 78025
Dr. BobbyG. Whiteside
Dr. Glenn Longley DepartmentofBiology
Department ofBiology Southwest Texas State University
SouthwestTexas StateUniversity San Marcos, TX 78666
SanMarcos, TX 78666
U.S. Fishand WildlifeService Liaison
Ms. Alisa M. Shull
USFWS, Ecological Services Field Office
10711 BurnetRoad, Suite200
Austin,TX 78758
RecoveryTeam
H
SanMarcos&ComalSprings&AssociatedAquaticEcosystemsRecovers Plan
DISCLAIMER
Recovery plans delineatereasonable actions thatare believedto be requiredto recover and/or
protect listed species. Plans arepublished by the U.S. Fish and Wildlife Service,sometimes prepared
with the assistance ofrecovery teams, contractors, State agencies, and others. Because offurloughs of
Federalemployees and ongoing litigation regarding theEdwards Aquifer and species coveredby this
plan, therewas considerable urgency to finalize thisplan. Therefore, the normal critique and inputto
thefinal version ofthe planwas minimal. The Service does, however, appreciate the RecoveryTeams
substantial efforts in completingthe earlier drafts ofthis plan. As is customary, objectives will be
attained and any necessary funds made availablesubject to budgetaryand other constraints affecting
the parties involved, as wellas the need to address other priorities.
Recovery plans do not necessarilyrepresent the views nor the official positions orapproval ofany
individuals or agencies involved in the plan formulation, other than the U.S. Fish and Wildlife Service.
They represent theofficial position ofthe U.S. Fish and WildlifeService onlyafter theyhave been
signed bythe Regional Director orDirector as approved. Approved recoveryplansare subject to modifi-
cationas dictated bynewfindings, changes inspeciesstatus, and the completion ofrecoverytasks.
Disclaimer
111
SanMarcos&CornalSprings&AssociatedAquatic EcosystemsRecovers’ Plan
LITERATURE CITATIONS
Literature citations should read as follows:
U.S. Fish and Wildlife Service. 1995. San Marcos/Comal (Revised) Recovery Plan. Albuquerque,
NewMexico. pp. x 93 with 28 pagesofappendices.
+
Additional copies ofthis plan,when finalized, may be purchased from:
Fish and WildlifeReference Service:
5430 GrosvenorLane, Suite 110
Bethesda, Maryland 20814
[phone] or [phone]
The feefor the plan varies dependingon thenumber ofpages ofthe plan.
Literature Citations
iv
SanMarcos&CarnalSprings&AssociatedAquaticEcosystemsRecoveryPlan
ACKNOWLEDGEMENTS
The Servicewould liketo expressits appreciation for the many individuals, groupsand agencies
who have been activelyworking to resolve problems and gather information needed to achieve the
goals ofstabilizingthe habitats andpopulations ofthese species, and making progress towardrecovery.
The Service looks forward to continued collaboration to achieve the conservation ofthese unique
resources.
Many individualsand groups have conducted or assisted in field research on the Comal and San
Marcos rivers, includingpeople from citydepartments, universities, state andFederal agencies, non-
profitgroups, local businesses, landowners, and interestedindividuals. Thanks to one andall.
The Service gratefully acknowledges theAlabamaMuseum ofNatural History and theIllinois
NaturalHistory Survey for useofthe line drawingofthe fountain darter foundin Figure4. In addi-
tion, thanks is due theTexas Parks andWildlife Department for permission to use the illustration of
Texaswild-rice used in Figure 6.
Adax,wkdgement3 v
SanMarcos& ComalSprings&AssociatedAquatic EcosystemsRecovery lw
EXECUTIVE SUMMARY
RECOVERY CRITERIA
CURRENT SPECIES’ STATUS
Delisting isconsidered unattainable in
the near future for all five species due to the
The fountain darter, San Marcos gambusia,
potential forextinction from catastrophic events.
Texasblind salamander, andTexas wild-rice are
Consequently, this plan calls for the establish-
endangered.The SanMarcos salamander is
ment and continued maintenance ofrefugia
threatened. Critical habitat is designated for all
capability for all five species in case ofa cata-
except theTexas blind salamander.The fountain
strophicevent. Downlisting is considered fea-
darter occurs in the San Marcosand Comal
sible for the fountaindarter, Texaswild-rice, and
systems in centralTexas. The Texas blindsala-
Texas blindsalamander and detailed criteria are
mander is restricted to the EdwardsAquifer. The
givenin theplan. The potential fordownlisting
other threespecies occur in the SanMarcos
system. Other species ofconcern alsooccur in theSan Marcos gambusia isproblematic. In-
terimobjectives are given forthat speciesto
theseecosystems includingthreethat havebeen
measure progress toward preventing extinction.
proposed forlisting: Peck’s Caveamphipod,
Comal Springs riffle beetle, and the Comal
ACTIONS NEEDED
Springs dryopid beetle.
1. Assure sufficientwater levels in the
HABITAT REQUIREMENTS
Edwards aquifer and flows in Comal and
AND LIMITING FACTORS
San Marcos Springsto maintain habitat
all lifestages ofthefive listed
for
All species are aquatic and inhabit ecosys- species and integrity ofthe ecosystem
tems dependent on theEdwardsAquifer. All but upon which they depend.
the subterraneanTexas blind salamander occur
2. Protectwater quality.
in spring-fed systems. Loss ofspringflowsdue to
drawdown ofthe aquifer is one ofthe primary
3. Establish andmaintain populations for all
threats. Other threats include nonnativespecies,
five listedspecies in theirhistoric habitats.
recreational activities, predation, and direct or
indirecthabitat destructionor modificationby
4. Conduct biological studies necessary for
humans (e.g., dambuilding, bank stabilization,
successful monitoring, management, and
and control ofaquatic vegetation) and factors restoration.
thatdecrease waterquality.
5. Encourage partnerships with landowners
RECOVERY GOALS and agencies to develop and implement
conservation strategies.
The goals ofrecoveryare: 1) to secure the
6. Develop and implement a regional
survival ofthese species in their nativeecosys-
Aquifer ManagementPlan.
tems; 2) to develop an ecosystem approach using
strategies to address both local, site-specific, and 7. Develop and implement local
broad regional issues related to recovery; and 3) management and restoration plans to
to conserve the integrityand functionofthe address multiple threats.
aquiferand spring-fed ecosystems that these
species inhabit. 8. Promote publicinformation and
education.
ExecutiveSummary vi
SanMarcos&ComalSprings&AssociatedAquatic EcosystemsRecoveryPlan
Costs (Dollars 1000):
Prixority 1 Priority 1 Priority 2 Priority 3
Year Tasks Tasks Tasks Tasks Total
1996 256.0 506.5 234.5 5.0 1,002.0
1997 238.0 530.5 233.5 5.0 1,007.0
1998 205.0 439.5 182.0 5.0 831.5
1999-
2025 1,140.0 1,329.5 592.0 3,061.5
—
Total 1,839.0 2,806.0 1,242.0 15.0 5,902.0
DateofRecovery: Ifcontinuous progress is made, downlistingthefountain darter
and Texaswild-riceshould be possible by 2025.
ExecutiveSummary vii
San Marcus&Comalsprings & ssoccstedAquatic Bcosvsrersss Recovers Piais
TABLE OF CONTENTS
DisclailIIer
iii
Literature Citations
IV
~~~flOwledgements
ExecutiveSummary vi
Table ofContents viii
List ofFigures andTables
Overview ofthe Recovery Plan
PART I BACKGROUND INFORMATION
-
A. THE ECOSYSTEMS 6
Physiography and Hydrology 7
B. THREATS TO THE SPECIES AND THEIR ECOSYSTEMS 16
Water Quantity 16
Water Quality 18
HabitatModification 19
Nonnative Species 20
RecreationalActivities 21
Other Impacts
C. GENERAL CONSERVATION MEASURES 24
WaterQuantity 24
WaterQuality 25
Nonnative Species 25
Recreation 26
Habitat Maintenance, Restoration, and Enhancement 26
Captive Propagationand Contingency Plans 26
Education and Outreach 26
D. SPECIESACCOUNTS 27
San Marcos Gambusia (Gambusiageorgei) 27
Description 27
Historic and Present Distribution 27
Habitat 29
Life History/Ecology 29
Conservation Measures 30
Fountain Darter (Etheostomafonticola) 30
Description 30
Historical Distribution 32
Present Distribution 33
Habitat 33
Life History/Ecology 33
TableofContents viii