Southwestern Association of Naturalists Survey and Distribution of Invertebrates from Selected Springs of the Edwards Aquifer in Comal and Hays Counties, Texas Author(s): James R. Gibson, Scott J. Harden and Joe N. Fries Source: The Southwestern Naturalist, Vol. 53, No. 1 (Mar., 2008), pp. 74-84 Published by: Southwestern Association of Naturalists Stable URL: https://www.jstor.org/stable/20424894 Accessed: 17-02-2020 20:47 UTC REFERENCES Linked references are available on JSTOR for this article: https://www.jstor.org/stable/20424894?seq=1&cid=pdf-reference#references_tab_contents You may need to log in to JSTOR to access the linked references. JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact [email protected]. Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at https://about.jstor.org/terms Southwestern Association of Naturalists is collaborating with JSTOR to digitize, preserve and extend access to The Southwestern Naturalist This content downloaded from 147.26.181.231 on Mon, 17 Feb 2020 20:47:01 UTC All use subject to https://about.jstor.org/terms THE SOUTHWESTERN NATURALIST 53(1):74-84 MARCH 2008 SURVEY AND DISTRIBUTION OF INVERTEBRATES FROM SELECTED SPRINGS OF THE EDWARDS AQUIFER IN COMAL AND HAYS COUNTIES, TEXAS JAMES R. GIBSON,* ScoTJ. HARDEN, AND JOE N. FRIES National Fish Hatchery and Technology Center, United States Fish and Wildlife Service, 500 East McCarty Lane, San Marcos, TX 78666 (JRG, JNF) 8019 Riata Drive, San Antonio, TX 78227 (SJH) *Correspondent: randy [email protected] ABSTRACT-We surveyed four spring sites of the Edwards Aquifer to determine current distribution and abundance of spring and cave-adapted invertebrates, including three that are federally listed as endangered. We found 18 species from 12 families of endangered and stygobiontic fauna, similar to other surveys completed 10 years prior, and recorded new localities for Tethysbaena texana, Cirolanides texensis, Lirceolus hardeni, Lirceolus smithii, Stygobromus longipes, Stygobromus flagellatus, and Artesia subterranea. We also report discovery of new species of Bogidiellidae (near Parabogidiella), Ingolfiella, and Almueyzothyas. RESUMEN-Examinamos cuatro sitios de nacimento de aguas del acuifero Edwards para determinar las distribuciones y abundancias de invertebrados adaptados a manantiales y cuevas, incluyendo 3 especies que estan en peligro de extinci6n a nivel federal. Encontramos 18 especies de 12 familias de fauna estigobi6nticas parecidas a muestreos realizados hace 10 afnos. Reportamos nuevas localidades para Tethysbaena texana, Cirolanides texensis, Lirceolus hardeni, Lirceolus smithii, Stygobromus longipes, Stygobromus flagellatus y Artesia subterranea. Tambien reportamos el descubrimento de nuevas especias de Bogidiellidae (similar a Parabogidiella), Ingofiella y Almuerzothyas. The limestone aquifers of the Edwards Plateau Edwards Aquifer are listed as endangered by support about one-half of all springs in Texas, the United States Fish and Wildlife Service including some of the largest (Brune, 1981). (1997)-Comal Springs riffle beetle Heterelmis Bowles and Arsuffi (1993) identified 91 endemic comalensis, Peck's cave amphipod Stygobromus species in the permanent aquatic habitats of the pecki, and Comal Springs dryopid beetle Stygo Edwards Plateau with >40 described species of parnus comalensis. These aquifer-dependent spe stygobionts (Hershler and Longley, 1986r, Barr cies are subject to population reduction, or and Spangler, 1992). This aquifer is the major possible extinction, if water quality or quantity source of water for the rapidly growing city of is decreased due to drought or over-pumping. San Antonio. It also is important for agriculture, They only occur in Comal and Hueco springs in fisheries, and tourism. Water flowing down the Comal County and San Marcos and Fern Bank Guadalupe River supplied by the aquifer pro springs in Hays County, Texas (Fig. 1). vides important coastal habitat for estuarine Comal Springs, located in the city of New reliant species such as economically important Braunfels, is the largest spring system (mean shrimp, crabs, and fishes (Bowles and Arsuffi, discharge = 8,200 during 1927-2005; United 1993), as well as waterfowl that feed on these States Geological Survey, http://nwis.waterdata. species. Thus, it is important to maintain the usgs.gov/tx/nwis/discharge/, to 9,900 L/s dur quality and a sufficient quantity of water in the ingl882-1926; Brune, 1981) in Texas and the Edwards Aquifer. Periodic surveys of the stygo southwestern United States. Comal Springs is a biontic communities can be useful to detect spring complex with numerous discharge loca changes within the aquifer that might affect tions occurring along the 1,300-m reach forming those that rely on this resource. Three aquatic Landa Lake. Tracer testing performed by the invertebrates associated with springs of the Edwards Aquifer Authority (EAA) in 2002 This content downloaded from 147.26.181.231 on Mon, 17 Feb 2020 20:47:01 UTC All use subject to https://about.jstor.org/terms March 2008 Gibson et al.-Invertebrates from the Edwards Aquifer 75 / / - 1< 'sTRAVIS / I ~ ~ ~~~~~~~~~~~~~~~~~~~~~~~~/ X/ GILLESPIE B / BLANCO N I I X N I ~ ~ ~~~/ N / I / \ \ t / ~~~~ ~ ~~HAYS X fBASTROP KENDALL ,\Y' / ~~~~COMAL z ? W BEXAR ; \\ tv ~~~~~~~~~~~~~~~CALDWELL,RzrV GUADALUPE C;W,~~~~~~~~~~~~~~~~~~~~~~~~udlp River. // WILSON \\ ~~~~0 10 20 30 FIG. 1-Sites in south-central Texas surveyed for invertebrates by drift netting and hand sampling at spring openings at (1) Comal Springs, (2) Hueco Springs, and (3) Fern Bank Springs during spring and summer 2003. San Marcos Springs (4) was sampled using cotton-cloth lures during spring 2004 and 2006. In small map of Texas, rectangle indicates expanded region of named counties and dark polygon represents the artesian zone of the Edwards Aquifer. indicates convergent, conduit-dominated contribution flow to the springs and naphthalene paths in the Comal Springs area. Groundwater detected at Hueco and Comal springs from a discharging from Comal Springs originates diesel inspill in January 2000 about 6.5 km SW New regions as far as 225 km to the west. Discharged Braunfels suggest regional contribution (G. groundwater ranges in age from hours to Schindel, many pers. comm.). The occurrence of some years. The spring complex has had continuous of the same species at both Comal and Hueco flow with an exception in 1956, when flow springs ceased also suggests a regional component of for about 6 months after 7 years of drought flow. (Brune, 1975, 1981). San Marcos Springs, located in the City of San Hueco Springs, located 5.1 km N ComalMarcos, is the second largest spring system Springs, is a much smaller spring system (mean (mean discharge = 4,100 during 1916-1955; discharge = 1,100 during 1924-1978; Brune, Brune, 1981, to 4,900 L/s during 1956-2005; 1981, to 1,800 L/s during 2002-2006; UnitedUnited States Geological Survey, http://nwis. States Geological Survey, http://nwis.waterdata. waterdata.usgs.gov/tx/nwis/discharge/) in Tex usgs.gov/tx/nwis/discharge/) issuing from as. Sanallu Marcos Springs is a complex of many vial gravel about 90-150 m west of the artesian Guada springs upwelling into Spring Lake, lupe River. Hueco Springs, like Comal Springs, forming the head of the San Marcos River has a local and regional component; tracer (Brune, tests 1981). Records indicate this spring by Ogden et al. (1986) showed some complex local has not ceased flowing. Water discharg This content downloaded from 147.26.181.231 on Mon, 17 Feb 2020 20:47:01 UTC All use subject to https://about.jstor.org/terms 76 The Southwvestern Naturalist vol. 53, no. 1 ing from San Marcos Texas. Springs We alsohas comparedmultiple our results with those sources; southern flow of from C. B. theBarr San (in Antoniolitt.). area in Bexar County that bypasses Comal Springs and flow from the MATERIALS northern AND area METHODS-We of the collected invertebrates aquifer, south of the Barton using Springsdrift nets groundwa (0.45 by 0.30-m rectangular opening, 250 gm mesh) at Comal, Fern Bank, and Hueco ter divide near Kyle, Hays springs County. (Fig. Groundwater 1). From 2 May to 16 August 2003, we from the southern flow sampled paths discharges each site with from five drift nets twice in both the southern portion of springSpring and Lake summer while exceptwater Fern Bank Springs, which from the northern flow was paths sampled discharges with two from nets once in spring and twice in summer, totaling 46 samples. We deployed nets for the northern portion of the lake (G. Schindel, about 24 h and checked them every 4-6 h. Because so pers. comm.). few specimens were found at Fern Bank Springs during Fern Bank Springs is located the first 8 km sampling E Wimberley period, nets were left out for 67-74 h and 13 km NW San Marcos. and Achecked small oncecave dailystream during the last two sampling periods. Specimens of H. comalensis and S. pecki large empties into a pool before diffusely flowing over a enough to identify in the field were returned to the bluff and cascading into area the whereBlanco they River. were Many collected and all other inverte seeps emerge near the base brates of fromthis cliff.nets wereThese preserved in 70% ethanol for springs are influenced by later local study. recharge We calculated and may combined drift time (sum of be perennial with recorded hours netsdischarge were placed ranging at a site) for each spring system and drift rate (number collected/day) of each species. from 140 L/s on 31 May 1975 to 9 L/s on 1 May During March 2004 and March and April 2006, we 1978 (Brune, 1981; C.