Status Assessment and Watershed Planning for Plateau Shiner, Nueces River Shiner, and Nueces Roundnose Minnow in the Upper Nueces River Basin

STATUS ASSESSMENT AND WATERSHED PLANNING FOR PLATEAU SHINER, NUECES RIVER SHINER, AND NUECES ROUNDNOSE MINNOW IN THE UPPER NUECES RIVER BASIN

FINAL REPORT

Co-Principal Investigators

Robert J. Edwards, Department of Biology, University of Texas-Pan American, Edinburg, TX 78539 Gary P. Garrett, HoH Fisheries Science Center, Texas Parks and Wildlife Department, Mountain Home, TX 78058 Kerry Reeves, HoH Fisheries Science Center, Texas Parks and Wildlife Department, Mountain Home, TX 78058 Ryan Smith, The Nature Conservancy, San Antonio, TX 78250

1 December 2008 STATUS ASSESSMENT AND WATERSHED PLANNING FOR PLATEAU SHINER, NUECES RIVER SHINER, AND NUECES ROUNDNOSE MINNOW IN THE UPPER NUECES RIVER BASIN

Co-Principal Investigators

Summary

The Upper Nueces River Basin is composed of three main tributary systems: the Nueces, Frio, and Sabinal rivers. All three rivers were designated as Ecologically Significant Stream Segments by the Texas Water Development Board in regional water planning. The Texas Comprehensive Wildlife Conservation Strategy (Texas Parks and Wildlife Department 2005) and The Nature Conservancy (The Nature Conservancy 2004) have also designated the three rivers as high priorities. Additionally, about 60% of the Edwards Aquifer recharge water comes from the upper portion of the Nueces River basin, making riparian health important for plant, animal, and human communities throughout the region. It is thought riparian integrity in these rivers has declined, posing a threat to priority species and habitats, not to mention human use. One possible indicator of this decline is the apparent decrease in range and abundance of several fish species, notably but not exclusively, the plateau shiner (Cyprinella lepida), Nueces River shiner (Cyprinella sp.), and the Nueces roundnose minnow (Dionda serena). These species are thought to depend on perennial relative flows of clear water, and thus serve as an indicator of hydrologic function and water quality. We provide information on the status and range of these three species and their utility as indicators of hydrological integrity and watershed health. We also provide data that can be useful for a community-based action plan to help maintain the ecological integrity in critical portions of the three river basins.

Introduction

The upper Nueces River drainage supports a unique, highly endemic fish fauna that is dependent upon clear, cool, high quality spring inflows from the Edwards aquifer (Edwards et al. 2004). The plateau shiner (Cyprinella lepida) is an upper Nueces River drainage endemic minnow that inhabits clear, spring- fed streams in the upper Frio and Sabinal river systems (Mayden 1989, Hubbs et al. 2008). Because of morphological and genetic differences, plateau shiner in the upper Nueces River mainstem is now considered a distinct, undescribed species (Richardson and Gold 1995) currently known as the Nueces River shiner (Cyprinella sp.). There is need of more extensive morphological and life history information beyond the brief analysis of Matthews (1987) to enable more thorough characterization of these two species and formal description of Nueces River shiner. The Nueces roundnose minnow (Dionda serena) is endemic to the upper Nueces Basin, inhabiting vegetated runs and side-channel habitats in the mainstem tributaries (Hubbs et al. 1991, Mayden et al. 1992). Plateau shiner and Nueces River shiner are high priority and the Nueces roundnose minnow is a medium priority species in the Texas Comprehensive Wildlife Conservation Strategy (Texas Parks and Wildlife Department 2005).

Current known threats to watershed health in this area include certain existing agricultural practices, land use changes, and groundwater pumping. These have combined to create stream segments identified as impaired under Section 303(d) of the Clean Water Act. It is thought that these recorded changes, as well as more subtle impacts, may be a factor in population and range declines among the native fishes. If this is the case, these species may not only be of conservation interest as declining endemics and natives; they may also serve as sensitive indicators of hydrological integrity.

Recent collections suggest that Plateau shiner, Nueces River shiner, Nueces roundnose minnow and other members of the fish community may be experiencing decreases in local abundance, along with potential range decreases (Richardson and Gold 1995). However, there is still incomplete knowledge of the current range of Plateau shiner in the Frio and Sabinal rivers, and of the Nueces River shiner in the upper Nueces River. Information on habitat requirements, abundance, range and population trends is necessary to confirm the status and conservation need of these fishes. In addition, conservation and restoration strategies should be developed to help ensure the continued persistence of these fish populations. Effective conservation and restoration strategies will necessarily extend beyond the river banks and into the surrounding watershed. Consequently, other priority species within the Texas Comprehensive Wildlife Conservation Strategy (Texas Parks and Wildlife Department 2005) stand to benefit from conservation planning. Under the Conservancy’s comprehensive planning methodology, other aquatic and terrestrial species will be given consideration as well. Other aquatic species of potential concern within the proposed planning area include greenthroat darter ( Etheostoma lepidum ) and headwater catfish ( Ictalurus lupus ). There are also introduced populations of Guadalupe bass (Micropterus treculii) in the Nueces and Sabinal rivers, and genetic concerns surrounding this species in its native range has shown the importance of these populations. There are numerous terrestrial species of conservation priority (Texas Parks and Wildlife Department 2005) in the watershed as well, including but not limited to, the high priority golden-cheeked warbler ( Dendroica chrysoparia ), and black-capped vireo (Vireo atricapilla ), medium-priority painted bunting ( Passerina ciris ), Cassin’s sparrow ( Aimophila cassinii ) and dickcissel ( Spiza americana ), and low-priority rufous-crowned sparrow ( Aimophila ruficeps ) and Bell’s vireo ( Vireo bellii ). Notable plants occur here as well, such as big red sage ( Salvia penstemonoides ), sycamore-leaf snowbells ( Styrax platanifolius ssp. stellatus ), Texas snowbells ( Styrax platanifolius ), Texas mock-orange ( Philadelphus texensis ), narrow-leaf brickellbrush ( Brickellia eupatorioides var . gracillima ), and the endangered Tobusch fishhook cactus ( Sclerocactus brevihamatus ssp. tobuschii ). These and other terrestrial species also stand to benefit from watershed planning and protection.

The Nature Conservancy is currently engaged in watershed protection in this area, mainly as a participant in the City of San Antonio’s Aquifer Protection Program. The Conservancy also holds several conservation easements, and is actively exploring ways to increase conservation efforts in this part of the river basin. The focus and momentum created by a conservation action plan would be a strong, leveraging asset for developing additional support for these conservation efforts.

The objectives of this project were to:

1) Estimate current distributional range, habitat association and population status of Plateau shiner in the Frio and Sabinal Rivers, Nueces River shiner in the upper Nueces River, and Nueces roundnose minnow in the Frio, Sabinal, and upper Nueces rivers 2) Develop a conservation plan that addresses the needs of these and other high-priority aquatic and terrestrial species in the headwaters portions of the three watersheds.

Materials and Methods The fish communities were sampled using common-sense seines throughout the upper portions of the Nueces, Frio and Sabinal river watersheds concentrating on the Edwards Plateau region but extending downstream onto the Coastal Plain. Sampling was sufficiently intensive to characterize the fish community and determine standardized relative abundances. All potential habitats were sampled in proportion to their abundance and until additional species are no longer encountered. Fishes were sampled seasonally from spring 2007 to summer 2008. Collections were obtained during different seasons to allow measurements of seasonal fluctuations in population size of various species and to determine habitat usage and species associations at various life stages. Relative abundances were calculated for all species and reported along with the actual numbers of all fishes obtained. At each collection site, all specimens collected were identified and each species enumerated. Vouchers of all species collected were preserved, fixed in 10% formalin and preserved in 75% ethanol and placed for curation in the Texas Natural History Collection at the University of Texas at Austin.

Basic ecological information was collected for each site including a basic characterization of the physical environment including substrate characteristics and any obvious water or habitat alterations in order to evaluate their relationship to the species assemblages found and distributional patterns of the species of interest. All sites were georeferenced using standard GPS units and stream physical characteristics were recorded at each collection site during each season. Important water and habitat characteristics that were collected included relative flow velocity, channel morphology, substrates, vegetation types and density, and standard chemical parameters (dissolved oxygen, pH, conductivity, total dissolved solids and temperature).

An Index of Biotic Integrity (IBI) was calculated for each collection using methods modified from those of Linam et al. (2002) for Central Texas Plateau streams. In our formulation, we used the following scoring criteria:

Table 1. Scoring criteria for calculated IBI scores for collection sites in streams in the upper Nueces basin.

Scoring Criteria Metric 5 3 1 N species >9 >6 ≤6 N native cyprinids >4 3-4 <3 N benthic invertivore >1 >0 0 N sunfish species >3 2-3 <2 N intolerant species >1 1 0 % individuals as Tolerant species <26% 26-50% >50% (excluding Gambusia affinis ) % individuals as Omnivore species <9% 9-16% >16% % individuals as Invertivore species >65% 33-65% <33% % individuals as Piscivores species >8.4 3.9-8.4% <3.9% % individuals as non-native species <1.4% 1.4-2.7% >2.7% % individuals with disease or anomaly <0.6% 0.6-1.0% >1.0% N individuals/seine haul (estimated) >40 40 <40

Aquatic Life Use: > 52 Exceptional; 42-51 High; 30-41 Intermediate; <30 Limited

Each of the metrics used by Linam et al. (2000) were used unmodified with the exception of their two-part metric indicating the number of individuals in a sample. The Linam et al. (2000) method used the number of individuals per seine haul as one metric and the number of individuals collected per minute of electrofishing as another. We did not electrofish, so did not use that metric and the number of individuals captured per seine haul is highly dependent upon the personnel sampling, the habitat structure and other factors. For this reason, we used an estimated number of individuals captured per seine haul only and assigned an estimated value of 40 individuals per seine haul to all collections. This corresponded to the intermediate score of 3 for that metric such that it’s contribution to the overall score would be moderated. Because our seining method of collecting in all available habitats in proportion to their abundance is somewhat different that the method described in Linam et al. (2000), we left the Aquatic Life Use scoring criteria as described by Linam et al. (2000).

Study Location

The project area encompassed the headwaters region of the Nueces River Basin. This biogeographic unit is comprised of three rivers, including the Nueces, Frio and Sabinal rivers. Bandera, Medina, Real, Uvalde, Edwards and Kinney counties are the primary origin of these three quintessential hill country rivers, and according to The Nature Conservancy’s Edwards Plateau Ecoregional Assessment (The Nature Conservancy 2004), a total of 28 conservation areas, 5 aquatic and 23 terrestrial areas are within the proposed project area. Results

Seven sites were sampled in the Nueces River, and 5 sites in each of the Frio and Sabinal rivers. Four sites within each river system were sampled seasonally. Over 11,700 individuals of 24 species and 1 hybrid combination were captured during sampling (Tables 2-16). All three streams were dominated by cyprinids with moderately large components of centrarchids, other perciforms and poeciliids; assemblages that are typical of spring-fed headwater central Texas streams.

Table 2. Number of individuals and percent abundance of all captured fishes in the Nueces, Frio and Sabinal rivers 2007-2008. Shannon’s diversity index (H’) is also shown.

Nueces Frio Sabinal Nueces Frio Sabinal Species N N N % % % Astyanax mexicanus 104 119 82 2.17 3.22 2.44 Campostoma anomalum 38 82 85 0.79 2.22 2.53 Cyprinella lepida 354 1034 172 7.38 27.95 5.13 Cyprinella lutrensis 14 25 0.38 0.75 Cyprinella venusta 510 1637 1331 10.63 44.26 39.68 Cyprinella lepida x venusta 1 2 0.03 0.06 Dionda serena 557 195 5 11.61 5.27 0.15 Notropis amabilis 1862 184 758 38.81 4.97 22.60 Notropis stramineus 12 187 491 0.25 5.06 14.64 Pimephales vigilax 6 0.16 Moxostoma congestum 1 0.03 Ameiurus natalis 1 1 0.02 0.03 Ictalurus punctatus 5 16 6 0.10 0.43 0.18 Oncorhynchus mykiss 1 0.03 Gambusia affinis 996 105 141 20.76 2.84 4.20 Lepomis auritus 4 6 0.11 0.18 Lepomis cyanellus 11 0.33 Lepomis macrochirus 2 2 15 0.04 0.05 0.45 Lepomis megalotis 195 84 44 4.06 2.27 1.31 Lepomis microlophus 1 0.03 Micropterus salmoides 11 18 53 0.23 0.49 1.58 Micropterus treculii 36 70 0.75 2.09 Etheostoma lepidum 73 3 3 1.52 0.08 0.09 Cichlasoma cyanoguttatum 36 5 53 0.75 0.14 1.58 Oreochromis aureus 6 0.13

Number of Species 17 21 20 100.00% 100.00% 100.00% Number 4798 3699 3354 H' 1.81 1.67 1.85

Table 3. Number of fishes captured in the Nueces River at Highway 355 crossing (across from the Flying Bull Ranch), 29°48'42.24"N, 100°0'56.45"W.

Date 3/13/2007 6/12/2007 10/25/2007 4/24/2008 7/2/2008 N N N N N Astyanax mexicanus 1 2 3 Campostoma anomalum 2 2 5 8 Cyprinella lepida 22 25 12 77 22 Cyprinella venusta 1 Dionda serena 59 215 52 70 71 Notropis amabilis 233 54 213 62 19 Ictalurus punctatus 1 3 Gambusia affinis 141 141 205 102 127 Lepomis megalotis 4 30 3 26 14 Micropterus salmoides 1 Etheostoma lepidum 1 15 2 15 24 Cichlasoma cyanoguttatum 2 1 Oreochromis aureus 2 1

Number of Species 10 9 7 10 9 Number 467 485 488 362 289 H' 1.25 1.45 1.12 1.76 1.60

Table 4. Number of fishes captured in the Nueces River at three sites that were sampled only once from near Barksdale to near Montell on 3/13/2007.

Off Highway 55 immediately northeast of County Road 416 County Road 410 Site Barksdale northeast of Montell crossing 29°43'47.84"N, 29°32'58.41"N, 29°28'41.73"N, GPS 100° '35.67"W 99°59'42.68"W 100° '34.23"W Date 3/13/2007 3/13/2007 3/13/2007 N N N Astyanax mexicanus Campostoma anomalum 1 1 Cyprinella lepida 23 23 1 Cyprinella venusta 3 16 Dionda serena 20 8 12 Notropis amabilis 25 11 4 Notropis stramineus 1 Ictalurus punctatus 1 Gambusia affinis 5 35 1 Lepomis megalotis 4 1 5 Micropterus treculii 1 Etheostoma lepidum 1 3 2 Cichlasoma cyanoguttatum 2 1

Number of Species 9 8 10 Number 81 86 44 H' 1.60 1.58 1.76

Table 5. Number of fishes captured in the Nueces River at River Road crossing (Rocky River Camp) in Camp Wood, 29°40'0.42"N, 100° 1'43.13"W.

Date 6/12/2007 10/25/2007 4/24/2008 7/2/2008 N N N N Astyanax mexicanus 4 2 Campostoma anomalum 2 Cyprinella lepida 48 5 Cyprinella venusta 2 1 Dionda serena 30 2 6 5 Notropis amabilis 52 347 9 78 Notropis stramineus 2 1 2 Ameiurus natalis 1 Gambusia affinis 17 12 6 49 Lepomis macrochirus 1 1 Lepomis megalotis 24 17 17 7 Micropterus salmoides 1 1 Micropterus treculii 1 1 7 Etheostoma lepidum 2 1 Cichlasoma cyanoguttatum 1 21

Number of Species 10 5 11 12 Number 179 379 53 175 H' 1.71 0.37 2.00 1.55

Table 6. Number of fishes captured in the Nueces River at Highwy 55 crossing (immediately south of Highway 334 junction), 29°23'51.95"N, 100° 0'3.29"W.

Date 6/12/2007 10/25/2007 4/24/2008 7/2/2008 N N N N Astyanax mexicanus 38 9 9 35 Campostoma anomalum 2 4 4 Cyprinella lepida 23 27 18 17 Cyprinella venusta 9 90 33 99 Dionda serena 6 Notropis amabilis 66 8 68 545 Notropis stramineus 2 Gambusia affinis 49 5 34 26 Lepomis megalotis 14 8 11 Micropterus salmoides 4 Micropterus treculii 15 7 Etheostoma lepidum 2 2 2 Cichlasoma cyanoguttatum 1 1 Oreochromis aureus 3

Number of Species 10 7 9 11 Number 208 144 191 753 H' 1.77 1.20 1.81 1.04

Table 7. Number of fishes captured in the Nueces River at Highway 481 crossing (Fish Hatchery Road), 29° 7'17.14"N, 99°53'29.20"W.

Date 6/12/2007 4/24/2008 7/2/2008 N N N Astyanax mexicanus 1 Campostoma anomalum 7 Cyprinella lepida 8 3 Cyprinella venusta 124 69 63 Dionda serena 1 Notropis amabilis 20 39 9 Notropis stramineus 4 Gambusia affinis 21 1 19 Lepomis megalotis 4 4 2 Micropterus salmoides 3 1 Micropterus treculii 1 2 1 Etheostoma lepidum 1 Cichlasoma cyanoguttatum 6

Number of Species 10 8 7 Number 184 126 104 H' 1.15 1.19 1.24

Table 8. Number of fishes captured in the Frio River off Old Rocksprings Road crossing off Highway 336, 29°50'45.30"N, 99°46'18.23"W.

Date 3/14/2007 6/11/2007 10/26/2007 4/23/2008 7/2/2008 N N N N N Astyanax mexicanus 1 Campostoma anomalum 4 2 4 22 Cyprinella lepida 12 19 28 88 208 Cyprinella venusta 72 192 152 480 478 Dionda serena 14 12 Notropis amabilis 13 1 Notropis stramineus 3 9 4 16 107 Ictalurus punctatus 3 11 Gambusia affinis 7 3 17 Lepomis auritus 4 Lepomis megalotis 3 6 8 19 33 Micropterus salmoides 3 1 Cichlasoma cyanoguttatum 1

Number of Species 6 7 4 9 12 Number 101 232 192 640 892 H' 1.02 0.70 0.68 0.93 1.36

Table 9. Number of fishes captured in the Frio River at Highway 1120 crossing, 29°37'49.08"N, 99°44'41.5"W. This site was also surveyed on 7/2/2008, but not sampled.

Date 3/14/2007 6/11/2007 10/26/2007 4/23/2008 N N N N Astyanax mexicanus 1 9 4 Campostoma anomalum 9 11 5 Cyprinella lepida 124 82 66 186 Cyprinella venusta 25 46 42 35 Cyprinella lepida x venusta 1 Dionda serena 13 15 105 13 Notropis amabilis 15 29 51 63 Notropis stramineus 3 4 1 Ameiurus natalis 1 Ictalurus punctatus 2 Oncorhynchus mykiss 1 Gambusia affinis 11 4 10 1 Lepomis megalotis 1 5 1 Micropterus salmoides 1 Etheostoma lepidum 2 Cichlasoma cyanoguttatum 2

Number of Species 10 10 8 11 Number 203 205 280 312 H' 1.37 1.72 1.52 1.24

Table 10. Number of fishes captured in the Frio River at County Road 2690, below Concan, 29°26'50.86"N, 99°39'51.97"W. The 3/14/2007 sample was taken at Concan, 29°30'54.00"N, 99°41'51.18"W.

Date 3/14/2007 6/11/2007 10/26/2007 4/24/2008 N N N N Astyanax mexicanus 2 27 1 Campostoma anomalum 1 17 5 2 Cyprinella lepida 95 93 18 15 Cyprinella venusta 66 8 8 32 Dionda serena 7 1 3 Notropis amabilis 5 6 1 Notropis stramineus 24 16 Pimephales vigilax 6 Moxostoma congestum 1 Gambusia affinis 7 9 1 35 Lepomis macrochirus 1 Lepomis megalotis 1 6 1 Micropterus salmoides 8 Etheostoma lepidum 1 Cichlasoma cyanoguttatum 1 1

Number of Species 10 14 6 7 Number 208 175 60 89 H' 1.39 1.73 1.33 1.34

Table 11. Number of fishes captured in the Frio River at County Road 101 crossing, north of Knippa (end of river), 29°19'48.89"N, 99°39'16.02"W. This site was also surveyed on 7/2/2008, but the river was dry.

Date 6/11/2007 N Astyanax mexicanus 74 Cyprinella lutrensis 14 Cyprinella venusta 1 Dionda serena 12 Lepomis macrochirus 1 Micropterus salmoides 5

Number of Species 6 Number 107 H' 1.00

Table 12. Number of fishes captured in the Sabinal River at County Road 337 at the high bridge at Vanderpool, 29°44'38.68"N, 99°33'14.00"W. The 3/14/2007 collection was taken a short distance away in Vanderpool, 29°47'30.19"N, 99°34'27.29"W.

Date 3/14/2007 6/11/2007 10/26/2007 4/23/2008 7/3/2008 N N N N N Astyanax mexicanus 1 36 1 Campostoma anomalum 4 6 31 Cyprinella lepida 21 1 56 77 Cyprinella venusta 219 54 218 211 Cyprinella lepida x venusta 2 Notropis amabilis 1 1 5 10 Notropis stramineus 8 16 26 36 35 Gambusia affinis 89 8 2 30 Lepomis auritus 1 Lepomis macrochirus 4 Lepomis megalotis 2 4 1 Lepomis microlophus 1 Micropterus treculii 2 Etheostoma lepidum 1 Cichlasoma cyanoguttatum 1

Number of Species 4 10 7 8 8 Number 100 275 128 323 396 H' 0.43 0.84 1.37 1.00 1.39 Table 13. Number of fishes captured in the Sabinal River at Highwy 1050 crossing, 1 km southwest of Utopia, 29°36'42.15"N, 99°31'45.75"W.

N N N N Astyanax mexicanus 1 Campostoma anomalum 5 Cyprinella venusta 4 44 1 8 Dionda serena 1 Notropis amabilis 95 5 5 Gambusia affinis 1 3 1 6 Lepomis auritus 1 1 Lepomis macrochirus 1 Lepomis megalotis 1 1 1 Micropterus salmoides 3 Micropterus treculii 1 6 Etheostoma lepidum 2 Cichlasoma cyanoguttatum 32

Number of Species 5 6 6 8 Number 102 55 7 66 H' 0.33 0.77 1.75 1.64

Table 14. Number of fishes captured in the Sabinal River at Highway 187 high bridge crossing, south of Utopia, 29°31'0.59"N, 99°30'31.37"W.

Date 3/14/2007 6/11/2007 10/26/2007 4/23/2008 7/3/2008 N N N N N Astyanax mexicanus 2 23 5 13 Campostoma anomalum 5 10 24 Cyprinella lepida 3 2 4 4 2 Cyprinella venusta 19 105 104 258 85 Dionda serena 4 Notropis amabilis 4 250 25 357 Notropis stramineus 1 336 37 Gambusia affinis 8 12 16 12 3 Lepomis auritus 2 1 Lepomis megalotis 7 2 4 1 9 Micropterus salmoides 8 2 2 Micropterus treculii 4 1 29 12 Cichlasoma cyanoguttatum 20

Number of Species 8 10 8 10 10 Number 46 393 155 682 562 H' 1.70 1.04 1.10 1.20 1.29

Table 15. Number of fishes captured in the Sabinal River at Sabinal River off Dunlap Road at road crossing, immediately above where the river goes dry, 29°19'28.81"N, 99°28'38.72"W although the river was dry at this location when surveyed on 7/3/2008. The sample on 4/23/2008 was taken on the Highway 127 crossing, immediately north of Sabinal, 29°20'29.03"N, 99°28'46.68"W.

Date 4/23/2008 6/11/2007 N N Campostoma anomalum Cyprinella lepida 2 Cyprinella lutrensis 1 24 Cyprinella venusta 1 Notropis amabilis 1 Notropis stramineus 4 Ictalurus punctatus 5 Gambusia affinis 23 16 Lepomis cyanellus 11 Lepomis macrochirus 9 1 Lepomis megalotis 11 Micropterus salmoides 7 31 Micropterus treculii 17

Number of Species 7 9 Number 64 100 H' 1.66 1.72

Twenty-one creeks in the Nueces basin were also sampled or surveyed during the study (Table 16) and 653 fishes of 14 species were captured (Tables 17-19). Creeks not listed in these tables were dry at the time of the survey and no fishes were collected.

Table 16. Creeks sampled during the study period, with date of sampling and geographic coordinates.

Creek ID Code Creek GPS Coordinates 1 Indian Creek (Uvalde Co.) -- 8/7/07 29°17'50.37"N 99°53'21.12"W 2 Bullhead Creek #1 -- 8/7/07 29°50'37.53"N 99°55'29.13"W 3 Bullhead Creek #2 -- 8/7/07 29°50'1.27"N 99°56'31.25"W 4 Bullhead Creek #3 -- 8/7/07 29°50'33.76"N 99°58'17.33"W 5 East Prong Nueces River (Hwy 335) 29°53'10.40"N 100° 1'11.63"W 6 Camp Wood Creek #1 (Hwy 55) -- 8/7/08 29°41'0.61"N 100° 1'4.93"W 7 Camp Wood Creek #2 (Hwy 337) --8/7/07 29°42'1.15"N 99°58'49.38"W 8 Montell Creek (Hwy 55) -- 8/7/07 29°31'41.67"N 100° 1'14.26"W 9 Dry Frio R. -- 8/8/07 29°22'25.01"N 99°42'13.53"W 10 Brushy Creek -- 8/8/07 29°27'44.71"N 99°40'19.97"W 11 Unnamed Creek -- 8/8/07 29°30'52.39"N 99°43'42.56"W 12 Shut-in Creek -- 8/8/07 29°31'43.36"N 99°44'20.92"W 13 Sycamore Creek -- 8/8/07 29°32'16.47"N 99°44'18.65"W 14 Cherry Creek (Hwy 1050) --8/8/07 29°36'22.76"N 99°41'34.14"W 15 Cedar Creek (Hwy 336) -- 8/8/07 29°47'34.22"N 99°46'56.14"W 16 Dry Frio Creek -- 8/8/07 29°38'36.38"N 99°44'15.91"W 17 Indian Creek (Real Co.) -- 8/8/07 29°46'39.75"N 99°42'39.89"W 18 W. Sabinal R. -- 8/8/07 29°39'2.25"N 99°33'35.11"W 19 Jernigan Creek-- 8/8/07 29°45'31.89"N 99°34'46.33"W 20 Evans Creek-- 8/8/07 29°45'21.82"N 99°31'52.47"W 21 Mill Creek-- 8/8/07 29°45'58.72"N 99°30'12.36"W 22 Wedgeworth Creek-- 8/8/07 29°48'24.72"N 99°34'3.80"W 23 Marier Creek-- 8/8/07 29°47'32.94"N 99°34'34.95"W 24 Nolton Creek-- 8/8/07 29°21'51.87"N 99°31'19.94"W 25 Pulliam Creek -- 4/24/08 29°44'35"N, 100° 5'51"W 26 West Sabinal River -- 6/11/07 29°41'17.47"N, 99°36'0.85"W

Table 17. Number of fishes captured in the creeks sampled. See Table 16 for Creek ID identifiers and locations.

Creek ID Code 2 3 4 5 6 N N N N N Cyprinella lepida 6 25 7 1 Cyprinella venusta 2 13 Dionda serena 17 1 4 5 Notropis amabilis 13 5 16 3 17 Gambusia affinis 7 2 18 11 Lepomis macrochirus 1 Lepomis megalotis 7 1 8 1 Micropterus salmoides 4 1 Micropterus treculii 1 Etheostoma lepidum 1 1

Number of Species 4 6 7 9 3 Total 33 52 60 31 23 H1 1.33 1.27 1.61 1.76 0.69

Table 18. Number of fishes captured in the creeks sampled. See Table 16 for Creek ID identifiers and locations.

Creek ID Code 7 8 14 15 N N N N Campostoma anomalum 1 Cyprinella lepida 2 13 Cyprinella venusta 1 Dionda serena 5 6 Notropis amabilis 120 Notropis stramineus 5 Gambusia affinis 2 6 2 Lepomis macrochirus 4 Lepomis megalotis 1 1 Micropterus salmoides 2 Etheostoma lepidum 1 Cichlasoma cyanoguttatum 1 1

Number of Species 8 1 2 7 Total 134 1 10 29 H1 0.52 0.00 0.67 1.52

Table 19. Number of fishes captured in the creeks sampled. See Table 16 for Creek ID identifiers and locations.

Creek ID Code 16 18 25 26 N N N N Astyanax mexicanus 3 Campostoma anomalum 1 15 Cyprinella venusta 11 Dionda serena 161 Notropis amabilis 3 6 11 Gambusia affinis 6 15 3 Lepomis macrochirus 1 Lepomis megalotis 2 6 Micropterus salmoides 1 1 3 Etheostoma lepidum 31

Number of Species 2 5 5 6 Total 3 14 219 44 H1 0.64 1.40 0.88 1.51

Physicochemical data was obtained at each of the mainstem collection sites that were repeated sampled (Tables 20-22). Each of the sampled sites varied greatly in stream width depending upon local rainfall patterns. However, in general, these Nueces headwater streams shared many characteristics in common including, limestone bedrock with significant gravel and cobble bottoms, clear evidence of spring-flows with emergent vegetation and relatively shallow depths, relatively high pH values typical of limestone bedrock streams of the Edwards Plateau, relatively stable water temperatures, and dissolved oxygen levels generally around 10 ppm.

Table 20. Physicochemical measurements at the Nueces River sites.

6/12/07 10/25/07 4/24/08 7/2/08 CR 335 stream width (m) 40 5 - 10 20 2 - 7 depth (m) 0.3 - 0.5 0.5 0.5 - 1 0.3 - 0.5 relative flow high low low low temperature (C) 22.28 - 19.4 24.03 DO (ppm) 7.34 - 11.75 6.5 conductivity (mS/cm) 0.417 - 0.374 0.392 pH 7.98 - 8.44 8.53

Substrate gravel-rubble-cobble rubble-cobble-bedrock gravel-rubble-cobble gravel-rubble-cobble

10% emergent macrophyte vegetation 1% algae algae covered all banks 90% brown algae & filamentous algae

River Road stream width (m) 50 40 20 - 30 5 - 40 depth (m) 0.3 0.25 0.5 - 1 0.25 relative flow high moderate moderate low temperature (C) 25.21 - 23.5 25.69 DO (ppm) 10.29 - 9.6 5.55 conductivity (mS/cm) 0.422 - 0.369 0.392 pH 8.27 - 8.64 8.54 gravel-rubble-cobble- gravel-rubble-cobble- substrate gravel-rubble-cobble gravel-rubble-cobble bedrock bedrock 5% emergent macrophyte brown algae covered 5% Justicia & brown vegetation 1% emergent macrophyte & filamentous algae bottom algae

SH 55 stream width (m) 80 20 10 - 20 3 - 7 depth (m) 0.3 - 0.5 0.5 - 1 0.5 0.25 relative flow high (9.7 cms) mod-high (7.8 cms) moderate (2.4 cms) low (1.0 cms) temperature (C) 25.02 - 24.2 25.5 DO (ppm) 10.62 - 9.6 15.55 conductivity (mS/cm) 0.421 - 0.372 0.398 pH 8.43 - 8.67 8.63 gravel-rubble-cobble- gravel-rubble-cobble- substrate cobble-bedrock gravel-rubble-cobble bedrock bedrock vegetation none none none none

CR 481 stream width (m) 30 20 - 30 30 depth (m) 0.1 - 0.5 0.5 0.5 relative flow high (29.2 cms) 6.5 cms moderate (1.2 cms) low (0.5 cms) temperature (C) 25.69 26.1 28.04 DO (ppm) 9.87 10.3 16.65 conductivity (mS/cm) 0.297 0.464 0.387 pH 8.28 8.64 8.72 gravel-rubble-cobble- substrate gravel-bedrock cobble-bedrock bedrock vegetation none none none

Table 21. Physicochemical measurements at the Frio River sites.

6/11/07 10/26/07 4/23/08 7/2/08 Old Rocksprings Road (off CR 336) stream width (m) 3 - 5 5 - 10 7 10 - 15 depth (m) 0.3 - 0.5 0.25 0.5 0.1 - 0.3 relative flow mod-high moderate moderate moderate temperature (C) 30.95 15 23.4 28.4 DO (ppm) 9.45 - 10.64 8.44 conductivity (mS/cm) 0.313 - 0.316 0.278 pH 8.45 - 8.76 8.98 gravel-rubble-cobble- gravel-rubble-cobble- substrate gravel-bedrock gravel-rubble-bedrock bedrock bedrock 1% submerged none none 1% macrophytes vegetation macrophytes

CR 1120 stream width (m) 20 - 30 10 - 20 10 - 30 inaccessible depth (m) 0.3 - 0.5 0.5 0.5 relative flow high moderate moderate temperature (C) 25.63 19 21.7 DO (ppm) 10.46 - 10.8 conductivity (mS/cm) 0.44 - 0.414 pH 8.11 - 8.42 gravel-rubble-cobble- gravel-rubble-cobble- substrate gravel-rubble-cobble bedrock bedrock 10% emergent vegetation 5% emergent macrophytes 30% Justicia macrophytes

CR 2690 stream width (m) 30 - 40 30 30 depth (m) 0.3 - 0.5 0.5 0.5 - 1 relative flow moderate (0.1 cms) moderate (0.1 cms) moderate (0.1 cms) dry temperature (C) 28.06 22 20.9 DO (ppm) 9.77 - 10.73 conductivity (mS/cm) 0.446 - 0.404 pH 8.28 - 8.67 gravel-rubble-cobble- gravel-rubble-cobble- substrate gravel-rubble-cobble bedrock bedrock vegetation 2% emergent macrophytes none none

CR 101 stream width (m) 20 - 30 depth (m) 0.3 relative flow low dry dry dry temperature (C) 30.79 DO (ppm) 8.9 conductivity (mS/cm) 0.39 pH 8.42 substrate gravel-rubble-cobble 10% Justicia & vegetation submerged grasses

Table 22. Physicochemical measurements at the Sabinal River site.

6/11/07 10/26/07 4/23/08 7/2/08 CR 337 stream width (m) 15 - 20 20 20 - 30 8 depth (m) 0.1 0.25 0.5 0.1 - 0.3 relative flow moderate moderate moderate low temperature (C) 29.5 15 21.9 25.17 DO (ppm) 9.95 - 9.6 13.81 conductivity (mS/cm) 0.451 - 0.378 0.307 pH 8.41 - 8.67 9.01 gravel-rubble-cobble- detritus-rubble-cobble- substrate bedrock rubble-cobble-bedrock bedrock bedrock

vegetation none none none none

CR 1050 stream width (m) 30 15 8 7 depth (m) 0.5 - 0.75 0.5 0.5 -1 0.3 - 1 relative flow high moderate low low temperature (C) 24.27 20 21.5 25.47 DO (ppm) 10.06 - 10.36 14.27 conductivity (mS/cm) 0.511 - 0.5 0.408 pH 8.03 - 8.38 8.54 sand-gravel-rubble- gravel-rubble-cobble- substrate rubble-cobble-bedrock rubble-cobble-bedrock bedrock bedrock 10% emergent 50% submerged vegetation 20% Justicia 25% Justicia macrophytes macrophytes

CR 187 stream width (m) 20 30 20 10 - 15 depth (m) 0.5 0.5 0.5 - 1 0.25 relative flow high (4.0 cms) moderate (2.4 cms) moderate (0.4 cms) low (0.1 cms) temperature (C) 24.49 18 22.8 26.15 DO (ppm) 9.75 - 8.46 11.79 conductivity (mS/cm) 0.489 - 0.464 0.361 pH 8.11 - 8.19 8.46 gravel-rubble-cobble- sand-gravel-rubble- gravel-rubble-cobble- substrate gravel-rubble-bedrock bedrock bedrock bedrock vegetation none none none 2% emergent macrophytes

Dunlap Road SH 127 stream width (m) (m) 10 - 12 10 depth (m) (m) 0.5 0.5 - 1.5 relative flow low (0.3 cms) dry low (0.1 cms) dry temperature (C) 26.8 23.3 DO (ppm) (ppm) 8.18 8.99 conductivity (mS/cm) 0.42 0.515 pH 7.86 7.98 detritus-sand-gravel- substrate mud & bedrock bedrock 90% Justicia & vegetation submerged terrestrial none vegetation

Stream flow measurements are taken by the USGS at various sites within the Nueces river basin. Three stream gages were chosen to indicate water discharge, one for each of the three rivers. We compared data for the last decade and during the study period. For each of the streams a similar pattern was obtained. The study period of 2007-2008 was within the normal range of variation of each of the streams and the pattern during the study was a series of heavy rainfall in the spring and summer of 2007, which dramatically raised stream discharge, followed by an extended period of slowly falling stream flows (Figs. 1-3).

Fig. 1. Nueces River discharge for the decade 1998-2008 (A) and for the study period 2007- 2008 (B). Data are from the USGS Nueces River monitoring station 08192000 below Uvalde.

Fig. 2. Frio River discharge for the decade 1998-2008 (A) and for the study period 2007-2008 (B). Data are from the USGS Frio River monitoring station 08195000 at Concan.

Fig. 3. Sabinal River discharge for the decade 1998-2008 (A) and for the study period 2007- 2008 (B). Data are from the USGS Sabinal River monitoring station 081985000 near Sabinal.

We calculated a preliminary Index of Biotic Integrity (IBI) using the regionalized methods developed by the Texas Parks and Wildlife Department (Linam et al. 2002) for each sample taken and with the combined data for each of the three rivers Fig. 4. Individual sites in all three streams showed some variation, however, all calculated IBI values were with the Intermediate to High ranges, in agreement with similar findings by Linam et al. for nearby Edwards Plateau streams. IBIs calculated for all collections within a stream resulted in slightly higher overall IBI scores. The Frio and Sabinal rivers each had combined IBI scores of 52 indicating Exceptional water quality and the Nueces River had a combined score of 48 indicating High water quality. The creeks within the three watersheds had slightly lower IBI scores, as might be expected, and scores ranged between 30 and 44, indicating High to Intermediate water quality.

Fig. 4. IBI Scores for samples taken from the Nueces, Frio and Sabinal rivers during the 2007- 2008 sampling period.

Fig. 5. IBI Scores for samples taken from the flowing creeks in the upper Nueces basin during the 2007-2008 sampling period. Creek numbers correspond to the creek ID codes listed in Table 15.

The upper Nueces river basin is a significant stream with many unique elements. The water quality is generally high and the fish fauna is typical of high quality spring-fed streams within the southern Edwards Plateau. A number of significant impacts and threats were discovered during the course of the study, some of which include increased development along the watercourse, stream alterations, especially low-head dams along the Sabinal River, and, at times, intense recreational pressure, especially in the Frio River during the summer months. Even with these pressures, the headwater streams of the Nueces river basin maintain much of their integrity as evidenced by the numerous indicator fishes such as Cyprinella lepida, Dionda serena and Etheostoma lepidum . Care should be given to maintain these ecosystems as refuges for the unique suite of species found within.

Literature Cited

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Hubbs, C., R. J. Edwards and G. P. Garrett. 2008. An annotated checklist of the freshwater fishes of Texas, with keys to identification of species. Texas Journal of Science. Available from: http://www.texasacademyofscience.org/.

Linam, G. W., L. J. Klinesasser and K. B. Mayes. 2002. Regionalization of the Index of Biotic Integrity for Texas streams. River Studies Report 17, Texas Parks and Wildlife Department, 26 pp. + 11 appendices.

Mayden, R. L. 1989. Phylogenetic studies of North American minnows, with emphasis on the genus Cyprinella (Teleostei: Cypriniformes). Univ. Kansas Museum Natural History Miscellaneous Publication (80):1-189.

Mayden, R. L., R. M. Matson, and D. M. Hillis. 1992. Speciation in the North American genus Dionda (Teleostei: Cypriniformes). Pages 710-746 in R. L. Mayden, editor. Systematics, historical ecology, and North American freshwater fishes. Stanford Univ. Press.

Matthews, W. J. 1987. Geographic variation in Cyprinella lutrensis (Pisces: Cyprinidae) in the United States, with notes on Cyprinella lepida . Copeia 1987:616-637.

Richardson, L. R., and J. R. Gold. 1995. Evolution of the Cyprinella lutrensis species-complex. II. Systematics and biogeography of the Edwards Plateau shiner, Cyprinella lepida . Copeia 1995:28- 37.

Texas Parks and Wildlife Department. 2002. Regionalization of the Index of Biotic Integrity for Texas Streams. River Studies Report 17, 26 pp. + 10 app.

Texas Parks and Wildlife Department. 2005. Texas Comprehensive Wildlife Conservation Plan. Texas Parks and Wildlife Department, Austin, Texas.

The Nature Conservancy. 2000. The five-s framework for site conservation: a practitioner’s handbook for site conservation planning and measuring conservation success. Volume I. The Nature Conservancy, Arlington Virginia.

The Nature Conservancy. 2004. A biodiversity and conservation assessment of the Edwards Plateau ecoregion. Edwards Plateau Ecoregional Planning Team, The Nature Conservancy, San Antonio, Texas, USA.