TPWD 1964 F-9-R-12 #934: Fisheries Investigations and Surveys of the Waters of Region 5-A: Fisheries Reconnaissance

--- Page 1 --- A) ‘() P i - yy ie ft Pee (oe w fh fr @,A — wie SEGMENT COMPLETION REPORT As required by FEDERAL AID IN FISHERIES RESTORATION ACT TEXAS Federal Aid Project No. F-9-R-12 FISHERIES INVESTIGATIONS AND SURVEYS OF THE WATERS OF REGION 5-A Job No. B-22 Fisheries Reconnaissance Project Leader: Elgin M. C. Dietz J. Weldon Watson Executive Director Parks and Wildlife Department Austin, Texas Marion Toole Eugene A. Walker D-J Coordinator Assistant Director for Wildlife July 2, 1965 --- Page 2 --- ABSTRACT Seining collections from the Rio Grande River yielded 22 species of fish. Shiner minnows were the most numerous species taken. Gill netting collections on this stream yielded a relatively small number of game fish; slightly over 5 per cent of the total number taken. Gill netting data from Falcon Reservoir show the continued increase in the incidence of rough fish. Gizzard shad continue to be the most numerous species taken by this method. All game species, except blue catfish, showed a slight decrease percentage wise from last year's collections. Collection data from the channel impoundments on the Nueces River, except Lake Nueces and Holland Lake, show a relatively low incidence of game fish species. Lake Nueces, which is a new impoundment, and Holland Lake have a good game fish population and are providing much needed fisheries in their respec- tive areas. Collections from the Frio River show a good population of largemouth bass and sunfish species. These are providing a good fisheries for the shoreline and wade fishermen. Diversion Lake apparently still has a very sparse fish population as indi- cated by netting collections on this lake. The three impoundments in the San Antonio area, namely Elmendorf, Woodlawn and Davis Lakes, continue to provide much needed recreation for persons unable to fish outside the City of San Antonio. The relatively small streams of the Atascosa River and Cibolo Creek are greatly affected by irrigation practices throughout the region. These prac- tices greatly reduce the fish habitat and population. --- Page 3 --- SEGMENT COMPLETION REPORT State of Texas Name: Fisheries Investigations and Surveys of the Waters of Region 5-A Project No. F-9-R-12 Title: Fisheries Reconnaissance Job No. B-22 Period Covered: December 1, 1963 through November 30, 1964 Objectives: To conduct limited investigations to obtain current information concerning gross changes in fishing conditions and factors influencing fish populations. Introduction: During this study period, reconnaissance surveys were conducted on the Rio Grande River in Kinney, Maverick, Webb and Zapata Counties, as well as Falcon Reservoir in Zapata County; the Nueces River and its lakes in Uvalde, Zavala, Dimmit and La Salle Counties; the Frio River in Uvalde County; Diversion Lake in Medina County; Elmendorf, Woodlawn and Davis Lakes in Bexar County; the Atascosa River in Atascosa County; and Cibolo Creek in Bexar and Wilson Coun- ties. A checklist of all fish species collected is given in Table 1. Techniques Used: Fishes taken in netting samples were collected with standard gill nets con- sisting of six 25-foot sections of mesh varying from 1 to 34 inches square. Lengths, weights and numbers of netted fish were recorded in the field. From these records species composition, condition factors of individual specimens and species were computed. Fish collected by seining were taken in 12- by 4- common sense minnow seines or with 20- by 6-foot, %-inch mesh, straight seines,’” and were preserved in 10 per cent formalin solution for later identification and tabulation in the laboratory. Since more than one body of water was studied, the techniques used and/or findings will be taken up separately for these waters in the succeeding sec- tions of this report. RIO GRANDE RIVER Techniques Used and Findings: The Rio Grande River in Region 5-A, namely in Kinney, Maverick, Webb and Zavala Counties, was surveyed for the first time during this year. Falcon --- Page 4 --- Table 1. Checklist of fish species used in report Alligator gar Spotted gar Longnose gar Threadfin shad Gizzard shad Mexican tetra Blue sucker Smallmouth buffalo River carpsucker 10. Gray redhorse ll. Carp 12. Goldfish 13. Golden shiner 14. Speckled chub 15. Longnose dace 16. Rio Grande shiner 17. Texas shiner 8. Weed shiner 19. Tamaulipas shiner 20. Blacktail shiner 21. Red shiner 22. Plateau shiner 23. Proserpine shiner 24. Sand shiner 25. Ghost shiner 26. Roundnose minnow 27. Plains minnow 28. Bullhead minnow 29. Flathead minnow 30. Stoneroller 31. Channel catfish 32. Blue catfish 33. Black bullhead 34. Yellow bullhead 35. Flathead catfish 36. Tadpole madtom 37. Blackstripe topminnow &. Sheepshead minnow 39. Mosquitofish 40. Sailfin molly 41. Tidewater silverside 2. White bass 3. Largemouth bass Warmouth Green sunfish won nw fFWwWhHe Scientific Names Lepisosteus spatula L. oculatus L. osseus Dorosoma petenense D. cepedianum Astyanax mexicanus Cycleptus elongatus Ictiobus bubalus Carpiodes carpio Moxostoma congestum Cyprinus carpio Carassius auratus Notemigonus crysoleucas Hybopsis aestivalis Rhinichthys cataractae Notropis jemezanus texanus braytoni venustus lepidus proserpinus stramineus N. buchanani Dionda episcopa Hybognathus placita Pimephales vigilax P. promelas Campostoma anomalum Ictalurus punctatus I. fureatus I. melas I. natalis Pylodictis olivaris Schilbeodes gyrinus Fundulus notatus Cyprinodon variegatus Gambusia affinis Mollienesia latipinna Menidia beryllina Roccus chrysops Micropterus salmoides Chaenobryttus gulosus Lepomis cyanellus Alzlalzbe bt lzlz --- Page 5 --- -3- Table 1. Continued Common Names Scientific Names Green-Redear sunfish hybrid - cyanellus x L. microlophus Spotted sunfish - punctatus Redear sunfish - microlophus Bluegill - Macrochirus Redbreast sunfish - auritus Longear sunfish L. megalotis White crappie Pomoxis annularis Logperch Percina caprodes Greenthroat darter Etheostoma lepidum Freshwater drum Aplodinotus grunniens Rio Grande perch Cichlasoma cyanoguttatum Reservoir, located on the Rio Grande in the lower portion of the region, has been surveyed almost continuously since its beginning in 1953. Three reconnaissance trips were made to the Rio Grande River during this survey. The first, which was made in December, was for scouting and locating collection stations and points of access. It was found that the upper section, in the Eagle Pass area and in the Laredo vicinity, had numerous points of access, but heavy growths of aquatic and terrestrial vegetation made entry to the water next to impossible. Also, heavy siltation in the lower portion of the study area posed a difficult entry problem. The remaining section surveyed consists, for the most part, of rugged country with few roads or passes to the stream bed. In addition, fluctuating water level on the river posed the prob- lem of locating adequate waters for gill netting and seining sites. For example, the Rio Grande was some six feet lower in the summer of 1964 than in December 1963. Many collection sites located in December were of little or no value when revisited for sampling. Nine seining collection stations were sampled during this survey and yielded 22 species of fish (see attached map and Table 2). Shiner minnows were the most numerous fish in these collections. Table 3 gives the results of the gill netting samples taken from this stream. The longnose gar was the most numerous single species taken and ac- counted for approximately 64 per cent of the total collection. It will be noted that game fish species made up a very small portion of the collection with only slightly over 5 per cent. Although the game species composition may not average this low throughout the entire stream, these collections are prob- ably an indication of a low game fish population. Good catches of catfish, channel, blue and flathead are reportedly taken by trotlines and setlines from this stream. --- Page 6 --- - \ | () ‘e, “< Al LE) |. a ao | \) = | x MAVERICK and WEBB COUNTIES Kinney County Maver} ck County YN 1 Maverick Webb County County Eaqle Pass cones, LEGEND [277] Roads A Seining Sites @ Gill Net Collection Sites INSET | Webb County ee eee ay * o 2 4 6 & miles “~. Yaar, o ‘ay A a i --- Page 7 --- RE Species Longnose gar Gizzard shad Mexican tetra Blue sucker Smallmouth buffalo River carpsucker Speckled chub Longnose dace Rio Grande shiner Tamaulipas shiner Red shiner Sand shiner Plains minnow Bullhead minnow Channel catfish Flathead catfish Mosquitofish Sailfin molly Largemouth bass Green sunfish Bluegill Rio Grande perch Totals Table 3. Species Alligator gar* Spotted gar* Longnose gar* Gizzard shad* Blue sucker* Table 2. Smallmouth buffalo* River carpsucker* Car p* Channel catfish Blue catfish Flathead catfish White bass Freshwater drum* Totals Numbers Weights Fish Per Cent | Pounds Grams 1.16 | 77.00 34,927 5.61 12.46 5,651 63.97 | 377.20 171,096 5.61 4.53 2,053 0.58 | 2.25 1024: 9.88 i; 99.02 35,012 3.49 6.60 2,995 0.53 6.94 3,147 2.233 3.40 1,540 1.16 i 1.64 744 0.58 3.88 1,758 Lelé | 1.08 88 3.49 2.61 | 1,184 172 j100.00 | 598.61 | 261,616 20 1 | 34 i 4 i 1 | 18 2] 9 1251 17 | 17 1 23 $334 * Indicates rough fish species. a§ Stations Pait2; 3] 45 6) 7] | 1 1 ; 1 9 ! 3) 7] 3441 ! : 4 12 | 10 | 9 | 187 5 | 15 ! 3 | 91 | 10 18 | h 1 48 | 6 2 | 86 | 2 24 | 1 f 2 $4 24 4 1 i 6 Pf foi: - | f Rio Grande River seining results, 1964 i319 | 29 218 |/51 | 188 Fish Collections Gill netting results, Rio Grande River, 1964 7 3 9 Totals 2 2 2 3 1 2 | 1 12 2; 1 52 85 9 | 112 15 | 6 | 10 61 1 {| 38 | 99 ; 1 226 57 | 21 182 1 1 32 | 13 318 90 | 1 1 1 9 13 1 2 8 1 i 2 8 ra 21 6 7 7 3 11 1 2 1 1 99 }91 | 1352 i Mean "KK"! | Per Cent |, | | | 13.35 4 1,10 } 2.16 | 0.54 ' 65.40 | 0.40 | 0.78 | 2.14 {| 0.39 L<72 | 13.38 3.53 Lats 2.99 1.20 3.23 0.59 1.72 0.28 1.44 0.68 1.76 0.18 2.01 0.46 2.47 100.00 | --- Page 8 --- FALCON RESERVOIR Techniques Used and Findings: Gill netting collections for Falcon Reservoir show the continued increase in incidence of rough fish when compared to previous samples. This year's collections showed that over 71 per cent of the specimens taken were clas- sified as rough fish compared to 60 per cent for the previous year (Table 4). This is not a large overall increase, but indicates the continuation of the rough fish build-up. Gizzard shad were the most numerous single species and showed an increase from 49.12 per cent for 1963 to 60.42 per cent for this year. All game species, except blue catfish, showed a slight decrease percentage-wise when compared with last year's collection. Fishing success for the white crappie, mentioned in previous reports, was continued during this segment. However, the overall decrease in large- mouth bass fishing success was also continued during this year. Seining collections from Falcon Reservoir showed the red shiner to be the most numerous single species taken (Table 5). The tidewater silverside was also present in substantial numbers. NUECES RIVER Techniques Used and Findings: . The section of the Nueces River surveyed during this segment was confined to the area south of the Balcones Escarpment in Uvalde County to above Crystal City in Zavala County. This section consists of large pools, some of them covering several acres, and normally flows only during a rise on the river. Access is difficult,and only two areas were sampled by gill netting. Table 6 gives the results of these collections. Rough fish species were dominant among the specimens taken. Good fishing is reported from these ar@as, especially for catfish species and white crappie. Seining collections show a wide range of minnows as well as other fish species present (Table 5). Fish samples were also taken from five channel impoundments on the Nueces River including Lake Nueces, Comanche, Espantosa, Harris and Holland. Results of these surveys are discussed separately in the text below. LAKE NUECES Findings: This is the latest impoundment to be built on this stream and provides much needed fishing and water recreation in an area where public lakes are non-existent. --- Page 9 --- Table 4. Gill netting results, Falcon Reservoir, 1964 Fish Collections Numbers Weights Species ; Fish Per Cent Pounds Grams Per Cent Spotted gar* 23 White crappie Freshwater drum* Ls 0; Longnose gar* 1.83 0.46 Threadfin shad* 24 0 2.00 Gizzard shad* 60. 36. 2.00 Smallmouth buffalo* QO. Bie 3.50 River carpsucker* 1. 2 2.94 Carp* 1. 6.€ Zale Channel catfish 5:3 3. 1.48 Blue catfish 6. 8. 1532 Flathead catfish 0. 0. 1.77 White bass 3s 4. 2.44 Largemouth bass QO. QO. 2.20 Warmouth 0. 0. 3.50 Redear sunfish 0. 0. 4.47 Bluegill Lis 0. 4.00 8. 8. 2. 2% Li. 2. | 100.00 { Totals 347.00 | 384,193 *Indicates rough fish species. --- Page 10 --- Species Spotted gar Threadfin shad Gizzard shad Mexican tetra Smallmouth buffalo River carpsucker Gray redhorse Carp Golden shiner Texas shiner Weed shiner |. Blacktail shiner Red shiner Plateau shiner Sand shiner Ghost shiner Roundnose minnow Plains minnow Bullhead minnow Flathead minnow Stoneroller Black bullhead Tadpole madtom Blackstripe topminnow Sheepshead minnow Mosquitofish Sailfin molly Tidewater silverside Largemouth bass Warmouth Green sunfish Green-redear sunfish hybrid Spotted sunfish Redear sunfish Bluegill Redbreast sunfish Longear sunfish Logperch Greenthroat darter Rio Grande Perch Table 5. Reservoir 205 17 76 1 1974 13 154 107 360 1292 Seining results, 1964 Numbers of Fish Collected 27 64 100 75 166 ll 10 Diversion Elmendorf Atascosa for the Waters Surveyed Totals --- Page 11 --- =9- Table 6. Gill netting results, Nueces River, 1964 Fish Collections Mean "K" Species Fish Per Cent Spotted gar* 2 1.74 2.58 0.59 Longnose gar* 9 33.29 49.31 0.36 Gizzard shad* 5 2.29 3.439 1.97 Smallmouth buffalo* 3 1775 26.29 3473 ' Gray redhorse* 2 4.26 6.31 1.98 Channel catfish 1 2.06 3305 1.64 Blue catfish 1 1.44 243 1.76 Yellow bullhead* 7 1:65 2.44 2.06 Largemouth bass 1 2.00 2.96 2.41 Bluegill 5 0.77 Ob 3.65 White crappie 2 0.26 0.39 3.00 100.00 67.51 30,631 100.00 * Indicates rough fish species. --- Page 12 --- -10- Channel catfish and the gray redhorse were the most abundant species taken by gill netting on this lake (Table 7). This 19-acre impoundment has been stocked with game fish species since its completion in 1963 and is providing a good sport fisheries. COMANCHE LAKE Findings: This lake is located on Comanche Creek, a tributary of the Nueces River, approximately five miles west of Crystal City and covers about 500 surface acres when full. However, the lake fluctuates a great deal, because of irrigation and lack of rainfall, and is normally greatly reduced in size. Freshwater drum were the most numerous single species collected by gill netting from this lake during the study period (Table 8). The next two most numerous species were the smallmouth buffalo and gizzard shad. White crappie were the most numerous game species collected. This species provides good fishing during fall and winter months. It is recommended that additional channel catfish be stocked in this lake in an effort to build up a fishable population of this species. ESPANTOSA LAKE Findings: This channel impoundment is located on a branch of the Nueces River in the Crystal City area. This lake, as is true of all the lakes in this area, fluctuates a great deal because of its use to impound and divert water for irrigation. Because of this, the maintenance of a sport fish population is next to impossible. Gill net samples showed spotted gar and gizzard shad as the two dominant species collected (Table 9). White crappie was the dominant game species taken. Channel catfish have been stocked in this lake during the last two years in an effort to build up this game species, but relatively few were collected. It is recommended that the stocking of this species be continued for at least two more years. HARRIS LAKE Findings: This relatively small and shallow impoundment is located on the Nueces River west of Cotulla, La Salle County. The reported poor fishing of this lake is apparently due to the predominance of rough fish species (Table 10). Fisheries management practices to alleviate this problem would be virtually impossible, because of the heavy rough fish population present upstream from this lake. Also, the lack of access and size of the lake preclude any extensive fisheries management work. --- Page 13 --- =Ti< Table 7. Gill netting results, Lake Nueces, 1964 Fish Collections Mean "'K" Species Fish Per Cent Spotted gar* Gizzard shad* Gray redhorse* Channel catfish Flathead catfish Largemouth bass Warmouth Longear sunfish Rio Grande perch* Whe he he Wo hb Rananrna -& NOrU Ff WON bh WWPrnNMNMeENY YO 30.66 | 13,904 * Indicates rough fish species. Table 8. Gill netting results, Comanche Lake, 1964 Fish Collections Numbers [Weights | Mean "x" Fish__| Per Gent Longnose gar* 7 bs 0.40 Spotted gar* g 9.38 0.57 Gizzard shad* 13 13.54 1.92 Smallmouth buffalo* 15 15.63 3.48 Black bullhead* 1 1.04 2.03 Largemouth bass 2 2.08 3.12 Warmouth — 2 2.08 4.58 Bluegill 2 2.08 5.34 White crappie 9 9.38 3.20 Freshwater drum* 36 2.80 Totals 96 100.00 107.46 48,754 100.00 * Indicates rough fish species. --- Page 14 --- =[t~ Table 9. Gill netting results, Espantosa Lake, 1964 . Fish Collections Spee; | pecte? Per Cent Pounds Grams | Per Cent Spotted gar* 33 37.50 0.59 Gizzard shad* 25 28.40 7.49 1.8 Smallmouth buffalo* 541 | 10.62 3073 Channel catfish 4655 3.54 Le53 Bluegill 227 0.18 4.58 Redbreast sunfish 1.14 0.07 3.84 White crappie 13.63 4.99 3.03 Freshwater drum* 5.69 3.05 2.70 Rio Grande perch* 3.41 0.28 128 4.87 * Indicates rough fish species. Table 10. Gill netting results, Harris Lake, 1964 Fish Collections Numbers Weights Mean "K" Species Fish Per Cent Per Cent Alligator gar* Spotted gar* Longnose gar* ia) oocao £3 Gizzard shad* Smallmouth buffalo* BO White crappie Rio Grande perch* * Indicates rough fish species. --- Page 15 --- -13- HOLLAND LAKE Findings: Holland Lake is the last of the channel impoundments on the Nueces River in Region 5-A. It is located near the La Salle County line and covers an area of approximately 250 surface acres. Netting results on this impoundment showed an abundant white crappie population (Table 11). This was the most numerous single species collected and provides a good fisheries during most of the year. The high fishing pressure on this lake is no doubt due to the relatively high game fish population indi- cated by the netting collections for this lake. FRIO RIVER a Techniques Used and Findings: The fisheries study of this stream was confined to sections in Uvalde County, which are fairly representative of this stream. Large numbers of largemouth bass and sunfish species have been stocked in this stream during the past several years. The success of these plantings are apparently reflected in the relatively high percentages of these species in the netting and seining collections made on this stream (Tables 12 and 5). Shoreline and wade fishing are popular forms of angling and usually yield good success to the fisherman. , DIVERSION LAKE ~ a Techniques Used and Findings: Eight gill net collections from Diversion Lake on the Medina River produced only 59 fish (Table 13), tending to indicate the sparse fish population present in the lake. The planting of young largemouth bass and sunfish during the past three years has not been successful in establishing a good game fish popu- lation. The most numerous single species taken in nets was the gizzard shad. The relatively few specimens collected in seines indicate the lack of young fish and minnow species present (Table 5). ELMENDORF LAKE Techniques Used and Findings: Compared to the previous year, an increased number of fish were taken from Elmendorf Lake by gill netting. The planting of largemouth bass and sunfish --- Page 16 --- =[h= Table 11. Gill netting results, Holland Lake, 1964 Fish Collections : Numbers . Weights Mean "K" Species Fish | Per Cent Spotted gar* Longnose gar* Gizzard shad* Smallmouth buffalo* Largemouth bass Warmouth Redear sunfish Bluegill Redbreast sunfish White crappie Freshwater drum* 0. 0. a 3. 2 4. 4. 4, 4, 3. 3s * Indicates rough fish species. Table 12. Gill netting results, Frio River, 1964 Fish Collections [Numbers Per Cent Pounds Grams Per Cent | Spotted gar* Gizzard shad* Smallmouth buffalo* Gray redhorse* Channel catfish eo Nuss NM wo hm ao Ww re Largemouth bass Warmouth Green sunfish Bluegill Redbreast sunfish Rio Grande perch* 8 oumoran~ Ww~r~s oo Ww o POrRrONW cor ow o ow orWM~stor~ Wo — Totals 92 100.00 105.42 * Indicates rough fish species. --- Page 17 --- -18- Table 16. Gill netting results, Lake Davis (Formerly Esquivel Lake), 1964 . Fish Collections | Species | 7 Carp* Goldfish* Golden shiner* Channel catfish Black bullhead*¥ Yellow bullhead* Largemouth bass Warmouth Green sunfish Bluegill Redbreast sunfish White crappie Rio Grande perch* 3. 6. 2. Ts Di ea 2 4, De 4. Ba Be 5. * Indicates rough fish species. Table 17. Gill netting results, Atascosa River, 1964 - Fish Collections | Numbers i Fish Per Cent Spotted gar* Longnose gar* Gizzard shad* Smallmouth buffalo* Car p* Black bullhead* Flathead catfish Largemouth bass Bluegill Redbreast sunfish Longear sunfish Freshwater drum* Rocco wWwwOoOUWrPP +a £ NOE PW MS rPN NY WH OO Totals * Indicates rough fish species. --- Page 18 --- -17- LAKE DAVIS Techniques Used and Findings: As was reported the previous segment, a fish kill, caused by insecticide pollution in October 1963, removed most of the game fish population from this lake. Netting results this year show a reduction from 50.51 per cent to 26.68 per cent for the combined game fish species collected (Table 16). Plantings of game species after the kill and during this year were made to rebuild this population. Seining collections (Table 5) show that the minnow population has partially recovered from this kill with the red shiner being the most numerous species taken by this method. : ATASCOSA RIVER oA Techniques Used and Findings: This small stream was surveyed during this segment, and the fisheries resources were found to be poor. Because of extensive irrigation in this area, the stream is reduced to pools for most of the year. This practice greatly affects the fish population. Seining and netting are very difficult on this stream. Most of the banks are steep and covered with trees and other terrestrial and aquatic plants. The reduced water level adds to the collection problem. Gill netting collections showed the gizzard shad to be the most numerous species taken (Table 17). Game fish comprised only 18.19 per cent of the total specimens collected. Fisheries management practices for this stream in its present condition are virtually impossible. Seining collections show the mosquitofish and sailfin molly present in substantial numbers (Table 5). CIBOLO CREEK ae Techniques Used and Findings: This stream is also affected by irrigation practices throughout this region. Because of this, the stream is intermittent and usually flows only shortly after a rise from rains on its watershed. Gizzard shad made up the largest per cent of the fish species collected by gill netting with 33.85 (Table 18). The combined game species represented 24.80 per cent, with white crappie accounting for 9.78 ver cent. Seining collections made on Cibolo Creek show the shiner minnows well represented in the specimens taken (Table 5). --- Page 19 --- -16- Table 14. Gill netting results, Elmendorf Lake, 1964 SESE Collections | Numbers Mean "K" Species Fish Per Cent Per Cent Golden shiner* Black bullhead* Yellow bullhead* Largemouth bass Warmouth Green sunfish Bluegill Totals * Indicates rough fish species. Table 15. Gill netting results, Woodlawn Lake, 1964 Mean '"K" Car p* 182 8.02 Sel5 Goldfish* 4.65 15.08 4.07 Golden shiner* 0.61 0.30 2.33 Channel catfish 5.47 27.33 1.69 Black bullhead* 13:15 . 9.41 2.31 Yellow bullhead* 3.44 34 2.08 2623 Flathead catfish 0:21 &, 5.40 1.86 Largemouth bass Ls21 Bis 3.58 2.96 Redear sunfish 0.21 oF 0.06 3.61 Bluegill 27 4351 10. 7.41 4.00 Redbreast sunfish 15.18 6.4 4.33 4.37 Longear sunfish 0.21 0. 0.05 4.48 Warmouth 0.21 0. 0.10 Beh White crappie 2007 L 24. 16.42 3433 Rio Grande perch* 0. Ox 0.43 6.43 Totals 494 100.00 146.34 67,279 |100.00 * Indicates rough fish species. --- Page 20 --- -15- Table 13. Gill netting results, Diversion Lake, 1964 Fish Collections Numbers Weights Mean “K" Species Pounds || Grams | Per Cent Longnose gar* Gizzard shad* Smallmouth buffalo* Carp* Channel catfish White bass Largemouth bass Warmouth Green sunfish Redear sunfish Bluegill NRPePhM wow HP - Soce Or OWrEU aw Ooo OoONnwWaWN wo. ~ WWWW NN ewe Oo 100.00 4 41.00 * Indicates rough fish species. possibly contributed to this increase. Bluegill sunfish were the most numerous single species taken with 40.91 per cent of the total collected (Table 14). The sailfin molly and the mosquitofish accounted for the major portion of the fish collected by seining from this lake (Table 5). WOODLAWN LAKE Techniques Used and Findings: Gill netting collections from Woodlawn Lake continued to show a good game and panfish population during this period of study with 75.72 per cent (Table 15). This is a slight increase from last year, but the reduced number of collections and specimens taken probably account for this difference. This lake continues to provide much needed fishing recreation for young anglers and other persons unable to fish outside the City of San Antonio. Because of this, continuing efforts should be made to provide good fishing in this lake. --- Page 21 --- -19- Table 18. Gill netting results, Cibolo Creek, 1964 _ __ Fish Collections Numbers Weights Mean "K" Species Fish | Per Cent | Pounds | Grams | Per Cent _| Spotted gar* Longnose gar* Gizzard shad* Smallmouth buffalo* River carpsucker* Gray redhorse* Channel catfish Flathead catfish Largemouth bass Bluegill Redbreast sunfish Warmouth White crappie NWP PEPHMORPRNONWNOO 100.00 165.17 * Indicates rough fish species. Discussion Fisheries problems reported in Segment Completion Report Job D-1 for this and previous segments become apparent when data and field notes collected for this job are analyzed. The tables in this report show the abundance and predominance of rough fish species present in nearly all waters covered by this survey. In some waters the game fish species are almost non-existent. The severe water fluctuation of most impoundments and streams studied, resulting from extensive irrigation, greatly aggravates this situation. Prepared by _ Elgin M. C. Dietz Approved by ; Vo pean. Soot. Project Leader Coordinator Date July 2, 1965 Kenneth C. Jurgens Regional Supervisor