TPWD 1965 F-6-R-12 #995: Fisheries Investigations and Surveys of the Waters of Region 5-B: Fisheries Reconnaissance

JOB COMPLETION REPORT As required by FEDERAL AID IN FISHERIES RESTORATION ACT TEXAS Federal Aid Project No. F—6~Rw12 FISHERIES INVESTIGATIONS AND SURVEYS OF THE WATERS OF REGION 5—B Job No. 3-20 Fisheries Reconnaissance Project Leader: Charles T. Menu J. Weldon Watson Executive Director Parks and Wildlife Department Austin, Texas Marion Toole Eugene A. Walker D~J Coordinator Assistant Director for Wildlife January 18, 1965 ABSTRACT Seven lakes and a part of the San Antonio River were visited during this segment to see if any appreciable changes in the fish populations had occurred since the previous survey. Blue catfish (lctalurus furcatus), the only game fish species, comprised 17.24 per cent of the total number and 6,97 per cent of the total weight of the fish taken in the nets in Harlingen City Lake, There appeared to be a re— lative decrease in the game fish, both in numbers and in weight. I.n Bentsen State Park Lake, rough fish species including spotted gar (Lepisosteus productus ), smallmouth buffalo (Ictiobus bubalus), bluegill (Lepomis macrochirus) and Rio Grande perch (Cichlasoma cyanoguttatum) were dominant both in numbers and in weight with 86 36 per cent and 94 31 per cent, respectively, Rough fish, primarily bluegill and gizzard shad (Dorosoma cepedianum) are dominant in Fort Brown Lake Despite their predominance, the bass and catfish are in good condition. Rough fish species including alligator gar (Lepisosteus spatula), spotted gar, longnose gar (Lepisosteus osseus), threadfin shad (Dorosoma p_£enense), gizzard shad, carp (C yprinus carpio), freshwater drum (Aplodinotus grunniens) and Rio Grande perch comprised 94 85 per cent of the total number and 95.55 per cent of the total weight of fish taken in Llano Grande Lake. Game fish species showed a relative increase both in numbers and in weight in Campacuas Lake, The game fishes include channel catfish (Ictalurus punctatus), blue catfish, warmouth (Chaenobryttus gulosus), white crappie (Pomoxis annularis) and black crappie (E, nigromaculatug), In Delta Orchards Lake, near Monte Alto in Hidalgo County, game fish species including channel and blue catfish and freshwater drum showed a relative de— crease both in number and in weight; Rough fish species including spotted and longnose gars, gizzard shad, grey redhorse (Moxostoma congestum), yellow bullheads (Ictalurus natalis) and Rio Grande perch were dominant both in numbers and in weight in the San Antonio River. The blue catfish population showed a relative increase in numbers in Lake Corpus Christi. Otherwise, there were no significant changes in the fish pop- ulation. Water hyacinth control work on Lake Corpus Christi should be continued, However, no other deve10pmental or management work is recommended. JOB COMPLETION REPORT State of Texas Project No. F—6-R—12 Name: Fisheries Investigations and Surveyg 9f the Watersflgf Region 5-3 Job No, B-20 Title: Fisheries Reconnaissangg —n—n—n—p Period Covered: January 1, 1964 through December 312 1964, Objectives: To obtain current information concerning gross changes in fishing con~ ditions, and to obtain current information regarding factors influencing fish populations, Techniques Used: Standard, 125~foot long, gill nets and common sense minnow seines were used to sample fish populations, The gill nets consisted of nylon webbing, 8 feet deep, with five 25~foot long sections of 1—, l%—, 2—, 2%- and 3—inch square mesh, Nets were set overnight at previously established netting stations and fish specimens were taken from them the following morning, The netted specimens were weighed in grams and measured in millimeters in the field: Sex and sexual de- velopment and the occurrence of parasites in the individual specimens were re- corded: Seined specimens were preserved and taken to project headquarters at Mathis for identification, A list of the common and scientific names of fish species taken during this study is included as Table l, Routine water quality analyses were made on the various lakes and a limited check was made of the surrounding area of each lake to determine land usage and possible sources of pollution, The water level data for Lake Corpus Christi were obtained from officials at Wesley Seale Dam. Fisherman usage of the various lakes was determined by talking to camp owners, game wardens and sometimes to fishermen, Public access is available to all the lakes and rivers studied in this segment, Common name Scientific name Alligator gar Lepisosteus spgtula Lacdpede Spotted gar L, oculatus (Winchell) Longnose gar L1 osseus CLinnaeus) Threadfin shad Dorosoma p_£enense (Gunther) Gizzard shad cepedianum (Le.Sueur) Mexican tetra Astyanax mexicanus CFilippi) Smallmouth buffalo Ict.iobus bubalus (Rafinesque) Grey redhorse Moxostoma congestum (Baird and Girard) Carp Cyprinus carpio Linnaeus Pugnose minnow OpsoEoeodus_gemiligg Hay Tamaulipas Shiner Notropis braytoni Jordan and Evermann Red Shiner N lutrensis (Baird and Girard) Bullhead minnow Pimephales vigilax (Baird and Girard) Flathead minnow P, promelas Rafinesque Channel catfish Ictalurus punctatus (Rafinesque) Blue catfish l1 furcatug (LeSueur) Black bullhead l9 melas (Rafine.sque) Yellow bullhead I: natalis (LeSueur) Flathead catfish Pylodictus olivaris CRafinesque) Tadpole madtom Schilbeodes gryinus (Mitchill) Blackstripe topminnow Fundulus notatus (Rafinesque) Sheepshead minnow Cyprinodon variegatus Lacépéde Mosquitofish Gambusia affinis (Baird and Girard) Sailfin molly Mollienisia latipinna LeSueur Amazon molly M, formosa CGirard) Striped mullet Mugil cephalus Linnaeus' Tidewater silverside Menidia beryllina (Cope) White bass Roccus chrysops (Rafinesque) Largemouth bass Micropterus salmoides CLacepede) Warmouth Chaenobryttus gulosus (Cuvier) Redear sunfish Lepomis microlophus (Gunther) Bluegill L macrochirus Rafinesque White crappie Pomoxis annularis Rafinesque Black crappie P nigromaculatus (LeSueur) Freshwater drum Aplodinotus grunniens Rafinesque Rio Grande perch Cichlasoma gianoguttatum (Baird and Girard) Naked goby Gobiosoma bosci Lacépede Findings: Harlingen City Lake This 20wacre lake is located in downtown Harlingen and is the city's water supply reservoir. Water in the lake originates from the Rio Grande River and reaches the lake through a system of gravity flow irrigation canals. Public angling is permitted on this lake without restrictions or limita— tions, but little fishing is done due to the sizable rough fish population. Netting - Three netting collections were made on this lake in February. All told, 29 fish of five species were taken (Table 2). The game fish species included blue catfish (Ictalurus furcatus) only. Channel catfish Clctalurus punctatus), white bass CRoccus chrysops), largemouth bass CMicropterus salmoides) and white crappie (Pomoxis annularis) and black crappie CE. nigromaculatus) were all taken in previous surveys but none were found in this survey. Table 2. Results of gill netting, Harlingen City Lake, February, 1964 . . .. ._ . ._ .. _mm______________._L___T____w1_____nw__i________L_7 Species Numbers Per Cent of I Weight Per Cent of ____Total_Number (soundsi‘nC Total Weight Longnose gar 16.2 32.27 Gizzard shad 2.6 5.18 Smallmouth buffalo 24.6 49.00 Blue catfish* 3.5 6.97 Freshwater drum 3.3 6.58 Per Cent Game Fish Per Cent Rough Fish * Indicates game fish On the basis of the limited netting data, game fish showed a relative de- crease both in numbers and in weight. In 1963, game fish species comprised 22.54 per cent of the total number and 3.64 per cent of the total weight as compared to 17.24 per cent of the number and 6.97 per cent of the weight in 1964. Gizzard shad CDorosoma cepedianum), freshwater drum CAplodinotus grunniens), longnose gar (Lepisosteus osseus) and smallmouth buffalo CIctiobus bubalus), in that order, were the most abundant rough fish species taken. Collectively, they comprised 77.46 per cent of the total number and 96.36 per cent of the total weight of the fish netted. The length—weight statistics of the fish taken in nets are shown in Table 3. The average "K” factors are in line with those of the 1963 recon- naissance survey. Table 3. Length—weight statistics of fish taken with gill nets, Harlingen City Lake, February, 1964 Standard length Longnose gar Gizzard shad Smallmouth buffalo Blue catfish Freshwater drum Seining — Seining collections were made at two stations. All told, 152 fish of 7 species were taken in the seining colleCtions (Table 4). Mosquito- fish (Gambusia affinis), red shiners (Notropis lutrensis) and tidewater silver- sides (Menidia beryllina), in that order, comprised 95.40 per cent of the total number. The most noticeable change concerned the threadfin shad (Dorosoma petenense); they comprised less than 1 per cent by number as compared with more than.40 per cent in 1963. This apparent ”reduction” is probably due to a seining error. Table 4. Seining results, Harlingen City Lake, February,l964 Numbers Per Cent of Taken _ __ ___ Total Number_ Threadfin shad Red Shiner Flathead minnow Mosquitofish Amazon molly Tidewater silverside Naked goby Lake Conditions — Submerged vegetation is lacking due to the turbidity. Shoreline vegetation, however, consists mainly of bulrushes mixed with a few cattails. Secchi disc readings of light penetration ranged from 11 to 13 inches. It is believed that the turbidity is caused by bottom—feeding fishes which keep silt in suspension rather than the prevailing southeasterly wind. Recommendations - Fishermen should be encouraged to fish for catfish and crappie. A commercial fisherman might be necessary and desirable to harvest the rough fish in the near future. Bentsen State Park Lake Netting — Three gill netting collections were made on this lake in May, 1964. The second check, scheduled for November, was not made due to the extremely low water conditions. There were only a few areas where the water was as much as two feet deep. A total of 22 fish of five species was taken in the netting collections. Rough fish species, including spotted gar (Lepisosteus oculatus), smallmouth buffalo, bluegill (Lepomis macrochirus) and Rio Grande perch (Cichlasoma cyanoguttatum) were dominant both in number and in weight (Table 5). The only game fish species taken in the nets, warmouth (Chaenobryttus gulosus), comprised less than 15 per cent of the total number and 5.69 per cent of the total weight. Table 5. -Resu1ts of gill netting, Bentsen State Park Lake, May, 1964 Per Cent of Wei ht Per Cent of Total_Number Spotted gar Smallmouth buffalo Warmouth* Bluegill Rio Grande perch Per Cent Game Fish Per Cent Rough Fish * Indicates game fish Seining — The seining results are shown in Table 6. Mosquitofish and threadfin shad comprised 93.02 per cent of the total number of fish taken. Though there is a good supply of forage fish, it appears that there are few bass and crappie in the lake to crop them. Table 6. Results of seining, Bentsen State Park Lake, May, 1964 Numbers Per Cent of Taken _ Total Number Threadfin shad Gizzard shad Red.shiner Sheepshead minnow Mosquitofish Tidewater silverside Bluegill Rio Grande perch The length-weight statistics are shown in Table 7. No appreciable changes were noted for any species. Table 7. -Length-weight statistics for fish taken with gill nets, Bentsen State Park Lake, May, 1964 Standard Length 'nu. Wei:ht .zrams ”K” Factors _ Ran;e Average Ran;e Avera;e Ran;e 'Avera;e Spotted gar 479-494' 486 0.65—0.82 Smallmouth buffalo 490-490 490 4.81—4.81 Warmouth 147-165 155 4.46-4.98 Bluegill 94-112 101 3.56-4.57 Rio Grande perch 69-144 109 3.73-5.20 Lake Conditions - The water level has been extremely low all year. The upper portion of this oxbow lake is dry, but a total of approximately 10 acres of water still remainsin the lake. By November, the lake had gone down even lower than it was in May. For that reason the lake was not checked as originally planned. Recommendations — Since the water level is so erratic, no management or developmental work is proposed or planned. Should a more favorable water supply become available, some management work should be initiated. Fort Brown Lake This 33-acre lake, located in downtown Brownsville, was drained in the spring of 1962, dredged in the summer of that same year and refilled in the fall. The water used in refilling the lake came from the Rio Grande River and contained many undesirable fishes. Therefore, the lake was treated with rotenone to remove all fishes. The state fish hatchery near Brownsville stocked a large number of largemouth bass fingerlings in December, 1962. Netting - Four gill netting collections were made in February, 1964, and took a total of 162 fish of 7 species (Table 8). Of the seven species, three were classed as game fish (channel catfish, white bass and largemouth bass). All told, the game fish species comprised 16.66 per cent of the total number and 37.64 per cent of the total weight. Table 8. Results of gill netting, Fort Brown Lake, February, 1964. Numbers Per Cent of I Per Cent of Taken Total Number 5 Total Wei ht Threadfin shad 9 '" 5.56 1.1 1.30 Gizzard shad 61 37.65 44.7 52.89 Channel catfish* 6 3.70 11.1 13.14 White bass* 2 1.23 1.9 ' 2.25 Largemouth bass?"c 19 l 11.73 18.8 22.25 Bluegill 64 39.51 6.7 7.93 Rio Grande perch l 0.62 0.2 0.24 100.00 Per Cent Game Fish 37.64 Per Cent Rough Fish 62.36 * Indicates game fish The most noticeable change in the fish population since the 1963 check is the presence of rough fish. None were found in the 1963 check, but this year they comprised 83.34 per cent of the total number and 62.36 per cent of the total weight. Doubtless, these fish entered the lake from the Rio Grande which is its main source of water. The length—weight statistics are presented in Table 9. All values are considered normal for fishes in this area of Texas. Table 9. Length-weight statistics of fish taken with gill nets, Fort Brown Lake, February, 1964 Standard Length nu Wei_ ht -rams ”K” Factors 3 S-ecies Ran; e Avera- e Ran-e Avera; e Ran;e _ IAvera;e' Threadfin shad 119-145 - Gizzard shad 187-288 163F652 Channel catfish 270—388 391-1247 White bass 205-244 306-567 Largemouth bass 155—331 94-1049 Bluegill 92-111 29-67 Rio Grande perch 127—127 112-112 Seining — One seining collection was made and took 22 fish of four Species (Table-10). Bluegills and mosquitofish, in that order, comprised 90.90 per cent of the collection. One specimen of largemouth bass, approximately 3 inches in length, was taken and indicated that the bass had spawned. In addition to the fish, 46 freshwater shrimp (Palaemonetes sp.) were taken in the collection. Table 10. Seining results, Fort Brown Lake, February, 1964 Per Cent of Total NUmber Mosquitofish Largemouth bass Bluegill Rio Grande perch Lake Conditions - Secchi disc readings ranged from 19 to 28 inches, as com— pared with 60 to 82 inches a year earlier. This noticeable change is almost certainly due to the abundance of rough fish, most of which are bottom feeders. The higher turbidity should aid in the prevention of excessive submerged vegetation.