TPWD 1963 F-6-R-10 #863: Fisheries Investigations and Surveys of the Waters of Region 5-B: Job No. B-20 Fisheries Reconnaissance

--- Page 1 --- JOB COMPLETION REPORT As required by ' FEDERAL AID IN FISHERIES RESTORATION ACT TEXAS Federal Aid Project No. F-6-R-10 FISHERIES INVESTIGATIONS AND SURVEYS OF THE WATERS OF REGION 5-B Job No. B-20 Fisheries Reconnaissance Project Leader: Charles T. Menn H. D..Dodgen Executive Secretary Texas Game and Fish Commission Austin, Texas Marion Toole Eugene A. Walker D-J. Coordinator Director, Program Planning May 27, 1963 --- Page 2 --- ABSTRACT Four public lakes and a portion of a resaca were visited during this segment to see if any appreciable changes in the fish populations had occurred since previous surveys. Fort Brown Lake, included in the 1961 reconnaissance survey, was not worked during the current segment due to recent draining and deepening of the lake. In Delta Orchards Lake, near Monte Alto in Hidalgo County, game species including channel and blue catfish, white crappie and freshwater drum showed a relative increase in numbers and a relative decrease in weight. In Bentsen State Park Lake, rough fish species including alligator gar, gizzard shad, bluegill and Rio Grande perch were dominant both in numbers and in weight with 86.45 per cent and 78.49 per cent respectively. Game fish species including blue catfish, white bass, largemouth bass and warmouth comprised 23.47 per cent of the total number and 5.96 per cent of the total weight of fish taken in nets in Harlingen City Lake. Resaca de la Guerra, near Brownsville, has an abundance of spotted gar, smallmouth buffalo, carp, striped mullet, bluegills and freshwater drum, but has a surprisingly lack of gizzard shad and river carpsucker, Thus an intensive resurvey was initiated (see completion report for Project F-6-R-10, Job B-22). Gizzard shad showed a relative increase of nearly 100 per cent in Lake Corpus Christi; however, this figure is based on very limited data and is not taken to be conclusive. Other than continued water hyacinth control work on Lake Corpus Christi, no recommendations for Federal Aid developmental work are made in this report. --- Page 3 --- JOB COMPLETION REPORT State of Texas Project No. F-6-R-10 Name: Fisheries Investigations and Surveys of the Waters of Region 5-B Job No. B-20 Title: Fisheries Reconnaissance Period Covered: January 1, 1962 through December 31, 1962 Objectives: To conduct limited investigations and to obtain current information concerning gross changes in fishing conditions and 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-foot deep, with five 25-foot long sections of 1-, 1%-, 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 development and the occurrence of parasites in the individual specimens were recorded. 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. Water analyses were made only on Delta Orchards Lake. In order to determine land usage and possible sources of pollution, a limited check was made of the surrounding area of each lake. In comparing water levels, reference points were established on all lakes encountered with the exception of Lake Corpus Christi. The data for this lake were obtained from officials at Wesley Seale Dam. Fishermen usage of the various lakes was determined by talking to camp owners, game wardens and sometimes to fishermen. Public access is available to all of the lakes studied in this segment. Findings: Delta Orchards Lake Delta Orchards Lake, a 2,200 surface acre irrigation reservoir near Monte Alto in Hidalgo County, is a part of the Hidalgo and Willacy Counties --- Page 4 --- Table 1, Checklist of species re Common name Alligator gar Spotted gar Longnose gar Threadfin shad Gizzard shad Smallmouth buffalo Carp Pugnose minnow Red shiner Shiner Channel catfish Blue catfish Flathead catfish Sheepshead minnow Mosquitofish Sailfin molly Amazon molly Striped mullet Tidewater silversides White bass Largemouth bass Warmouth Redear sunfish Bluegill White crappie Black crappie Freshwater drum Rio Grande perch =D = ferred to in text and tables, Scientific name Lepisosteus spatula Lacépede L. oculatus (Winchell) L. osseus (Linnaeus) Dorosoma petenense (Gunther) D. cepedianum (LeSueur) ictiobus bubalus (Rafinesque) Cyprinus carpio Linnaeus Opsopoeodus emiliae Hay Notropis lutrensis (Baird & Girard) Notropis sp. Ictalurus punctatus (Rafinesque) i. furcatus (LeSueur) Pylodictis olivaris (Rafinesque) Cyprinodon variegatus Lacépede Gambusia affinis (Baird & Girard) Mollienesia latipinna LeSueur M. formosa (Girard) Mugil cephalus Linnaeus Menidia beryllina (Cope) Roccus chrysops (Rafinesque) Micropterus salmoides (Lacepéde) Chaenobryttus gulosus gulosus (Cuvier) Lepomis microlophus (Gunther) L. macrochirus Rafinesque Fonoxi annularis Rafinesque » nigromaculatus (LeSueur) pee reer grunniens Rafinesque Cichlasoma cyanoguttatum (Baird & Girard) --- Page 5 --- Water Control and Improvement District No. 1. The reservoir contains approxi- mately 20,000 acre-feet of water which is used to irrigate nearly 70,000 acres of farm land. Water in the lake comes from the Rio Grande River and reaches the lake through a system of gravity flow irrigation canals. Public angling in this lake is permitted for a fee of 25 cents per person per day. Trotline fishing is prohibited except to persons who are issued special permission. Fishing pressure decreased during the year due to the recent closing of a nearby U. S. Air Force base. Netting - In March 1962, five netting collections took a total of 231 fish of nine species (Table 2). The game fish species taken in nets included channel and blue catfish, white crappie and freshwater drum. Normally the drum is considered a rough fish species, but is classed as a game fish in this case because anglers at Delta Orchards Lake harvest them in large numbers the year around. ; Of the total fish taken in nets, game fish species comprised 71.43 per cent of the number and 32.14 per cent of the weight. A year previously, game fish comprised 68.17 per cent and 38.67 per cent by number and weight respectively. On the basis of these limited data, it appears that game fish species are increasing in numbers but decreasing in weight. Compared with netting data for the same period in 1961, both blue catfish and white crappie showed relative increases in numbers. Blue catfish comprised 15.58 per cent of the 1962 net collection as compared to 10.63 per cent in March 1961. White crappie increased from 10.33 per cent in March 1961 to 21.21 per cent in March 4962. Another game fish species, freshwater drum, however, showed a relative decrease during the 12-month period from 46.92 per cent in March 1961 to 33.77 per cent in March 1962. Longnose gar showed an increase in numbers while gizzard shad showed a decrease in numbers during the period from March 1961 to March 1962. This may be explained in part by the gar feeding on the shad. The average "K" factors, or indices of physical condition, for all four game fish species showed definite increases over the specimens taken in March 1961. Among the rough fish species, the average "K" factor of the small- mouth buffalo increased from 2.95 in the March 1961 collections to 3.28 in the March 1962 collections. Table 3 shows the length-weight statistics of the nine species of fish taken in nets. Seining - Two seining collections took a total of 245 specimens of nine species (Table 4). Tidewater silversides comprised more than 75 per cent of the collections and threadfin shad comprised nearly 10 per cent. Stomach analyses - Algae or fish remains were found in most of the channel and blue catfish stomachs. Visceral round worms were found in many of the white crappie and freshwater drum stomachs. --- Page 6 --- USTF owes soPOTpUT x LG°8Z ysta y8noy Jueg 19g €7° Tl Yystq oweyg queg t30g 00001 6-022 oo-oor | rez | reno | y% WNIp ToJeMYseTy x oTddeio o3TYyM % UsTZIe9 ont % YUSTZ Ie Touuey) oTeygnq YInowT TT eug peys prezzty 1e3 ssousuoy ze3 peqjods 1e8 10R7e3ITIV 2Y8TOM [eROT (spunod) Zequny, Teo UsyeL setoeds JO Jueg 1t38g sy 3T3OM JO QUSeD Ieg sioequnyn Z96T YOLEW ‘SYST spreyoig eITeq ‘But Jeu TIT3 Jo sj{nsoy =z eTqGeL we --- Page 7 --- £6°C-88°T Z9-G¢ 9/Z-8ET wnip 1ejeMyselg GE°E-S7°T See-7I O@2-GL etddez> oITYyM L8°T-¥T'T S67Z-SS TIS-691 ystyqeo entg TS*T-047°T 8Ie-vL O0SZ-OLT ysty7eo TouueyD 80°7-€9°C T8€7-778 OT7-867¢ oTezING YANowTTeus L8°T-vE°T T61-2% 07C-ZET peys prezzTto 8S°0-TE"0 SLOS-OTE SS6-E€47 1e3 asouszuoyT 89°0-95°0 PETI-76€ OSS-€6E€ ze8 peqjodg 1Z£°0-02°0 1707-9T9T | 699-7219 1e3 1OWeSTTIV eseroay | _osuey——=«~_—seSeaeay asuey aseraAy [___ asuey —_ ; : : : - : sotoeds SIOROPF YW, (sue1z3) 743TeM (s1ejewT TT TW) qasuey piepueis Z961T YoLeW SeyeT spreyorg eITed ‘sjeUu TITS Te UeUTIedxe YIM Uaye} YSTF FO soTAsT}eAs JYSTom-yABUEeT “*¢E eTQeL --- Page 8 --- sTe qo], SOPISIOATTS TaReMAaPT] AT Tow uozeuy AT TOW UTFTTeS ystyoqtnbsopq MouUTU peoaysdaays LeuTYys psy MOUUTU ssoUusng peys prezzty peys UT}peeryy, ~ JeIOT, FO que) tog J96T YOreH ‘aye] spreyoig eajeq ‘sq[nsexr BuTUTeS “*y aTqey --- Page 9 --- ~Vni Lake Conditions - Although algae was found in several catfish stomachs, aquatic vegetation is scarce in the lake, This may be attributed in part to the fact that the prevailing, strong, southeasterly winds keep silt in suspension in this shallow lake, Recommendations - Since wild fish from the Rio Grande River have constant access to Delta Orchards Lake, population control work would be ineffective and therefore is not recommended. It is recommended, however, that commercial fishing with nets be permitted in order to harvest as many of the undesirable fish as possible. Commercial netters should be prohibited from taking catfish so that this population be kept as abundant as possible. In addition to the commercial netting of rough fish, it is recommended that white crappie and freshwater drum be harvested as heavily as possible by anglers in order to make full use of these species. Bentsen State Park Lake Netting - Three gill netting collections were made on this lake in April 1962. A total of 177 fish of seven species was taken and rough fish species, including the alligator gar, gizzard shad, bluegill and Rio Grande perch were dominant both in numbers and in weight (Table 5). Of the three game fish species taken, blue catfish and largemouth bass are the most important sport fishes. Their numbers, however, are limited, This lake was chemically treated for a complete kill of fish in January 1960 (see Job Completion Report for Project F-14-D-4, Job 16a25) and restocked with largemouth bass in March 1960. Attempts in June 1960 to screen native fish from the incoming water of the Rio Grande River were unsuccessful (see Supplementary Report for Project F-14-D-4, Job 16a25). The length-weight statistics of the netted specimens are presented in Table 6. No appreciable change was noted for any species. Seining - The single seining collection was comprised of 21 fish of five species and included threadfin shad, gizzard shad, mosquitofish, tidewater silversides and redear sunfish (Table 7). Of these, the threadfin shad, which comprised 24 per cent of the netting collection, is the best forage fish. Mosquitofish dominated the collection, as they did a year earlier. No young largemouth bass were taken in the collection, indicating poor spawning success. Lake Conditions - The water level has been abnormally low all year. The upper portion, or bend, of this oxbow lake is dry, but a total of approximately 10 acres of water still remains in both "arms" of the lake. A new irrigation canal, completed in July 1961, was built immediately north of the state park to provide more water for farmers in Hidalgo County Water Control and Improvement Districts Numbers 7 and 14, Water is pumped directly from the Rio Grande River to supply the canal. At one time it seemed as though an agreement would be reached whereby the park lake would get its water from the irrigation canal. However, no such agreement has as yet been reached. --- Page 10 --- YsSTy aues sajeoTpury, “<-YUStTy Y8nor quag reg YsSTy sues jUueD 19g s[Te 0] yoied epueiy oty TItSenTg % YInNou1eM ¥% sseq Uqnowssie 7 x% YSTFIEO ONT peys przezzty ze3 109e3ITIV UBTEM [eIOL (spunod) saqunyNy [eIOL usye Jo jue9 139g sqy3TOM JO JUeD 13g sioquny, satoeds Z961 Ttady ‘oyey, yzeg o7eI4g Usesqueg ‘S8uTQJeU TITS FO sj{[NseyY "G eTqel --- Page 11 --- 07°? Le°y T8°€ 0s*z y8°T 00°? TO*T asetoay | _osuey ft Bereny a Buey 07° 7-09°% 6L°9-ET V7 SO°7-8S°E 88°7-07°72 c6°T-LL°T cS°2-69'T TO°*T-10°T S10}0e8F ,%,, VET-VET YL-8E YCE-99 V6L-8IT 9€6-778 c6 €6€-67 c67T 009€-0S2 (swei3) 3Y43TOM Z96L [tady ‘ayey yreg 27eI1g UesqUeg ‘sjqouU [{[T3 [equewtiedxe yIIM usye] YSTJ JO sOTAsTIeIS JYSTeM-YIsUeT SVT LOT 84YT Sée BSE (S29 OWTT[TW) YAsUEeT pzrepueqs GVI-SHT 0721-26 00¢-02T SOE-89T OLE-OSE OLC-V7ET OTZ-OTZL e3sue "9 eTqeL yored apurery oty TIT senT@ yqnouzeM sseq Yy Inowes1e7 ysty3eo ented peys piezzty ze3 1OWPSTLIV psereeds --- Page 12 --- “10 Table 7. Seining results, Bentsen State Park Lake, April 1962 Threadfin shad ‘Gizzard shad Mosquitofish Tidewater silversides Redear sunfish ee eee --- Page 13 --- =Li- Recommendations - Periodic netting and seining checks should be continued to check changes and developments in the fish population. An annual reconnais- sance survey should be adequate. No further developmental work is planned because of the unfavorable water supply. Harlingen City Lake This 20-acre 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 limitations, but little fishing is done due to the preponderance of rough fish species, Netting - Six gill netting collections were made on this lake: three in April and three in September, In these collections, a total of 98 fish of ten species was taken (Table 8). The game fish species taken in nets included blue catfish, white bass, largemouth bass and warmouth. Of the total fish netted, game fish comprised 23.47 per cent of the number and 5.96 per cent of the weight. No comparison was made since this was the first such reconnaissance survey made of this lake. Longnose gar, gizzard shad and smallmouth buffalo, in that order, are the ranking rough fish species. Collectively, they comprised 63.27 per cent of the total number and 84.80 per cent of the total weight of the fish netted. The length-weight statistics of the fish taken in nets are presented in Table 9, The average "K'' factors appear to be normal for all species of fish in this area. Seining - Four seining collections were made at two stations. The combined results included 197 fish of seven species (Table 10). Tidewater silversides, threadfin shad, mosquitofish and pugnose minnow, in that order, comprised 91.88 per cent of the total number. Stomach Analyses - Shad, tidewater silversides and unidentifiable fish remains were found in most of the spotted and longnose gar stomachs, while insect remains were found in most of the blue catfish stomachs. Algae was also present in several of the catfish stomachs. Stomachs of the gizzard shad, smallmouth buffalo, striped mullet and freshwater drum were not examined, Lake Conditions - Although algae was found in several catfish stomachs, aquatic vegetation is scarce in the lake. Shoreline vegetation consists mainly of bulrushes, mixed with a few cattails. Secchi disc readings of light penetration ranged from 10- to 11%-inches. It is believed that the turbidity is caused largely by bottom-feeding fishes --- Page 14 --- ~¥9- YSTy ewes sazeoTpuly x YSTJ Ysnor JueD Jeg YSTJF ewes qusg t039g sTeqOL wnip rezeMYysely xu qnowreM x% sseq YNoWes1eT xy sseq oqTUM eT [nu pedtizas * YUSTJIBO NTA oTesgnq YANoUT Teus peus piezzty 1e38 ssousguoy 1e3 pejjods qYUBZTEM [eIOT (spunod) Jaqunyn [e207 usye L, JO quag 19g qYSTOM JO JueD 13g siequnyn sotoedg Z961 Aequejdesg pue [Iady ‘ayeq ATO UssuT[AeYH ‘BuUTAQeU TITS Jo sj[nsey “8 eTdeL --- Page 15 --- i STSTS0TT TTA y33ueT prepueis $10}0eF ST°€-09°% LO°9-Le° 4 TV C-T7°S T9°C-19°% ST°?-ST'°Z 9T°?-6T'°T LE°S-8T"E ST°?-SE'T 8S°0-6€°0 S£°0-09°0 dhs Z961 tequejdes pue [Tidy ‘aye AaT9 useSuT{IeY (suez3) T6€-0S 09-09 OSE-OSE 8S7-8S7 VETI-VETT YOET-08 970S-TTT VOT-EV 6797-6€S ad e728 *‘sjou TIT3 [eqUowTIedxs YIM usaye} YsTZ JO sotqstjeqs WYStTem-yYyRSueT 977-771 cLI-2rt WYC-7T 097-092 GLE-GLE 76E-6LT 967-907 clc-92T S86-787 _Sé9-OTS "6 aTqeL unip LszeMYysely YANOWULeM sseq yjnouesie7 sseq o7TUM qe TIN pedtz3g ystyqe9 ante oTeyjnq YyInday] Teug peys piezzty 1e3 ssousuoyT 1e3 peajods --- Page 16 --- ~14- Te IO], Fo quey 128g Z96T “ET tequieqdas Sayey AVTO UssuTTIAeW ‘sq[nser ButTutesS sTeq0], SOPISIOATIS 19a}eMepT] AT [Ow uozeuy ystyoqtnbsow A9uTUS AeUuTYS poy MOUUTU ssousng peys UTypeeryy, “OT PT9PL --- Page 17 --- i 5m which keep silt in suspension, rather than the prevailing southeasterly wind. Recommendations - Under present conditions, catfish and crappie are the species most likely to afford good sports fishing. Anglers should be encouraged to fish for both gars and smallmouth buffalos and controlled commercial netting should be permitted but the taking of catfish should be prohibited. Resaca de la Guerra Resaca de la Guerra is an old stream bed of the Rio Grande River which skirts a portion of the northern edge of the City of Brownsville. The water in the resaca is pumped from the Rio Grande River approximately four miles away. Netting - Five gill netting collections were made during the reconnaissance period, however, data were obtained from only four nets because one was stolen. The gill nets took a total of 76 fish of 12 species (Table 11). Rough fish species including spotted gar, smallmouth buffalo, carp, striped mullet, bluegill and freshwater drum comprised 64.48 per cent of the total number and 80.55 per cent of the total weight. Smallmouth buffalo ranked first by number and first by weight, and spotted gar ranked second by number and weight. Game fish species including channel, blue and flathead catfish, largemouth bass and white and black crappie comprised 35.52 per cent of the total number and 19.45 per cent of the total weight. The length-weight statistics of the fish taken in the nets are presented in Table 12, Since no comparable data are available, no comparison was made, but all average '"'K"' factors appear to be normal for this area. Seining - A total of 26 fish of five species was taken in one seining collection (Table 13). Tidewater silversides comprised 50 per cent of the total number taken. Stomach Analyses - Insect remains were found in the stomach of one bass and also in the stomach of one bluegill. Unidentifiable fish remains were found in the stomach of one white crappie. All other stomachs of carnivorous species were empty. Recommendations - It was recommended that a more intensive study be made of Resaca de la Guerra in order to formulate plans for improving sports fishing. This work was done under Job B-22, D-J Project F-6-R-10. Lake Corpus Christi Netting - A total of eight gill net collections was made on Lake Corpus Christi during September 1962. All were surface sets in water ranging from 5- to 55- feet in depth. All told, these nets took 425 fish of 13 species (Table 14). --- Page 18 --- -16- ysT} owes sa zeoTputy SS°08 87°79 Sy’ ot SSE 00°O0OT 3Yy3TeamM [TeIOL (spunod) requnyN [eIOL usyeL JO 4Usag 13g 2Y3TOM JO queg 19g siequnyl Z9O61T ACW SPATOND ST op eoeSay‘SSuUTAJEU [[T3 JO sq[nsey usTy Y8norl queD rag UST} owes JUaD 138g sjTeqO] wnip TeJeMYyserg x otddeio yoeTg x oeTddezo a3TYyM TIF SenTg x sseq YnowsZzeT] JeT[nNu podtazqas x YsTy qe. peoyze lA % USTFIeO ENT x YSTy eo Toeuueyg die9 oTeygnq YANouTTeus ze3 pajjods setoeds “TT eTde --- Page 19 --- «1l7< TS°¢-G6°T VL°S-E9°S GC°EWZT°E 89° 7-76°E 8o°C- SLT Te°T-T8°T LE°S LETS 08° T-€9°T 9L°1T-92'°T £6°C-L6°7 86 €-06'° Z 8£°0-0S°0 0°6€E S*OTT O° L9G 0° 70ZE O° €ZL €° 80€ 0° 96€ T' 9st 7° S9G Z961 SOW SetEnd eT ep eoesoy ‘sqou [TTS [ejueuTiedxe yIIM usyeI YsTF JO soTAsTIeIs AYSTem-yRBuUeT cOV-TST 9ET-OET G77~S6 CULE cET@e8 196-196 HOZE"H0ZE | 9€6-O01S 9€6-LL 96€-96€ €999-G9 98L1-8zz | 9L7~ CBT ELT-89T cOT-EVI cOT- 76 88T-9ST GTE“STE €TS-€TS CLE-STE LLE=ELT LET-LET TSS-TCL €S9-87E °¢@L PTIPL unip Lejyemysolg etddezs yoeltg atddezo o3TyM TIT Sen Tq sseq yqnowssi1e 7 Je[Tnu pedtaqs ystyyeo peoysey aA ystTyieo ant ysty eo Touuey) dieg OTeFING YANoUTTeUS ie38 paqjods setoods --- Page 20 --- «ip~ Table 13. Results of seining collections, .Resaca de la Guerra, May 15, 1962 Per Cent Species of Total Number Gizzard shad Mosquitofish Tidewater silversides Redear sunfish Rio Grande perch --- Page 21 --- -19- WYSTamM Teo], JO 4ueDg Azsg (spunod) SIY4STOM AoquNN [eIOL JO queD 13g ueyeL sloqunyy YsTy owes sajeotputy YSTJF YBnozr Us) 198g ysTy owes juag 1r3sg STBIO], yoied apueiy ory unip TeqeMyselg x otddeio yoelTg x otddeizs a qty LIF SenT % SSeBq 33TUM % YSTF}eO onTg x YSTy}eo TouueyD oTeyFnq YInowyTTeug peys paezzty 1e3 ssousuoy 1e3 pajjods 1e3 1OeBITIV sotoeds Z96T teqmejdeg ‘T3stzy9 sndiog syeT ‘BuTaIeU [{IB3 Jo sjqnsey “HT eTAdeL --- Page 22 --- Phin Rough fish species including alligator, spotted and longnose gars, gizzard shad, smallmouth buffalo, bluegill, freshwater drum and Rio Grande perch comprised 59.52 per cent of the number of fish netted, and 72.07 per cent of the weight. Gizzard shad alone comprised 40 per cent of the total fish taken in nets. However, these limited data are not considered conclusive in that the resurvey of 1961 showed the shad population to be 21.53 per cent. It is probable that this high percentage of shad is largely due to the fact that most of the nets were located in open water areas where shad are more likely to be found. ; No largemouth bass were taken in nets, but fishermen catch this species in good numbers, especially in the spring and fall. Collectively, channel and blue catfish, and white and black crappie comprised 37.42 per cent of the number, and 21.64 per cent of the weight. The white bass were concentrated in the lower portions of the lake in September but most fishermen reported that they were unsuccessful in catching them. The length-weight statistics presented in Table 15 are normal for this lake. No significant changes were noted, Seining - Three seining collections took a total of 447 fish of eight species (Table 16). Tidewater silversides, threadfin shad and red shiners, in that order, were the most frequently encountered fishes. Collectively, these three species comprised 85.91 per cent of the fish seined. Stomach Analyses + Unidentifiable fish remains were found in the stomachs of both alligator and spotted gar. Also, one catfish was found in an alligator gar's stomach. Insect remains were found in three white bass stomachs, fish remains were in two stomachs, and seven were empty. Lake Conditions - Chemical control of water hyacinths in the upper portions of Lake Corpus Christi was continued under Job 15a4, Project F-15-D-4, Such work is necessary in order to maintain access for fishermen (see completion report for Project F-15-D-4, Job 15a4). Water stargrass has become a problem around boat docks and boat channels. This problem will be partly solved when the lake refills. The water level varied from one to five feet below the 88-foot crest of the dam during the year (Table 17). In early June 1962, the lake rose two feet, but soon began to drop again. Undoubtedly the dropping water level will affect the spawning of centrarchids, especially largemouth bass and crappies, if it continues into the next spring. --- Page 23 --- «21 = 76° 0-76° 1 08°S-61°7C 8S°E-TEE £9°€-0S°Z 08°7-86°€ 7L°S-L6°7T L0°€-67°T T6°T-92°T 69°S-00°% VL°C-LO'T G9°O0-TE*O €c°T-ZE°0 96°0-02L°0 TY-TY TZOT-6S ELT-94T 907-647 EG-GE 670T-78% 88ST-8v TS8-¥1 YCETV- T8ET 089-SZ 8EEV-LEL GSEtE-Z8T cO0L-060€ 76-76 S8c-ZET 69T-79T 1¥C-O7T OTT-06 TOE-97¢ 799-9471 SSE-EOT CCU-7BE SOE-LTT S96-9€S 869-77E GL8-969 yorod opuery oTy wnip TaqeMYyselg etddeizo. yorltg atddezo aqTuM TI? Sentg sseq oqTYM ysty3eo ent ystyjeo Teuueyg oTezFng YAnouyTTeus peys prezzty ze3 ssousuoyT ze3 pejjodg 1e3 LOWeSITLIV S10}08F Wy (swei3) Iyu3Teay (stejeWTT TW) yAsue7T piepueis © _ _ 7961 ATequejdasg ‘tTAstazyg sndiog asyeyT ‘sjou [IT3 Te UoUTIsedxe YIM Usye. YSTF JO soTAstjAejs JYSTem-yAsUEeT “Cl eTqeL --- Page 24 --- -22- Te oy, Fo queg 10g° Z961 tequejdes ‘t4stayg sndio9 oye] ‘sa[Nser B3uTUTeS sTeq0] yorod apueiy oTYy TIt8enTg SOPTSAIZATTS A3azeMepTy, ystyzo tnbsop ystj}eo TeuueypD ZoutTys pey MOUUTU asousng peys uTypeoryl sotoods “OT PTdFL --- Page 25 --- 74. 92.91 29 £77 C961 T96T “AON *390 ‘q3dag 4sn3ny Aqne aune Aen Ttady yo1ey *“qoq *uer °20q ~8 62 61 6 62 61 6 O€ OZ OT O€ OZ OT TE 12 It_T 61 6 O€ 0 “7961 AeqUIsAON YSnorzYI [961 Aaquied.aq ‘sTeAeT 197eM TASTIYQ sndi0yg oye] @ OT TE Té TT “ZT TIPL T 6L 08 T8 c8 €8 18 c8 98 £8 88 68 06 [eAeT eos Ure aAOge j90q --- Page 26 --- Bin Recommendations = Quarterly checks should be made on the lake during the coming segment to gather more information on the status of the fish popu- lation. Water hyacinth eradication will be attempted through the use of aircraft. For information purposes a comparison of netting success is included as Table 18, ( —_ Prepared by Charles T. Menn Approved by y Z Z rT Project Leader Coordinator Date May 27, 1963 Kenneth C. Jurgens Regional Supervisor --- Page 27 --- -25- JEN FO 3004/YSTd jo spunog aseLIAV JON/USTA jo spunog a8 e1sAV *PepnyTOUT JOU ST pUe UsTOJS SseM Jas aUO 4Nq ‘Jas |TOM SjoU aATAy 9L qysnep JeN JO | JeN/USTA qysnep SJeN FO SION UST Fo 200g/ysta | Jo requny ustgq jo qa0q Fo jo spunog JO Aequny | aBe1LOAV Zaqunn Laquny Zaquny a3 e1IAV 3y8neo YyYsTy JO spunod pue azdqunu JO SWI9} UT SoyYe, [[e uo BuTj}ZeU T[T3 Fo ssv9oong “eT sTqeL Z96L Aequeqdes y [tTady aye], AATO uesuttTszey Z961T ITtady ayey_ yreg o3e9S9 uosjusag C96T YOAeH aye] spreyoig eqpaq 7961 Tequiaqdag Tastayg sndiop oye] 7961 AEH BIIOEND BI ep eoesay aqeq pue oyeyT