(1964–1965) Fisheries Resurvey of Lake Granite Shoals, Job Completion Report

--- Page 1 --- JOB COMPLETION REPORT As required by FEDERAL AID IN FISHERIES RESTORATION ACT Federal Aid Project No. F-2-R-12 FISHERIES INVESTIGATIONS AND SURVEYS OF THE WATERS OF REGION 2-B Job No. B-24(b): Fisheries Resurvey of Lake Granite Shoals Project Leader: R. L. White J. Weldon Watson ; Executive Director Texas Parks and Wildlife Department Austin, Texas Marion Toole Eugene A. Walker D-J Coordinator Assistant Director for Wildlife June 25, 1965 --- Page 2 --- ABSTRACT Lake Granite Shoals was resurveyed to determine the effect of commercial netting on the lake. There has not been a reduction of rough fish in the lake effected by the commercial netting of smallmouth buffalo. To date, data collected indicate a replacement of the harvested buffalo by the river carpsucker. The carpsucker is, from both a fishing as well as a nutritional standpoint, the least desirable of the rough fish species. The job will be continued to obtain more conclusive evidence as to this ratio shift within the rough fish complex. --- Page 3 --- JOB COMPLETION REPORT State of Texas Project No. F-2-R-12 Name: Fisheries Investigations and Surveys of the Waters of Region 2-B Job No. B- 24(b) Title: Fisheries Resurvey of Lake Granite Shoals Period Covered: February 1, 1964 - January 31, 1965 Objectives: 1. To determine the effect of commercial netting on the carpsucker, Carpiodes “Carpio, --buffalo, Ictiobus bubalus, population ratio. 2. To determine the overall effect of commercial netting of rough fish on the fish population of Lake Granite Shoals. Procedures: A total of 166 gill nets, standardized for use on all DJ projects, were set in Lake Granite Shoals. The overnight sets were made at stations which were selected to give maximum coverage of the lake. Seining samples were taken with a twenty-foot straight seine in an effort to obtain relative abundance figures on juvenile forage fish in the lake, Water quality studies were carried out on the lake in conjunction with netting and seining operations. Data collected in reconnaissance work on the lake was examined closely to determine changes or trends, in the fish population, which could be attributed to commercial netting on the lake. Table 1 is a checklist of the fish species mentioned in this report. Find nes: shoals during the ing for rough its second year, te commercial rough h welpht and number z my, netably, smalin Ag can be seen in T Lich removal operat + has oot decreased over Al thouch there ihe ' OWE eant ratie --- Page 4 --- -2- buffalo by commercial netting has been succeeded by an increase in the river carp- sucker population. Table 4 and the accompanying graph illustrate the number of buffalo caught per hundred feet of net as compared with the number of carpsucker caught per hundred feet of net over the past six years. As can be seen, minor fluctuations in the figures characterize the first four years, followed by a de~ finite replacement of the buffalo by the carpsucker. Significantly, this replace- ment can be correlated with the initial removal of buffalo by commercial netting. Table 5 contains the pounds of buffalo and carpsucker collected per hundred feet of net over the past six years. These figures, correspondingly emphasize the definite shift in the buffalo-carpsucker ratio. In screening the data collected, it was noted that a considerable number of the river carpsucker collected were in the 3/4 pound to 1% pound category, and averaged from 13 to 15 inches in length. These particular carpsucker are more than likely between thirteen and eighteen months in age, making them the spawn following the start of commercial fishing operations on the lake. From the numbers collected, as well as the condition of the individual species, the spawn has experienced: an unusually high rate of survival. Since river carpsucker and small mouth buffalo require almost identical food and environment, the increase in carpsucker population can certainly be attributed in part, if not completely, to the increase in available habitat effected by the removal of the smallmouth buffalo. Seining samples of the lake did not present any unusual data, and are not presented in this report. The information will, however, be kept on file for future reference. Water quality study data collected for the lake during the past year will also be kept on file at project headquarters. ; Discussion: The theory of project personnel that commercial netting of a lake results in an adverse change in the fishery complex is being borne out on Lake Granite Shoals. From the data collected during this the initial phase’ of the job, there appears to be a definite shift in the buffalo-river carpsucker ratio, with virtually no change in the rough fish-game fish complex. Popular belief is that the removal of the buffalo results in a decreased rough fish population, but the void is being filled by an increasing carpsucker population. In a life history study entitled "A Laboratory Study of the Food Habits of Four Species of Rough Fish in Lake Diversion, Texas," Dr. W. W. Dalquest labeled the carpsucker as the least desirable of all the freshwater species of Texas. Also, the carpsucker is very selfigm harvested by anglers, yet buffalo are fished for quite successfully on enclosed docks , marinas, etc. In view of this, it appears that the sole effect of commercial netting is not the reduction of the rough fish population, but rather, the replacement of one undegirable species, the buffalo, with a less desirable species, the river carpsucker. It should be noted that the adoption of a standardized gill net for all Dingell-Johnson jobs may have some bearing on the statistics. These nets are longer than the ones employed up to 1963, as fifty feet of 34" mesh has been added. This additon would theoretically increase the buffalo harvesting efficiency by 25 percent. Presumably ‘then, the ratio of buffalo-carpsucker would have favored the --- Page 5 --- -3- carpsucker to a greater extent had the previous experimental gill nets been employed. Because this is the initial phase of this investigation, it is difficult to arrive at definite conclusions, Despite the strong shifts in the buffalo-carpsucker ratio, it is felt that additional data should be collected to rule out the possibility of fluctuations caused by population cycles within the individaul species. Recommendations: In order to collect additional data to substantiate the carpsucker-buffalo shift, it is recommended that this job be continued. € L Prepared by _ Richard L. White approvedby L712 -eest A pote Project Leader “ (Coordinator) JOHN E. TILTON Regional Supervisor Date: June 25, 1965 --- Page 6 --- SCIENTIFIC NAME Lepisosteus osseus Dorosoma cepedianum Ictiobus bubalus Carpiodes carpio Moxostoma congestum Cyprinus carpio Notemigonus crysoleucas Ictalurus punctatus Ictalurus melas Ictalurus natalis Pylodictis olivaris Roccus chrysops Micropterus treculi Micropterus salmoides Chaenobryttus gulosus Lepomis cyanellus Lepomis microlophus Lepomis macrochirus Lepomis megalotis Pomoxis annularis Aplodinotus grunniens -4- TABLE 1 A CHECKLIST OF SPECIES COMMON NAME Longnose gar Gizzard shad Smallmouth buffalo River carpsucker Gray redhorse sucker European carp Golden shiner Channel catfish Black bullhead Yellow bullhead Flathead catfish or yellow catfish White bass Guadalupe bass or Texas spotted bass Largemouth bass Warmouth Green sunfish Redear sunfish Bluegill sunfish Longear sunfish White crappie Freshwater drum --- Page 7 --- TABLE 2 LAKE CRANITE SHOALS Netting Data 1964 PER CENT PER CENT SPECIES ___NUMBER BY NUMBER WEIGHT ~—sBY WEIGHT Lepisosteus osseus 45 0.91 105.35 1,46 Doresona \cepedianum 1,542 31.34 692.39 9.58 Icticbus bubalus 577 11.73 2,902.04 40,15 Garpiodes carpio 1,438 29.23 2,112.52 29.23 Moxostoma congestum 8 C.L6 2t,G1 9.45 Cyprinus carpio 80 1.63 363,90 582 Notemigonus crysoleucas 5 Q,10 0.95 0,01 ictalurus punctatus 90 1,83 169.63 2.35 ictalurus melas 3 0.96: 0.75 0.01 ictalurus natalis 5 Q.10 1.57 0.02 Pylodictis olivaris 55 1.12 393.18 5,44 Roccus chrysops 73 1.48 68.24 9,94 Micropterus treculi 27 0.55 29.70 0.41 Micropterus salmoides 51 1.04 49.76 0.69 Chaenobryttus gulosus 43 0.87 14.07 6.19 Lepomis cyanellus 25 0,51 3.67 0.05 Lepomis micrcolophus 25 0.54 3.97 0,05 Lepomis macrochirus 600 12.20 90.72 1.26 Lepomis megalotis 34 0.69 2.74 0.04 Pomoxis annularis 190 2.92 55.63 0.77 Aplodinotus grunniens —24 is Si 150.23 _-—220R_ TOTALS 4,920 190,00 75227.92 100,00 --- Page 8 --- ahs TABLE 3 PERCENTAGE OF ROUGH FISH LAKE GRANITE SHOALS 1959 1960 1961 1962 1963 1964 PER CENT BY WEIGHT 79.02 85.57 88.71 90.14 85.94 87.81 PER CENT BY NUMBER 70.59 72.54 73.89 735.82 73.88 77-17 --- Page 9 --- raph to Table TIT co oe no ee % Rough fish by Number 100 __.__.. ¥ Rough Fish by Weight = Eee 1959 91) --- Page 10 --- -8- TABLE 4 Number of Fish Caught Per 100 Feet of Net Lake Granite Shoals ee SPECIES 1959 1960 1961 1962 1963 1964 Smallmouth Buffalo 6.12 5.30 3.20 7Tofl 3.23 2.32 River carpsucker 4.17 6-40 5.20 4,19 5.18 5.78 Year Feet of Net Set 1959 2875 1960 3000 1961 3250 1962 6250 1963 6750 1964 24900 TABLE 5 Pounds of Fish Caught Per i100 Feet of Net Lake Granite Shcals SPECIES 1959 1960 1961 1962 1963 1964 Smallmouth buffalo 15,21 15.47 13.07 22.93 14.79 11.65 River carpsucker 3.63 6.96 5.36 5.13 6.86 8.48 SE RR A --- Page 11 --- Number | CCPC SEaeeeee CI 8 FORE eo COC eee COPE eee Graph to Yoble TV. mee Smallmouth Buffalo wee ltiver Carnsycker SERRE PPT rere PT reer SRS ee eee ee ptt l TT TT PPP TPT 4 INT TI aN Lit tt Tria aan Hh PTT Ty ERE e Re) ee Nee CI] Cy CCC COC 2 0 COC Poo pt TN N a - INET PPT SERAU rH San see Rep | See Number of lhtourh Fish Caught Per 100 Peet, of Net ~ || Suaue HH LT IN aan PP etre PPP rey Poodle lied alae lisa olen iedaclielindanshecdeclard egheileedicchaclasaiohlied e) O O 03 --- Page 12 --- | Graph to Table V. Paunds of Fish Caught Per 100 Feet of Net ponds eee Smallmouth buffalo Pg —River Carpsucker PITTI LLL OLLIE err EE EEE EEL CEL EEL LEE LLL ECC PPETrLererercirrrecircLeLLOCLeL LL LLL pepe EC a Trriitiribere et Lette ee : EECCA SEES EEE EERE See PTT TOOL eLeLeLLLLLEE ELECT rr a PICCOLO CBMELLLECLLLELLLCL ELL LLL an | SRR eee ABREU REEE EE BERR ORME eee SE RR eee SS RS 2 ESE SEES? MABE Se Pee eee, ee | SRR RRR OR RR ee eee ] td Hissansnesee dessaaceed dassusnccsnenssssseeeusswssweesssssscenseessasssessseeessess SSSR Re PR Be Ce ee at tet ttetbatafaded tat afed tt TE tt EE pte f aun ER REESE "A i in eo TT a SRR ee nl ts | a et tT TTT TT RES so elaonler bron = ERR Re Be ee eee BEB PT A PL A eee | TET Te) eS CR RGEE RET ERERERE EER AEE ERE RORREGnGRnnanonnee * * 1963 LY6 2, a co ee a PEh SUSAR TERR eek ee ew x Var