TPWD 1966 F-2-R-13 #1059: Fisheries Resurvey of Lake Lyndon B. Johnson (Granite Shoals), Job Completion Report, Project F-2-R-13

--- Page 1 --- JOB COMPLETION REPORT As required by TEXAS FEDERAL AID IN FISHERIES RESTORATION ACT Federal Aid Project No. F-2-R-13 FISHERIES INVESTIGATIONS AND SURVEYS OF THE WATERS OF REGION 2-B Job No. B-24(b): Fisheries Resurvey of Lake Lyndon B. Johnson (Granite Shoals) Marion Toole D-J Coordinator Project Leader: Richard L. White J. Weldon Watson Executive Director Texas Parks and Wildlife Department Austin, Texas June 16, 1966 Eugene A. Walker Director, Wildlife Services --- Page 2 --- ABSTRACT Data collected during the second of three segments for this job indicated a continued reduction of smallmouth buffalo and concurrent increase in river carp- sucker, seemingly correlated with the selective harvest of buffalo by commercial fishing. All data collected for this job will be compiled and published at the conclusion of the third segment. a, --- Page 3 --- Job Completion Report State of Texas Project No. F-2-R-13 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, 1965 - January 31, 1966 Objectives: 1. To determine the effect of commercial netting on the river carpsucker (Carpiodes carpio) - smallmouth wffalo (Ictiobus bubalus), population ratio in Lake Lyndon B. Johnson (Granite Shoals). 2. To determine the over-all effect of commercial netting of rough fish on the fish population of Lake Lyndon B. Johnson (Granite Shoals). Procedures: Fifteen gill net sets were made monthly at selected sites. Each net consist- ed of 150 feet of mesh graduated from one inch to three and a half inches square mesh (in 25 feet sections). Seine collections were taken monthly in an effort to supplement gill net data. All data collected were examined to determine fish population changes which might be correlated with commercial fish harvest. Scientific names of fishes mentioned are included in the checklist (Table 1). Only common names will be used in the body of this report. Discussion: During the project segment, the second of three for this job, commercial fishing efforts were continued on the lake. This operation selectively removes smallmouth buffalo almost exclusively, through the use of large mesh gill nets. This technique is representative of that commercial fishing in Texas freshwaters which is done under contract with the Texas Parks and Wildlife Department. Data collected during the first segment of this job suggested that the selective harvest of smallmouth buffalo had not resulted in an over-all reduction in rough fish. There was, however, a significant shift in the ratios of buffalo to river carpsucker. As buffalo numbers and total weight declined, the correspond- ing carpsucker figures appeared to increase (Job Completion Report B-24(b), F-2-R-12, June, 1965). That general trend continued during the segment reported here. Percent by number of all rough fish taken indicates some reduction in the ratio of rough fish caught to game fish caught (Table 2). This is accounted for primarily by a significant increase in sunfish, classed among game fish species, and not by an actual reduction in rough fish numbers (Table 3). This view is supported by the fact that percent by weight of rough fish taken did not decline significantly (Table 2). --- Page 4 --- SCIENTIFIC NAME Lepisosteus csseus Dorosoma cepedianum Ictiobus bubalus Carpiodes carpio Moxostoma congestum Cyprinus carpio Carassius auratus Notemigonus crysoleucas Notropis venustus Ictalurus punctatus Ictalurus melas Ictalurus natalis Pylodictus olivaris Roccus chrysops Micropterus salmoides Chaenobryttus gulosus Lepomis cyanellus Lepomis microlophus Lepomis macrochirus Lepomis auritis Lepomis megalotis Pomoxis annularis Aplodinotus grunniens Cichlasoma cyanoguttatum -2- TABLE 1 A CHECKLIST OF SPECIES COMMON NAME Longnose gar Gizzard shad Smallmouth buffalo River carpsucker Gray redhorse sucker European carp Goldfish Golden shiner Spottail shiner Channel catfish Black bullhead Yellow bullhead Yellow catfish or flathead catfish White bass Texas spotted bass Largemouth bass Warmouth Green sunfish Redear sunfish Bluegill sunfish Redbreast sunfish Longear sunfish White crappie Freshwater drum Rio Grande perch --- Page 5 --- TABLE 2 PERCENT OF ROUGH FISH TAKEN IN GILL NETS LAKE LYNDON B, JOHNSON 959 1960 961 1962 19631964965 Percent By Weight 79.02 85.57 88.71 90.14 85.94 87.81 86.25 Percent By Number 70.59 72.54 73.89 75082 73.88 7717 67.63 --- Page 6 --- -4- TABLE 3 LAKE LYNDON B. JOHNSON NETTING DATA 1965 Percent Percent Species Number By Number Weight By Weight Longnose gar 216 3.20 559.89 6.40 Gizzard shad 1,909 28.25 950.86 10.87 Smallmouth buffalo 413 6.11 2,344.54 26.81 River carpsucker . 1,723 25-50 2,844.89 32.54 Gray redhorse sucker 22 0.33 34.07 0.39 European carp 104 1.54 532.31 6.09 Goldfish 1 0.01 1,69 0.02 Golden shiner 7 0.10 1.39 0.02 Spottail shiner 1 0.01 0.31 0.01 Channel catfish 113 1.67 192.25 2.20 Black bullhead 2 0.03 0.62 0.01 Yellow bullhead 1l 0.16 4.01 0.04 Yellow catfish or flathead catfish 79 1.17 413.23 4.73 White bass 111 1.64 126.49 1.45 Texas spotted bass 40 0.59 30.91 0.35 Largemouth bass 113 1.67 112.74 1.29 Warmouth 87 1.29 23.94 0.27 Green sunfish 27 0.40 4.11 0.05 . Redear sunfish 89 1.32 11.77 0.13 Bluegill sunfish 1,245 18.42 147.53 1.69 Redbreast sunfish 2 0.03 0.26 0.01 Longear sunfish 50 0.74 4.35 0.05 White crappie 231 3042 134.28 1.53 Freshwater drum 160 2.37 265.93 3.04 Rio Grande perch _ 2 0.03 0.44 0.01 TOTALS 6,758 100.00 8,742.81 100.00 --- Page 7 --- SPECIES Smallmouth buffalo River carpsucker TOTALS -5- TABLE 4 NUMBER OF FISH CAUGHT PER 100 FEET OF NET LAKE LYNDON B, JOHNSON 1959 1960 1961 1962 1963 1964 1965 6.12 5-30 3.20 7oJ1 3.23 2.32 1.53 4.17 6.40 5.20 4.19 5.18 5.78 6.38 10.29 11.70 8.40 11.90 8.41 8.10 7.91 TABLE 5 SPECIES Smallmouth buffalo River carpsucker POUNDS OF FISH CAUGHT PER 100 FEET OF NET LAKE LYNDON B. JOHNSON 1959 1960 1961 1962 1963 1964 1965 15.21 15.47 13.07 22.93 14.79 11.65 8.68 3.63 6.96 5.36 5.13 6,86 8.48 10.54 TOTALS 18.84 22.43 18.43 28.06 21.65 20.13 19.22 --- Page 8 --- -6- Otherwise, the data indicated continued reduction of smallmouth buffalo and concurrent increase in river carpsucker (Tables 4 and 5). As reported in the tables, number and weight of buffalo caught per hundred feet of net have decreased from 7.71 and 22.93 in 1962 to 1.53 and 8.68 in 1965. In the same period, number and weight of carpsucker have increased from 4.19 and 5.13 in 1962 to 6.38 and 10.54 in 1965. Since the carpsucker is considered less desirable than the smallmouth buffalo (Job Completion Report B-24(b), F-2-R-12), it appears possible that continued selective harvest of buffalo may prove injurous to the fish population as a whole. Recommendations: This job has entered the third and final segment. When all field data has been collected, detailed analysis will be made. Results and conclusions will be published, probably as an issue of the Texas Parks and Wildlife Department Inland Fisheries Series. Prepared by Richard L. White __ Approved by Veto Sante. Project Leader Coordinator Date June 16, 1966 GARY _ WOOD Regional Supervisor