TPWD 1962 F-7-R-10 #755: Fisheries Investigations and Surveys of the Waters of Region 1-A: Experimental Management of the Rita Blanca Lake Fishery, Job Completion Report

JOB COMPLETION REPORT As required by FEDERAL AID IN FISHERIES RESTORATION ACT TEXAS Federal Aid Project No. F—7-R~10 FISHERIES INVESTIGATIONS AND SURVEYS OF THE WATERS 0F REGION I—A Job No. E-3 Experimental Management of the Rita Blanca Lake Fishery Project Leader: Lonnie Peters H. D. Dodgen Executive Secretary Texas Game and Fish Commission Austin, Texas Marion Toole Eugene A. Walker D-J Geordinater ' Director, Program Planning March 26, 1963 ABSTRACT Changes in the composition of the fish p0pu1ation during this segment were slight. The only important change was that the relative abundance of channel catfish decreased about six per cent, while the relative abundance of black bullheads increased about six per cent. An additional 97 flathead catfish were obtained from the Colorado City Lake, tagged and released in Rita Blanca Lake during this segment. Subsequent recoveries of these fish were made in May, July, October, and December. The tagged flatheads were found to have lost weight during the two-month-period following their release, but recoveries in the following months revealed fairly good weight increases for most fish. A total of 40 catfish spawning devices, made from concrete-weighted five-gallon pails was placed in Rita Blanca Lake to promote better reproduction of channel catfish. Brush piles were installed at four localities to provide added protection to the white crappie p0pulation, which appears to be increasing steadily. For the second consecutive year, golden shiners were absent from the gill net collections and were much less abundant in seine samples than they were in previous years. Predation and continued parasitism by an anchor worm, Lernaea sp., has kept the golden Shiner p0pulation greatly reduced since 1960. JOB COMPLETION REPORT State of Texas Project No. F-7-R-10 Name: Fisheries Investigations and Surveys of the Waters of Region 1-A Job No. E—3 Title: Experimental Management of the Rita Blanca Lake Fishery Period Covered January 1, 1962 - December 31, 1962 Objectives: To initiate and conduct experimental management practices at Rita Blanca Lake, to restore balance in the fish population through the control of excessive populations of golden shiners, black bullhead catfish, and goldfish. Techniques Used: Periodic netting and seining collections were made to determine changes in the composition of the fish p0pulation and to evaluate the results of experi- mental management practices previously employed. Additional flathead catfish were stocked to replace those that had died or were taken by fishermen. These additional flatheads, which were stocked in March, were measured, weighed and tagged before being released, in order to provide a means for determining growth rates of this species. Brush piles were installed to provide cover for white crappie. Channel catfish spawning devices were constructed and installed at various locations. Attempts were made to reduce the golden Shiner, goldfish, and black bullhead catfish populations by seining. Findings: Fish Collections Four gill net collections were made during this segment to determine com- position changes in the fish pOpulation. Basically there has been little change as compared with the data collected during the previous segment, except that channel catfish showed a 6.53 per cent decrease, while black bullheads showed a corresponding 6.81 per cent increase in numbers. For the second consecutive year, golden shiners were absent from the gill net collections. The percentage of game fish in the four net collections made during this segment varied from 8.18 per cent to 68.75 per cent and averaged 26.44 per cent. In percentage by weight, however, game fish accounted for 64.31 per cent. Channel catfish and flathead catfish each accounted for roughly one- fourth of the total weight of fish taken. Bullheads continue to be abundant in numbers but very small in size, averaging 0.17 pounds this year, which is a slight increase over last year's average of 0.15 pounds. Tables 1, 2, 3 and 4 give the percentage composition by number, weight, and the average weight of fish taken by gill nets in February, July, October and December of this year. Table 5 is a composite of Tables 1 to 4. Table 1. Percentage Composition by Number and Weight and Average Weight of Fish Taken From Rita Blanca Lake, February 12, 1962. Per Cent Per Cent by Total by Average Species Number Number Weight Weight Weight River Carpsucker 1 .16 3.42 1.04 3.42 Channel Catfish 70 _ 11.02 99.59 30.14 1.42 Black Bullhead «438 68.98 76.82 23.25 0.18 Flathead Catfish 8 1.26 113.53 34.36 14.19 Largemouth Bass 1 .16 4.08 1.24 4.08 White Crappie 117 18.42 32.93 9.97 0.28 Totals 635 100.00 330.37 100.00 Game Fish 196 30.86 Rough Fish 439 69.14 _ Per Cent Per Cent by Total by Average Species Number Number Weight Weight Weight Carp 1 .69 3.85 4.18 3.85 CarleGoldfish 5 3.48 16.75 18.16 3.35 Goldfish 5 3.47 6.89 7.48 1.37 Channel Catfish 18 12.50 31.23 33.87 1.73 Black Bullhead 34 23.61 7.59 8.23 0.22 Flathead Catfish 1 0.69 7.27 7.88 7.27 White Bass 3 2.08 3.75 4.07 1.25 White Crappie 76 52.78 14.79 16.04 0.19 Bluegill Sunfish 1 0.70 0.08 0.09 0.08 Totals 144 100.00 92.20 100.00 Game Fish 99 68.75 Rough Fish 45 31.25 Table 3. Percentage Composition by Number and Weight and Average Weight of Fish Taken From Rita Blanca Lake, October 17, 1962. MW Per Cent Per Cent by Total by Average Species Number Number Weight Weight Weight Goldfish 7 2.84 6.41 10.41 0.91 Channel Catfish 7 2.85 11.59 18.82 1.65 Black Bullhead 182 73.99 28.90 46.93 0.15 White-Bass 1 0.40 2.10 3.40 2.10 White Crappie 49 19.92 12.59 20.44 0.25 Totals 246 100.00 61.59 100.00 Game Fish 57 23.17 Rough Fish 189 76.83 m——w_——-—rvrr——r"———v“—vr—T—T—r——v——rr——r-rr—-r—T—"v-r——*—"”“—““““mr**“*"*—“*— Table 4. Percentage Comp031tion by Number and Weight and Average Weight of Fish Taken From Rita Blanca Lake, December 20, 1962. Per Cent Per Cent by Total by Average Species _ Number Number Weight Weight Weight Goldfish 2 ' 0.45 1.70 1.76 0.85 Channel Catfish 2 0.45 6.19 6.44 3.09 Black Bullheads 402 91.37 61.12 63.54 0.15 Flathead Catfish 2 0.45 12.44 12.93 6.22 White Bass 2 0.46 2.61 2.71 1.30 Largemouth Bass 1 0.22 4.00 4.16 4.00 White Crappie 29 6.60 8.13 8.46 0.28 Totals 440 100.00 96.19 100.00 Game Fish 36 8.18 34.70 Rough Fish 404 91.82 65.30 Table 5. Percentage Composition by Number and Weight and Average Weight of Fish Taken From Rita Blanca Lake by Gill Nets in February, July, October and December 1962. W Per Cent Per Cent by Total by Average Species Number Number Weight Weight Weight River Carpsucker 1 0.06 3.42 0.59 3.42 Carp 1 0.07 3.85 0.68 3.85 Goldfish 14 0.96 15.00 3.63 1.07 Carp X Goldfish 5 0.34 6.89 1.21 1.38 Channel Catfish 97 6.63 148.60 26.05 1.53 Black Bullhead 1,056 72.13 174.43 30.58 0.17 Flathead Catfish 11 0.75 133.24 23.36 12.11 White Bass 6 0.41 8.46 1.48 1.41 Largemouth Bass 2 0.13 8.08 1.42 4.04 White Crappie 271 18.52 68.44 12.00 0.25 Totals 1,464 100.00 570.41 100.00 0.39 Game Fish 387 26.44 366.82 64.31 0.95 Rough Fish 1,077 73.56 203.59 35.69 0.19 Seining results indicate that there was a good spawn of white crappie this year. Out of 10,719 fish taken with 200 and 300 foot seines, 5,247 were white crappie. Bullheads taken in seines totaled only 3,038 which is quite a contrast to last year's seining results. Goldfish and golden shiners each comprised about 10 per cent of the seine catch, while all other species were of minor importance. Table 6 gives the seining results on six dates during this segment. There was no evidence of reproduction by either white bass or flathead catfish, and it appears that there was very limited reproduction of channel catfish and largemouth bass. It should be noted that golden shiners were relatively scarce in the seine samples as compared to their abundance in previous years. Prior to 1961, Table 6. Percentage Composition of Fish Taken by a Two-Hundred and a Three-Hundred—Foot Seine From Rita Blanca Lake, 1962. Date Feb. 11 Feb. 12 August 23 Dec. 20 ' Dec. 21 Dec. 22 Total Ssecies Number_ Per Cent Number Per_Cent _Number _Per_Centp_Number _Per_Cent_ Number _Per Cent Number Per Cent _Npmber Per Cent 0 15 0.51 0 1 0.03 Carp 0 0 16 0.14 Goldfish 199 34.26 516 52.49 92 3.12 256 9.64 29 0.93 2 0.48 1,094 10.21 Carp X Goldfish 0 0 0 0 50 1.60 0 50 0.47 Golden Shiner 301 51.81 205 20.86 378 12.81 4 0.15 79 2.52 0 967 9.02 Fathead Minnow 0 0 7 0.24 0 0 0 7 0.06 Channel Catfish 3 0.51 1 0.10 36 1122 0 0 2 -0.48 42 0.40 Black Bullhead 59 10.16 150 15.26 1,671 56.62 205 7.72 570 18.21 383 91.40 3,038 28.34 White Bass 0 0 3 0.10 0 1 0.04 2 0.48 6 0.05 Largemouth Bass 17 2.92 31 3.16 96 3.25 12 0.46 12 0.38 1 0.24 169 1.58 Bluegill Sunfish 0 11 1.12 0 0 52 1.66 0 63 0.59 Sunfish Sp. 2 0.34 0 18 0.61 0 0 0 20 0.18 Whit .0 . . ___635 ._ - _ . _ . .. _. - 9 Totals 581 100.00 983 100.00 2,951 100.00 2,655 100.00 3,130 100.00 419 100.00 10,719 100.00 literally gallons of golden shiners could be taken in one drag with a 300—foot seine. Predation and parasitism have kept this species greatly reduced in 1961 and 1962. Twenty-foot seine results, given in Tables 7 and 8, show that the fathead minnow and the plains killifish were the most abundant minnow species taken. Table 7. Results of Seining With a Twenty-Foot Seine from Rita Blanca Lake, October 17, 1962. Species Number Per Cent Goldfish l 0.40 Red Shiner 26 10.44 River Shiner 2 0.81 Fathead Minnow 138 55.42 Plains Killifish 81 32.53 Largemouth Bass 1 0.40 Totals 249 100.00 Table 8. Results of Seining With a Twenty—Foot Minnow Seine from Rita Blanca Lake, December 20, 1962. Species Number Per Cent Goldfish 55 14.70 Black Bullhead 225 60.16 Red Shiner 1 0.27 Fathead Minnow 85 22.73 Largemouth Bass 8 2.14 Totals 374 100.00 Habitat Improvement In September 1962, several brush piles were placed in Rita Blanca Lake to aid the crappie p0pu1ation. Brush (mostly green elm), tied in bundles two to three feet in diameter and ten to twelve feet in length, was weighted and sunk in areas having water depths of eight to eleven feet. A majority of these brush piles were located in the deeper water near the dam, and all of the brush piles were located along cables supported by floating barrels. It is h0ped that these brush piles will lend protection to small crappie as well as provide fishermen with well—located places to fish for crappie. Figure I shows the locality of the brush piles. A total of 40 channel catfish Spawning devices was installed during this segment. These spawning containers, shown in Figures 2 and 3, were made of five-gallon pails weighted with concrete. The spawning devices were located at depths of two to four feet in areas having hard sand or rocky bottoms. They were installed too late to provide spawning places this year, but it is hOped they will promote much-needed natural reproduction of channel catfish in 1963. LEGEND CDnCt“;°. It; 5 re “d ; D 8 ___ Brush mas 161W“ _— jPawhEnj (an: 3.13:. __ Road “99¢, 1 Mai) 0F R’é'rs Blanca Lalfie Showing Lota'ruo'u' OF Brush Piles and Approximate Leta-HOM- of. CtzTFBL‘ SP8 tuning car“. In. I Figure 2. A pile of spawning cans ready to be placed in Rita Blanca Lake. Figure 3. A Spawning can made of two five-gallon cans with concrete added for weight. Flathead Catfish Introductions The original stocking of flathead catfish was in November 1959, when 285 fish were transferred to Rita Blanca from Lake Stamford. Reports of these fish having been found dead or taken by fishermen indicated that since 1959 the flathead population had been reduced considerably below the one per acre stocking ratio desired. In March 1962, an additional 97 flatheads were obtained from the Colorado City Lake and released in Rita Blanca. These fish were all tagged, weighed, and measured before being released in order that future re- coveries would show growth rates and weight increases. Figures 4 and 5 show tagged flatheads recovered in December 1962. Several of these tagged flatheads were recovered during this segment and their weights and tag numbers were recorded. In all, 34 recoveries were made. One recovery, by a fisherman, was made on June 27, 1962, about 3% months after the fish were released. All of the remaining recoveries were made with gill nets. Six flatheads were recovered twice during the year. The tagged flathead taken by a fisherman was tag No. 5611 and weighed 8.50 pounds when stocked on March 9, 1962. It was reported to have weighed 11.25 pounds when taken June 27. On May 9, two months after the tagged flatheads had been released, 18 recoveries were made with gill nets. When stocked, these 18 fish ranged from 5.00 to 17.50 pounds and averaged 11.15. All but four of these fish showed weight losses when recovered. Losses in weight ranged from 0.04 for the smallest fish in the group to 2.13 pounds for One of the largest fish. The average weight of the 18 flatheads was 10.69 pounds when recovered on May 9, therefore, the average weight loss per fish was 0.47 pounds for the two month period. In terms of weight loss per pound of body weight, the total weight of the 18 fish was 200.75 pounds when tagged, the total weight loss was 8.42_ pounds, so the rate of loss was 0.04 pounds per one pound of body weight. The four fish showing weight gains in May ranged from 9 to 12 pounds in weight when tagged. Their weight gains varied from 0.08 to 1.76 pounds. One of these four was recovered a second time, while three of the fish showing weight losses in May were recovered a second time later in the year. Five tagged flatheads were recovered in July. One fish weighed the same as it did when released, one had lost 0.50 pounds, while three showed good weight gains. These five fish ranged from 4.00 to 9.50 pounds and averaged 8.05 pounds when tagged. When recovered, they ranged from 7.00 to 14.00 pounds and averaged 10.50 pounds. The average weight gain per fish was 2.45 pounds, while the rate of weight gain per pound of body weight was 0.30 pounds increase per one pound of body weight. The fish showing a weight loss of 0.50 pounds had been previously netted on May 9, at which time it showed a 0.79 pound loss, (weight gains or losses are all relative to the fishes' weight when tagged). Injuries to this fish when netted on May 9 probably caused this fish not to gain weight. A similar case was that only one flathead out of eight recovered in December showed a weight loss at that time, and it had also been previously recovered in May. In October, two tagged flatheads were taken. When tagged, one fish weighed 7.50 pounds, the other 14.50 pounds. Their recovery weights were 9.00 and 22.00 pounds respectively. The second fish had gained 7.50 pounds in slightly over seven months, and had been previously recovered on May 9 at which time it weighed 14.19 pounds.