TPWD 1955 F-5-R-2 #167: Inventory of Species Present in San Angelo Reservoir: Segment Completion Report, Project No. F-5-R-2, Job B-3

--- Page 1 --- — STATE Texas PROJECT NO. F-5-R-2, Job B-3 ( LON PERIOD June 22, 1954 - May 1, 1955 Y XN UO vy Nan \ ny Segment Completion Report Lawrence S. Campbell Project Leader William G. McClelland Assistant Project Leader Inventory of Species Present in San Angelo Reservoir. OBJECTIVES To determine the species present and their relative abundance as well as to determine the ecological factors influencing their distribution. PROCEDURE Thirty-nine gill net collections were made at twelve netting stations in San Angelo Reservoir. Experimental nylon gill nets measuring 125 ft. long x 8 ft. in depth and made up in five, 25 ft. sections, were used. Mesh size for these nets increased pro- -essively in each following section at one-half inch intervals beginning with one-inch sso and terminating with a three inch mesh section. Nineteen seining collections were made at fourteen localities along the lake hore. In nearly all collections both 26 ft. " mesh bag seines and 15 ft. i" mesh com- fon sense seines were used. To estimate relative abundance at each seining station a fa) th BB count was made of all individuals taken in two hauls with a 26 ft. }#" mesh bag seine. Tn addition, a four ft. common seine with 1/16" mesh was used to collect samples of fry Pollowing spring spawning. Water analysis for dissolved carbon dioxide and oxygen content was taken each mouth and surface temperature, pH and the climatic conditions were recorded for each netting collection. In net collections, most fish were identified, counted, weighed, measured and sexed in the Pield. A sample number of each species was examined for stomach content and a scale sample taken. On occassion it was necessary to preserve an individual, its stomach or some other organ for more detailed examination in the laboratory. When this was required, the specimen was preserved in 10% formalin. FINDING During the segment the reservoir receded from elevation 1893 to elevation 1885, a loss of approximately 12,107 acre feet volume. In 1954 the city of San Angelo purchased all water stored between elevations 1886 and 1908 from the Upper Colorado River Authority. \e first water withdrawn for city use was released during the late spring months of 1955. ue method of lowering the lake and the time of the releases may have been detrimental to --- Page 2 --- ny Bo the spawning activity of several game species, primarily largemouth black bass (Microp- therus salmoides). The lowest dissolved oxygen content recorded during the segment was 77 ppm. and the maximum carbon dioxide content obtained a water analysis checks was 7 pom. Minimum surface water temperature recorded was 51° F. and the maximum record was 68° P, Turbidity, except following the rainfall run- _ in June 1954, was 0.0. Netting Colleetions: Thirty-nine net sets captured 1,345 individuals of twelve species. As re- corded in Table No. I, few significant population ratio changes are indicated by this aernoe of sampling. Numerical increases for gizzard shad (Dorosoma cepedianum), river arp suckers (Carpiodes carpio), and white bass (Morone chrysops) are apparent, and per- centages for southern channel catfish (Ictalurus punctatus), white crappie (Pomoxis aot and largemouth black bass (Micropterus salmoides) decreased. No flathead Pilodictus olivaris) were taken in netting collections, but a number of these att wich are known to have been taken by sportsmen. During the segment nineteen seining collections captured 1,742 individuals of sixteen species. Mosquito fish (Gambusia affinis), gizzard shad —— cepe~ dianur), avd spotted sunfish (Lepomis punctatus) were less numerous than in 1953-54, and per tages for red shiners (Notropis Tate lutrensis), Blacktail shiners (Notropis stus};, and parrot minnows (Pimephales vigilax) TneFeadedl, Juvenile white bass oro! “chrysops) were taken for the first time in October 1954. Because recession of tne lake made it neces ssary to move the location of several seining stations, a duplication of the first segment work was impossible. amarks : A continuance of this job has been requested and approved for next segment. SUMMARY i. The volume of the lake was decreased by 12,107 acre feet during the segment. é. The method and time of withdrawal of water for municipal purposes oer have been detrimental te the spawning of some game species, WNotabl largemouth black bass. 3. Netting results indicated an increase in gizzard shad, river carp suckers, and white bass and a decrease in southern channel catfish, largemouth black bass, and white crappie. ‘Iming collections indicated increases in red shiners, blacktail shiners, 4 Seinin and parrot minnows. Decreases were noted in mosquito fish, gizzard shad and spotted sunfish. 5. A continuance of this job has been requested and approved for next segment. --- Page 3 --- Table I Netting Collections From San Angelo Reservoir b by % by Species July Aug. Sept. Oct. Nov. Dec. Jan. Feb. Mar. Apr. Total No. Wt. Avg. K Dorosoma cepedianum 14 0 21 4O 24 37 35 Fxe) 99 33 352 25.99 6.89 185 Carpiodes carpio 31 13 14 34 60 87 119 68 17 56 499 36.89 67.32 2h6 Cyprinus carpio 0 0 1) @) 0 ie) 3 0 1 0 he 230 2925 260 Moxostoma congestum 0) 0) 0 0) 0 O 3 L 0 0) 4 2 30 o431 227 Aplodinotus grunniens 0 0 8 0 6 y 5 3 8 2 36 2.66 2.54 = 2h Ameiurus natalis 0) O ) O O e) 1 0 O Oo 1 OF eO77 210 Micropterus salmoides 21 5 6 he 0 2 2 12 0 2 54, 3.69 6.58 252 Morone chrysops @) 0 9 O 0 2 0 A 3 O 18 1.33 .693 223 Pomoxis annularis 30 21 ) 21 15 12 6 20 1 O 126 9.30 6.87 337 Lepisosteus osseus 0 0 ) 0 0 fe) ©) 1 1 0 2 W476 423 51 Iectalurus punctatus \ 12 18 13 0 11 2 36 15 19 = 130 6.90 6.60 197 Lepomis (sunfishes) 0 60 19 12 L 0 2 21 4 1 128 9.50 .69 408 100 =s«.111 95 124 106 167 4176 196 166 113 1,354 100 100 --- Page 4 --- Species Gambusia affinis Notropis lutrensis Notropis venustus Pimephales vigilax Dorosoma cepedianum Carpiodes carpio Micropterus salmoides Morone chrysops Pomoxis annularis Ictalurus punctatus Lepomis cyanellus Lepomis macrochirus Lepomis microlophus Lepomis megalotis Lepomis humilis Lepomis auritus Table II Seining Collections From San Angelo Reservoir July Aug. Sept. Oct. Nov, Dec. Jan» Mar. 36 100 48 12 8 ) @) 36 140 90 ks 147 12 21 25 12 12 ) 20 12 ) 10 9g 0 8 10 9 21. 13 re) fe) 25 20 10 30 8 8 14 8 Oo h ) h fe) 2 fo) 9 0 8 4 10 21 ©) 2 3 2 0) fo) @) 12 3 2 @) 12 8 3 14 20 Fe 2 4 ) i 0) 0 1 @) 6) fe) ©) 2T 12 20 30 12 0 12 21 35 14 31 30 18 14 11 38 2 2 4 10 0 @) 5 5 12 6 \ 4 fo) 0 3 2] 0) 9) 2 0 O ©) 3 6) fe) O 1 6 0 0 2 20 313 251 2he 334. 80 65 gu 192 Apr. no i Li 12 Ve) fs ke Po 4O 1,782 % by No. 5.22 2.30 100.00