TPWD 1954 F-5-R-1 #70: Inventory of Species Present in Lake Nasworthy: Job Completion Report, Project F-5-R-1

--- Page 1 --- STATE noone 7 PROJECT NO, F-5-R-1, Job B-l PERIOD June 22, 1953 - June 22, 1954 Job Completion Report Lawrence S. Campbell TITLE Inventory of Species Present in Lake Nasworthy. OBJECTIVES To determine the species present and their relative abundance and to determine the ecological factors influencing their distribution. PROCEDURE Forty-eight gill nets were set for twelve collections. Experimental nylon gill nets measuring 125 ft. long by eight ft. deep and made up in five, 25 ft. sections were used. Mesh size for these nets increased progressively in each following section at half inch intervals beginning with a one-inch mesh section and terminating with a three-inch mesh section. Twenty-four seining collections were made at eight seining stations in the reser- ir. In nearly all collections both 26 ft., $" mesh bag seines and 15 ft., ¢" common sense seines were used. To estimate relative abundance a count was made of all individ- uals taken in two hauls with a 26 ft. i" bag seine. In addition to this work, collections with 4 ft. common sense 1/16" mesh fry seines were taken. Water analysis to determine dissolved carbon dioxide and oxygen content was tak- en for each netting collection and surface temperature, pH and the climatic conditions were recorded for each netting and seining collection. Turbidity was taken on six occas- ions. In netting collections, samples from each collection and for each species were weighed, measured and sexed. This work was done in the field. A scale sample was taken from a sample number of individuals for each species and stomachs containing food were preserved for laboratory analysis. Similar work for seining collections included ident-~- ification, weighing and measuring and the preservation of all indivuals whose identify was questionable in 10% formalin. PINDING Lake Nasworthy is located approximately 6.5 miles southwest of the City of San Angelo. The dam creating this reservoir is one-fourth mile below the confluence of the Middle and South Concho Rivers, is an earth fill construction with concrete retaining gates and is 5,480 feet long. The reservoir was created by the Upper Colorado River Auth- ority and has been sold to the City of San Angelc. The impounded water is used exclus- sly for municipal and industrial consumption. When the lake is at emergency spillway vel it has about 1,300 surface acres and contains about 14,040 acre feet of water. At that elevation the lake has about 28 miles of shoreline. The contributing watershed of 2,659 square miles is San Angelo Sandstone forma- tion and top soils are usually Abeliene sand or Frio clays and loams. The vegetative cover --- Page 2 --- 2. is mesquite-grassland association and the area is currently employed in farming and ranche g. The climate is semi-arid, having annual average rainfall of 19.7 inches. The aver- uge annual discharge for the South and Middle Concho Rivers is 162 c. f. s.3; however, a maximum flow of 230,000 c. f. s. was recorded in September, 1936 and recent annual dis- charles have been 1.62 c. f. s. in 1952 and 50.le. £f. s. in 1953. The lake's water is usually turbid (12 to 18); the maximum carbon dioxide content recorded was 14 ppm and the minimum dissolved oxygen content recorded at that time was 3 ppm. Dissolved carbon dioxide was usually about 8 - 11 ppm and oxygen was usually about 5 to 8 ppm. pH for the reservoir was from 8.2 to 8.5. NETTING RESULTS Forty-eight experimental gill net sets resulted in the capture of 1,351 individ- uals of 16 species. In Table ll, the numerical and weight dominance of river carp suckers (Carpiodes carpio), gizzard shad (Dorosoma cepedianum), carp (Cyprinus carpio) and long- nose gar (Lepisosteus osseus) is adequately demonstrated. However, the latter species may be less numerous than indicated. White bass (Morone chrysops) and southern channel cat- fish (Ictalurus punctatus) appear to be dominant game species. In Table 1, failure of net- ting to indicate significant population fluctuations for most species is interpreted as a possible indication that little change in ratios has occured during the study period and that under the conditions now existing the lake may be regarded as balanced. SEINING RESULTS Twenty-four seining collections were used in compiling the data for Table 111. Fifteen species and 2,553 individuals were captured. In addition to that data, several her species were taken in other collections where relative abundance estimation was not attempted. Since Lake Nasworthy was not adequately cleared of woody vegetation prior to inundation, seining stations were difficult to establish and rapid growth of bullrushes (Scirpus sp.) and cattails (Typha latifolia) made reclearing necessary at some seining stations. For those reasons percentages for some species may be erroneous, however appar- ent trends toward increases in white bass, largemouth black bass (Micropterus salmoides) and shiners (Notropis) may be indicative of gradual improvement in the lake condition. --- Page 3 --- SUMMARY do 2. Forty-eight gill net sets were made at twelve locations. One thousand, three hundred and fifty-one individuals of sixteen species were captured. Twenty-four seining collections captured 2,553 individuals of fifteen species, and additional species were obtained where relative subundance data was not taken. Water analysis showed dissolved carbon dioxide content to be from 9 to 14 ppm and dissolved oxygen to be from 3 to 11 ppm. pH was from 8.2 to 8.5, arid tur- bidity 12 to 18, Dense aquatic vegetation in the upper lake and near the mouth of the South Con- Concho River has extremely rapid growth on shallow flats. This vegetation is primarily bullrushes (Scirpus sp.), pondweeds (Potomogeton natans and P. spir- illus) and cattails (Typha latifolia). It is concluded that netting results may error in actual percentages but the dominance of the lake by river carp suckers, carp, gizzard shad and longnose gar is adequately demonstrated. Seining results may error in the percentages for some species but trends indi- cate a general improvement in the lake condition. --- Page 4 --- oO wAY ON 18. 19. 20. Checklist of Species of Fish from Lake Nasworthy June 22, 1952 to June 22, 1954 Common Name Longnose gar Gizzard shad River carpsucker German carp Gray redhorse sucker Golden shiner Blacktail shiner Red shiner Texas chhiner Parrot minnow Southern channel catfish Flathead catfish common mosquitofish Largemouth black bass Warmouth bass Green sunfish Spotted sunfish Redear sunfish Bluegill Orange spotted sunfish Yellowbelly sunfish Western longear sunfish White crappie Logperch Freshwater drum Scientific Name Lepisosteus osseus Dorosoma cepedianum Carpiodes carpio Cyprinus carpio Moxostoma congestum Notemigonus crysoleuvcas Notropis venustus Notropis lutrensis Notropis amabilis Pimephales vigilax Ictalurus punctatus Pilodictus olivaris Gambusia affinis Micropterus salmoides Chaenobryttus coronarius Lepomis cyanellus Lepomis punctatus Lepomis microlophus Lepomis macrochirus Lepomis humilis Lepomis auritus Lepomis megalotis Pomoxis annularis Percina caprodes Aplodinotus grunniens --- Page 5 --- 02°T “3555 One O26 queotedg te. gt TES 18407 ___teqann T2304 saystiung sn }eqzound snanTe.ot Saeptomtes snzeqdozotw ~2'ot 9° 6L sdosAzyo suctoW STIBATTO sngotpottd STTeL3uU snantony sueTuunIs snqyoutpoTdy wngsesucs emo .soxop snesso snaysostdey otdago snutadég ctdazes sepotdie9 wNUBT pSsda. eBlosascg Sung few“ ady" “zen “aed SUOTPOSTTON Buta gen --- Page 6 --- STeqOF, seyustjung | ¢”~<“‘«‘“‘é CTT ST XouIOg SOplompTes Snaeydoso 1g°T LTS = QL°T OT’ Of°9 OZ" HE T19 95 ~ sngeqound snanpejor ee gO "SAV Que Oye - Ole Oz" Of TL Oe°L Ove € STAGATTO SNOTpOT Td go °Say SIRE ee —3- cae Sr Tee OSS = BOE OST Og ORE i t@ ss Su TUUNAT snzouTpoTdy oe SOON Tee oft Ole OS Tt oal Ot -angSaSuoS emo ISOXON a De. ore 35 SSE ORL —3y es ee C7 aetna ST gg Too a “3 Svicas Gunaaay a ce oo an a Seo —~eE5 —~ ee a8 Sore ToT OTS = ESTO EC eC OSES emo sozog — Aa % $a % 29M "30 "9M “Bay ‘dog _ setoedg | SUOTJOSTTON Suryqayy ~ 8TqeL --- Page 7 --- Lt €St STL S&T gte one ¢ Ot Tz od, t27 unuetpedss emosozog a Td O ) O otdies sapotdazes e) O dL O O snqgtaine stwodey ty 0) e) i 8 snydoTototM stmodat Ec LT Tz Lz TE SnITyooioem stuodetT b zZ HT 9 S StqyoTesem stmodey eT € TT TT Te snvTTeusso stmodatT S @ at OT T2 STiepTnuue stxomog Z 0 € 6 tH sdosfkayo auc.zoy ty fe) eT Fa + SeptoupTes snzeqidorzotw 6) ) ) O TE XBTTSTA sopteydoamtg TQ S 0 e) (6) seoneToséro snuostwe.0n 0 d, TT O QT snysnuea stdargon i) 0) OT ie) O SstsuerqaT stdoszacy @) QT €T Th 2g sTUTIJe BTsnques "*309 +~°adeg Suy A~np ounp _-« Safoadg SUGTYDSTTOD Bututreg : “TT STaeL --- Page 8 --- Lake NaswortTHy OAm COUNTY PARK