TPWD 1975 F-6-R-22 #1683: Region 2-C Fisheries Studies: Reservoir Categorization, Final Report, Project F-6-R-22

FINAL REPORT As Required By EEDERAL AID IN FISHERIES RESTORATION ACT TEXAS Eederal Aid Project F-6—R-22 Region 2-C Fisheries Studies Objective III: Reservoir Categorization Project Leader: Roger L. McCabe Assistant Project Leader: Kenneth K. Sellers Clayton T. Garrison Executive Director Texas Parks and Wildlife Department Austin, Texas Lonnie J. Peters Robert J. Kemp Chief, Inland Fisheries Director, Fisheries November 18, 1974 Abstract Predictability of large reservoir management practices affecting standing crop has been speculative, due to physical, chemical, and biological variables. Many of these variables are controllable, but cause and effect relationships, involving these variables and standing crop, change in different reservoir types. The purpose of this study is to collect standardized data on major reservoirs in central Texas and to categorize these reservoirs based on the resulting data. Descriptive data were up-dated on 14 major reservoirs, and physical, chemical, and biological sampling was conducted on Lakes Belton and Whitney. Since this study is being terminated prematurely, and data from only two reser- voirs have been acquired, no attempt at categorization was made. Data similar to those collected here will be obtained under a new State-Wide management project, and when sufficient amounts have been accumulated, categorization should be carried out. FINAL REPORT State: Texas Project Number: F-6-R-22 Project Title: Region 2-C Fisheries Studies Study Title: Reservoir Categorization Period Covered: From January 1, 1973 To December 31, 1974 Objective Number: III Job Number: 10 Objective: To categorize the major reservoirs of Fisheries Region 2-C. Background: Better predictability in reservoir fisheries management practices is badly needed. Physical, chemical, and biological variables of reservoirs have profound effects on fish populations and in many instances these variables can be manipulated by man. Knowledge of vital cause and effect relationships can provide fishery man- agers with insight for making recommendations based on fact rather than speculation. The relationship of certain enviornmental factors to standing crop has been lemonstrated by Carlander (1955), Hayes and Anthony (1964), Jenkins (1968; 1970) Ryder (1965) and others. Using regression analyses between independent and dependent variables, these investigators have identified significant factors that influence standing crops of fishes in certain reservoir types. Due to the large number of environmental variables and their interactions, data analysis has become very complex. Past survey and inventory records maintained by the Texas Parks and Wildlife Department contain primarily fish population information, but lack much of the additional environmental data needed for categorization. The purpose of this study is to obtain standardized physical, chemical, and biological data from 14 major reservoirs (over 500 acres) and their tailwaters, and to correlate these data by automatic data processing. This report covers two segments of a proposed five year study. Procedures: The first segment of the study was used primarily for familiarizing personnel with reservoirs in the study area, selecting sampling techniques and sampling sites, and acquiring descriptive data. Descriptive data forms were compiled on each of the 14 major reservoirs in Region 2—C. Data were recorded for the following par- ameters: age of reservoir, year sampled, drainage area, location, surface elevation, surface area, volume, mean depth, maximum depth, outlet depth, shoreline length, growing season, storage ratio, thermocline depth, mean annual water level fluctation, total alkalinity, total dissolved solids, depth of visibility, shore development, basin geology, riprapping, controlling authority, and reservoir use. Descriptive data were obtained from ”Engineering Data on Dams and Reservoirs in Texas” and "Dams and Reservoirs in Texas, Historical and Descriptive Information", publications of the Texas Water Development Board; ”Water Resources Data for Texas- Part 2 Water Quality Records”, 1969-73, publications of the U.S. Geological Survey; water level reports prepared by the U.S. Army Corps of Engineers; correspondence with controlling agencies; and actual field sampling. Due to the extent of sampling required, only two reservoirs were selected for study during the second segment. Lake Belton, a 12,300 acre lake in Bell County, and Lake Whitney, 23,500 acre lake in Hill and Bosque counties, were chosen so that sampling would coincide with other field activities. Monthly water analyses were run from January through September, 1974, with the exception of the August sample at Lake Whitney. Sampling stations were located at middle and lower lake sites in the lakes proper, and tailwater stations were located 200 meters below the dam and 2 miles downstream (Figs. 1 and 2). Lake parameters tested were: dissolved oxygen, temperature, pH, turbidity, conductivity, total alkalinity, total dissolved solids, sulfates, nitrates, phosphates, settleable solids, and secchi disc transparency. Tailwater parameters were the same, but also included hydrogen sulfide readings. Samples were taken between 10:00 AM and 4:00 PM. Dis— solved oxygen and temperature profiles were read at 1 meter intervals from surface to bottom and the remaining parameters, other than secchi, were read from surfape, middle, and bottom samples each month. Sulfates, nitrates, and phosphates were recorded only during April and July. Dissolved oxygen and temperature were determined with a Model 51A YSI oxygen meter and specific conductance was read from a Model 33 YSI conductivity meter. Turbidity, total alkalinity, hydrogen sulfide, and sulfates were determined with a Hach DR-EL portable laboratory. Total dissolved solids, nit- rates, and phosphates were determined by the Regional Parks and Wildlife Department Chemist using standard methods. Settleable solids were measured with 1200 milliliter Imhoff cones after settling approximately 24 hours. Standing crop estimates were made from cove rotenone samples. Three coves totalling 5.0 acres were sampled between September 9th and 25th at Lake Belton (Fig. 1), and three coves totalling 10.7 acres were sampled between August 13th and 28th at Lake Whitney (Fig. 2). Coves were measured using plane table methods and were sounded to determined volume. Block nets made of 3/4 inch bar mesh webbing were used to isolate sampling areas. Nets were dropped at approximately 10:00 PM and treatment began at approximately 8:00 AM the following morning. Approximately 100 fishes of various sizes and species were captured from elsewhere in the lake, measured, tagged with Floy anchor tags, and released into the cove. The mean recovery rates from tagged fishes were used to project recovery rates for all fishes recovered from each cove. Liquid rotenone (5%) was applied at a rate sufficient to insure a total kill and was mixed thoroughly. The day of application and the day following were considered as two recovery days. All fishes were separated by species and inch classes, beginning at 1.49 inches and progressing in 1 inch increments (i.e., 0-l.49= inch class 1, 1.50- 2.49= inch class 2, 2.50-3.49= inch class 3, etc). Total numbers of each inch class were counted both days, but total weights of each species inch class were measured from only the first day's recovery. Average weights for both recovery days were calculated from the first day's recovery. The average number and total pounds of each species inch class for each cove were estimated by dividing the number and weight recovered y the area of the cove. The observed standing crop of each species inch class was determined by weighting the area of each cove and calculating the simple averages of the individual cove results. The total observed standing crop for each species was obtained by adding the simple averages of the individual inch classes. The adjusted standing crop estimate in numbers and weight was obtained by projecting the mean reCovery percentage from all tagged specimens to the total observed standing crop. Structures for determining age and growth were obtained from select species in both lakes during 1974. Scales, otoliths, and pectoral spines were removed for use in back calculating growth. This procedure was intended for acquiring comparative growth data from representative sport fishes and was not intended for detailed population dynamics work. Samples of channel catfish, white bass, striped bass (from Lake Whitney), largemouth bass, white crappie, and walleye (from Lake Belton) were collected during April and May. Fishes were collected by experimental gill nets (8 ft. deep and 150 ft. long, having graduated bar mesh ranging from 1-3% inches), frame nets (4 ft. deep and 6 ft. wide, having 1 inch bar mesh) and electro shocking (220 volt D.C. current, max. 3,000 watts). Scales were removed from the left side, below the lateral line, at the tip of the pectoral fin.« The two saggittal otoliths were removed from scaled fishes and the left pectoral spine was removed from channel catfish. Specimens were air dried and stored in envelopes. Reading and measurement of annual marks was not accomplished, due to the shortened work schedule. Vegetative surveys scheduled for August or September were deleted due to extreme drops in water elevation at both lakes. The percent of each lake covered by vege- tation was to have been visually estimated, but virtually all marginal vegetation was liminated due to drought conditions. Findings: Reservoir descriptive data from major reservoirs in Region 2-C were combined with like data from other regions by the Austin office in unpublished form. Des- criptive data on Lakes Belton and Whitney were updated to include 1974 information (Tables 1 and 2). depth of approximately 9 to 12 meters with a drop in September to about 18 meters (Tables 3 and 4). Although no August readings were taken at Lake Whitney, the July mid lake profiles showed the thermocline depth to be about 7 meters (Table 5), while the lower lake profile indicated a weak thermocline at approximately 12 to 16 meters (Table 6). September profiles at Lake Whitney showed gradual oxygen and temperature gradients. Lake Whitney (Table 9 and 10) exhibited higher conductivity, total dis- solved solids, and sulfate values than Lake Belton (Tables 7 and 8), but other phy— sicochemical parameters were comparable. These similarities were also shown in the lakesI tailwaters (Tables 11 and 12). The observed standing crop estimate (both number and weight per acre) was higher for Lake Whitney than for Lake Belton, although the species of fish present were nearly identical (Tables 13 and 14). Broad size ranges were shown for most species (Tables 15 and 16), although some species and inch classes known to occur, were totally lacking. Tagged fish recoveries of 62 percent for Lake Belton and 59 ercent for Lake Whitney were recorded. When these percentages were projected to the observed standing crop data the adjusted standing crop figures became substant— ially higher (Tables 13 and 14). Structures for age and growth determination were taken from 228 fishes, 119 from Lake Belton and 109 from Lake Whitney. Walleye (4), striped bass (10), and white crappie were not captured in adequate numbers for back calculation. Approximately 30 Specimens of various age classes are needed for this work. A checklist of fish species encountered during all sampling efforts is provided in Table 17. Analysis: No attempt was made to analyze these data for the purpose of categorization. This procedure was scheduled for the fifth year of the study, when comparative data from all 14 reservoirs were to have been acquired. Analysis of the accumulated data would require complex computer programming, which would necessitate making provisions for computer time. Recommendations: This study is being terminated prematurely, due to overlap with procedures to be carried out under a State-Wide management project effective January 1, 1974. Data to be acquired under this new project will parallel those gathered for categorization. When sufficient data have been acquired state-wide, models should be developed by Parks and Wildlife Department data processing personnel that will group similar reservoirs and identify environmental parameters that significantly affect standing crops in those particular types of reservoirs. Prepared by: C— Roger L. McCabe Project Leader Date: November 18, 1974 Robert Bounds Regional Director Inland Fisheries, Region II Approved by: ingell-Johnson Coordonator Literature Cited Carlander, Kenneth D. 1955. The standing crop of fish in lakes. J. Fish. Res. Bd. Canada 12(4): 543-570. Hayes, F.R., and E.H. Anthony. 1964. Productive capacity of North American lakes as related to the quantity and trophic level of fish, the lake dimen- sions, and the water chemistry. Trans. Amer. Fish Soc. 93(1): 53-57. Jenkins, Robert M. 1968. The influence of some environmental factors on standing crop and harvest of fishes in U.S. reservoirs. Reservoir Fishery Resources Symposium, Athens, Ga., April 1967. Publ. by So. Div., Amer. Fish. Soc., pp. 298-321. 1970 The influence of engineering design and operation and other environmental factors on reservoir fishery resources. Water Res. Bul. 6(1): 110-119. Ryder, R. A. 1965. A method for estimating the potential fish production of north temperate lakes. Trans. Amer. Fish. Soc. 94(3): 214-218. McGregor Park Mid lake I Morgan‘s Point Lower lake I' Water sample stations ‘- Cove rotenone locations Fig 1. Map of Lake Belton showing water sample stations and Cove rotenone locations. Mid lake Cedar Creek r4 Cedron Creek Park ‘- ——-Lofers Bend Park - . Lower lake I- Water sample stations '-.~ Tailwater stations ‘- Cove rotenone locations \V _Fig. 2. Map of Lake Whitney showing water sample stations and cove rotenone locations. -g- \ . Table 1. Lake Belton descriptive data. Reporting biologist Roger L. MCCabe ‘ W... Reservoir name ___ Belton __________n_____ Year impounded 1954 Year sampled _,_J£EEL______*_._1_ 2 Drainage area (mi. ) - 3,560 ._______ Location Bell County; ApprOX. lat 31006': 10115 97028! _____________________ Surface elevation (ft. msl) 594.0 Surface area (acres) 12,300 Volume (acre-ft.) 457,600 Wm“— Mean depth (ft.) Maximum depth (ft.) Outlet depth (ft.) __* Shoreline length (mi.) _ ____H__“_______________Hm____________ Growing season (frost-free days) Storage ratio 0.23 __#fl__l____ 'Thermocline depth (ft.) ______gZ§;&9________H______________ Mpan annual water level flpptuation (ft.) 10.33 over 5 yrs. ‘Tptal alkalinity (mgil) 1 Total dissolvgd solids (mgil) I 256 Depth of visibility (£11.) I 6 1...... I 8.75 Shore development m__________________ ——-———-—— ———————-—-—— Basin geology' Limestone Rpck riprap_present (yes or no) Yes Qgpgppllipg_authority U.S. Arm Cor s of Enginee£§“__ Reservoir use _ ‘Flood control, conservation, recreapion