Lake Whitney - 2003 Survey Report
Prepared by John Tibbs and Michael S. Baird
Inland Fisheries Division
District 2-B, Waco, Texas
This is the authors' summary from a 47-page report. For a copy of the complete report, use the download link in the sidebar.
Whitney Reservoir was surveyed in the fall of 2003 by boat electrofishing and trap netting, and spring of 2004 by gill netting. This report summarizes survey results and contains a management plan for the reservoir based on those findings.
Lake Whitney is located on the Brazos River in Bosque and Hill counties, and is used for flood control, electrical power production, and recreation. The 23,560-acre impoundment has a drainage area of 17,656 square miles, a storage capacity of 622,800 acre-feet, and a shoreline length of 225 miles. Mean and maximum depths are 27 and 108 feet respectively. The reservoir was approximately 6 to10 feet below conservation pool (533 feet) during the 2003 and 2004 sampling, so fish habitat was primarily bluffs, rocky shoreline, and sandy beaches. Bank fishing and boat access on the reservoir is good. Currently, there are no handicap-specific facilities.
- Prey species: The gizzard shad electrofishing catch rate was lower in 2003 (140.5/hour) than in 2001 (281.5/hour), but higher than previous years (1999, 11.0/hour; 1998, 61.5/hour; 1997, 62.0/hour). The index of vulnerability (i.e., the percentage of individual gizzard shad less than 8 inches total length, thought to be vulnerable to predation) or IOV was 75.4 (DiCenzo et al. 1996), indicating most of the shad were of a size used as forage by sportfishes. Threadfin shad were collected at a rate of 15.0/hour during 2003 electrofishing, lower than in 2001, when 198.5/hour were collected, similar to 1997 (12.0/hour) and 1998 (15.5/hour), and much higher than 1999, when none were collected. Bluegill were collected at a rate of 179.0/hour during 2003 electrofishing, lower than in 2001 (382.0/hour), but higher than the average of 1997-1999 (92.7/hour). Specimens exceeding 10 inches were collected, but an RSD8 of 1 indicates that few are available to anglers. The redbreast sunfish electrofishing catch rate was 13.5/hour, lower than the average of the previous four years (58.5/hour). An RSD8 0f 4 indicates some quality-sized fish are available to panfish anglers.
- Catfishes: Blue catfish were collected at a rate of 1.1/net night during 2004 gill netting surveys. This is very similar to the average catch rate for the previous four surveys (1.2/net night). Anglers spent 0.5 hours/acre seeking blue catfish in the 2000 creel survey. Catch and harvest rates were less than 0.1/hour however. The 2004 gill netting catch rate of channel catfish was 2.1/net night, similar to the average of the previous four surveys (3.3/net night). All collected fish exceeded the minimum length limit of 12 inches. Anglers spent 0.5 hours/acre seeking channel catfish, catching them at a rate of 0.4/hour, and harvesting them at a rate of 0.3/hour. Although angler effort for both species remained similar to 1999, catch and harvest rates were much lower in 2000.
- Temperate basses: White bass were collected at a rate of 1.1/net night during 2004 gill netting, which was similar to the average of the previous four surveys (1.2/net night). All of the aged fish (N=14) were from the same year class, indicating highly variable recruitment during recent years. This may be the result of the golden alga. Anglers spent 0.3 hours/acre seeking white bass, catching them at a rate of 1.3/hour and harvesting them at a rate of 0.8/hour. The gill netting catch rate of striped bass in 2004 was 1.5/net night, which was similar to the previous four samples (1.6/net night). Catch rates for the three years previous to the first golden alga outbreak in 2000 weren’t appreciably better, averaging only 2.7/net night). Three year classes were represented in the aged fish, indicating annual stockings were successful despite repeated golden alga outbreaks. Anglers spent 3.0 hours/acre seeking striped bass, catching them at a rate of 0.4/hour and harvesting them at a rate of 0.2/hour. Effort was higher in 2000 compared to the previous three years, but catch and harvest rates were slightly reduced compared to 1998 and 1999.
- Black basses: Smallmouth bass were represented by a single individual during 2003 electrofishing (0.5/hour). This was similar to the 2001 survey (1.0/hour), but far removed from the 1998 sample in which 25.5/hour were caught. Without a commitment to supplementary stocking, the smallmouth bass fishery in Whitney reservoir is not likely to recover. Anglers spent 0.1 hours/acre seeking smallmouth bass in 2000, catching them at a rate of 0.5/hour. No harvest was recorded. Spotted bass were collected at a rate of 2.0/hour during 2003 electrofishing, similar to the average of the previous four surveys (6.1/hour). The spotted bass population in Whitney is characterized as low density, with occasional individuals over 13 inches in length. Largemouth bass were collected at a rate of 49.0/hour during 2003 electrofishing, similar to the average of the previous four surveys (69.1/hour). An RSD14 of 41 indicated that 41% of fish 8 inches and greater in length were of legal size, which compared well with the average of the previous four years (RSD14 = 33). Condition was good, as Wr’s exceeded 90 for all sizes. Introgression of Florida bass genetics continued, as the percent Florida alleles and percent pure Florida bass achieved the highest levels ever recorded (58.3% and 13.3%, respectively). Anglers spent 0.6 hours/acre seeking largemouth bass, catching them at a rate of 0.5/hour, and harvesting them at a rate of <0.1/hour. Anglers spent 0.8 hours/acre seeking “black bass” a grouping that included largemouth and smallmouth bass and occasionally, spotted bass. They caught these three species at a rate of 0.6/hour and harvested them at a rate of <0.1/hour.
- White crappie: The white crappie trap netting catch rate in 2003 was 1.9/net night. This was down from the average of the previous three surveys (9.8/net night). However, the fish were in good condition with Wr’s near or exceeding 100 for all sizes. Three year-classes were represented in the survey and fish were present in every inch-class from 2 inches through 13 inches. Anglers spent 0.2 hours/acre seeking white crappie in 2000, catching 0.6/hour and harvesting 0.5/hour.
Based on current information, Whitney Reservoir should continue to be managed with current regulations. Close attention should be paid to golden alga issues and the appropriate action taken. Water level issues should be discussed with the controlling authorities with the goal of maintaining pool levels. All opportunities to obtain smallmouth bass for stocking should be explored.
Performance Report as required by Federal Aid in Sport Fish Restoration Act Texas Federal Aid Project F-30-R-29 Statewide Freshwater Fisheries Monitoring and Management Program