Inks Reservoir - 2005 Survey Report
Prepared by Marcos J. De Jesus and Stephan J. Magnelia
Inland Fisheries Division
District 2-C, San Marcos, Texas
This is the authors' summary from a 27-page report. For a copy of the complete report, use the download link in the sidebar.
Fish populations in Inks Reservoir were surveyed in 2005 using electrofishing and in 2006 using gill nets. This report summarizes the results of the surveys and contains a fisheries management plan for the reservoir based on those findings.
Inks Reservoir is a 768-acre impoundment of the Colorado River. It was constructed in 1938 by the Lower Colorado River Authority (LCRA) for purposes of hydroelectric power, recreation and water supply. The reservoir lies within the Edwards Plateau eco-region, and its shoreline length is 20.5 miles. Inks Lake State Park borders the reservoir and provides access to approximately 30 percent of the shoreline. A significant portion of the shoreline has been developed by private property owners or is under control by the LCRA.
Important sport fish include white bass, striped bass, largemouth bass, and catfish species. The management plans for 2001 and 1996 were to continue monitoring populations under existing regulations. The Florida subspecies of largemouth bass was stocked in the reservoir in the late 80s and early 90s to increase Florida largemouth bass genetic influence in the population. Adult channel catfish have been stocked on when available by the Inks Dam National Fish Hatchery through an agreement with the LCRA. White bass were managed under a 12-inch minimum length limit. The regulation was rescinded in September 2004 after an analysis indicated environmental factors, not angler harvest, were probably more influential in determining white bass population density.
- Prey species: Gizzard shad, threadfin shad, bluegill, and redbreast sunfish were the predominant sources of forage. Threadfin shad were more abundant in this survey than previously recorded.
- Catfishes: Channel catfish were present in low – moderate density. Blue catfish and flathead catfish were also present in the reservoir, but provide only a marginal fishery.
- Temperate basses: White bass presence was good. Striped bass were present in low densities. Emigration from Lake Buchanan through water releases is probably maintaining the striped bass presence in Inks Reservoir.
- Black basses: Presence of largemouth bass was moderate. Twenty-two percent of adults in the 2005 sample were greater than or equal to 14 inches. Largemouth bass growth continued to improve in 2005. Inks Reservoir also contains Guadalupe bass, which are slow growing.
The reservoir should continue to be managed with existing fishing regulations. The largemouth bass and sunfish fisheries should be promoted. Furthermore, fish attractors should be installed at the state park fishing piers to increase catch rates for pier anglers. Conduct general monitoring with gill nets and electrofishing surveys in 2009 – 2010. Conduct aquatic vegetation survey in 2009.
Performance Report as required by Federal Aid in Sport Fish Restoration Act Texas Federal Aid Project F-30-R-30 Statewide Freshwater Fisheries Monitoring and Management Program