Purtis Creek State Park Lake - 2004 Survey Report
Prepared by Timothy J. Bister and Richard A. Ott, Jr., PhD
Inland Fisheries Division
District 3-C, Tyler, Texas
This is the authors' summary from a 29-page report. For a copy of the complete report, use the download link in the sidebar.
Purtis Creek State Park Lake was surveyed during the period June 2004 to May 2005 using electrofishing, trap nets, gill nets, littoral zone habitat and vegetation surveys, and an angler access and facilities survey. This report summarizes the results of the surveys and contains a management plan for the reservoir based on those findings.
Purtis Creek State Park Lake is a 349-acre reservoir on Purtis Creek, a tributary of the Trinity River. The impoundment was constructed by the Texas Parks and Wildlife Department in 1985 for recreational and soil conservation purposes. Boat and bank access are both good. There are two handicap accessible fishing piers. Hydrilla has continued to require periodic herbicide treatment to provide access to the fishing piers, boat ramp, and swimming beach. Purtis Creek State Park funded the treatment of 13 acres of hydrilla with SONAR SRP in April 2005, which was applied by the TPWD Inland Fisheries Aquatic Habitat Enhancement crew. Problems associated with this hydrilla infestation will likely continue. Hydrilla should be treated with SONAR, as necessary, to allow continued access for lake users. Native vegetation now covers 116 surface acres (33%).
- Prey species: Sunfish have traditionally been the predominant prey available to largemouth bass in Purtis Creek State Park Lake. However, electrofishing catch rates of bluegill and redear sunfish have recently declined. Bluegill catch rates have declined from 311 fish/hour in 2001 to 35 fish/hour in 2004. No redear sunfish were collected in 2004, but the 2003 fall electrofishing survey produced 208 fish/hour. The abundance of submersed aquatic vegetation has made electrofishing difficult in some areas of the lake and this may be negatively affecting sunfish catches. Also, redear sunfish may reside in deeper water in areas making them less vulnerable to electrofishing. Gizzard shad provide supplemental prey, but the majority of individuals were too large to be utilized by predators. The electrofishing catch rate of gizzard shad has declined from 119 fish/hour in 2002 to 28 fish/hour in 2004. However, threadfin shad catch rates have increased from 10 fish/hour in 2003 to 235 fish/hour in 2004, which were all of a size available to predators.
- Catfishes: Gill net sampling on Purtis Creek State Park Lake typically yields very low catches of catfish. Only one blue catfish and no channel catfish were collected during the 2005 gill net survey. Natural recruitment of catfish has always been limited in Purtis Creek, presumably as a result of heavy predation by largemouth bass. Therefore, stockings of advanced size channel or blue catfish ($12 inches) may be needed to sustain recreational angling opportunity for catfish in this reservoir.
- White bass: White bass were collected in gill nets for the first time in 2005. Only 16 fish were collected (3.2 fish/net night). A sub-sample of 10 fish collected for age-and-growth analysis indicated that 2 year classes (age 1 and age 2) were present in the reservoir. It is not known how this species was introduced to the waterbody. However, due to the lack of suitable spawning habitat, population density should remain low.
- Sunfishes: The special 7-inch minimum length limit harvest restriction on sunfishes was discontinued September 2002 as recommended by Ott et al. (2001). Electrofishing catch rates of all sunfish species have been variable since 2000; however, large sunfish (>6 inches) are available to anglers.
- Black bass: Annual electrofishing surveys at Purtis Creek State Park Lake continue to indicate the presence of a high-quality and relatively stable largemouth bass population. Since 2000, spring electrofishing catch rates of stock-size fish ($8 inches) has ranged from 79 to 110 fish/hour and fall catch rates have ranged from 78 to 139 fish/hour. Mean relative weight (Wr) in each inch class has generally been >90 during fall sampling. However, some individual fish have been in extremely poor condition presumably as a result of hooking injuries. The mean age of a sample of 13 fish, between 13.6 and 15.4 inches TL, was 3.8 years (range = 2 to 7). Size structure of the population indicated a large proportion of the fish above quality length (PSD = 74, RSD-14 = 68).
- Crappie: The quality of the white crappie population in Purtis Creek has declined since the 2000 trap net survey. Total catch (11.2 fish/net night) was similar to 2000 surveys; however, catch of stock-length fish ($5 inches) and legal-size fish declined in 2004. However, a successful 2004 year class should recruit to the fishery by fall 2005. Growth of white crappie was good. Age and growth analysis of 23 fish approximately 10 inches in length indicated that all were age 1. Condition of white crappie was excellent with most inch groups having a mean Wr >100.
- The largemouth bass population at Purtis Creek State Park Lake is managed with a catch-and-release only regulation to maintain high angling catch rates. Population trends should be monitored with annual spring and fall electrofishing. With this highly restrictive harvest regulation, Florida largemouth bass genetics will provide the best opportunity for production of trophy-size fish. Therefore, largemouth bass genetics should be monitored every other year to determine the necessity of future stocking of Florida largemouth bass.
- White bass have recently been discovered in this reservoir. Lack of suitable spawning habitat should limit their abundance; however, gill netting and age and growth analyses should be utilized to monitor their status in the reservoir.
- Due to the lack of catfish recruitment, the stocking of advanced size fingerlings (>12 inches) may be required to maintain this fishery. Because this is a state park facility, Purtis Creek State Park Lake will be considered a high priority for stocking, assuming these size fish are available in our hatchery system. Efforts should be made to seek additional sources of fish or outside funding partners in this effort.
- The hydrilla infestation at Purtis Creek State Park Lake has required continued control in access areas. The abundance of hydrilla should continue to be monitored during scheduled annual vegetation surveys.
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