Lake Jacksonville - 2004 Survey Report
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Prepared by Richard A. Ott, Jr., PhD and Timothy J. Bister
Inland Fisheries Division
District 3-C, Tyler, Texas
This is the authors' summary from a 24-page report. For a copy of the complete report, use the download link in the sidebar.
Lake Jacksonville was surveyed during the period June 2004 to May 2005 using electrofishing, trap netting, gill netting, a littoral zone habitat survey, an aquatic vegetation survey, 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.
Lake Jacksonville is a 1,208-acre reservoir on Gum Creek (a tributary of the Neches River), Texas, built to provide water for municipal and industrial purposes. Boat and bank angler access is adequate. Handicap-specific facilities are present in the parking lot and restrooms near the main boat ramp. Water is clear and very low in productivity (mean mg/m3 chlorophyll a = 1.41). Fertilization of 300 acres was initiated in 1993 to increase primary productivity, but was discontinued in 1995 after hydrilla was discovered. An integrated vegetation management plan was initiated in 1997 in an attempt to control hydrilla and diversify the native plant community. The plan had three phases: phase 1 included herbicide control of the hydrilla; phase 2 called for construction of a fish barrier at the outflow and limited stocking (200 fish) of triploid grass carp; phase 3 included introduction of native aquatic plants to diversify the plant community. In spring 1999 the City of Jacksonville removed the fish barrier in the belief that it caused flooding of low-lying properties; thereby preventing any additional grass carp stocking. Annual hydrilla control has continued with herbicide and physical removal. However, hydrilla has continued to expand in coverage.
- Prey species: Sunfishes (redbreast, bluegill, and redear) were the dominant prey species at Lake Jacksonville in fall 2004. Total catch rate of all sunfish species combined (625 fish/hour) was somewhat below that in 2002 (873 fish/hour) but is similar to 1998 and 2000 (682 and 617, respectively). The majority of sunfishes collected were < 4 inches in length and were available as prey. Sunfish are not highly sought-after by anglers. Electrofishing catch rate of gizzard shad (4 fish/hour) was low but similar to previous years; however, most were too large (> 12 inches) to provide benefit as prey. Threadfin shad were also collected but are low in abundance (8 fish/hour).
- Catfishes: Lake Jacksonville supports a low-density channel catfish population with poor natural recruitment. No channel catfish were collected in gill nets in 2004 and historical catch rates were low (1.2 fish/net night in 2002 and 0.2 fish /net night in 1999). Survival of young catfish in Lake Jacksonville is likely limited, in part, due to predation by largemouth bass, clear water, and absence of spawning sites. Both fingerling and adult channel catfish were last stocked in Lake Jacksonville in 1994. Without additional stockings of advanced size (9-12 inch) channel catfish it is unlikely that this species will provide a viable fishery.
- Black basses: Lake Jacksonville has shown potential to produce trophy-sized fish (15.12 lbs, 1986) and is a popular lake for local tournament angling interests. Florida strain largemouth bass were stocked in Lake Jacksonville from 1975-1979 and again in 1999 and 2000. The initial stocking was successful in establishing and maintaining Florida bass genes in this population and was likely responsible for the existing lake record. Subsequent stockings have maintained a relatively high (> 50%) Florida bass allele frequency. Allele frequency was estimated at 56% in 2004 and the percentage of pure Florida strain largemouth bass in a sub-sample of age-0 largemouth bass collected in fall 2004 was 12%. The electrofishing catch rate in 2003 (79 fish/hour) was similar to previous years. Proportional stock density (PSD) was 46; within the target range of 40-70. Relative stock density (RSD-14) was higher than that recorded since 1995 and may be related to changes in legal harvestable length from 14 inches to 18 inches in September 2000. Mean relative weight (Wr) was >90 for most inch classes (>12 inches) and was indicative of adequate prey availability. Individual ages of a sub-sample of fish from 13.1 to 15.9 inches in length ranged from 2 to 4 with a mean age of 3.2 years.
- Crappie: No crappie (white or black) were collected in gill nets in spring 2005. Lake Jacksonville has historically had low crappie recruitment but good growth (Ott and Bister, 2001). Stocking of nearly 300,000 crappie fingerlings (black and white) in 1988 failed to increase catch rate in subsequent trap netting. It is likely that crappie recruitment is adversely affected by largemouth bass predation in the clear water present in Lake Jacksonville.
Based on current information, Lake Jacksonville fishing regulations should be maintained at their current status. Because of the importance of the largemouth bass fishery at Lake Jacksonville, biennial electrofishing and electrophoretic sampling should continue with the next sampling scheduled for fall 2006. Annual assessment of hydrilla coverage should be continued with a yearly vegetation survey. To allow for a greater range of control techniques the City of Jacksonville should be encouraged to rebuild the fish barrier at the outflow to allow stocking of additional grass carp as was recommended in the integrated management plan. To promote the fishery and clarify harvest regulations angler information projects should be continued utilizing news releases, regulation posters, public presentations, and the TPWD web site.
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