(Source: Texas Parks and Wildlife Department )

Fairfield – Texas Parks and Wildlife Department Inland Fisheries management and Kills and Spills Team (KAST) biologists investigated a localized fish kill on Fairfield Lake the first week of September.

Inland Fisheries management staff conducting an aquatic vegetation survey on the reservoir discovered the kill and notified the regional KAST biologist at 10:00 A.M. on September 4 that numerous fish of all species (notably large redfish) were dead.

Fish were located along the shoreline of a cove from immediately northwest of the dam to the spillway (see attached map). A second smaller kill (involving primarily gizzard and threadfin shad) was investigated in a cove approximately one-half mile south of the main kill. The fish appeared to have died no earlier than Wednesday, September 3.

KAST personnel proceeded to the lake and conducted a thorough investigation and enumeration of the kill. Water quality field data were measured both in and out of the area where dead fish were observed. In the late afternoon and early evening of September 4, five 100-yard fish counts were conducted along approximately 1.5 miles of shoreline where the fish were observed.

Water quality field data collected in late afternoon indicated a localized area of high oxygen and abundant phytoplankton in the larger of the two areas where the fish kill occurred. High daily fluctuation in oxygen level is consistent with abundant phytoplankton. Photosynthesis during daylight increases oxygen concentration; respiration by the phytoplankton during periods of darkness (or heavy cloud cover) rapidly reduces oxygen concentration.

Water quality and other field observations were not able to conclusively identify the exact cause of the current kill but were able to measure its extent. Initial estimates from the TPWD fish kill investigation show approximately 7,345 fish died in the two locations of the kill. The fish appeared to have perished where they were found, because prevailing winds were blowing out of rather than into the coves where they died, and fish appeared to have forced their way into shoreline vegetation while still alive.

Species involved in the kill included red drum, bluegill, largemouth bass, gizzard and threadfin shad, channel and flathead catfish, tilapia and gar. Unfortunately, the majority (51%) consisted of large red drum.

TPWD has stocked over 5.3 million red drum in Fairfield Lake since 1984, and the estimated 3,750 red drum lost in the present kill is unlikely to permanently impact this popular fishery.

Ironically, Inland Fisheries staff initiated a six-month angler creel survey to assess the red drum fishery on Memorial Day, and this on-going evaluation will be able to help document the effect of the kill.

Although the cause of the fish kill is still unknown at this time, TPWD is continuing its investigation. TPWD Inland Fisheries staff observed live fish, both in and out of the kill area, while conducting the count on September 4. TPWD Inland Fisheries staff will be surveying the fish community at Fairfield Lake later this fall as part of their routine standardized monitoring.

The TPWD Kills and Spills Team is a group of biologists who respond to pollution reports or natural incidents that threaten state fish or wildlife resources. If you see dead or dying fish or wildlife or pollution threatening fish and wildlife, please contact the 24-hour Communication Center at (512) 389-4848, or contact your local game warden. Additional information about KAST is available at http://www.tpwd.state.tx.us/texaswater/kast/pages/homepage.html.