Restocking Complete After ’07 Fish Kill

Texas Parks and Wildlife Department fisheries biologists have completed the final step in a three-phase effort to reestablish fish populations in Canton City Lake following a July 2007 fish kill.

Approximately 1,750 channel catfish ranging in length from 6 – 12 inches were delivered by Tyler Fish Farm and stocked along the northwest shore of the lake.

Restocking efforts began in March when 3,500 coppernose bluegill and redear sunfish were introduced into the lake to establish a prey base for larger fish.

In June, 2,500 Florida largemouth bass were stocked, completing the second phase of the restocking plan. All fish were provided by Tyler Fish Farm and paid for by the TPWD Kills and Spills Restitution Fund.

In July 2007, TPWD Kills and Spills investigators responded to a report by the city of Canton of a massive fish kill at Canton City Lake.

Investigators documented the fish kill which involved multiple species and determined that low dissolved oxygen was to blame. It was clear that the low oxygen levels caused the fish mortality, but it was not determined what caused the oxygen to drop.

Natural processes are most likely the cause, as heavy rains produced extensive runoff into the lake and increased decomposition of organic matter in the lake. As bacteria break down this material, they use up the dissolved oxygen in the water.

If there is sharp rise in decomposition, fish can suffer from the decreased oxygen levels. This appears to be what happened in Canton City Lake in July 2007. A subsequent survey of the lake by investigators in August 2007 determined that oxygen levels had returned to normal.

TPWD fisheries biologists conducted an electro fishing survey in September 2007 to look at the remaining fish population. Although numerous fish had survived the fish kill, it was apparent that larger game fish, such as largemouth bass and channel catfish, were limited in the lake.

Fisheries biologists immediately formulated a plan to restock the lake. The plan involved stocking smaller sunfish species first, then allowing the fish several months to establish and acclimate to the lake. Florida largemouth bass were then stocked followed by the recent addition of channel catfish.

The money used to buy the fish from Tyler Fish Farm was provided by the Kills and Spills Restitution Fund. The fund, which has been in existence since the early 1990’s, is paid for by responsible parties that break state civil laws regulating illegal discharges and/or the illegal killing of public fish and wildlife resources.

Normally used for education and public outreach, the funds occasionally have been approved for fish restocking. The restocking of Canton City Lake is one of only two such projects to be approved for restitution under the fund.

So will the lake experience another fish kill in the future? The fish kill in July 2007 was most likely due to rarely seen natural conditions. The lake does not have a history of low oxygen levels or fish kills, so a repeat of the same environmental conditions that were to blame is unlikely.

Large fish kills on any public water body should be reported immediately by calling the TPWD Kills and Spills 24-hour hotline: (512)-389-4848.

TPWD fisheries biologists will survey the lake during summer 2009 to determine the health of the fish population and to assess the restocking plan.