Thurmond Lake fish kill subsiding
Augusta Chronicle link
By Rob Pavey | Staff Writer
Thursday, Aug. 27, 2009 9:27 a.m.
One of Thurmond Lake’s most severe – and most peculiar – fish kills appears to be subsiding.
”It certainly has slowed down considerably, but we are still picking up a few fish almost every day,” said Jamie Sykes, fisheries biologist for the Army Corps of Engineers.
An unusual sequence of events that included the rapid refilling of Thurmond Lake this spring after low water and drought last year has created a layer of deoxygenated water far below the surface of the reservoir. The layer, confined to the area behind the dam, trapped and asphyxiated many large gamefish.
Since Aug. 8, biologists monitoring the situation have recovered 1,727 dead fish – mostly adult striped bass from five to 10 pounds.
The fish kill has also begun affecting hybrid bass, which typically are more resistant to such fish kills, Mr. Sykes said.
Hybrid bass are manufactured by fisheries officials by crossing striped bass with white bass. The resulting sportfish is a fast-growing, hard-fighting, good eating blend of the two species that is usually more tolerant of lower oxygen levels and warmer temperatures.
“Early on, when this started, we weren’t seeing many hybrids at all,” Mr. Sykes said. “Toward the end here, mainly in the last seven days, we’ve been getting many more hybrids than stripers, as a percentage.”
This week, almost all the dead fish recovered both above and below Thurmond Dam were hybrid bass, he said. “At this point, though, we’re not finding many fish at all. The peak was around mid-month when we were finding as many as 160 a day. By yesterday, we found just 17 fish and all of them were hybrids.”
Although the situation is slowly correcting itself, biologists are attempting to get some benefit from the fish kill by using the fish in a research project that was already under way by the S.C. Department of Natural Resources.
The South Carolina scientists are studying characteristics of hybrids and would have needed to catch and kill a number of them anyway to remove their earbones, known as otoliths, for the research. “We’ve been giving them the fish we collect to help with those projects,” he said.