Warmer water killed fish, scientist says
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Thursday, May 18, 2006 The Grand Rapids Press
HOLLAND -- Federal officials agree with the state: a fish die-off this spring in Lake Macatawa was caused by a sudden rise in water temperatures, not pollutants or toxins.
The U.S. Environmental Protection Agency looked into the issue this week at the request of U.S. Rep. Pete Hoekstra, R-Holland. Life Scientist Pete Jackson of the EPA's Chicago office said his workers reviewed reports and data filed by Michigan officials.
"There were no indications of any outside organisms or toxins in the water that might cause the kill," Jackson said Wednesday.
Jay Wesley, a fish biologist with the Michigan Department of Natural Resources, said Wednesday the die-off has nearly stopped because waters have cooled in recent days.
"We could still see another fish kill occur because large amounts of nutrients are entering the lake from the run-off of heavy rains," Wesley said.
Nutrients from farm and home fertilizers encourage algae growth that lowers oxygen levels, which could cause more fish to die. Most of the dead fish were larger sheepshead, carp and gizzard shad, which can be affected quickly by low oxygen levels.
Last month, Hope College Professor Graham Peaslee, with the chemistry and geological/environ-mental department, said his records showed the lake temperature was 45 degrees on April 10 and climbed to 62 degrees by April 20.
