- The Washington Times - Sunday, March 25, 2007

ROANOKE — Scientists and volunteers are working this spring on the Shenandoah River to find the source of the mysterious fish kills on the river for the past several years.

State scientists, with freshwater fish experts at Virginia Tech and Virginia Commonwealth University, have a lengthy list of tests to be performed on river water, sediment and fish.

“We’ll gather a lot of good data and learn a lot about the river this year,” said state Department of Environmental Quality biologist Don Kain.

A minor fish kill was reported last week on the North River, a Shenandoah tributary, but it didn’t fit the pattern of the past three years: large kills involving several species beginning in March.

“We’re holding our breath,” Mr. Kain said. “This is really right at the time when they began the last three years.”

Last spring, northern hogsuckers died in the mainstream Shenandoah River, and smallmouth bass and sunfish died in the North Fork of the Shenandoah and in the South River. The year before, 80 percent of the smallmouth bass and redbreast sunfish died in the South Fork, and a similar kill occurred on the North Fork in 2004.

There was a kill in December on the main branch of the Shenandoah that affected several hundred fish, mostly hogsuckers.

Mr. Kain and another biologist Friday counted about 25 dead white suckers on a 3-mile stretch of the North River. The fish had been dead for a couple of days, he said, so it won’t be possible to determine how they died.

Mr. Kain said scientists don’t want more fish to die, but without another kill, their research may be hindered.

The most likely reasons for fish kills have been ruled out, and so far officials have no explanation for the symptoms of chronic stress that the dead fish displayed. Many bore lesions that resembled cigar burns, and some had males and female characteristics.

Scientists have tested fish samples for nutrients such as nitrogen and phosphorous, and this spring, they plan to look for compounds such as heavy metals and pesticides and other chemicals used specifically in the largely agricultural Shenandoah Valley.

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