The Department of Environmental Quality and the Department of Game and Inland Fisheries continue to track and investigate springtime fish disease and mortality events that have occurred in several rivers in the western part of Virginia in recent years.

Since 2004, fish disease outbreaks and mortality have occurred in the Shenandoah River basin. In spring 2007 similar events began in the upper James and Cowpasture rivers. The impacts appear to be most severe among smallmouth bass and sunfish, although other types of fish also have been affected.

Outbreaks often are accompanied by open sores, or skin lesions, in many of the diseased fish. Typically these events have begun in the spring when water temperatures rise into the 50s and have continued until water temperatures reach the mid-70s, generally running from early April until mid-May.

Studies by state and federal scientists and several university researchers have focused on water chemistry, general health of fish and other aquatic life, and fish diseases. Initial findings suggest links between certain bacteria and the disease outbreaks. Ongoing studies involving DEQ, DGIF and the U.S. Geological Survey’s Leetown, W. Va., Science Center, continue to explore the role of bacterial communities, along with environmental and contaminant factors that may cause immune suppression.