Parasite forces Md. to kill 80,000 trout

HAGERSTOWN, Md. - A parasite that causes trout to swim in circles until they die has been found in two hatcheries in western Maryland, meaning 80,000 fish that would have been stocked in lakes and streams this year will instead be destroyed, an official said Thursday. The organism, which is not a risk to humans or other fish, deforms the spines and skulls of trout in what is known as "whirling disease." It has devastated wild rainbow trout in the West and is now found in 22 states, according to the Whirling Disease Foundation.Twenty percent fewer rainbow and brown trout will be stocked this spring across Maryland, Lunsford said.The parasite, Myxobolus cerebralis, has long been known to exist in the Potomac River's North Branch, which is several miles from both hatcheries. It might have been spread to the hatcheries from mud on the feet of birds or bears, said H. Robert Lunsford, director of freshwater fisheries.The Department of Natural Resources will test for the disease in Maryland waterways that hold wild trout in hopes of learning how far the organism has spread, Lunsford said."We'll do a pretty big effort when the swim-out fry emerge from gravel in late spring," he said.