|
Coursey Springs' role in fish disease not likely, but nothing's ruled out yet, state officials say
BY CHARLES GARRATT • STAFF WRITER
WILLIAMSVILLE - Does Coursey Springs fish cultural station have a connection to recent diseased and dying fish in the Cowpasture river?
"It's a fair question," says Virginia Department of Game and Inland Fisheries biologist Paul Bugas.
While Bugas and others investigating the fish kill in the Cowpasture believe the odds of Coursey Springs being a factor are slim, they can't completely rule out the possibility.
"We are a big player in the watershed," Bugas said about the hatchery near Williamsville.
Coursey Springs is the largest trout-rearing station in Virginia's system of hatcheries and cultural stations.
No fish are hatched at Coursey Springs, but small fish from hatcheries are reared to stocking size. Most of the trout from Coursey Springs are stocked in rivers and streams west of the Blue Ridge from Alleghany County north.
The bacteria causing the lesions and deaths among the sunfish family in the Cowpasture River is Aeromonas salmonicida, according to Bugas. This bacteria was first identified in 1890 among trout in a German hatchery.
The United States Geological Survey Fish Health Branch at the Leetown Science center has produced a pamphlet on this bacteria. The USGS Fish Health Branch is participating in the studies to determine the cause of the fish kills in the Cowpasture and other Virginia rivers.
A. salmonicida was first thought to be a disease of only cold water fish, such as trout and salmon. However, it has been found in species as diverse as goldfish and warm water species including bass and sunfish.
According to the USGS, the bacteria can be a major problem in cultured fish. Even in cultured fish populations, the bacteria does not normally attack healthy fish. Like the fish found in the Cowpasture, cultured fish succumb when scales are damaged by abrasion or the fish is first stressed by other factors. It is those other factor or factors that remain a mystery in the Cowpasture.
Gary Martel, director of the DGIF fisheries division, was the director at Coursey Springs from 1983 to 1990. He doesn't believe fish culture at Coursey Springs has had a negative impact on the Cowpasture. But he, too, says, "We never say we discount anything."
The cultural station uses fungicides and antibiotics to control disease in the dense populations of trout. Keeping wild trout out of the fish ponds where they might spread disease is one of many management issues the facility deals with.
Good management practices tend to eliminate problems with disease, Martel says. Even with good management, Coursey Springs has had some significant fish kills, he adds.
The largest fish kill he recalls occurred during the mid-80s when flooding damaged the hatchery in Paint Bank. Fish were transported to Coursey Springs, but flooding and power outages made it impossible to maintain the proper environment.
"Hundreds of thousands of fish died," said Martel - mostly tiny, recently hatched trout. As in other fish kills at Coursey Springs, the dead fish were buried on site, Martel said. Dead fish don't keep very long, he added, and quick disposal is necessary.
Martel and Bugas explain the outfall from Coursey Springs flows into Spring Run and then into the Cowpasture. Spring Run, also known as Pheasantry Run, is a stocked trout stream.
Sedimentation ponds are used to reduce the quantity of nutrients and waste that enters Spring Run. No disease or fish kills have been seen in Spring Run, they said.
Dead fish have also been found in the Cowpasture upstream of Coursey Springs, says Bugas. In addition, fish from Coursey Springs have been stocked in many rivers and streams around the state where there is no sign of the problems found in the Cowpasture. A link, if there is any, between the fish kill this spring in the Cowpasture and Coursey Springs is not likely.
The state is planning a major renovation of Coursey Springs. A study in the early '90s recommended major changes to "improve cleanliness in terms of fish health and remove more of the effluent," Martel says.
In addition, the renovation will reduce damage to ponds by muskrats and birds. The $5 million-$10 million project is expected to begin in about a year.
Along with changes to the facility, contractors will do stream restoration to improve habitat. Spring Run, as the name suggest, is a spring feed stream providing the cold water necessary for trout.
Over the years, the banks along Spring Run have collapsed in places. With the changes to water treatment at Coursey Springs and improved habitat in Spring Run, even the small chance that diseases could escape from Coursey Springs in to the Cowpasture should be reduced, Martel says.
| 
