WASHINGTON — In West Virginia’s Appalachian Mountains, fish are vanishing. The number of species has fallen, the populations of those that remain are down, and some individual fish look a little skinny.
A new government study traces the decline in abundance to mountaintop removal, the controversial coal-mining practice of clear-cutting trees from mountains before blowing off their tops with explosives.
When the resulting rain of shattered rock hits the rivers and streams that snake along the base of the mountains, minerals released from within the stone are changing the water’s chemistry, the study said, lowering its quality and causing tiny prey such as insects, worms and invertebrates to die.
“We’re seeing significant reductions in the number of fish species and total abundance of fish downstream from mining operations,” said Nathaniel Hitt, a research fish biologist for the U.S. Geological Survey’s office in Kearneysville, W.Va., and one of the study’s two authors.
Mr. Hitt and his co-author, Doug Chambers, a biologist and water-quality specialist in the Charleston, W.Va., office of the USGS, took a 1999 study of the Guyandotte River basin’s fish populations by Penn State University researchers to compare them over time.
For two years starting in 2010, they sampled the populations in waters downstream from an active mountaintop coal-mining operation. In one of the sample areas, the Mud River watershed, which contains the largest tributary of the Guyandotte River, at least “100 point source pollution discharge permits associated with surface mining have been issued,” the study said.
North America’s central Appalachian Mountains, where the basin lies, are considered a global hot spot of freshwater-fish biodiversity, but few researchers have investigated the impact of mountain strip mining on stream fish, and the effects “are poorly understood,” the study said.
Mr. Hitt and Mr. Chambers found that the number of species was cut in half, and the abundance of fish fell by a third. The silverjaw minnow, rosyface shiner, silver shiner, bluntnose minnow, spotted bass and largemouth bass, along with at least two other species detected before their study, were no longer there.
Another fish species, the small and wormlike least brook lamprey, never before detected, had moved in. In areas of the river basin where there was no mountaintop mining, fish flourished. In addition to species that were in those waters previously, seven new ones were found, including the spotfin shiner, the spottail shiner and the golden redhorse.
“I think if we only focus on the fact that it’s fish, ... some people will say, ‘So what?’ ” Mr. Chambers said. But fish and invertebrates they eat are canaries in a coal mine for researchers, “indicators of the water quality,” he said.
Research such as the USGS’s study of mountaintop mining, published online this month by the Society for Freshwater Science, is viewed with suspicion in coal country, where mining operations provide thousands of jobs.United States - North America - West Virginia