Disaster on the micro-level:
On the Dan, determining the health of low-lying river creatures such as mussels, clams, crawfish and dragonflies will determine the health of the fish in the river, and later, the birds and animals that feed on those fish. The fear, said Brian Williams, also a Dan River Basin Association program manager, is that the entire food chain along the upper Dan could be imperiled by the presence of coal ash and its poisonous heavy metals. (The Dan River stretches some 200 miles; about 70 miles is affected by the spill.)
Already, though, Williams described the river bottom on the Dan a mile or two below the spill as a virtual “kill zone” for macroinvertebrates because of the amount of toxic sludge that’s settled. At the spill site, there is a coal ash bar some five feet thick and 75 feet long. Coal ash has been detected along the river bottom some 70 miles eastward downstream — all the way to the John Kerr Reservoir north of Raleigh.
Even those critters who survive this calamity will absorb toxins and heavy metals, which will form a bioaccumulation chain that will eventually make any fish pulled from the river or Kerr Lake inedible. Or, more precisely, fish that shouldn't be eaten. Humans are also subject to bioaccumulation.