Since Hoeft's initial discovery 32 years ago, fewer than 50 diamond darters have ever been captured. The elusive fish live mainly in sandy shoals, and when threatened they burrow into the bottom.
Scientists had assumed the diamond darter population to be quite low until recently.
"Dr. Welsh has come up with a way to find them more readily, and some of the specimens have been sent to a company to be raised [in captivity]," Cincotta said. "The word on them now is that there are more out there, but we can't easily collect them because we can't electrofish or net them effectively, and the water they live in tends to be too deep to wade."
In fact, Cincotta believes there are more diamond darters today than there were in the 1980s.
"A lot of [water quality issues] have improved on the Elk since the Clean Water Act went into effect [in 1972]," he explained. "Several species, such as the spotted darter and the western sand darter, are more widespread now than they were back then."
Even so, Cincotta believes changes to water chemistry caused by mining and gas drilling have the potential to adversely affect the river's ecology.
"We're already finding substances such as sulfates and chlorides in Elk tributaries where mining is taking place, and we don't yet know what the effects of those substances will be on the river as a whole," he said. "Also, we don't know what impacts [gas] drilling might have."
In the Fish and Wildlife Service's news release on the diamond darter, the service's state field office supervisor said the Elk's waters "face pervasive threats from coal mining, oil and gas development, erosion, timber harvesting and poor wastewater treatment."
The service's biologists also chose to include 100 miles of Kentucky's Green River as diamond darter habitat, even though no diamond darters are known to live there. The service's news release characterized the Green River mileage as "unoccupied critical habitat."
Now that the diamond darter has been proposed for the federal endangered list, the issue will be opened to public comment and input. The law requires a decision to be made within a year.
Reach John McCoy at johnmc...@wvgazette.com or 304-348-1231.