The U.S. Fish and Wildlife Service last week proposed that the diamond darter be placed on the federal Endangered Species List. If the silvery little member of the perch family becomes the first Mountain State fish to end up on the list, 23 miles of the Elk - from King Shoals downstream to Coonskin Park - would be considered the species' "critical habitat."

Bret Preston, fisheries chief for the state Division of Natural Resources, said endangered status would likely force mining, construction, and gas drilling companies to take special precautions when working along the lower Elk and its tributaries.

"When federal permits are required, there would also be a requirement to look at potential impacts on endangered species," Preston said. "The [darter's presence] might require companies to alter the location of a project, limit the amount of in-stream work that is done, or the time of year when the work is done."

DNR biologists would even need to change the way they conduct fish-sampling surveys.

"We knew there was potential for the diamond darter to be listed," Preston said. "So we looked for ways to avoid or minimize impacts. We looked at the methods we use for electrofishing, seining and trap netting. Knowing [the darters'] preferred habitat, we said we wouldn't operate boats in shallow riffle areas that could be diamond darter habitat. Instead of running the boat through with the motor on, we'll either get out and pull the boat through or avoid the area entirely."

Scientists didn't even know diamond darters existed until 1980, when former DNR district biologist Mike Hoeft collected one from the Elk near Coonskin Park.

"Mike knew he had something different, so he called me up," said Dan Cincotta, the DNR's non-game fish biologist. "We realized it was [similar to] a crystal darter, a species once abundant in the Midwest but now gone from most of its former range."

In the next several years, Cincotta captured a few more of the hard-to-find fish and took a closer look at them. He discovered physical characteristics that didn't quite match up with those of Midwestern crystal darters.

"Our fish here has a bigger head, a bigger mouth, a distinctive break in the pigments of its face, and it has sickle-shaped pelvic fins," Cincotta explained. "I wrote a paper on it in 1986."

To distinguish the differences, scientists began referring to Elk River fish as "Elk River crystal darters." That name stayed in effect until 2008, when Stuart Welsh, a professor at West Virginia University's School of Forestry and Natural Resources, concluded that the mysterious little denizens of the lower Elk were indeed a species all their own.

Welsh and his partner, Robert Wood, gave the species the common name "diamond darter," and proposed it be given the scientific name Crystallaria cincotta  in honor of Cincotta's field and lab work.

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.