Friday 16 October 2009

Search may be last for Maryland fish not seen in 2 decades

By Timothy B. Wheeler
Baltimore Sun reporter
October 16, 2009

Last call for the Maryland darter. The elusive little fish, one of the rarest in the world, hasn't been seen in 21 years. Now, government and university biologists are teaming up for one more, perhaps final search for it in Harford County, where it's never been spotted more than sporadically since it was first noticed almost a century ago in a fast-flowing creek near Havre de Grace.

Named for the only state in which it's ever been found, this bottom-feeding member of the perch family has been seen in just three creeks off the lower Susquehanna River. No one has spied more than a handful of them at any one time since the 1960s. Repeated efforts to locate them in the past two decades have come up empty-handed.

But biologists say they're going to give it one more go, and at least some believe there's a chance they'll still find it, using new gear and searching for in at least one new place - the lower Susquehanna itself.

"It provides a little bit of hope that, hey, here's a new gear that's never been used before, let's pull it around in the river and see if by chance we pick it up," says Jay Kilian, a fisheries biologist with the Maryland Department of Natural Resources.

If it does turn up again, the find would be the biological equivalent of the Holy Grail, the rediscovery of something special that so many have searched for in vain - and all but written off as lost forever.

The darter was first spotted in 1912 by a pair of biologists collecting fish in Swan Creek, and a year later officially identified as a new species, Etheostoma sellare. It wasn't seen again until 1962, when some graduate students found another in Gasheys Run, a tributary to Swan Creek. About the same time, a bunch were found in Deer Creek, near where it empties into the Susquehanna.

Scientists collected about 70 of them to study them, a then-standard research tactic that Andy Moser of the U.S. Fish and Wildlife Service now calls "unfortunate." That was the last time anyone saw that many again.

One reason for the darter's rarity could be its extremely limited range. It's only been found at the fall line of those three streams, in the last riffles of water before it smooths out on its way to the river. Those areas, the upper limits of where ships and boats can sail upstream, happen to be where many colonial settlements sprang up and became towns, so sediment and pollution from land disturbance may have driven down the species' numbers, biologists speculate.

Whatever the reason it's been so hard to find, Moser says, biologists want to make one last, determined push to see if the fish could still be out there.

Frostburg State University biologist Rich Raesly, the last to see the darter in the wild, is coming east to join the hunt, though mainly "just to put this to rest."

He's snorkeled in Deer Creek, where he last spotted the fish, to no avail. He's also used electrofishing gear, which stuns but does not kill fish, so they float to the surface, where they're easier to spot.

"A glimmer of hope, personally, is all that I see," Raesly says.

Still, seemingly long-lost fish have turned up. In 1995, Raesly and another biologist independently spotted another darter that hadn't been seen in 51 years in two different streams off the Patuxent River. For that reason alone, there's great reluctance to write off this or any species.

"Whenever someone proclaims this thing as truly gone, somebody finds one and it's embarrassing," says Raesly.

The search is of more than academic interest. Because the Maryland darter is officially classified as an endangered species, it is protected by federal law from activities that might further threaten its existence. Farmers were asked to avoid applying pesticides near the creeks - keeping back as far as a quarter-mile for aerial spraying of some chemicals.

That was a hardship, at least for a while, says Lee McDaniel, who raises cattle, corn, soybeans and alfalfa on 800 acres along Deer Creek. The Maryland Farm Bureau petitioned the government in the mid-1990s to declare the fish extinct and lift the restrictions. The fish and wildlife service denied the request, saying there needed to be a more thorough search to definitively determine the darter's fate. Since then, efforts to locate the darter have been fitful, hampered by a lack of funding.

Now, federal officials have scraped together $30,000, enough to mount the beginning of an all-points search. Officials are turning to Exelon, the power company that owns the Conowingo Dam, for help to continue the search beyond next spring.

Starting this month, biologists will check the darter's old haunts again. But they're also expanding their search to the Susquehanna, on the theory that a fish only rarely seen in the shallow creeks may make its real home in the deeper waters of the river.

Joining the search will be Tom Jones, a biologist from Marshall University, who's been successful at turning up darters and other rare fish in West Virginia rivers using an electrified net towed along the bottom by a boat. The net, a smaller version of the otter trawls used by oceangoing fishermen, is outfitted with electric cables that stun fish so they can't swim away and evade the net.

What difference does it make if a fish only rarely seen has passed from the scene?

Rare fish like the Maryland darter are a bellwether of stream health, says Kilian. If they disappear, other fish could be in trouble next. Deer Creek still seems to be in good shape, the DNR biologist says, but Swan Creek and Gasheys Run are "highly impacted" by the development around Aberdeen and Havre de Grace. And similar pressures are building on Deer Creek.

Plus, losing a species says something about stewardship of natural resources, he suggests.

"It's a piece of Maryland history, just like any of our state parks and cultural history," says Kilian. "It's something we should pass on and hope it's still out there. ...The Maryland darter, if it's gone, is gone from the entire world, which is pretty sad."

Maryland darter
Scientific name: Etheostoma sellare
Length: 2 to 3 inches
Markings: Four dark stripes across back, spot behind each eye.
First seen: 1912, in Swan Creek; Last seen: 1988, in Deer Creek
Diet: snails, fly larvae
Spawning area: unknown

http://www.baltimoresun.com/features/green/bal-md.gr.darter16oct16,0,3770282.story

(Submitted by Chad Arment)

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