Article published August 25, 2009
Fish kill remains a mystery
Puzzled wildlife officials seek clues in Swan Creek
By STEVE POLLICK
and TOM HENRY
BLADE STAFF WRITERS
A team of state wildlife officers, some of them in kayaks, continued to search Swan Creek yesterday for the source of a massive kill that has claimed tens of thousands of fish, including yellow perch, bass, and other prized gamefish.
The fish were discovered Sunday. Countless fish were still believed to be dying in oxygen-depleted water last night.
"All I know is it's in the thousands. They're dying as we speak," Paul Kurfis said yesterday after getting the latest update from one of about seven wildlife officers assigned to the field investigation.
Mr. Kurfis, chief of law enforcement for the Ohio Department of Natural Resources' northwest Ohio district office, said Toledo environmental services is aiding the natural resources department in its investigation.
He stopped short of describing the area as a moving dead zone, in part because investigators don't know what has caused it or how far it extends. They have not detected any unusual odors, oily sheens, or discoloration.
A dead zone, by definition, is a section of water with so little oxygen that life cannot exist."It's a moving slug of depleted oxygen," Mr. Kurfis said.
Algae robs water of oxygen.
This is the time of year for algae blooms, but there is no major outbreak of algae in the creek, Mr. Kurfis said.
He said officials are baffled and frustrated by the mystery.
"You can follow it in the water, but you can't tell what it is," Mr. Kurfis said.
The problem was discovered in the vicinity of Detroit Avenue. In addition to yellow perch, the losses include crappie, white bass, and largemouth bass, some 12 inches or longer. One northern pike 25 inches long was found.
The presence of such gamefish indicates the water was of good quality before the die-off.
Mr. Kurfis said wildlife officers would continue looking for answers by moving upstream and tallying dead fish.
They have been testing the water for pH - its relative acidity or alkalinity - and ammonia-like odors, which sometimes are linked with kills. But so far the only indicator of trouble has been low dissolved-oxygen readings.
Mr. Kurfis said the scene Sunday on the creek, in roughly a two-mile stretch near Highland Park, was unbelievable.
"A small tributary coming in was OK, and fish were just stacked at the mouth of it trying to get good water," he said.
Investigators were struck by the massive numbers of round gobies dying by the thousands.
"We didn't know they were in the creek," Mr. Kurfis said.
Gobies are among a host of an invasive pest species from eastern Europe that have infested Lake Erie in recent years. They enter the lake via ballast water dumped from seagoing ships.
Gobies, a main predator of zebra mussels, spread throughout the Great Lakes and their tributaries as the waterways became colonized by the mussels. Gobies have no value as sportfish, but are preyed upon by larger fish and some species of birds.
Mr. Kurfis said gobies were "jumping out of the water and on shore."
Contact Steve Pollick at:
spollick@theblade.com
or 419-724-6068.
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