# Sign of health: Whitefish spawn in Detroit River



## outfishin_ (Jul 28, 2004)

DETROIT (AP) -- In a sign of the returning health of the Detroit River, whitefish have resumed spawning there after an absence of the better part of a century, biologists say.
Each fall, millions of spawning whitefish from Lake Erie used to swarm to the border waters' wide, shallow rapids. By 1916, the whitefish were nearly gone, driven off by industrial pollution and dredging that removed the rapids to allow big ships to pass.
"This is amazing. It's the cumulative effect of 35 years of pollution control, and we are beginning to see at least the beginning of the recovery of a sentinel species," said John Hartig, manager of the Detroit River International Wildlife Refuge.
The spawning whitefish were discovered in the refuge. Sentinel species are those that are sensitive to pollution and habitat destruction.

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Whitefish remain among the most popular commercial fish of the Great Lakes, most being caught in Lakes Superior, Michigan and Huron. About 8 million pounds are netted from U.S. waters in those three lakes annually. A relatively small commercial fishery operates in the deeper, eastern end of Lake Erie.
In the 1800s, many whitefish ran the Detroit River rapids each fall and were valuable as a commercial species. By 1870, Michigan supplied most of the eggs for whitefish hatcheries around the Great Lakes.
Thomas Todd, deputy director of the Great Lakes Science Center in Cleveland, said researchers occasionally discovered larval whitefish in Lake St. Clair and the Detroit River in the 1970s, "but they assumed they were fish that had washed down from Lake Huron."
"There's no question about the fish we found this spring," he told the Detroit Free Press for a story Monday. "We were able to suck eggs out of the gravel, and we found larval whitefish so small that they had to have hatched near where they were found. The fish that produced them came out of Lake Erie."
"Maybe our next step is creating spawning habitat out there," Todd said. "Wouldn't it be incredible if we could play a role in rehabilitating Lake Erie's whitefish stocks?"
Hartig said it would be years before there are enough whitefish in the river to matter to anglers or commercial fishing.
The river now has excellent fishing for walleye, smallmouth bass and muskellunge, with lesser catches of perch, northern pike and white bass.
The whitefish eggs and larvae were collected by the U.S. Geological Survey's Great Lakes Science Center in Ann Arbor from the Canadian side of the Detroit River opposite Grosse Ile.
Since 1972, oil and phosphorous discharges into the river have dropped about 95 percent, and mercury contamination in fish has dropped about 70, said Leon Carl, director of the Great Lakes Science Center.
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On the Net:
Detroit River International Wildlife Refuge: http://www.fws.gov/midwest/DetroitRiver 
Great Lakes Science Center: http://www.glsc.org 
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