Whitefish spawning shows river's health

[GLF]

A 90-year comeback for Detroit waterway

Biologists have found evidence this spring that whitefish are spawning in the Detroit River for perhaps the first time in 90 years -- excellent news for the health of the international border waters.

Until the early 1900s, millions of spawning whitefish from Lake Erie swarmed every fall to the enormous, shallow rapids of the Detroit River. By 1916, the whitefish had all but disappeared, victims of industrial pollution and channel dredging that dynamited the rapids to clear the river for big ships.

"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, where the spawning whitefish were discovered. Sentinel species are ones sensitive to pollution and habitat destruction.

Whitefish remain the most popular commercial fish of the Great Lakes, though most are netted in the lakes Superior, Michigan and Huron. More than 8 million pounds are netted from U.S. waters in those lakes each year. A relatively small commercial fishery exists toward the deeper, eastern end of Lake Erie.

In the 1800s, so many whitefish ran the Detroit River rapids each fall and were so valuable as a commercial species that, 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 had found 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. 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," he said.

"Maybe our next step is creating spawning habitat out there," he said. "Wouldn't it be incredible if we could play a role in rehabilitating Lake Erie's whitefish stocks?"

Hartig said it would be a long time before there are enough whitefish in the Detroit River to be of significance to anglers or commercial fishing.

The river already has excellent fishing for walleye, smallmouth bass and muskellunge and, to a lesser extent, perch, northern pike and white bass.

Mike Zielinski, a former charter fishing guide who lives on Horse Island in Gibraltar near where the river enters Lake Erie, said anglers have caught the occasional whitefish in the river for 20 years.

"At first I didn't know what they were. I thought they were mooneyes until I looked them up in a book," Zielinski said. Some walleye fishermen who use high-tech underwater television cameras also have seen the occasional whitefish for about 10 years.

The whitefish eggs and larvae collected by the U.S. Geological Survey's Great Lakes Science Center in Ann Arbor came from the Canadian side of the Detroit River opposite Grosse Ile near the area called Hole in the Wall.

Dr. Leon Carl, director of the Great Lakes Science Center, said that, since 1972, oil and phosphorous discharges into the river have declined more than 95% and mercury contamination in fish has declined 70%. He said he hopes an artificial reef built near Belle Isle will help sturgeon successfully spawn.