A new study conducted by Richard E. Peterson, a toxicology professor at the University of Wisconsin – Madison School of Pharmacy, suggests that dioxins and related chemicals may have contributed to the extinction of lake trout in Lake Ontario prior to 1960 and to the recruitment failure of stocked lake trout since then.
Released, inexplicably, at a news conference in Seattle, Washington, by the Wisconsin chapter of Sea Grant, the study was met with skepticism and, in some instances, outright disdain.
Dr. William Horns, Great Lakes specialist for the Wisconsin Department of Natural Resources, objected primarily to the news release issued by Sea Grant to announce the study. “The headline in Sea Grant’s news release appears to distort the comments of Dr. Peterson. Where Peterson was cautious in his statements, the Sea Grant news release was not. Peterson is quoted as saying, ‘Our data suggest that dioxins and related chemicals may have contributed to the extinction of lake trout in Lake Ontario prior to 1960 and to the recruitment failure of stocked lake trout since then.’ The news release headline distorts that by saying ‘Cause Found . . .’ What Peterson characterized as a possible factor is described by Sea Grant as a ’cause.'”
“Some evidence suggests that contaminants are not a problem for lake trout reproduction in Lake Michigan,” Horns continued. “Lake trout eggs are spawned naturally in Lake Michigan, hatch there, and survive beyond the sac fry stage. Healthy lake trout fry have been collected from Lake Michigan from time to time for nearly twenty years. Those fish had survived past the sac fry stage of development when the problems described by Peterson occur.”
Horns adds, “Reproduction by most native and many introduced species is excellent in Lake Michigan. Lake whitefish are reproducing extremely well. Michigan biologists claim as many as 2 million naturally reproduced chinook salmon smolts may be reproduced annually in their streams.”
Another scientist noted that Peterson’s own work acknowledged that there should be no appreciable mortality from dioxin since the early 1980s. Still another scientist responded to the Sea Grant news release abruptly, saying “This is just junk.”
While Sea Grant has traditionally enjoyed high regard from the sport fishing community, the Wisconsin group’s latest release may be placing the national program’s integrity and credibility at risk. One area angler, Scott Morgan, asked “Is Sea Grant now reverting to the same questionable methods EPA uses?”
It is generally agreed among the scientific community that any combustible product that burns will generate dioxin. Common forest fires and rare volcanic eruptions generate hundreds of thousands of times more dioxin than do man-made compounds. Dr. Mark Cohen, at a recent International Joint Commission (IJC) meeting, acknowledged that forest fires are a main source of dioxin. The IJC and U.S. EPA, to name just two agencies, agree that non-point source pollution, or atmospheric deposition patterns, account for up to 95 percent of the pollution dumped into the Great Lakes.
