| Dioxin blamed
for disappearance of Great Lakes trout |
|
| The Midland Daily News | 11/09/2003 |
| CHICAGO (AP) –
It’s long been a whopper of a whodunit, the mysterious disappearance of the lake
trout from the Great Lakes. Now, experts say they think they’ve identified the suspect that killed off the fish in a few decades, leaving behind a devastated Great Lakes commercial fishing industry and a void that was filled by invasive species. A 15-year federal study suggests that minute traces of a type of industrial pollution – specifically, dioxins – probably played a large role in killing off the king of the world’s largest freshwater system. "This is as close to a smoking gun as we’ve found," said Stephen Whiteman, spokesman for the University of Wisconsin Sea Grant Institute in Madison. The results of the study fly in the face of long-held theories that overfishing and the invasion of sea lampreys wiped out the lake trout in the middle of the last century. The study examined the drop in the number of fish in Lake Ontario. Led by the U.S. Environmental Protection Agency and the Sea Grant Institute, a team looked at trout population dating back to 1865. Philip Cook, an EPA research chemist, said the team found that the climbing levels of dioxins, which first showed up in measurable levels in the 1930s, directly correspond with the quick demise of the trout in Lake Ontario. "The toxicity alone explains what happened" to the lake trout, Cook said. Cook said that during the 1960s the dioxin level was so high it was impossible for lake trout larvae to survive. "The mortality rate was 100 percent," he said. He said there was heavy commercial fishing for nearly a century before the lake trout population crash. And lampreys, an eel-like, parasitic creature, first found their way into the Great Lakes when the Welland Canal opened in 1829. The study focused on Lake Ontario. But researchers believe it will help determine what happened in all the Great Lakes, including Lake Michigan where the lake trout was wiped out in 1956, just 12 years after the commercial catch of lake trout was 6 million pounds. Some are skeptical about the study’s findings. Dan Thomas, president of the Great Lakes Sport Fishing Council, maintains that commercial overfishing is to blame for the lake trout’s disappearance. One question the study didn’t answer is why even though the dioxin levels have been dropping since the 1970s, only in Lake Superior is there a self-sustaining population of lake trout. Copyright 2003 Associated Press. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed. |
|
| İMidland Daily News 2003 | |
For additional articles like this one, go to the Tittabawasse River Watch web site www.trwnews.net for complete coverage of the Tittabawassee River Dow Chemical dioxin contamination saga. . The Newspaper / Media page of our site contains an extensive archive of media articles dating back to January 2002. The source organization's web site link is listed to the right of the article, visit often for other news in our area. The Newspaper / Media page may be accessed by scrolling down to the bottom of the CONTENTS section and clicking on the Newspaper/Media link.