Many types of popular sports fish found in the Great Lakes remain so heavily contaminated by industrial chemicals such as dioxins, PCBs, and methyl mercury that they are unfit for human consumption, says a report released Thursday by Environmental Defence, a Toronto-based conservation group.
The report says that while there have been reductions in contaminants in parts of the Great Lakes, severe problems remain, particularly for fish caught in Lake Ontario, where there has been a marked rise in the number of advisories recommending reduced fish consumption. Contamination levels are also worrisome in Lake Huron and many areas with unsafe-to-eat fish remain in Lake Erie and even Lake Superior, the least polluted of the Great Lakes.
The fish species reviewed included coho salmon, rainbow trout, walleye, pike, and lake trout.
”The trends in fish consumption advisories clear indicate that the lakes continue to be polluted to such an extent that human health is threatened,” it said, calling for steps to significantly reduce pollution emissions in the Great Lakes basin and deal with the continuing legacy of dangerous chemicals, such as PCBs, once used electrical equipment but banned in 1970s. Even though PCBs have not been used for decades, they are still being found in some fish at unsafe levels.

The report was based on a comparison of Ministry of Environment recommendation on the safety of various types of fish issued in 2005, and another released earlier this year.
About five million kilograms of industrial pollutants are being released directly into he lakes, according to the report.
Although fish are a food source high in protein and many health experts recommend regular consumption of them, the report said it did not want to discourage people from eating fish but wanted to highlight the need for continuing action to reduce discharges of harmful chemicals into the water.
”Fish advisories due to damaging levels of toxic contamination in Great Lakes fish serve as a potent warning that to safeguard the Great Lakes as a vital resource and international treasure, we must dramatically reduce pollution in the basin,” it said.