Great Lakes Article:

Great Lakes' health gets mixed results in environmental study

Drinking water ranks high; exotic species, toxins threaten fish

By JO SANDIN
Article courtesy of the Milwaukee Journal Sentinel

Oct. 5, 2001

The Great Lakes still rank among the world's best sources of drinking water, but they are under siege from invasive species, airborne toxins and urban sprawl and, much of the time, they are not a safe place to swim.

That's the consensus of scientists in the United States and Canada who jointly released their fourth biennial assessment of the "State of the Great Lakes."

The 2001 report released this week by the U.S. Environmental Protection Agency and its Canadian counterpart, Environment Canada, rates the health of the Great Lakes as measured by 33 environmental indicators ranging from deformities and tumors in fish (poor) to contaminants in colonial nesting birds (good).

"Levels of toxic chemical contamination have dropped in many fish species," said Thomas Skinner, EPA Region 5 administrator. "However, many fish are still unsafe to eat. Contaminant levels will need to continue to decline for many years before advisories can be lifted or modified."

The report - which is the most comprehensive measure of factors affecting the Great Lakes and their drainage basins - noted these signs of good health:

• The health and abundance of the walleye fishery, although catches were highest in Lake Erie and lowest in Lakes Michigan and Superior.
• A drop of 50% to 90% in concentrations of contaminants in the eggs of herring gulls since monitoring began in 1974, although those in Lake Michigan continue to have high levels of DDE, a degraded product of the now-banned pesticide DDT.
• The minimal level of chemical contaminants in drinking water, even before treatment.

Only two symptoms of poor health were cited: deformities and tumors in fish, particularly in Lake Erie, and continued invasions from exotic species, which were named as the greatest biological threat to Great Lakes aquatic systems.

However, beach closings increased and the number of beaches that experienced no closings decreased.

Moreover, the report noted: "Population growth causing both increased demands made on sewage treatment plant capacities and the probability of release of untreated effluent, as well as more private treatment systems, especially in resort/vacation areas, may cause an increase of undetected releases of inadequately treated waste."

No specific lakes or parts of the Great Lakes system earned "good" ratings, and Lake Michigan's health was described as mixed with improvement for fish populations but deterioration for fish habitat.

Numbers of sea lamprey, an exotic predator that was one of the first to ravage Great Lakes fisheries, have been relatively stable in Lake Michigan. However, populations in the north part of the lake have increased because of an expansion of the large Lake Huron lamprey population.

Although lake trout are reproducing naturally throughout Lake Superior, natural reproduction remains at very low levels or is non-existent in the rest of the Great Lakes.