Great Lakes water safe to drink, not to swim, scientists
Article courtesy of MILWAUKEE JOURNAL SENTINEL
MILWAUKEE -- 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, 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
The report -- which is the most comprehensive measure
of factors affecting the Great Lakes and their drainage
basins -- noted these signs of good health:
health and abundance of the walleye fishery, although
catches were highest in Lake Erie and lowest in Lakes
Michigan and Superior.
drop of 50 percent to 90 percent 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 product of degraded pesticide
DDT, now banned.
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 the greatest
biological threat to Great Lakes aquatic systems.
However, beach closings increased and the number of
beaches that experienced no closings decreased.
No specific lakes or parts of the Great Lakes earned
"good'' ratings, and Lake Michigan's
health was described as mixed, with improvement for fish
populations but deterioration for fish habitat.
Although lake trout are reproducing naturally throughout
Lake Superior, natural reproduction remains at very low
levels or is nonexistent in the rest of the Great Lakes.