Food source for Great Lakes fish
United Press International
ANN ARBOR, Mich. -- Whitefish in the Great Lakes are
getting thinner because their main food source, the diporeia,
a half-inch-long, shrimp-like creature, is disappearing.
Biologists at the Great Lakes Environmental Research
Laboratory in Ann Arbor, Mich., have found the diporeia,
considered the freshwater shrimp, have been wiped out
in portions of Lake Erie, Lake Michigan and Lake Ontario
-- about 17,000 square miles.
Some of the whitefish caught now are much smaller and
studies on their stomachs have found that the fish have
been feeding on zebra mussels and another invasive species
known as quagga mussels, the Detroit News reported.
"The shells (from the mussels) pack their stomachs
and they think that they are full, but the shells have
no nutritional value," said Tom Nalepa, of the Great
Researchers have not been able to determine whether the
diporeia decline is a result of contaminants, pathogens
Fish that rely on diporeia for food will have to find
another food source or die if biologists can't find the
cause and remedy the diporeia decline.