Environment
3:58 pm
Tue January 11, 2011

Fish die-off along Chicago lakeshore

The Chicago Sun-Times is reporting "a bizarre scene evolving along the Chicago lakefront."

Geese and mallard ducks are apparently gulping down thousands of dead fish that are in the ice or floating in the open water around the ice.

The paper quotes Lake Michigan Program biologist Dan Makauskas who says:

"Gizzard shad are pretty sensitive. On the toughness scale, [they] are pretty soft."

Some biologists attribute the die-off to lower oxygen levels because of ice cover around the lakefront.

Former Muskegon Chronicle reporter Jeff Alexander wrote about a gizzard shad die-off on Mona Lake in Muskegon County back in 2008.

That die-off was attributed to a hard winter as well. From Alexander's report:

Gizzard shad die-offs are common in several area lakes. The fish often die during winter as ice cover decreases oxygen levels in the water; the fish also die from thermal shock when the lake warms up rapidly in the spring, said Rich O'Neal, a fisheries biologist for the Michigan Department of Natural Resources.

Gizzard shad are members of the herring family and are native to the Great Lakes.