Say it ain’t so, thousands of dead fish were found in recent days dead along the Chicago lakefront in recent days. The three- to five-inch fish, members of the herring family, were dying in droves, frozen in chunks of ice or simply going belly-up in open water.
The fish die-off has turned the local ecosystem somewhat topsy-turvy, as Canada geese and mallards have been swooping in to the cold Lake Michigan waters to prey on the dead shad.
The birds don’t ordinarily eat fish at all, but naturalist Joel Greenberg told the Chicago Sun-Times that they’re “opportunistic.”
More from the Sun-Times, on the cause:
“Gizzard shad are pretty sensitive,” Lake Michigan Program biologist Dan Makauskas said. “On the toughness scale, the herrings are pretty soft.”
Gizzard shad, members of the herring family, are more sensitive to drops in oxygen levels than most fish. And thick ice came early to Chicago harbors in December.
Makauskas, who speculated that the young shad may not have built up enough reserves to survive the early onslaught of extreme cold, agreed the die-off is abnormal.