Science | mysterious animal deaths Thousands of Fish Dead Along Chicago Lakefront This type of herring is particularly sensitive, says biologist By Evann Gastaldo Posted Jan 11, 2011 11:14 AM CST Copied Ice floes drift on the Lake Michigan in Chicago, Sunday, Jan. 31, 2010. (AP Photo/Nam Y. Huh) Yet another mass animal death: Along the Chicago lakefront, gizzard shad—a type of herring—are dying off in large numbers. Thousands, maybe more, are dead and frozen or floating in Lake Michigan, the Sun-Times reports. Geese and ducks are feeding on the dead and dying fish. Gizzard shad are fairly sensitive, particularly to drops in oxygen levels; the early arrival of ice in the harbors could also be a factor. One biologist says the situation is abnormal, but click for a possible explanation for all the die-offs. Read These Next North Carolina shooting suspect once walked the red carpet. The gunman who killed 4 at a Michigan church was an ex-marine. 'We heard a big bang,' says churchgoer in Michigan Skydivers leap from plane 2 minutes before fatal crash. Report an error