Thousands of Fish Dead Along Chicago Lakefront This type of herring is particularly sensitive, says biologist By Evann Gastaldo, Newser Staff Posted Jan 11, 2011 11:14 AM CST 6 comments Comments Ice floes drift on the Lake Michigan in Chicago, Sunday, Jan. 31, 2010. (AP Photo/Nam Y. Huh) (Newser) – 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.