Fish Kills

Fish kills occur at various locations on the Illinois River. The largest known fish kill occurs when a barge is unloading anhydrous ammonia at Creve Coeur on July 31, 1961. A hose breaks, releasing the chemical fertilizer, killing 5,387,580 fish for a distance of 25.7 miles; most of these are gizzard shad (Stinauer 1974).

Another large fish kill occurs on June 21 and 22, 1964, but the exact cause unknown. An estimated 3,536,536 fish are killed, mostly gizzard shad. The extent of the kill is 62.5 miles, from Meredosia in Morgan County to 12 Mile Island in Jersey County (Stinauer 1974).