Late in October 1952, large numbers of waterfowl were found dead upon the water and shores of Storm Lake, Iowa. Several of the dead birds, two semiconscious Franklin gulls and a bucketful of the water which had a thick greenish scum of algae on the surface were submitted to the Iowa Veterinary Diagnostic Laboratory at Ames for investigation. Water-bloom poisoning was suspected as being the cause of death of the birds.