MUNSTER | What caused some 200 fish to die off suddenly in the Little Calumet River in late June may never be known.
Collection of water and fish from the along a quarter-mile stretch of the river near Calumet Avenue on June 30 proved inadequate for analysis, according to the Indiana Department of Environmental Management and the Indiana Department of Natural Resources.
When the fish kill was reported June 30, DNR conservation officers gathered at the site along with representatives from IDEM, the Lake County hazmat team and the Munster Police Department.
IDEM representatives collected water samples, which were taken to South Bend to determine if pollutants were present in the river. At the time, DNR Conservation Officer Keith Wildeman said scientists would check if recent heavy rains carried a substance into the river that killed the fish.
However, IDEM spokeswoman Amy Smith said this week the water samples were “not useable.”
“There was not enough water collected to perform an analysis,” Smith said.
IDEM representatives checked the site of the fish kill again July 3 and “observed there were live fish in the river,” she said.
“At that point, officials did not recommend additional water samples be taken," she said.
It is possible the fish kill was caused by “natural conditions present at the time, (due to) weather," she said.
Problems with the condition of the fish collected June 30 also prevented biologists at the DNR Indiana Fish Hatcheries from detecting possible contamination, said Lt. William Browne, of the DNR's Law Enforcement Division.
The minnow, sucker and bluegill removed from the river were too decomposed to study for cause of death, Browne said.
“In order for a necropsy to be of assistance, the fish must be in ‘struggle,’ or very freshly deceased,” he said. “The purpose for a necropsy of an appropriate sample would be to detect contamination.”
At a recent Little Calumet River Basin Development Commission study session, Chairman William Baker said perhaps a lightning strike during thunderstorms that hit the area before the dead fish were discovered caused the problem.