HERRIN - Mayor Vic Ritter called it a "natural phenomenon." That's the expert opinion of state Department of Natural Resources field workers in Marion after inspecting the 60-acre Herrin City Lake No. 1 Friday, where a few thousand dead fish had floated to the top of the water from a lack of sufficient oxygen.

©Chuck Novara / The Southern
Fish line the bank of Herrin City Lake No. 1 on Monday after a fish kill earlier in the week.

"There's no rhyme or reason for it," Ritter said. "That lake is a good lake, one of the best in the area. But this kind of fish kill has happened in Marion, Du Quoin and many other areas before."

Ritter said the combination of hot weather and low water level from the lack of rain led to a reduced oxygen level for many of the fish.

"What that basically does is suffocate the fish," the mayor said. "Another problem might be that we had too many fish in the lake, which took away from the oxygen level, too."

Ritter said Pine Lakes Golf Course owner Phil Preston contacted the city about the problem Friday. The mayor dispatched some city workers to help with the cleanup. Preston refused comment on Monday.

"The city owns the lake, but Phil uses some of the lake water for his golf course," Ritter said. "There was also a fish kill on their pond a few years ago when Valgene (Gould) owned the course. This is something that is natural and happens from time to time."

DNR district fisheries biologist Chris Vickers said fish kills like this one typically happen in the heat of the summer, often under cloudy or overcast conditions when water levels are low.

"The lack of sunshine reduces the ability of the plankton in the water to produce oxygen," Vickers said. "And the plankton also use up the oxygen."

He added there was a fish kill at Mermet Lake in Massac County earlier this summer.

"The Herrin lake will recover before too long," he said. "The fish that were killed were mostly the larger adult fish. There is still a sufficient number of fish left to allow the lake to recover to its prior state, which was great."

Vickers said the city had no legal obligation to clean the lake of the dead fish but chose to do so anyway.

"I think the mayor was concerned about the smell and how it would affect the neighbors," he said.