Heat likely the cause of hundreds of dead fish at Lombard Lagoon

The hundreds of dead fish removed from a neighborhood pond Wednesday in Lombard were an alarming sight, but Mother Nature likely played a role in their demise.

The fish apparently died as a result of oxygen deprivation related to the scorching heat and shallow depths of the Lombard Lagoon, park district officials say.

A neighbor of the pond at Grace Street and Marcus Drive reported the dying fish shortly about noon Tuesday, interim Parks Superintendent Dean Styburski said. The park district responded with the full weight of his department, assembling 24 employees for the cleanup effort.

By Wednesday afternoon, as air temperatures hovered around 90 degrees, some 400 to 500 carcasses from the so-called "fish kill" had been cleared from the pond, Styburski said.

Aquatic management consultants advised the park district Wednesday that the worst of it is seemingly over, though there still may be additional deaths, Styburski said.

Consultants from Crystal Lake-based Environmental Aquatic Management LLC suspect that warming waters depleted the pond of the oxygen necessary for fish to survive. Which is why Styburski was crossing his fingers for rain and wind to stir up waves and help oxygenate the Lombard Lagoon, a 4.35-acre pond no deeper than 6 feet and fed by stormwater.

"It's pretty well exposed to the sun in all directions," Styburski said. "It's a very open pond."

When he returned to the pond later Wednesday, conditions had improved.

"We had a few more fish to pick up, but it was looking pretty good," Styburski said. "We had some good wind out there, so that was helpful."

At one point a destination fishing spot, the pond has not been stocked for "quite a while," Styburski said, so natural reproduction has generated its fish population.

Crews pulled all sorts of fish, mostly blue gills, catfish, carp, bullheads and various smaller varieties, Styburski said.

In a statement posted to the district's website, officials said tests of the water and oxygen levels will be taking place this week.

"During the next few week(s) and months we will determine what if anything we could have done to alleviate the situation, the potential for adding aeration to the pond, as well as determining best time to restock the pond," the statement read.

Consultants will provide the park district with details about mechanical aerators that would introduce additional oxygen to the pond, Styburski said.

"We'll do a man-made effort," he said.