DeKALB | The smell of dead fish has recently filled the air by the East Lagoon with many washed up on shore.

Mike Saari, director of the NIU physical plant, said the main cause of this is when a body of water, such as the lagoon, thaws out during the spring. This temperature change makes the water turbulent, moving the water from colder to warmer.

“The warm water comes to the surface and the cold water is almost like a temperature inversion,” Saari said. “That action stirs up a lot of organic material at the bottom of the lagoon and you get concentrations of algae, which makes the oxygen in the water.”

Saari said this is a natural phenomenon and has nothing to do with pollution or unusual events.

“It’s something that does occur from time to time depending on the weather and how the actual temperature is throughout the spring.”

Matt Wolfe, a fishery biologist at the Ohio Department of Natural Resources, said this past winter has been pretty severe, but the main problem starts in the summer.

“With the summer being as hot as it was it made it a worse problem than it usually is,” Wolfe said. “The higher than normal temperatures we had cause a lot of vegetation growth throughout the summer. Fast forward to the winter. Vegetation can survive through the winter as long as there’s sunlight penetrating the ice.”

Wolfe said because of the dramatic snow storms, the snow on the pond acted as a reflector to incoming sunlight.

“Once the light gets cut off, that vegetation starts to die,” Wolfe said. “Once that dies, it sucks up the oxygen and you’re going to have a fish kill throughout the spring.”

The fish may actually have been dead as early as early January, but Wolfe said once they died they just floated to the bottom. Once the lake thawed is when the fish washed up to shore.

“This is very typical, especially in small ponds,” Wolfe said. “If there is no flow of water or a water fountain to keep the water turning then it will happen.”

Wolfe said the only ways to combat this are either to shovel the ice or to install a fountain.

Freshman nursing major Aly Lopez said she first noticed the fish along shore about three weeks ago.

“I was walking to class past the lagoon and noticed about four or five dead fish washed up on the side,” Lopez said. “About a week later I saw a few more washed up.”

Lopez said she was surprised at first and was wondering if there was something wrong with the lagoon.

Saari said the Grounds crew usually goes by the lagoon on a daily basis and disposes of any fish encountered along the shore.