Beware of dead fish washing up on the shores of Lake Michiganthis summer.

An unprecedented number of a species known as alewives has beendying out recently due to fluctuations in the water temperature,said Adam Abajian, the recreation program manager at the Evanstonlakefront.

Passers-by have been noticing the dead fish in the lake forabout a week.

“Every season we have dead alewives,” Abajian said. “They tendto die out when the water gets warmer quickly.”

This season, however, there are many more of them because thetemperature of the water has risen more quickly than in previousyears. Abajian said that the last time he witnessed a largedying-out of alewives was about five or six years ago. They werenot seen in large numbers over previous years because “the waterdidn’t get warm fast enough.”

Medill senior Miriam Berg said she was taking a walk toward thelakefront about a week ago when she first noticed them.

“I was walking along Dempster (Street) toward the lake and therewere all these shiny things,” Berg said. “I thought they wereshells at first, but then I realized they were dead fish. They wereall contorted and gross.”

She said the lips of the silver fish were gaping out. “Ishuddered just to even be near them.”

Abajian said the dead fish appeared along the shore this seasonabout two weeks ago. He expects there to be more dead fish washingup along the shore in the next few weeks.

“I’m expecting a pretty bad year,” he said. “It tends to happenmostly at once … but it usually peters out by the end of theseason.”

Abajian said the temperature increase has not been that greatand said the low level of water this season probably accounted forthe early increase of the water temperature.

“We didn’t have a very precipitous winter,” he said. “We haveless water than in past years, but it’s getting back tonormal.”

According to Abajian, alewives are not a natural fish in LakeMichigan and were probably accidentally introduced through thebilge water of a steamship that passes from the ocean throughcanals in the Great Lakes. He said they first appeared in the 1930sand 1940s.

“In the ’50s,” he said, “there were known to be truckloads ofthem.”

“They’re an ocean fish, so they tend not to do very well here,”said Wayne Brofkan, a scientist for the Illinois National HistorySurvey.

He said marine changes in water temperature tend to be moregradual than in the lake. “Depending on how (the fish) are fed,they suffer mortalities because of the extra energies needed whenthe temperature rises.”

Abajian said his lifeguard staff will be working to clean thedead fish up off the beach using rakes, shovels and abeach-cleaning device.

“We dig a deep hole and bury them in the sand,” he said.

Evanston’s beaches are not yet open, but Abajian said he doesn’tbelieve the fish will deter people from coming. Most people wholive here know about this, so there have not been very many recentcomplaints.

“If the weather’s warm,” Abajian said, “people will come to thebeach.”

But according to Berg, the fish can be seen at other placesbesides the beach.

“It’s not just along the shore,” she said. “There were dead fishembedded in the crevices of the rocks.”

The fish were still there on Dillo Day and scared her off fromwading into the lake, she said. “It looked like God had takenbuckets of dead fish and dumped them along the shore.”