'The alewives are coming! The alewives are coming!'

July 7, 2011

It's summer. We're all enjoying the great outdoors, and some of us are going to the beach. But go back to 1967, and check out Time magazine for today's date, July 7. Chicagoans were battling the alewives.

An alewife is a type of herring.  It's about 7 inches long and weighs a few ounces. The largest concentration of alewives is in the waters off New England. There's even a major street in Cambridge, Mass named Alewife Parkway.

Anyway, during the 1930s, these alewives got into Lake Michigan. Their numbers stayed small because a bigger fish--the trout--would eat the alewives. But then the sea lamprey came along and ate the trout. Sea lampreys don't eat alewives. That left the lake with all these alewives, and no predator.

The alewife population grew and grew. By the 1960s there were so many of them in the waters around Chicago they became national news. Time was only one of the media outlets that reported the story.

To be fair, the alewives weren't much of a problem as long as they swam around in deep water and went about their business. The trouble came when they reached the end of their life span. Then we got the grand Alewife Die-Off.

This became an annual Chicago event, like the swallows returning to Capistrano. One day there'd be a few dead alewives drifting in toward shore. The next day more would arrived. Soon their bodies would be clogging the shallow water or washing up onto the beach.

Of course, those alewives would be decaying, and you can imagine the smell--well, you probably don't want to. The flies would swarm in and the beaches would be a mess. The city would have to use tractors and bulldozers to clear off the sand.

Nobody knows how many dead alewives there were in any one year. Experts said hundreds of millions, maybe a billion. A pilot flying over Lake Michigan saw a ribbon of drifting alewife carcasses 40 miles long.

Eventually the federal government started putting salmon into the lake. The alewife population went down. Now Chicagoans could once again use the beaches in summer.

But lately we've been hearing about the Asian carp. If that thing gets into the lake, scientists say it will force out the salmon. With the salmon gone, what will happen next?

Maybe it's time to start working on a screenplay for a new disaster movie. Call it "Return of the Alewives."