I spent the days on either side of my seventieth birthday at my mom’s house near Green Bay, Wisconsin. On one of those days, my sister, my brother, my sister-in-law, Manyu, and I took a day trip to the small city of Algoma. Once a commercial fishing village on Lake Michigan, Algoma is now a sport fishing destination with a fleet of charter fishing boats. On the afternoon of our visit, the waterfront was experiencing an alewife die-off.* Herring-like fish filled the waters along shore. Thousands were dead, hundreds more were dying. The near dead tried to swim, but the moment they stopped moving their tails, their bodies turned sideways and floated to the surface. The die-off must have been only a day or two old, as none of the carcasses had started to decompose, (i.e, they didn’t stink yet).
Gulls, terns, and pelicans were drawn in by the fish, but the piscivorous birds must have already had their fill. Instead of scarfing up easy prey, they lounged on the wharf’s piers and breakwaters. As a kid growing up in Green Bay, I often
saw gulls and terns, but don’t remember ever seeing a pelican. DDT in the aquatic food chain during the 1960s made it a bad time for the larger species of fish-eating birds. The white pelican population in northeastern Wisconsin, along with that of bald eagles and double-crested cormorants, was decimated. All three birds have staged comebacks, and (so long as the lake’s not frozen) I now see pelicans whenever I visit my mom.
After decades of decline, alewife numbers on Lake Michigan are on the rise. They are not native to Lake Michigan, but they are the main food source for the trout and salmon that were intentionally introduced into the lake to control alewife numbers. The Great Lakes are now such a disturbed ecosystem that I don’t even know whether an upswing in the population of an invasive species is necessarily a bad thing.
* Alewife commonly suffer summerkill. As oceanic fish that migrated up the Saint Lawrence Seaway, they successfully reproduce in the Great Lakes, but seem intolerant of seasonal temperature changes.
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