11/08/2006

Editorial

Dead birds on the beach deliver a dire message

About 2,800 dead gulls, cormorants, mergansers, grebes and 150 common loons have been found on the beaches of Sleeping Bear Dunes National Lakeshore since August. Tests reveal they died of Type E botulism.

The bird die-off comes as a surprise here, but Sea Grant programs in New York, Pennsylvania and Ontario have monitored similar die-offs on Lakes Erie and Ontario for a decade. An estimated 25,000 birds now die annually along their shores. Reports also reveal a growing number of dead native fish, soft-shell turtles and mud puppies.

These die-offs are an environmental disaster brewing since the first zebra mussel was discovered in Michigan's Lake St. Clair 25 years ago. They're also a disturbing public health issue. In Pennsylvania, beach-walkers are warned to keep their dogs away from dead fish, birds and rotting, smelly piles of dead algae on the beach. Anyone picking up carcasses is instructed to wear gloves and double-bag the birds.

Scientists are still learning how dormant Type E botulism spores on the bottom of the lakes get into the food chain. Ongoing research points to the interaction of four invasive species — cladaphora algae, zebra and quagga mussels and round gobies.

The spores appear to come to life in the tissues of the mussels, which don't die but pass on a paralyzing Type E toxin to the round goby, a small exotic fish that feeds on them. The gobies are eaten by fish-eating birds and native bottom feeders like sculpin, a favorite food for native species.

The algae and mussels have a close relationship. More sunlight gets to the bottom of the lake because of mussel feeding frenzies on zooplankton. The algae thrives on the extra light and mussel waste products. It begins to rot as it uses up oxygen and floats to the surface and shore in smelly heaps. Gulls and other shore birds scavenge the algae mats for mussels and dead fish.

It's not a pretty picture. The dead birds on our lakeshore are a shrieking warning. Invasive species can't be ignored. They will continue to degrade the ecology of the Great Lakes into a wet and deadly desert for native species. We must find effective ways to control invasive species already in the Great Lakes and to block the continuing flow of hitchhikers arriving in the ballast tanks of ocean-going vessels.

If we want to save what's left, we have to adopt and enforce strict regulations for treating and dumping of ballast waters in the Great Lakes. The effort will cost billions over many years, but ignoring the problem will cost even more.

The willpower to do this won't come from U.S., Canadian and Great Lakes governments without public concern and pressure. It's time for public outrage.

The die-offs aren't a one-time occurrence. They are a small sign of what is yet to come — if we do nothing.