Dan Egan of the Milwaukee Journal Sentinel writes that on June 1, 1988, everything changed for the Great Lakes as a young researcher from Windsor made a discovery about invasive species in Lake St. Clair.
It was sunny, hot and mostly calm — perfect weather for the young researchers from the University of Windsor who were hunting for critters crawling across the bottom of the lake.
Sonya Santavy was a freshly graduated biologist aboard the research boat as its whining outboard pushed it toward the middle of the lake that straddles the U.S. and Canadian border. On a map, Lake St. Clair looks like a 24-mile-wide aneurysm in the river system east of Detroit that connects Lake Huron to Lake Erie. Water pools in it and then churns through as the outflows from Lakes Superior, Michigan and Huron swirl down into Erie, then continue flowing east over Niagara Falls into Lake Ontario, and finally out the St. Lawrence River to the Atlantic Ocean.
The water moves so fast through Lake St. Clair because the lake is as shallow as a swimming pool in most places, except for an approximately 30-foot-deep navigation channel down its middle. The government carved that pathway long ago to allow freighters to sail as far inland as Milwaukee and Duluth.
When water levels are low or sediment is high, the channel isn't deep enough and sometimes ships have to lighten their loads to squeeze through. That means dumping water from ship-steadying ballast tanks — water taken onboard outside the Great Lakes, water that too often and for too long swarmed with exotic life from ports around the globe.
As the three young researchers were drifting over a rocky-bottomed portion of Lake St. Clair on that steamy Wednesday morning, Santavy decided to drop her sampling scoop into the cobble below. She was hunting for muck-loving worms but figured she'd take a poke into the rocks because, well, to this day, she still doesn't know.
"I can't even explain why it popped into my head," Santavy says. "I thought — if we get nothing, we get nothing, and I'll just mark it off that this is not an area to sample."
Up came a wormless scoop of stones, the smallest of which were pebbles not much bigger than her fingertips.
But there was something odd about two of these tinier stones. They were stuck together.
She tried to muscle them apart but she couldn't.
Then she realized that one of them was alive.
