Wednesday, April 18, 2012

New Rules Seek to Prevent Invasive Stowaways in Ballast water: Great Lakes

Nearly a quarter-century has passed since an oceangoing ship from Europe docked somewhere in the Great Lakes and discharged ballast water carrying tiny but tenacious zebra mussel larvae from Europe.

Within a few years after they turned up in Lake St. Clair, between Lakes Huron and Erie, the small freshwater mussels and their larger and even more destructive cousins, quagga mussels, had coated lakebeds throughout the region, clogging intake valves and pipes at power, water treatment and manufacturing plants.

The filter-feeding mussels have since helped to upend the ecosystems of the Great Lakes, fouling beaches, promoting the growth of poisonous algae and decimating some native fish populations by eating the microscopic free-floating plant cells on which their food web depends.

“They didn’t just spread — they completely colonized the Great Lakes,” said Andrew Buchsbaum, director of the National Wildlife Federation’s Great Lakes office. Read More