Zebra mussels’ damage make them the worst of all Great Lakes exotic species, scientists say
April 10, 08 by TheFleetIf you're new here, you may want to subscribe to our RSS feed. Thanks for visiting!
by Jeff Alexander | Source: Grand Rapids Press
The mussels are just two of 185 exotic species in the Great Lakes. About 120 of those species were imported by ocean ships that discharged ballast water from foreign ports into the lakes, according to government data.
After zebra mussels shut down the water treatment plant in the city of Monroe in 1989, the U.S. and Canadian governments required some ocean ships to flush ballast tanks with sea water before entering the lakes. But those regulations only applied to about 15 percent of ocean ships, and the number of exotic species has continued to increase.
Starting this year, all ocean ships must flush ballast tanks with salt water from the Atlantic Ocean before entering the Great Lakes.
The U.S. Congress and the Coast Guard have been working for years to develop rules requiring ocean ships to clean ballast tanks with filters, heat or chemicals. Shipping industry officials have been reluctant to install costly ballast water treatment systems until there is a standard they must meet.
