Nonnative Organisms Rampant in San Francisco Bay Ecosystem

Plants and animals not native to the area have made San Francisco Bay the “most invaded aquatic ecosystem in North America,” a government report says. The report, prepared for the Fish and Wildlife Commission, is to be released Friday at a forum in Washington, D.C., sponsored by Sen. John Glenn (D-Ohio) the same day he plans to introduce legislation barring the discharge of organism-laced ballast water in estuaries.

In the last decade, such intruders as New Zealand sea slugs, Chinese mitten crabs, Atlantic Ocean green crabs and Asian clams have been arriving at a rate of one new species every three months. The report said at least 212 species of organisms not indigenous to the region were found in the bay and delta.