Home Archived April 24, 2019

Access USGS - San Francisco Bay and Delta

Main Page
Who are they?
How did they get here?
What have they done?
What are they doing now?
California may be next!
Benthic Ecology Home
Access Home
The History and Effects of Exotic Species in San Francisco Bay
San Francisco Bay Project, Water Resources Division
J. Thompson, F. Parchaso, A. Alpine, J. Cloern, B. Cole, O. Mace, J. Edmunds, J. Baylosis, S. Luoma, F. Nichols
California may be next!
Invasion of the Zebra Mussel
Potential Zebra Mussel extent mapBoats with Zebra Mussels have been stopped at the California border. If it invades San Francisco Bay, it will survive in the north bay and the rivers. The potential range is wide-spread (see map at left). The Zebra Mussel attaches to any hard surface and native fauna such as crayfish and clams and many die.
Click on any photo to see larger images.
Zebra Mussel
Zebra Mussel
Zebra Mussel attached to clam
Zebra Mussels attached to clam
Zebra Mussel attached to crayfish
Zebra Mussels attached to crayfish
Zebra Mussels by the thousands encrust equipment at Detroit Edison's Monroe generating station.
Zebra Mussel attached to equipment
Maintenance costs to remove Zebra Mussels from structures (like the gear pictured here) exceeded $17 million in 1995.
Zebra Mussel clogging pipe
Planktonic larvae allow Zebra Mussels to spread quickly and to settle in small places. They have clogged a three foot diameter pipe in less than three months.
The Zebra Mussel was introduced into the Great Lakes in 1986 by ballast water. It has spread rapidly throughout the midwest, but not west of the Continental Divide or east of the Appalachian Mountains.
Zebra Mussel damage extent map

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo USAGov: Government Made Easy U.S. Department of the Interior | U.S. Geological Survey
Page Last Modified: Thursday, 13-Dec-2007 12:21:11 PST