Grunion Found in San Francisco Bay

California grunion, a small silverside fish famous for its midnight mass-spawning on southern California beaches, was confirmed in incidental catches from surface trawls on Fisheries Ecology Division (FED) research cruises in the San Francisco Bay.

Six preserved specimens, captured in May 2004 and in May and June 2005 near the Golden Gate Bridge, were recently examined and confirmed as grunion (Leuresthes tenuis) by FED and UC Santa Cruz scientists. An additional 33 individuals from June 2005 were likely grunion but not preserved for verification.

Grunion are very uncommon north of Monterey Bay. Their recent appearance in the San Francisco Bay, first seen in 2001, has been noted with considerable interest by experts including Karen Martin (Pepperdine University) and Bob Lea (California Department of Fish & Game). Martin and Lea have a brief article on the subject submitted for publication in California Fish and Game. (October 2, 2006)