Ernie Koepf and his deckhand Anna Lee bringing in a catch. The herring fishery in the Bay is really after pregnant females, whose eggs are removed and sold as a delicacy in Japan. Photo by David Sanger.

By Demian Bulwa, Chronicle Staff Writer State wildlife regulators canceled the San Francisco Bay herring fishing season for the first time Thursday, hoping to rebuild a population that has plunged dangerously low. The 4-0 vote by the state Fish and Game Commission follows a long decline in bay herring. The drop is blamed on environmental factors, not on overfishing. But John Mello, a senior biologist with the state Department of Fish and Game, said the herring population has now “reached a point where any fishing mortality inhibits the rebuilding of the stock.” Fishers are primarily interested in herring roe, which is prized as a delicacy in Japan. Herring are also an important part of the food chain, supporting birds, larger fish and marine mammals. Biologists say below-average rainfall for the past three years may have hurt the herring population, with calmer ocean conditions diminishing the upwelling of nutrients. The Cosco Busan oil spill in November 2007 may have hurt the fish as well, although studies have not been completed.

Herring season canceled via Apocadocs