Historical occurrence of coho salmon (Oncorhynchus kisutch) in streams of the Santa Cruz Mountain region of California: response to an Endangered Species Act petition to delist coho salmon south of San Francisco Bay

Abstract

In November 2003, the National Marine Fisheries Service received a petition from Homer T. McCrary to redefine the southern extent of the Central California Coast Coho Salmon Evolutionarily Significant Unit (CCC Coho Salmon ESU) to exclude populations that spawn in coastal watersheds south of the entrance to San Francisco Bay (i.e., the Golden Gate). The petitioner’s primary premise is that the coho salmon populations inhabiting this region for the last century are the result of introductions of nonnative stocks from locations north of San Francisco. The petitioner presented four main lines of information to support his conclusion: (1) historical (pre-1905) accounts suggesting that the southern boundary of the CCC Coho Salmon ESU was at or north of San Francisco Bay, (2) information and historical accounts on stocking of nonnative coho salmon from Baker Lake, Washington, between 1906 and 1910, which the petitioner contended pre-dated any records of coho salmon occurring in streams south of San Francisco Bay; (3) archeological studies conducted in the central California coast region that had failed to detect coho salmon remains in Native American middens; and (4) assertions that the dynamic nature of the physical environment of the Santa Cruz Mountains is not conducive to persistent coho salmon populations.

Citation

Spence, Brian C.; Duffy, Walter G.; Garza, John Carlos; Harvey, Bret; Sogard, Susan M.; Weitkamp, Laurie A.; Williams, Thomas H.; Boughton, David A. 2011. Historical occurrence of coho salmon (Oncorhynchus kisutch) in streams of the Santa Cruz Mountain region of California: response to an Endangered Species Act petition to delist coho salmon south of San Francisco Bay. NOAA Technical Memorandum NMFS-SWFSC-472. 113 p.