SWFSC Fisheries Ecology Division Director Churchill Grimes gave a presentation to the Marine Fisheries Advisory Committee (MAFAC) convened May 12 in Monterey, CA, on the causes for the decline of the Sacramento River fall Chinook fishery on the west coast in 2008.
The presentation summarized the results of the working group convened jointly by the NMFS Southwest and Northwest Fisheries Science Centers that concluded the proximate cause for the decline of the 2004 and 2005 brood years was poor ocean conditions which failed to allow the development of the normal food chain supporting feeding, growth, and survival of out-migrating juveniles. Ultimate blame was attributed to long-standing and ongoing degradation of freshwater and estuarine habitats and the subsequent heavy reliance on hatchery production. Degradation and simplification of freshwater and estuary habitats over a century and a half of development have changed the Central Valley Chinook salmon complex from a highly diverse collection of numerous wild populations to one dominated by fall Chinook salmon from four large hatcheries.
The presentation was made to support the work of a MAFAC subcommittee to develop guidelines for declaration of fishery disaster by NMFS.
(May 19, 2009)