Declines in nearshore rockfish recruitment and populations in the southern California Bight as measured by impingement rates in coastal electrical power generating stations

Publication Date



California, impingement, power plant, Recruitment, survey

Journal or Book Title

Fishery Bulletin


We used data from fish-impingement studies of the coastal electric generating stations of Southern California Edison Company to examine patterns of nearshore rockfish abundance in the southern California Eight. The impingement data spanned 17 years (1977-93), comprised a minimum of several surveys per month and included power plants from throughout much of the Eight. Sixteen rockfish species were taken and six (olive rockfish, Sebastes serranoides; brown rockfish, S. auriculatus; bocaccio, S. paucispinis; blue rockfish, S. mystinus; treefish, S. serriceps; and grass rockfish, S. rastrelliger) accounted for 99% of all rockfish caught. Most of these fishes were between 0 and 2 years old. Catch rates for all six of these species have dropped substantially since the inception of the survey in 1977. Catch rates peaked in the early 1980s, dropped by a factor of over 100 to a low in 1984, and have generally remained low through 1993. One species, blue rockfish, has not been taken since 1984. We compared our rockfish impingement data from one power station in King Harbor, Redondo Beach, with data from scuba transects conducted during the same period within King Harbor. The results of the two surveys strongly suggest that the catch rates of rockfishes by power plants reflect the abundance of these fishes surrounding the plants. We suggest that the reduction in the abundance of nearshore rockfishes in the southern California Eight is due to both decreased recruitment success,reflecting long-term adverse oceanographic conditions, and to overfishing







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