Especially Sockeye Salmon in the Bering Sea and Adjacent Waters from 1972 to the mid 2000s

• Main Authors: Toru Nagasawa, Tomonori Azumaya
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: horizontal distribution; CPUE trends; SST; Bering Sea; sockeye salmon; Pacific; Sockeye
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.182.9489; http://www.npafc.org/new/publications/Bulletin/Bulletin%20No.%205/NPAFC_Bull_5_001-013%28Nagasawa%29.pdf

Abstract: We present the mean CPUE distributions of five species of Pacific salmon in the Bering Sea and adjacent waters, based on long-term data from Japanese research-gillnet operations, 1972–2002. Many populations of three abundant Pacific salmon species (pink, chum, and sockeye salmon), have feeding migrations in the Bering Sea. There are two distinct patterns in the fluctuations in CPUE of major North Pacific salmon species in the Bering Sea. The CPUEs of pink and Chinook salmon increased after 1988 and remained high to 2005. The CPUEs of sockeye and chum salmon were low prior to 1977, peaked in 1980, declined until 1989, and then increased again until 2005. The trends in CPUE of sockeye and chum salmon seem to coincide with fluctuations in Bering Sea sea surface temperatures (SST) with higher densities of sockeye and chum salmon in the Bering Sea during warm periods and lower densities during cool periods, especially in sockeye. These increases and decreases in CPUE seem to coincide with the hypothesized regime shifts in 1977 and 1989. We also discuss the effects of the semidecadal fluctuations in the Bering Sea SST, and related fluctuations in sockeye salmon abundance.