Trends in Abundance and Biological Characteristics of Chum Salmon

Chum salmon are the second most abundant salmon in the North Pacific Ocean. In the 1930s, chum salmon were abundant along the Russian coast and in British Columbia. The total catch of chum salmon was small from the late 1940s into the 1970s but increased in the 1980s, reaching historically high levels from the 1990s to the present. Ocean distribution of chum salmon is affected by sea surface temperature. Ocean growth and fish size at maturity decreased in the 1970s and 1980s but recovered in the 1990s and 2000s. These trends in abundance and biological characteristics correlated with ocean conditions. An international cooperative salmon survey by the North Pacific Anadromous Fish Commission may elucidate the mechanisms underlying the relationships among these trends. For conservation and sustainable use of chum salmon stocks, we should monitor the abundance and biological characteristics of chum salmon both in the ocean and in rivers. All correspondence should be addressed to M. Fukuwaka. e-mail: [email protected] Trends in Abundance and Biological Characteristics of Chum Salmon Masa-aki Fukuwaka1, Tomonori Azumaya1, Toru Nagasawa1, Alexander N. Starovoytov2, John H. Helle3, Toshihiko Saito4, and Eiichi Hasegawa4 1Hokkaido National Fisheries Research Institute, Fisheries Research Agency, 116 Katsurakoi, Kushiro, Hokkaido 085-0802, Japan 2Pacific Scientific Research Fisheries Centre (TINRO-Centre), 4 Shevchenko Alley, Vladivostok 690950, Russia 3Auke Bay Laboratory, Alaska Fisheries Science Center, NMFS, NOAA, 11305 Glacier Hwy., Juneau, AK 99801, USA 4National Salmon Resources Center, Fisheries Research Agency, 2-2 Nakanoshima, Toyohira-ku, Sapporo 062-0922, Japan