Trends in Abundance and Biological Characteristics of Pink Salm< (Oncorhynchus gorbuscha) in the North Pacific Ocean

摘要

Pink salmon are the most widely distributed species of the genus Oncorhynchus. Biennial cycles in the timing of the spawning migration and catch values are characteristic of pink salmon stock dynamics. Over the long term, two periods of high levels of abundance have been observed on both the Asian and North American coasts of the Pacific Ocean. Large-scale trends in abundance vary less than regional abundances. Coincidences in trends in catch dynamics among odd-year and even-year broodlines were found for several fishery regions. The observed relationships suggest a response of both broodlines to global factors that influence pink salmon reproduction and survival. Trends in abundance are influenced by global factors that are not necessarily cyclical. The dynamics of solar activity and an increase in ocean heat content play a significant role in their cumulative effect. Current pink salmon stock abundance may be close to a historic maximum. There is reason to expect that this level will continue in the near future under the influence of increasing ocean heat content. Pink salmon biological characteristics are related to levels of stock abundance. Average size in specific regions can also be related to the structure of regional salmon stocks which consist of a variety of seasonal races and ecological groupings.