Trends in coho marine survival in relation to the regime concept

There was a synchronous and significant decrease in marine survival of coho salmon in the Strait of Georgia, Puget Sound, and off the coast from Calif ornia to Washington after 1989. This large-scale, synchronous change indica tes that trends in coho marine survivals were linked over the southern area of their distribution in the north-east Pacific, and that these linkages w ere associated with a common event. Indicators of large-scale climate chang e (the Aleutian Low Pressure Index) and of recent regional climate change ( the April flows from the Fraser River) also changed abruptly about the same time. The synchrony of trends in marine survival of aggregates of coho sto cks from three distinct marine areas and trends in climate indices implies that climate/ocean changes can have profound impacts on the population dyna mics of coho salmon. The trend towards low marine survival may persist as l ong as the trends in the climate indicators do not change.