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Historical catch records suggest that climatic variability has had basin-wide effects on the northern Pacific and its fish populations, such as salmon, sardines and anchovies^,,,,,,. However, these records are too short to define the nature and frequency of patterns. We reconstructed ∼2,200-year records of sockeye salmon abundance from sediment cores obtained from salmon nursery lakes on Kodiak island, Alaska. Large shifts in abundance, which far exceed the decadal-scale variability recorded during the past 300 years^,,,,,,,, occurred over the past two millennia. A marked, multi-centennial decline in Alaskan sockeye salmon was apparent from ∼100?BC to AD 800, but salmon were consistently more abundant from AD?1200 to 1900. Over the past two millennia, the abundances of Pacific sardine and Northern anchovy off the California coast, and of Alaskan salmon, show several synchronous patterns of variability …