Fisheries productivity in the northeastern Pacific Ocean over the past 2,200 years

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 anchovies1,2,3,4,5,6,7. 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 years1,2,3,4,5,6,7,8, 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. But sardines and anchovies vary out of phase with Alaskan salmon over low frequency, which differs from the pattern detected in historical records5,6. The coherent patterns observed across large regions demonstrate the strong role of climatic forcing in regulating northeastern Pacific fish stocks.