A Pacific Interdecadal Climate Oscillation (PDO) has been identified as a recurring pattern of ocean–atmosphere climate variability in the midlatitude North Pacific basin. This pattern has influenced salmon production in the North Pacific over the past century, with significant shifts in salmon production regimes occurring around 1925, 1947, and 1977. The PDO affects coastal sea and continental surface air temperatures, as well as streamflow in major west coast river systems from Alaska to California. Historical records show that salmon production has varied significantly, with some years experiencing record catches and others seeing dramatic declines. The PDO is characterized by interdecadal climate fluctuations, with positive and negative phases that influence marine and terrestrial ecological variables in western North America. The study analyzed climate records and biological data to highlight the connections between interdecadal climate variability and ecological changes in the North Pacific. The PDO is also linked to salmon production, with evidence suggesting that marine climate variability strongly influences many Pacific salmon populations. The study found that the PDO has a significant impact on salmon production, with positive PDO years often associated with enhanced streamflows and favorable nearshore ocean conditions for high biological productivity. The PDO's influence on salmon production has important implications for fisheries management, as it highlights the need to account for long-term climate variability when setting management goals. The study also notes that the PDO is closely related to the El Niño-Southern Oscillation (ENSO), with both showing similar spatial and temporal patterns. However, the PDO's slower, longer-term variability is more closely linked to salmon production than the faster, more frequent ENSO events. The findings suggest that the PDO will continue to influence salmon production in the North Pacific, with potential shifts in abundance every few decades. The study underscores the importance of understanding and monitoring the PDO to better manage fisheries in the region.A Pacific Interdecadal Climate Oscillation (PDO) has been identified as a recurring pattern of ocean–atmosphere climate variability in the midlatitude North Pacific basin. This pattern has influenced salmon production in the North Pacific over the past century, with significant shifts in salmon production regimes occurring around 1925, 1947, and 1977. The PDO affects coastal sea and continental surface air temperatures, as well as streamflow in major west coast river systems from Alaska to California. Historical records show that salmon production has varied significantly, with some years experiencing record catches and others seeing dramatic declines. The PDO is characterized by interdecadal climate fluctuations, with positive and negative phases that influence marine and terrestrial ecological variables in western North America. The study analyzed climate records and biological data to highlight the connections between interdecadal climate variability and ecological changes in the North Pacific. The PDO is also linked to salmon production, with evidence suggesting that marine climate variability strongly influences many Pacific salmon populations. The study found that the PDO has a significant impact on salmon production, with positive PDO years often associated with enhanced streamflows and favorable nearshore ocean conditions for high biological productivity. The PDO's influence on salmon production has important implications for fisheries management, as it highlights the need to account for long-term climate variability when setting management goals. The study also notes that the PDO is closely related to the El Niño-Southern Oscillation (ENSO), with both showing similar spatial and temporal patterns. However, the PDO's slower, longer-term variability is more closely linked to salmon production than the faster, more frequent ENSO events. The findings suggest that the PDO will continue to influence salmon production in the North Pacific, with potential shifts in abundance every few decades. The study underscores the importance of understanding and monitoring the PDO to better manage fisheries in the region.