International Pacific Halibut Commission

About: International Pacific Halibut Commission is a other organization based out in Seattle, Washington, United States. It is known for research contribution in the topics: Halibut & Hippoglossus stenolepis. The organization has 62 authors who have published 112 publications receiving 7403 citations. The organization is also known as: International Fisheries Commission.

The Pacific Decadal Oscillation

Abstract: The Pacific Decadal Oscillation (PDO) has been described by some as a long-lived El Nino-like pattern of Pacific climate variability, and by others as a blend of two sometimes independent modes having distinct spatial and temporal characteristics of North Pacific sea surface temperature (SST) variability. A growing body of evidence highlights a strong tendency for PDO impacts in the Southern Hemisphere, with important surface climate anomalies over the mid-latitude South Pacific Ocean, Australia and South America. Several independent studies find evidence for just two full PDO cycles in the past century: “cool” PDO regimes prevailed from 1890–1924 and again from 1947–1976, while “warm” PDO regimes dominated from 1925–1946 and from 1977 through (at least) the mid-1990's. Interdecadal changes in Pacific climate have widespread impacts on natural systems, including water resources in the Americas and many marine fisheries in the North Pacific. Tree-ring and Pacific coral based climate reconstructions suggest that PDO variations—at a range of varying time scales—can be traced back to at least 1600, although there are important differences between different proxy reconstructions. While 20th Century PDO fluctuations were most energetic in two general periodicities—one from 15-to-25 years, and the other from 50-to-70 years—the mechanisms causing PDO variability remain unclear. To date, there is little in the way of observational evidence to support a mid-latitude coupled air-sea interaction for PDO, though there are several well-understood mechanisms that promote multi-year persistence in North Pacific upper ocean temperature anomalies.

Effects of interdecadal climate variability on the oceanic ecosystems of the NE Pacific

Abstract: A major reorganization of the North-east Pacific biotatranspired following a climatic ‘regime shift’ in the mid1970s. In this paper, we characterize the effects ofinterdecadal climate forcing on the oceanic ecosys-tems of the NE Pacific Ocean. We consider the con-cept of scale in terms of both time and space withinthe North Pacific ecosystem and develop a conceptualmodel to illustrate how climate variability is linked toecosystem change. Next we describe a number of re-cent studies relating climate to marine ecosystem dy-namics in the NE Pacific Ocean. These studies havefocused on most major components of marine ecosys-tems – primary and secondary producers, forage spe-cies, and several levels of predators. They have beenundertaken at different time and space scales. How-ever, taken together, they reveal a more coherentpicture of how decadal-scale climate forcing may affectthe large oceanic ecosystems of the NE Pacific. Finally,we synthesize the insight gained from interpretingthese studies. Several general conclusions can bedrawn.1 There are large-scale, low-frequency, and some-times very rapid changes in the distribution of atmo-spheric pressure over the North Pacific which are, inturn, reflected in ocean properties and circulation.2 Oceanic ecosystems respond on similar time andspace scales to variations in physical conditions.3 Linkages between the atmosphere/ocean physicsand biological responses are often different across timeand space scales.4 While the cases presented here demonstrateoceanic ecosystem response to climate forcing, theyprovide only hints of the mechanisms of interaction.5 A model whereby ecosystem response to specifiedclimate variation can be successfully predicted will bedifficult to achieve because of scale mismatches andnonlinearities in the atmosphere–ocean–biospheresystem.INTRODUCTIONIn this paper, we characterize the effects of interde-cadal climate forcing on the oceanic ecosystems of theNE Pacific Ocean. Our approach is first to reflect on anumber of recent studies relating climate to marineecosystem dynamics. These studies have focused onmost major components of marine ecosystems – pri-mary and secondary producers; primary, secondary andtop-level predators. They have been undertaken atdifferent time and space scales. However, taken to-gether they begin to reveal a more coherent picture ofhow decadal-scale climate forcing may affect the largeoceanic ecosystems of the NE Pacific. We then syn-thesize the insight gained from these studies with whatwe know about atmospheric and oceanic physics andhow they affect these marine ecosystems.Of particular importance to this paper is the con-cept of scale. Ricklefs (1990) defines scale as thecharacteristic distance or time associated with varia-tion in natural systems. He goes on to make threeimportant points about why the concept of scale is soimportant to developing an understanding of ecosys-tem structure and dynamics.Every process and pattern has a temporal andspatial extent.

Climate Variability, Fish, and Fisheries

Abstract: Fish population variability and fisheries activities are closely linked to weather and climate dynamics. While weather at sea directly affects fishing, environmental variability determines the distribution, migration, and abundance of fish. Fishery science grew up during the last century by integrating knowledge from oceanography, fish biology, marine ecology, and fish population dynamics, largely focused on the great Northern Hemisphere fisheries. During this period, understanding and explaining interannual fish recruitment variability became a major focus for fisheries oceanographers. Yet, the close link between climate and fisheries is best illustrated by the effect of “unexpected” events—that is, nonseasonal, and sometimes catastrophic—on fish exploitation, such as those associated with the El Nino–Southern Oscillation (ENSO). The observation that fish populations fluctuate at decadal time scales and show patterns of synchrony while being geographically separated drew attention to oceanograph...

Inverse Production Regimes: Alaska and West Coast Pacific Salmon

Abstract: A principal component analysis reveals that Pacific salmon catches in Alaska have varied inversely with catches from the U.S. West Coast during the past 70 years. If variations in catch reflect variations in salmon production, then results of our analysis suggest that the spatial and temporal characteristics of this “inverse” catch/production pattern are related to climate forcing associated with the Pacific Decadal Oscillation, a recurring pattern of pan-Pacific atmosphere-ocean variability. Temporally, both the physical and biological variability are best characterized as alternating 20-to 30-year-long regimes punctuated by abrupt reversals. From 1977 to the early 1990s, ocean conditions have generally favored Alaska stocks and disfavored West Coast stocks. Unfavorable ocean conditions are likely confounding recent management efforts focused on increasing West Coast Pacific salmon production. Recovery of at-risk (threatened and endangered) stocks may await the next reversal of the Pacific Decad...