Climate change and fisheries in the northeast U.S. shelf large marine ecosystem

The northeast U.S. continental shelf ecosystem is undergoing dramatic changes in response to climate forcing. Surface water temperatures are generally warming, but Arctic influences may be moderating this trend. As a result, the seasonal range in temperature is increasing and the volume of mid-temperature thermal habitats is deceasing. In addition, the "cold-pool", which provides thermal refuge for cold-water species during the summer, is constricting. These changes in temperature are affecting resource species. Approximately half the fish stocks examined are shifting poleward and/or changing depth distributions. Spawning distributions are also changing. As an example, Atlantic mackerel are shifting north and onshore as migration patterns change. From a community perspective, the fish assemblage is shifting to warmer water species. Two species studied to date illustrate a differential effect of climate change on fisheries with forecasts of sustainable yield decreasing for Atlantic cod (a cold-water species) and increasing for Atlantic croaker (a warm-water species). These forecasts poise a dilemma for single-species management; equilibrium reference points for cold water species may become unsustainable and rebuilding plans may fail because of underlying climate related changes. Ecosystem-based management approaches can provide a framework within which climate considerations can be incorporated into assessment models and management decisions.