Dissolved and particulate nutrient dynamics in the Northern Gulf of Alaska: a productive subarctic shelf ecosystem

Abstract

The Northern Gulf of Alaska (NGA) is a biologically productive system, culturally and economically sustaining Alaska’s coastal communities, with inorganic nutrients as an important foundation of this important food web. Nonetheless, seasonal cycles, interannual variability, and nutrient chemistry all influence nutrient dynamics, creating challenges in the overall understanding of the NGA ecosystem and the resources it provides. Therefore, this work examines nutrient sources, sinks, and trends over time and location to identify and explain key nutrient dynamics within the NGA. One key process is the exchange between dissolved (potentially bioavailable) and particulate nutrients that is examined in Chapters Two and Three. In Chapter Two, the seasonal and interannual cycles of dissolved nutrients are examined, and in Chapter Three, the sources, transport, and role of particles as nutrient reservoirs are considered. Finally, in Chapter Four, the Copper River, a major source of both dissolved and particulate nutrients to the nearshore NGA, and its associated freshwater plume are discussed with respect to the transport of resources under variable wind conditions.