Integrated research in the Arctic – Ecosystem linkages and shifts in the northern Bering Sea and eastern and western Chukchi Sea

Arctic marine ecosystems are in a period of rapid change. Research in recent years has documented dramatic shifts, including an earlier ice retreat, a longer ice-free season, and the loss of multi-year ice. In the absence of physical constraints related to sea ice and cold water, barriers to exchange of marine taxa between North Pacific and Arctic marine systems have eroded. Initially, transfers were predominantly in pelagic species. More recently, groundfishes and other demersal taxa also appear to be moving north, as the intensity of warming increases temperatures throughout the water column in the shallow continental shelves of Pacific Arctic. This Special Issue volume is devoted to studies that integrate research across various components of the northern Bering Sea and Chukchi Sea marine ecosystems. The intent is to characterize and investigate these changes and their controlling processes. Research presented here integrates studies from US and Russian waters to better understand physical processes and mechanisms in the regions immediately north and south of Bering Strait. Results document shifts in the distribution and dynamics of important fish stocks. Studies here also present new methodological approaches and refinements to existing methods, including automated instrumentation and passive acoustics. These approaches are particularly relevant to sampling in this remote region. Data and analyses provide new information on ecosystem structure and linkages, including oceanographic interactions and transport, pelagic production, and benthic deposition. Results provide evidence for accelerated sea-ice decline, climate-driven shifts in the spatial distribution of marine taxa, and ecosystem transformation. These results also inform forecasts of winners and losers in a warming Arctic.