Collaborative Research: Linking sea-ice retreat to plankton community structure and function in the Bering Sea: Data synthesis, biophysical modeling, and multi-decadal projection

University Of Rhode Island, Kingston RI

Investigators

Abstract

Funds are provided to use the diverse and comprehensive dataset collected during the BEST/BSIERP field program of 2007-2010 to carefully structure and parameterize a new, system- and life-stage specific biophysical model. The PIs? approach differs from traditional NPZ type ecosystem modeling because of the inclusion of life-stage specific zooplankton components and will permit them to better understand the impact of the changing environment on plankton phenologies and on carbon cycling. They will focus on spring conditions, when sea ice is present or retreating, to understand the linkages and functional relationships between different components of the plankton ecosystem and to understand the interaction of zooplankton life histories with the timing and extent of sea ice and stratification of the water column. Syntheses of biological rate processes measured at sparsely distributed process stations with standing stocks and physical and chemical data from the broadly distributed survey stations will identify which components and processes are most important in controlling the structure and function of the system and will independently derive a data-based mechanistic synthesis against which the model's internal pathways can be tested. They will use model-based scenario testing to examine how projected future change in environmental conditions, especially sea ice, may impact planktonic ecosystem structure and function, and to identify the key trophic and physiological mechanisms to which this ecosystem response is most sensitive. The timing and extent of sea ice cover in the eastern Bering Sea influence the timing of plankton production, the composition and abundance of the zooplankton, and ultimately the availability of food for upper trophic levels including commercially important fish species such as pollock. The PIs propose to gain a greater understanding of the potential impact of ongoing climate change on this planktonic ecosystem. Specifically, they ask: How will climate change, and the anticipated earlier retreat in seasonal sea ice, warmer water temperatures, and reduced sea ice extent alter the structure and function of the planktonic food web during spring, and thus the ultimate fate of algal production in the Bering Sea, the utilization and cycling of carbon, and the production and availability of zooplankton as prey for upper trophic levels, including commercially important fish species?