NPRB Proposal Summary Page

of Proposed Work (250 words or less): The Bering Sea shelf has experienced significant climatic changes over the past 30 years. During this period of intense physical variation, dramatic and unexpected changes have taken place in the southeastern Bering Sea ecosystem, including large fluctuations in jellyfish biomass. To explore to effects of climate change on jellyfish populations, we will use a 27-year time series of jellyfish catches, which extend through two major regime shifts in the Bering Sea. Preliminary analyses indicate linkages between regime shifts (as indicated by several biophysical indices) and jellyfish biomass in the southeastern Bering Sea. The proposed research will significantly expand these preliminary analyses by (1) ascertaining linkages between current flow and jellyfish distribution and abundance, (2) determining effects of variations in physical (sea ice, temperature, atmospheric variables, currents) and biological (zooplankton, forage fish) conditions on spatial patterns of jellyfish using generalized additive modeling, (3) predicting future jellyfish populations under various climate scenarios, and (4) establishing the distribution and abundance patterns of young jellyfish (ephyrae) relative to environmental conditions. Jellyfish are important predators and competitors of fish, and thus it is critical to understand how fluctuations in climate affect jellyfish population dynamics in the southeastern Bering Sea.