Collaborative Research: Effect of a Warming Climate on Arctic Shelf and Basin Calanus Populations: Implications for Pan-Arctic Ecosystem Dynamics

Copepods of the genus Calanus are the keystone pelagic species in Arctic pelagic ecosystems. Ecosystem structure in the Arctic Ocean and marginal seas is significantly influenced by Calanus population dynamics and production that in turn determines the amount of primary production available either for benthic or pelagic food webs. Calanus are an important food source for pelagic fish species such as capelin, herring, pollock, and larval cod. Therefore, it is not surprising that ecosystems that support a high biomass of these large-bodied, lipid-rich copepods also have rich fisheries (e.g. Bering and Barents Seas). Ongoing warming of the Arctic seas due to climate change will have dramatic impacts on the shelf and basin ecosystems, potentially leading to regime shifts or shifts of biogeographic boundaries of the Calanus spp. Such shifts can have dramatic impacts both to the shelf ecosystems and to the exchange of carbon between Arctic shelves and basins. Furthermore, changes in Arctic shelf ecosystem structure and function can cascade up to upper trophic levels including commercially important fish species and marine mammals that in turn can significantly impact both indigenous and world human populations.

Biological-physical coupled models and numerical experimentation will be used to explore the physical and biological factors that control Calanus population dynamics and biogeographic boundaries in the Arctic Ocean and marginal seas, and to investigate the impacts of various climate warming scenarios on the potential for Calanus mediated regime shifts in these systems. The Arctic Ocean Finite Volume Coastal Ocean Model integrated physical model system will be coupled to an individually-based Calanus model and a 4-stage Calanus concentration model. The physical model incorporates the atmosphere, ice, and ocean components of the system and establishes the environmental framework in which the Calanus population dynamics operate. The Chukchi and Barents Seas are similar in many ways yet different in others. The analyses will focus on these two shelf-seas and adjacent basins, however, the results of the analyses will be applicable to Calanus dynamics on all Arctic shelves. Data will be integrated from a wide range of physical and biological data sets, including the SBI program.