The Pacific Arctic Region (PAR) is experiencing major reductions in seasonal sea ice and increases in seawater temperatures. A key uncertainty is how the marine ecosystem will respond to these shifts in the timing of spring sea ice retreat or delays in fall sea ice formation. Recent observations of reduced sea ice extent and duration and seawater warming are linked to shifts in species composition and abundance, as well as northward range expansions in higher trophic predators (e.g. gray and humpback whales, and commercially harvested fish). There is also direct evidence of negative impacts on ice-dependent species such as walruses. Some distribution shifts may be driven by changes in lower trophic level productivity that directly cascade into higher trophic levels. Spatial changes in carbon production and export to the sediments\u00e2\u20ac\u201das indicated by macrofaunal community composition and biomass, changing sediment grain size, and range extensions for lower trophic levels\u00e2\u20ac\u201dare additional observations that have grown out of recent sampling efforts. An international consortium of scientists has implemented a coordinated Distributed Biological Observatory (DBO) that undertakes selected biological measurements at multiple trophic levels, simultaneously collected with hydrographic surveys and satellite observations. The DBO approach provides multiple repeat sampling each year and new, more seasonally continuous data on the status and developing trends for the PAR ecosystem. This continuing project will focus on the following research questions: (1) Will an earlier sea ice retreat and changes in seawater hydrographic properties (salinity, temperature, and nutrients) influence the composition of pelagic and benthic prey species, and how will upper trophic organisms be affected? (2) What is the impact of seasonal changes in hydrography on the lateral and vertical distribution of primary production and export production to the benthos? (3) What will be the ecosystem responses to latitudinal changes in environmental drivers and can we forecast the biological response to components of the food web through ecological modeling?<\/p>\n","protected":false},"excerpt":{"rendered":"
The Pacific Arctic Region (PAR) is experiencing major reductions in seasonal sea ice and increases in seawater temperatures. A key uncertainty is how the marine ecosystem will respond to these shifts in the timing of spring sea ice retreat or delays in fall sea ice formation. Recent observations of reduced sea ice extent and duration […]<\/p>\n","protected":false},"author":6,"featured_media":0,"template":"","meta":{"_links_to":"","_links_to_target":""},"tags":[21],"principal-investigator":[313],"funding-agency":[314],"class_list":["post-1813","research-projects","type-research-projects","status-publish","hentry","tag-past","principal-investigator-karen-frey","funding-agency-national-science-foundation"],"yoast_head":"\n