Document Type

Article

Department/Program

Virginia Institute of Marine Science

Publication Date

2014

Journal

NATURE COMMUNICATIONS

Volume

5

Abstract

Understanding the mechanisms by which climate variability affects multiple trophic levels in food webs is essential for determining ecosystem responses to climate change. Here we use over two decades of data collected by the Palmer Long Term Ecological Research program (PAL-LTER) to determine how large-scale climate and local physical forcing affect phytoplankton, zooplankton and an apex predator along the West Antarctic Peninsula (WAP). We show that positive anomalies in chlorophyll-a (chl-a) at Palmer Station, occurring every 4-6 years, are constrained by physical processes in the preceding winter/spring and a negative phase of the Southern Annular Mode (SAM). Favorable conditions for phytoplankton included increased winter ice extent and duration, reduced spring/summer winds, and increased water column stability via enhanced salinity-driven density gradients. Years of positive chl-a anomalies are associated with the initiation of a robust krill cohort the following summer, which is evident in Adelie penguin diets, thus demonstrating tight trophic coupling. Projected climate change in this region may have a significant, negative impact on phytoplankton biomass, krill recruitment and upper trophic level predators in this coastal Antarctic ecosystem.

DOI

10.1038/ncomms5318

Keywords

KRILL EUPHAUSIA-SUPERBA; SOUTHERN ANNULAR MODE; CLIMATE-CHANGE; SEA-ICE; MARINE ECOSYSTEM; VARIABILITY; PHYTOPLANKTON; DISTRIBUTIONS; OCEAN; RECRUITMENT

Creative Commons License

Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.

Share

COinS