Document Type
Article
Department/Program
Virginia Institute of Marine Science
Publication Date
2013
Journal
Marine Ecology Progress Series
Volume
492
First Page
253
Last Page
272
Abstract
An inverse food-web model for the western Antarctic Peninsula (WAP) pelagic food web was constrained with data from Palmer Long Term Ecological Research (PAL-LTER) project annual austral summer sampling cruises. Model solutions were generated for 2 regions with Adélie penguin Pygoscelis adeliae colonies presenting different population trends (a northern and a southern colony) for a 12 yr period (1995−2006). Counter to the standard paradigm, comparisons of carbon flow through bacteria, microzooplankton, and krill showed that the diatom−krill−top predator food chain is not the dominant pathway for organic carbon exchanges. The food web is more complex, including significant contributions by microzooplankton and the microbial loop. Using both inverse model results and network indices, it appears that in the northern WAP the food web is dominated by the microbial food web, with a temporal trend toward its increasing importance. The dominant pathway for the southern WAP food web varies from year to year, with no detectable temporal trend toward dominance of microzooplankton versus krill. In addition, sensitivity analyses indicated that the northern colony of Adélie penguins, whose population size has been declining over the past 35 yr, appears to have sufficient krill during summer to sustain its basic metabolic needs and rear chicks, suggesting the importance of other processes in regulating the Adélie population decline
DOI
doi: 10.3354/meps10534
Keywords
Inverse model · Food web · Antarctica · Microzooplankton · Krill · Ecosystem state change · Climate change
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Recommended Citation
Sailley, Sevrine F.; Ducklow, Hugh W.; Moeller, Holly V.; Fraser, William R.; Schofield, Oscar M.; Steinberg, Deborah K.; Garzio, Lori M.; and Doney, Scott C., Carbon fluxes and pelagic ecosystem dynamics near two western Antarctic Peninsula Adélie penguin colonies: an inverse model approach (2013). Marine Ecology Progress Series, 492, 253-272.
doi: 10.3354/meps10534
