Contribution of sea ice microbial production to Antarctic benthic communities is driven by sea ice dynamics and composition of functional guilds

TitleContribution of sea ice microbial production to Antarctic benthic communities is driven by sea ice dynamics and composition of functional guilds
Publication TypeJournal Article
Year of Publication2018
AuthorsWing S.R, Leichter J.J, Wing L.C, Stokes D., Genovese S.J, McMullin R.M, Shatova O.A
JournalGlobal Change Biology
Volume24
Pagination3642-3653
Date Published2018/08
Type of ArticleArticle
ISBN Number1354-1013
Accession NumberWOS:000437284700031
KeywordsAlgae; antarctica; Biodiversity & Conservation; climate change; delta-c-13; Environmental Sciences & Ecology; Food web; food-web; inorganic carbon; mcmurdo sound; Ocean ecosystem; Organic matter; particulate organic-matter; rock; ross sea; sea ice; stable-isotope; Trophic position; walls
Abstract

Organic matter produced by the sea ice microbial community (SIMCo) is an important link between sea ice dynamics and secondary production in near-shore food webs of Antarctica. Sea ice conditions in McMurdo Sound were quantified from time series of MODIS satellite images for Sept. 1 through Feb. 28 of 2007-2015. A predictable sea ice persistence gradient along the length of the Sound and evidence for a distinct change in sea ice dynamics in 2011 were observed. We used stable isotope analysis (delta C-13 and delta N-15) of SIMCo, suspended particulate organic matter (SPOM) and shallow water (10-20m) macroinvertebrates to reveal patterns in trophic structure of, and incorporation of organic matter from SIMCo into, benthic communities at eight sites distributed along the sea ice persistence gradient. Mass-balance analysis revealed distinct trophic architecture among communities and large fluxes of SIMCo into the near-shore food web, with the estimates ranging from 2 to 84% of organic matter derived from SIMCo for individual species. Analysis of patterns in density, and biomass of macroinvertebrate communities among sites allowed us to model net incorporation of organic matter from SIMCo, in terms of biomass per unit area (g/m(2)), into benthic communities. Here, organic matter derived from SIMCo supported 39 to 71 per cent of total biomass. Furthermore, for six species, we observed declines in contribution of SIMCo between years with persistent sea ice (2008-2009) and years with extensive sea ice breakout (2012-2015). Our data demonstrate the vital role of SIMCo in ecosystem function in Antarctica and strong linkages between sea ice dynamics and near-shore secondary productivity. These results have important implications for our understanding of how benthic communities will respond to changes in sea ice dynamics associated with climate change and highlight the important role of shallow water macroinvertebrate communities as sentinels of change for the Antarctic marine ecosystem.

DOI10.1111/gcb.14291
Short TitleGlob. Change Biol.
Student Publication: 
No
Research Topics: 
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