Assimilation of different food sources by the antarctic krill (Euphausia superba): implications for bentho-pelagic coupling in an Antarctic Coastal ecosystem

Aquatic Sciences Meeting, Aquatic Sciences: Global And Regional Perspectives - North Meets South, 22-27 February 2015, Granada, SpainZooplankton faecal pellets are an important source of organic carbon, providing high energy pulses to the benthic realm. In shallow coastal environments, this pathway becomes very important since particles reach the bottom fast, so that faecal pellets degradation and recycling in the water column is low. However, the way in which zooplankton use and process food resources affects the biogeochemical fate of their faecal pellets and, consequently, benthic energy budgets. Potter Cove (King George Island, South Shetlands) is a small Antarctic fjord where a rich benthic fauna exists, in spite of generally low primary production; food sources sustaining the benthic production remain unclear. To better understand the link between plankton and benthos we selected the Antarctic krill, a key species in polar ecosystems, and an abundant ascidian species as key organisms to construct a simple organic matter pathway model. We tested a variety of potential food sources for krill in terms of assimilation efficiency, faecal pellets production and energetic quality to evaluate the contribution of the species to the organic carbon flux to the benthos in this Antarctic coastal ecosystemPeer Reviewe