Trends towards thinner and reduced sea ice cover in the Arctic may influence the deposition of sea-ice algae to the seafloor, with unknown consequences for the community composition and structure of the benthos, and for the biogeochemical cycling.
More...Trends towards thinner and reduced sea ice cover in the Arctic may influence the deposition of sea-ice algae to the seafloor, with unknown consequences for the community composition and structure of the benthos, and for the biogeochemical cycling. Within this study, the influence of changing organic matter type on faunal interactions and microbial communities were examined. The response to different diets as proxies of enriched ice algal deposits and pelagic phytoplankton blooms on the activities of three key Arctic-boreal benthic species (the bivalves Astarte crenata and Bathyarca glacialis, and the sea star Ctenodiscus crispatus) on microbial communities was examined. Animals and sediments were collected from the Barents Sea, sediment sieved and settled into aquaria (L x W x H: 20 x 20 x 35) to a depth of 15 cm with 20 cm overlying seawater. Cores were transferred to Southampton University. Five replicate cores of each animal species were allocated to one of the two food treatments. Incubations took place for 124 days after which measurements of bioturbation, bioirrigation, nutrients, lipids and microbial community composition were made. For microbial community composition, 0.25 g sediment from the uppermost 0.5 cm of sediment was subjected to DNA extraction (Qiagen DNA Power Soil kit) and 16S rRNA genes amplified using the V4 16S rRNA gene primers 515F and 806R. Sequencing was preformed on a MiSeq Personal Sequencer (Illumina) using the V2 500 reagent kit by commercial contract (NU-OMICS, Northumbria, UK).
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