Journey to the deep sea: Do Arctic sea-ice bacteria hitchhike on ice-algal aggregates?

josephine.rapp [ at ]


In 2012 Arctic sea ice declined to a record minimum. As a consequence of the melting, large sub-ice filaments of the diatom Melosira arctica were released and sank to the seafloor, resulting in a widespread deposition of fresh ice-algal material at 4400 m water depth. Elevated rates of oxygen consumption in sediments with algal deposits indicated remineralization by bacteria and evidenced a response of the entire ecosystem down to the deep sea to elevated carbon flux rates (Boetius et al. 2013, Science 339: 1430-1432). Bacteria play essential roles in carbon and nutrient cycling not only at the seafloor but also in the sea ice and in the water column, contributing significantly to Arctic ecosystem functioning. We sampled a wide range of Arctic environments from the surface to the deep sea, in order to compare bacterial communities from sea ice, melt ponds, surface seawater, deep-sea sediment with and without algal aggregates. Structure and composition of bacterial communities showed strong environmental specificity, with distinct differences between surface and deep-sea environments. Yet, some taxa were shared between algae aggregates from the surface and the seafloor, suggesting a transport of surface-derived bacteria to the deep ocean, as a consequence of rapid sea-ice melt.

Item Type
Conference (Talk)
Primary Division
Primary Topic
Research Networks
Peer revision
Not peer-reviewed
Publication Status
Event Details
AWI PhD Days 2015, 01 Jun 2015 - 04 Jun 2015, Sylt, Germany.
Eprint ID
Cite as
Rapp, J. Z. , Fernández Méndez, M. , Bienhold, C. and Boetius, A. (2015): Journey to the deep sea: Do Arctic sea-ice bacteria hitchhike on ice-algal aggregates? , AWI PhD Days 2015, Sylt, Germany, 1 June 2015 - 4 June 2015 .


Download (17MB) | Preview
Cite this document as:


Research Platforms


Funded by

Edit Item Edit Item