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Mon, Nov

A research vessel collects data whilst tentatively navigating the frozen Arctic seas. Credit: Alfred Wegener Institute, Sea Ice Physics Group.

Science

Life under the frozen basins of the Central Arctic is unforgiving.

Long winters, permanent sea-ice cover, and little food creates an environment with much less diversity in comparison to our temperate oceans. This extreme environment also presents challenges to scientists when collecting data, making knowledge about marine life here relatively unknown. However, an extensive new study by researchers at the Max Planck Institute for Marine Microbiology, Germany, has set out to gain a greater understanding of how the Arctic environment influences the species composition, density, and biomass of communities on the sea floor.

A total of 10,117 individual specimens were collected from 1993, 2012, and 2015 in the Amundsen and Nansen basins as well as on the slope of the Barents and Laptev seas. Each individual was weighed and counted separately, and this information was then combined with environmental data in order to understand the distribution of life under the Central Arctic.

Researchers found that sea floor communities along the slopes and basins were clustered into five separate groups according to depth. This ranged from the shallow waters of the continental shelf to the increasing depths of the continental slope and the abyssal plain more than four kilometers deep.

As seen in temperate waters, species diversity decreased with depth which is consistent with the food available for marine life as the oceans become deeper. Interestingly, a species of polychaete worm and bryozoan were recorded in the Amundsen and Nansen basins for the first time. This has led to the researchers believing that the biodiversity of the Central Arctic basins has not yet been adequately sampled.

In this remote ocean, insufficient data are available to track diversity or biomass changes over time, but the authors hope this study will provide a baseline for answering critical questions in the future about the effects of climate change on vulnerable Arctic waters.

By Ellis Moloney

Vedenin, A., Gusky, M., Gebruk, A., Kremenetskaia, A., Rybakova, E. and Boetius, A. (2018). Spatial distribution of benthic macrofauna in the Central Arctic Ocean. PLOS ONE, 13(10), p.e0200121.

Funding of this study was provided by the Alfred Wegener Institute (Polar Regions and Coasts in a Changing Earth System = PACES II program, and by the European Research Council Advanced Grant 294757)