Patterns and trends of macrobenthic abundance, biomass and production in the deep Arctic Ocean

Abstract

Little is known about the distribution and dynamics of macrobenthic communities of the deep Arctic Ocean. The few previous studies report low standing stocks and confirm a gradient with declining biomass from the slopes down to the basins, as commonly reported for deep-sea benthos. In this study, we investigated regional differences of faunal abundance and biomass, and made for the first time ever estimates of deep Arctic community production by using a multi-parameter artificial neural network model. The underlying data set combines data from recent field studies with published and unpublished data from the past 20 years, to analyse the influence of water depth, geographical latitude and sea-ice concentration on Arctic benthic communities. We were able to confirm the previously described negative relationship of macrofauna standing stock with water depth in the Arctic deep sea, while also detecting substantial regional differences. Furthermore, abundance, biomass and production decreased significantly with increasing sea-ice extent (towards higher latitudes) down to values <200 ind m⁻², <65 mg C m⁻² and <73 mg C m⁻² y⁻¹, respectively. In contrast, stations under the seasonal ice zone regime showed much higher standing stock and production (up to 2500 mg C m⁻² y⁻¹), even at depths down to 3700 m. We conclude that particle flux is the key factor structuring benthic communities in the deep Arctic Ocean as it explains both the low values in the ice-covered Arctic basins and the higher values in the seasonal ice zone.

• Deep sea
• benthos
• macroinvertebrate
• carbon flux.

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Acknowledgements

The authors thank the captains, crews and shipboard parties of the RV Polarstern ARK-VIII, ARK- XIII/2, ARK-XXVII/2 and ARK-XXVII/3 cruises for help with work at sea. The authors thank Jölund Asseng (Alfred Wegener Institute) for information and help in importing sea-ice concentration data into Arc GIS and Professor Dr Ursula Schauer (Alfred Wegener Institute) for helpful information about Arctic seawater temperatures. The authors further thank Sergey Y. Gagaev, Alexey V. Golikov and Victor Petrjashev from the Zoological Institute of the Russian Academy of Sciences for the taxonomical work on ARK-XIII/2 samples. The authors also thank the anonymous reviewers for their constructive comments. This work was supported by the European Research Council ABYSS advanced grant (294757) to AB. RD and TB were supported by the POLMAR graduate programme.

Notes

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