Spatial distribution of benthic macrofauna in the Central Arctic Ocean

Area of Science:

• Marine Biology
• Arctic Oceanography
• Deep-Sea Ecology

Background:

• Arctic abyssal plains have lower macrobenthos biomass and density than continental slopes due to sea-ice cover and low primary productivity.
• Knowledge gaps exist regarding bathymetric and regional influences on macrobenthos diversity in Arctic basins.

Purpose of the Study:

• To synthesize macrobenthos data for a baseline assessment of Arctic macrofauna community composition.
• To investigate bathymetric and regional effects on macrobenthos diversity in Arctic basins.

Main Methods:

• Quantitative analysis of species composition, abundance, and biomass from samples collected between 1993 and 2015.
• Data synthesized from 37 stations across the Barents and Laptev Seas slopes and Nansen and Amundsen Basins abyssal plains.
• Clustering of benthic communities into five distinct depth ranges.

Main Results:

• A parabolic pattern of macrofauna species diversity was observed, with a peak at the shelf edge (100-300 m).
• This diversity pattern deviates from the mid-slope peak typical of temperate oceans.
• The polychaete Ymerana pteropoda and bryozoan Nolella sp. were identified for the first time in the deep Nansen and Amundsen Basins.

Conclusions:

• The study provides a baseline for future research on Arctic change impacts on benthic communities.
• Limited standardized data restricts the assessment of recent sea-ice loss effects on macrofauna.
• Arctic macrobenthos exhibit unique depth-related diversity patterns compared to other ocean regions.