Abundance and distributional patterns of benthic peracarid crustaceans from the Atlantic sector of the Southern Ocean and Weddell Sea

Di Franco, Davide; Linse, Katrin ORCID: https://orcid.org/0000-0003-3477-3047; Griffiths, Huw ORCID: https://orcid.org/0000-0003-1764-223X; Haas, Christian; Saeedi, Hanieh; Brandt, Angelika. 2020 Abundance and distributional patterns of benthic peracarid crustaceans from the Atlantic sector of the Southern Ocean and Weddell Sea. Frontiers in Marine Science, 7, 554663. 10.3389/fmars.2020.554663

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Official URL: https://www.frontiersin.org/article/10.3389/fmars....

Abstract/Summary

Climate change is influencing some environmental variables in the Southern Ocean (SO) and this will have an effect on the marine biodiversity. Peracarid crustaceans are one of the dominant and most species-rich groups of the SO benthos. To date, our knowledge on the influence of environmental variables in shaping abundance and species composition in the SO’s peracarid assemblages is limited, and with regard to ice coverage it is unknown. The aim of our study was to assess the influence of sea ice coverage, chlorophyll-a, and phytoplankton concentrations on abundance, distribution and assemblage structure of peracarids. In addition, the influence of other physical parameters on peracarid abundance was assessed, including depth, temperature, salinity, sediment type, current velocity, oxygen, iron, nitrate, silicate and phosphate. Peracarids were sampled with an epibenthic sledge (EBS) in different areas of the Atlantic sector of the SO and in the Weddell Sea. Sampling areas were characterized by different regimes of ice coverage (the ice free South Orkney Islands, the seasonally ice-covered Filchner Trough and the Eastern Antarctic Peninsula including the Prince Gustav Channel which was formerly covered by a perennial ice shelf). In total 64766 individuals of peracarids were collected and identified to order level including five orders: Amphipoda, Cumacea, Isopoda, Mysidacea, and Tanaidacea. Amphipoda was the most abundant taxon, representing 32% of the overall abundances, followed by Cumacea (31%), Isopoda (29%), Mysidacea (4%), and Tanaidacea (4%). The Filchner Trough had the highest abundance of peracarids, while the South Orkney Islands showed the lowest abundance compared to other areas. Ice coverage was the main environmental driver shaping the abundance pattern and assemblage structure of peracarids and the latter were positively correlated with ice coverage and chlorophyll-a concentration. We propose that the positive correlation between sea ice and peracarid abundances is likely due to phytoplankton blooms triggered by seasonal sea ice melting, which might increase the food availability for benthos. Variations in ice coverage extent and seasonality due to climate change would strongly influence the abundance and assemblage structure of benthic peracarids.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	10.3389/fmars.2020.554663
Additional Keywords:	The Weddell Sea, Southern Ocean, ice coverage, environmental variables, Peracarida, Crustacea, abundance, distribution pattern
Date made live:	27 Oct 2020 08:24 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/527500

Item Type:

Publication - Article

Digital Object Identifier (DOI):

10.3389/fmars.2020.554663

Additional Keywords:

The Weddell Sea, Southern Ocean, ice coverage, environmental variables, Peracarida, Crustacea, abundance, distribution pattern

Date made live:

27 Oct 2020 08:24 +0 (UTC)

URI:

https://nora.nerc.ac.uk/id/eprint/527500