DOI: 10.5285/5927ce18-0020-451d-b904-9fd78e118976
title: Macrobenthic Mollusca from Prince Gustav Channel and Duse Bay, Eastern Antarctic Peninsula collected by epibenthic sledge in March 2018

description: In 2018 RRS James Clark Ross investigated the marine benthic biodiversity of the Prince Gustav Channel area and the macrobenthic molluscan fauna collected by epibenthic sledge (EBS) has been assessed for species richness, abundance and assemblage composition as well as for functional traits. In total 20,307 mollusc specimens assigned to 50 morphospecies and 4 classes (Solenogastres, Bivalvia, Gastropoda and Scaphopoda) were identified. Assemblage analyses across the Prince Gustav Channel area did not show apparent pattern or separation across depth, taxon or station. To set the bivalve dataset into a wider context, unpublished bivalve species richness and abundance data from EBS collected stations in the area influenced by the Weddell Gyre were added. This doi dataset provides data for 1) PGC EBS locations, 2) PGC EBS molluscan abundances, 3) PGC molluscan functional traits, 4) Weddell Gyre EBS stations (300 - 2000 m depth), 5) Weddell Gyre EBS bivalve standardised 1000 m trawl length abundances (300 - 2000 m depth). Funding was provided by NERC urgency grant NE/R012296/1 'Benthic biodiversity under Antarctic ice-shelves - baseline assessment of the seabed exposed by the 2017 calving of the Larsen-C Ice Shelf'.
description: The Prince Gustav Channel data were collected during expedition JR17003a in 2018. The EBS holds an epi-and a suprabenthic net sampler (Brenke, 2005). Each of these nets has an opening of 100x33 cm and net mesh size of 500 µm. The cod ends are equipped with net-buckets containing 300 µm mesh windows. On deployment 1.5 times cable length to water depth were laid out and then EBS was trawled for 10 minutes on the seabed at a 1 knot for deployments in 500 m to 1500 m. Once on the deck, the content of the samplers was immediately fixed in 96% undenaturated and pre-cooled (at -20 °C) ethanol. Samples were stored in a -20 °C freezer for at least 48 h to reduce degradation of DNA for subsequent genetic studies. During this time, samples were gently rolled every three to six hours. Ethanol was changed once for all sub-fractions. The haul distances were calculated based on equation (4) in Brenke (2005). For comparison between stations abundance data were standardised to 1000 m2 trawled area. In the laboratory, samples were initially sorted under a stereomicroscope to class level and, whenever possible, classified to morphospecies level. Juvenile specimens were assigned to family or genus level. Live specimen numbers were counted for abundance data and thanatocoenosis were not taken into account. For comparison between stations abundance data were standardised to 1000 m2 trawled area. PGC bivalve assemblages based on species richness and abundance data were compared with other unpublished bivalve assemblage data collected by EBS and held by K. Linse from stations within the Weddell Gyre region, collected during previous expeditions (ANDEEP II &III, EASIZ III & III, BIOPEARL I) in 300 - 2000 m depth
description: British Antarctic Survey Epi-benthic Sledge was built based on the EBS design by Brenke (2005), further details can be found at http://vocab.nerc.ac.uk/collection/L22/current/NETT0182/.
description: Standard protocols for EBS deployment were followed. Data entry of EBS deployment data was linked to vessel's USBL system.