East Weddell Sea echinoids from the JR275 expedition

Abstract Information regarding the echinoids in this dataset is based on the Agassiz Trawl (AGT) and epibenthic sledge (EBS) samples collected during the British Antarctic Survey cruise JR275 on the RRS James Clark Ross in the austral summer 2012. A total of 56 (1 at the South Orkneys and 55 in the Eastern Weddell Sea) Agassiz Trawl and 18 (2 at the South Orkneys and 16 in the Eastern Weddell Sea) epibenthic sledge deployments were performed at depths ranging from ~280 to ~2060 m. This presents a unique collection for the Antarctic benthic biodiversity assessment of an important group of benthic invertebrates. In total 487 specimens belonging to six families, 15 genera, and 22 morphospecies were collected. The species richness per station varied between one and six. Total species richness represents 27% of the 82 echinoid species ever recorded in the Southern Ocean (David et al. 2005b, Pierrat et al. 2012, Saucède et al. 2014). The Cidaridae (sub-family Ctenocidarinae) and Schizasteridae are the two most speciose families in the dataset. They comprise seven and nine species respectively. This is illustrative of the overall pattern of echinoid diversity in the Southern Ocean where 65% of Antarctic species belong to the families Schizasteridae and Cidaridae (Pierrat et al. 2012).


Project title: JR 275 RRS James Clark Ross 2012
Personnel: Huw Griffiths, Camille Moreau, Jennifer Jackson, Chester Sands, Rachel Downey, Adam Reed, Melanie Mackenzie, Paul Geissler, Katrin Linse Funding: This study is part of the British Antarctic Survey Polar Science for Planet Earth Programme funded by the Natural Environment Research Council. Funding for T. Saucède to visit and identify material was provided by the vERSO program (Ecosystem Responses to global change: a multiscale approach in the Southern Ocean). This is contribution no. 3 to the vERSO project (www. versoproject.be), funded by the Belgian Science Policy Office (BELSPO, contract n°BR/132/A1/vERSO). This is a contribution to the SCAR (Scientific Committe on Antarctic Research) AntEco (State of the Antarctic Ecosystem) Programme.
Study extent description: The study area of this dataset was set in the Eastern Weddell Sea and focused on sampling the continental shelf, upper slope and overdeepened shelf basins of the Filchner Trough region of the Weddell Sea (Knust and Schröder 2014). This dataset presents species occurrences and species richness of the individual trawls (Agassiz Trawl and Epibenthic Sledge deployments). Our sampling regime was designed to investigate patterns of biodiversity, and once compared to other sources of material, biogeography and phylogeography in the benthos of this region of the Southern Ocean. The Filchner Trough region is an oceanographically interesting area that includes regions of cold Antarctic Bottom Water (ABW) production. One of the other characteristics of the area is the perennial sea ice cover and the presence of very large icebergs.
Design description: The South-Eastern Weddell Sea is a relatively under sampled area on the Antarctic continental shelf, according to a recent gap analysis carried out by Griffiths et al. (2011). EvolHist (Evolutionary History of the Polar Regions), a core project at the British Antarctic Survey, studied the South-Eastern Weddell Sea to assess the biodiversity at local and regional scales (comparable to the BIO-PEARL 2006 cruise to the Scotia Sea and the BIOPEARL II 2008 cruise to the Bellingshausen and Amundsen Seas) and investigate the phylogenetic relationships of selected marine invertebrate taxa and their biogeography in reference to the climatological, oceanographical and geological history of the Weddell Sea. The results are used to determine of the role of Antarctica and extreme environments in general in evolutionary innovation and generation of global biodiversity. The species presence data are added to SOMBASE (South-ern Ocean Mollusc Database www.antarctica. ac.uk/sombase). SOMBASE generated a significant portion of the initial core data system upon which SCAR's Antarctic Biodiversity Information Facility (AntaBIF, www.biodiversity.aq) was built. As AntaBIF (and its predecessor, SCAR-MarBIN) is the Antarctic Node of the international OBIS and GBIF networks, the SOMBASE data system was designed to comply with the Darwin Core standards. Regarding the dataset, the existing Data Toolkit from AntaBIF was used (http://ipt.biodiversity.aq/), following the OBIS schema (http://iobis.org/data/schema-and-metadata). The data-set was up-loaded in the ANTOBIS (Antarctic Ocean Biogeographic Information System) database (the geospatial component of SCAR-MarBIN), and the taxonomy was matched against the Register of Antarctic Marine Species, using the Taxon Match tool (http://www.scarmarbin.be/rams.php?p=match). The dataset meets the Darwin Core requirements and was designed around this data schema.
Sampling description: A single test location off the South Orkney Islands and a further six locations in the Eastern Weddell Sea at different depths ranging from 279 to 2058m have been sampled using an Agassiz Trawl (AGT) and an epibenthic sledge (EBS). Most of the Weddell Sea deployments were made along two transects, one running from south to north along the edge of the Filchner Trough and one running from west to east out of the Filchner Trough onto the shallower shelf. Two further localities in overdeepened basins close to the Brunt Ice shelf were sampled ( Figure 1, Stations 33-40). At each site, three replicate Agassiz trawls (individual stations) were taken and where the substrate was suitable (not too rocky) a single EBS deployment was conducted. The JR275 cruise report is available from the British Oceanographic Data Centre (www.bodc.ac.uk/data/ information_and_inventories/cruise_inventory/report/10598).
The AGT had an inner mesh size of 1 cm and a mouth width of 2 m. The EBS consisted of an epi-(below) and a supra-(above) net. Each of these nets has a mesh size of 500µm and an opening of 100×33cm. The cod end of both nets is equipped with net-buckets containing a 300µm mesh window (Brenke 2005). The AGT and EBS were trawled for 10 minutes (depending on depth, seabed type and the condition of the animals in the initial trawl) on the sea bed at a 1 knot speed. Following Brenke (2005), since the EBS epi-and supra-nets collect the same fauna, they were pooled and treated as a single sample.
Quality control description: A species name was given to each specimen when it was possible. Identifications and taxonomic accuracies are based on David et al. (2005aDavid et al. ( , 2005b, Pierrat et al. (2012), and Saucède et al. (2014). When identification was inconclusive, e.g. for small specimens at very early stages of development, only family or genus names were assigned. These specimens were referred to as gen. sp. or genus name sp. respectively and might belong to one of the species listed in the dataset (Table 2). Specimens referred to as Abatus sp. 1 belong to none of the species listed in the dataset. The specimen referred to in the dataset as Amphipneustes aff. similis is very similar in morphology to A. similis but it presents distinctive morphological characters that are not diagnostic of the aforementioned species. While included in this dataset as Amphipneustes aff. similis it is likely that this will be described as a new species after further morphological and genetic analyses.
This dataset presents species occurrences and species richness of the individual AGT and EBS deployments.

Method step description:
-Agassiz trawl sampling in the Weddell Sea -Once on board, the samples were photographed as total catch and then handsorted into groups varying from Phylum to species level collections. Representatives of many taxa were photographed in detail. The wet-mass (biomass) of the different taxa was assessed by using calibrated scales (with accuracy and resolution of 0.001 kg). Samples were fixed in 96% undenatured and precooled (at -20°C) ethanol (Linse 2008) and kept for a minimum of 48 hours in a -20°C freezer, with rotation of containers to ensure full preservation of material. -Epibenthic sledge sampling in the Weddell Sea -Once on the deck, the content of the samplers from the first deployment was immediately fixed in 96% undenatured and precooled (at -20°C) ethanol and kept for a minimum of 48 hours in a -20°C freezer. - The taxonomic identification was performed in the British Antarctic Survey laboratory using a stereomicroscope.