Mollusca collected by Agassiz trawl from the 2016 SO-AntEco Expedition to the South Orkney Islands, Antarctica - data

Jan Steger; Katrin Linse; Yi-Ming Gan; Huw Griffiths

doi:10.15468/hza883

Mollusca collected by Agassiz trawl from the 2016 SO-AntEco Expedition to the South Orkney Islands, Antarctica - data

Citation

Steger J, Linse K, Gan Y, Griffiths H (2024). Mollusca collected by Agassiz trawl from the 2016 SO-AntEco Expedition to the South Orkney Islands, Antarctica - data. Version 1.13. British Antarctic Survey. Occurrence dataset. https://ipt.biodiversity.aq/resource?r=bas_jr15005_molluscs&v=1.13 https://doi.org/10.15468/hza883 accessed via GBIF.org on 2024-12-12.

Description

Mollusca collected by Agassiz trawl from the 2016 SO-AntEco Expedition (JR15005) to the South Orkney Islands, Antarctica - data is an occurrence type dataset published by British Antarctic Survey.

Information regarding the Mollusca in this dataset is derived from Agassiz trawl (AGT) samples collected on shelf plateau and slope off the South Orkney Islands, Antarctica, within and outside of the South Orkney Islands Southern Shelf marine protected area. Sampling was conducted in the framework of the British Antarctic Survey/SCAR “South Orkneys - State of the Antarctic Ecosystem” (SO-AntEco) project aboard RRS James Clark Ross during expedition JR15005 in Austral summer 2016. Of 78 successful AGT deployments, 44 trawls at depths ranging from 235-2194 m contained living Mollusca, totaling 2276 individuals, 67 morphospecies and 163 distributional records. Of these, 1999 individuals were Bivalvia (accounting for 15 species), 158 Gastropoda (45 species), 113 Scaphopoda (2 species), 4 Polyplacophora (3 species) and 2 Aplacophora (2 species); empty shells were also collected and recorded in the data table. Three morphospecies (1 Bivalvia and 2 Gastropoda) were collected exclusively as empty shells, thus yielding a total of 70 morphospecies represented in the dataset. All individuals were preserved in undenatured ethanol and are stored as vouchers in the collections of the British Antarctic Survey, Cambridge, United Kingdom. This dataset constitutes a valuable contribution to the knowledge of megafaunal Mollusca associated with a range of benthic habitat types in the South Orkney Islands, an exceptionally diverse region of the Southern Ocean.

This dataset is published by British Antarctic Survey (BAS) under the license CC-BY 4.0. The publication of this dataset is funded by the Belgian Science Policy Office (BELSPO, contract n°FR/36/AN1/AntaBIS) in the Framework of EU-Lifewatch as a contribution to the SCAR Antarctic biodiversity portal (biodiversity.aq). Please follow the guidelines from the SCAR Data Policy (SCAR, 2022) when using the data. If you have any questions regarding this dataset, please contact us via the contact information provided in the metadata or via data-biodiversity-aq@naturalsciences.be. Issues with the dataset can be reported at https://github.com/biodiversity-aq/data-publication/

This dataset is part of the Biodiversity, Evolution and Adaptation Project of the Environmental Change and Evolution Program of the British Antarctic Survey. Cruise report of the expedition is available at https://www.bodc.ac.uk/resources/inventories/cruise_inventory/reports/jr15005.pdf

This dataset is associated with the data paper "Mollusca collected by Agassiz trawl from the 2016 SO-AntEco (JR15005) expedition to the South Orkney Islands, Antarctica - data” (Steger et al., 2023). It contains complementary data, additional details, and supplementary information that expand upon the research presented in the referenced data paper. Researchers can use this dataset to delve deeper into the findings and conduct further analyses.

Sampling Description

Study Extent

The study area encompasses the continental shelf and slopes of the South Orkney Islands archipelago, Scotia Arc, in the Atlantic sector of the Southern Ocean. This dataset presents the species occurrences, species richness and abundances of larger-sized (mostly more than 1 cm) molluscs based on individual AGT hauls. The South Orkney Islands are situated approximately 600 km north-east of the tip of the Antarctic Peninsula and hydrographically affected by the Antarctic Circumpolar Current in the north, and the Weddell Sea Gyre in the south (Barnes et al. 2009, Meredith et al. 2011, Dickens et al. 2014). Previous biodiversity analyses have shown that the South Orkney Islands are characterized by an exceptionally high biodiversity for a polar site, most of which is contributed by marine benthic species (Barnes et al. 2009). To protect representative examples of marine ecosystems, habitats and the biodiversity in the region, CCAMLR closed all demersal finfish fisheries around the islands in 1989 and established the SOISS MPA in 2009 (CCAMLR-XXVIII paragraph 7.1; CM 91-03), the world´s first and only MPA entirely in the high seas (Brasier et al. 2018).

Sampling

Mollusca were collected using a 2 m-wide Agassiz trawl with an outer 3 cm mesh-sized and an inner 1 cm mesh-sized nets following a standardized deployment protocol (see below). Six major clusters of sampling stations were located to the south, west, north west (subdivided into two sites: “North West” and “North West Trough”), north and north east of the South Orkney Islands, as well as at Bruce Bank. Targeted sampling depths were 500, 750, 1000, 1500 and 2000 m. Furthermore, a single Agassiz trawl was taken on the shelf off Signy Island at approximately 200 m depth. If conditions permitted, three replicate AGTs were taken at the shallower stations (500, 750 and 1000 m), while at least one haul was conducted at the deeper stations (1500 and 2000 m). Swath multibeam bathymetry was used to assess seafloor topography prior to AGT deployments, and if possible (less than 1000 m depth), in situ seafloor imagery conducted at the same sites using the shallow underwater camera system (SUCS) to gather additional information on local faunal density, biomass and abundance (see also Brasier et al. 2018). Once on the bottom, the AGT was trawled for 10 min at a speed of 1 kn. Of a total of 78 successful AGT deployments during JR15005, 44 deployments (depth range: 235-2194 m) contained living molluscs and are represented as individual sampling stations in our dataset.

Quality Control

Identification of Mollusca was performed at the BAS based on external morphological characteristics using specialized literature (e.g., Dell 1990, Hain 1990, Numanami 1996, Steiner & Linse 2000, Aldea & Troncoso 2008, Engl 2012, Kantor et al. 2016) and an available reference collection. Mollusca were identified to the lowest possible taxonomic level, excluding one live-collected specimen too damaged for morphological identification. Thirty-four percent of morphospecies (24 spp.) could only be classified at the generic level or above: 2 of these morphospecies were Solenogastres, 2 morphospecies Polyplacophora, 1 morphospecies Bivalvia, and 19 morphospecies Gastropoda. Taxa not identified to species level represent distinct morphospecies and do not belong to any other species in the dataset. Further morphological and genetic studies are required to clarify the status of these taxa. In morphospecies likely to represent undescribed species, DNA has been extracted for future COI sequence analysis. Three of the 70 morphospecies (Cuspidaria tenella, Torellia sp. 1, and Falsilunatia cf. scotiana) were collected only as empty shells. The classification and accepted nomenclature were matched against the World Register of Marine Species (WoRMS Editorial Board 2018). Coordinates were plotted on map to verify the actual geographical location corresponds to its locality. Event dates were converted into ISO 8601 and verified with the field reports.

Method steps

Benthic sampling with a 2 m-wide Agassiz trawl in the South Orkney Islands.
On board, the catch was hand-sorted into different higher taxa, with Mollusca segregated mostly to class level. Their wet mass was assessed and the animals subsequently fixed in 96 % ethanol.
Taxonomic identifications of the molluscan specimens were performed at the British Antarctic Survey (Cambridge, UK), based on morphological characters and with the aid of a stereomicroscope.
Of species potentially new to science, DNA was extracted for future molecular analysis.

Taxonomic Coverages

Animalia
rank: kingdom
Mollusca
rank: phylum
Bivalvia
rank: class
Gastropoda
rank: class
Polyplacophora
rank: class
Scaphopoda
rank: class
Solenogastres
rank: class

Geographic Coverages

South Orkney Islands

Bibliographic Citations

Aldea, C. & Troncoso, J.S. (2008): Systematics and distribution of shelled molluscs (Gastropoda, Bivalvia and Scaphopoda) from the South Shetland Islands to the Bellingshausen Sea, West Antarctica. Iberus 26(2): 43-117. -
Barnes, D.K.A., Kaiser, S., Griffiths, H.J. & Linse, K. (2009): Marine, intertidal, freshwater and terrestrial biodiversity of an isolated polar archipelago. Journal of Biogeography 36(4): 756-769. -
Brasier, M.J., Grant, S.M., Trathan, P.N., Allcock, L., Ashford, O., Blagbrough, H., Brandt, A., Danis, B., Downey, R., Eléaume, M.P., Enderlein, P., Ghiglione, C., Hogg, O., Linse, K., Mackenzie, M., Moreau, C., Robinson, L.F., Rodriguez, E., Spiridonov, V., Tate, A., Taylor, M., Waller, C., Wiklund, H. & Griffiths, H.J. (2018): Benthic biodiversity in the South Orkney Islands Southern Shelf Marine Protected Area. Biodiversity: 1-15. -
Dell, R.K. (1990): Antarctic Mollusca. With special reference to the fauna of the Ross Sea. Royal Society of New Zealand, Bulletin 27, Wellington, New Zealand. 311 pp. -
Dickens, W.A., Graham, A.G.C., Smith, J.A., Dowdeswell, J.A., Larter, R.D., Hillenbrand, C.D., Trathan, P.N., Arndt, J.E. & Kuhn, G. (2014): A new bathymetric compilation for the South Orkney Islands region, Antarctic Peninsula (49°–39°W to 64°–59°S): Insights into the glacial development of the continental shelf. Geochemistry, Geophysics, Geosystems 15(6): 2494-2514. -
Engl, W. (2012): Shells of Antarctica. Conchbooks, Hackenheim, Germany. 402 pp. -
Hain, S. (1990): Die beschalten benthischen Mollusken (Gastropoda und Bivalvia) des Weddellmeeres, Antarktis [The benthic seashells (Gastropoda and Bivalvia) of the Weddell Sea, Antarctica]. Berichte zur Polarforschung 70: 1-181. -
Kantor, Y.I., Harasewych, M.G. & Puillandre, N. (2016): A critical review of Antarctic Conoidea (Neogastropoda). Molluscan Research 36(3): 153-206. -
Meredith, M.P., Nicholls, K.W., Renfrew, I.A., Boehme, L., Biuw, M. & Fedak, M. (2011): Seasonal evolution of the upper-ocean adjacent to the South Orkney Islands, Southern Ocean: Results from a “lazy biological mooring”. Deep Sea Research Part II: Topical Studies in Oceanography 58(13): 1569-1579. -
Numanami, H. (1996): Taxonomic Study on Antarctic Gastropods Collected by Japanese Antarctic Research Expeditions. Memoirs of National Institute of Polar Research, Series E (Biology and Medical Science) 39: 1-244. -
Steiner, G. & Linse, K. (2000): Systematics and Distribution of the Scaphopoda (Mollusca) in the Beagle Channel (Chile). Mitteilungen aus dem Hamburgischen Zoologischen Museum und Institut 97: 13-30. -
WoRMS Editorial Board (2018): World Register of Marine Species. Available from http://www.marinespecies.org at VLIZ. - doi:10.14284/170
The Scientific Committee on Antarctic Research. (2023). SCAR Report 42 - September 2022 - SCAR Data Policy (2022). Zenodo. - https://doi.org/10.5281/zenodo.7825314
Steger J, Linse K, Gan Y-M, Griffiths HJ (2023) Mollusca collected by Agassiz trawl from the 2016 SO-AntEco (JR15005) expedition to the South Orkney Islands, Antarctica - data. Biodiversity Data Journal 11: e105888. - https://doi.org/10.3897/BDJ.11.e105888

Contacts

Jan Steger
originator
University of Vienna
AT
userId: https://orcid.org/0000-0001-7021-810X

Katrin Linse
originator
British Antarctic Survey
GB
userId: https://orcid.org/0000-0003-3477-3047

Yi-Ming Gan
originator
Royal Belgian Institute of Natural Sciences
BE
email: data-biodiversity-aq@naturalsciences.be
userId: https://orcid.org/0000-0001-7087-2646

Huw Griffiths
originator
British Antarctic Survey
GB
email: hjg@bas.ac.uk
userId: https://orcid.org/0000-0003-1764-223X

Huw Griffiths
metadata author
British Antarctic Survey
GB
email: hjg@bas.ac.uk
userId: https://orcid.org/0000-0003-1764-223X

Yi-Ming Gan
metadata author
Royal Belgian Institute of Natural Sciences
BE
email: data-biodiversity-aq@naturalsciences.be
userId: https://orcid.org/0000-0001-7087-2646

Huw Griffiths
administrative point of contact
British Antarctic Survey
GB
email: hjg@bas.ac.uk
userId: https://orcid.org/0000-0003-1764-223X

Yi-Ming Gan
administrative point of contact
Royal Belgian Institute of Natural Sciences
BE
email: data-biodiversity-aq@naturalsciences.be
userId: https://orcid.org/0000-0001-7087-2646