Invertebrates from the ANTARXXVII Leg1 expedition to the Bransfield Strait, Antarctica - data

Study Extent

The sampling was carried out in Admiralty Bay, Maxwell Bay and Bransfield Strait.

Sampling

The amphipod trap was deployed in two different stations close to Machu Picchu base in the Admiralty Bay. About 400 grams of Chilean pickerel fish was used as bait inside the trap. Organisms caught inside the trap were placed in a bucket with cold sea water and sorted. Samples were photographed and immediately preserved and stored in a -20 °C freezer in the laboratory. About 20 amphipod individuals or pleopods were preserved in All protect Tissue reagent as well as DNA/RNA shield for later molecular analyses. A part of the amphipod individuals was also frozen for later flow cytometry and the remaining amphipods were preserved in pure ethanol (99% p.a.) and placed at -20°C for storage. Sorting and processing were done as quickly as possible to prevent degradation of nucleic acids and proteins. Samples were also labelled inside the bottle using ethanol resistant paper and outside the bottle using an ethanol proof marker. Ethanol was replaced after three days. Isaacs-Kidd midwater trawl (IKMT) has a net with a mesh size of 500 µm and was used for pelagic sampling by attaching it on the A-frame crane located at the back of the vessel. The IKMT was deployed at 175 meters and was then towed for 5 minutes. Samples were collected by detaching the cod-end from the net. Amphipods were sorted from the rest of the samples and photos were taken immediately. Organisms were also immediately placed in absolute ethanol (99% purity) afterwards. Van Veen grab sampler allows the sampling of sediments and bottom fauna. Van Veen sampler was deployed at 6 stations in Admiralty Bay and 13 stations along the Bransfield Strait and 1 station within Maxwell Bay. Sampling using the Van Veen grab took approximately 15 minutes from the time it was deployed to the time it came back onboard. In cases where the Van Veen did not close, it was re-deployed up to three trials and only until then was sampling terminated. Large specimens that were visible with the naked eye were immediately collected on board before sieving and were placed in their respective collection bottles with sea water and ice packs on the side to maintain temperature. Any sediment samples collected were sieved onboard using a hand-held kitchen sieve with 1 mm mesh size to collect organisms in the sediment. Further processing and sorting were done in the geological laboratory. To avoid DNA degradation and to keep the organisms alive, sorting was done using a tray with cold sea water with ice packs. Photos were also taken immediately, and organisms directly placed in absolute ethanol (99% purity) afterwards. Processing to storage was done as quickly and as efficiently as possible. All samples that were caught were identified and grouped to the lowest taxonomic level possible using the keys of Marine Wildlife King George Island Antarctica by Schories & Kohlberg (2016) and Rauschert & Arntz (2015). Other taxonomic keys and photographs provided by Cédric d'Udekem d'Acoz were also used for confirmation.

Quality Control

- All records were validated. - Coordinates were converted into decimal degrees and plotted on map to verify the geographical location and locality. - All scientific names were checked for typo and matched to the species information backbone of Worlds Register of Marine Species (http://marinespecies.org/) and LSID were assigned to each taxa as scientificNameID. - Event date and time were converted into ISO 8601 and verified with the field reports.

Method steps

1. - Sampling was carried out at different sites with different sampling devices (baited amphipod trap, Isaacs-Kidd midwater trawl or Van Veen grab sampler). Details of sampling methods are mentioned in the sampling description section. - Samples collected were sorted, photographed and preserved. Preservation method is indicated in the field "preparations" in data. - The quality control of the occurrence records are mentioned in the quality control section.

1. Animalia
   rank: kingdom
2. Arthropoda
   rank: phylum
3. Nemertea
   rank: phylum
4. Echinodermata
   rank: phylum
5. Annelida
   rank: phylum
6. Malacostraca
   rank: class
7. Asteroidea
   rank: class
8. Ophiuroidea
   rank: class
9. Bivalvia
   rank: class
10. Mollusca
    rank: phylum
11. Nematoda
    rank: phylum
12. Gastropoda
    rank: class
13. Ostracoda
    rank: class
14. Pilidiophora
    rank: class
15. Polychaeta
    rank: class
16. Pycnogonida
    rank: class

Bransfield Strait, Southern Ocean