Checklist of pioneer benthic taxa found on Autonomous Reef Monitoring Structures (ARMS) in Terra Nova Bay (Ross Sea, Antarctica)

Study Extent

This dataset provides the first temporal information on pioneer benthic communities using standardized structures such as Autonomous Reef Monitoring Structures (ARMS), never used in this area. It represents the organism sub-sampled from the structures’ plates, after immersion periods of 1, 2, 3 and 5 years, in a single location, Tethys bay (Terra Nova Bay, Ross Sea).

Sampling

Samples were collected using ARMS located at 25 metres of depth and 500 metres to “Mario Zucchelli” Research Station. Each ARMS consists of 10 PVC plates (22.5 x 22.5 x 0.5 cm) stacked one top of each other by a space of 1 cm nylon spacers at the corners of each plate, where four stainless steel bolts are threaded into, holding the entire structure together. This is then fixed on top of a large 45x35 cm PVC base plate, which allows the whole structure to be anchored to the seafloor by four stainless steel rods passing through large holes in the corners of the base plate. ARMS were deployed at sea for a different period, namely 1, 2, 3 and 5 years. These 6 structures were located in 2015 and were recovered in different years: 2 in 2016 (1 year later), 2 in 2017 (2 years later), 2 in 2018 (3 years later). In addition, one pair of ARMSs was installed in 2016 and recovered in 2021 (5 years later) and another additional pair of ARMSs was installed in 2017 and recovered in 2022 (5 years later).

Quality Control

All records were validated. Coordinates were plotted on map to verify the actual geographical location. 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 dates are compliant to ISO 8601 standard.

Method steps

1. ARMS have been recovered thanks to the help of PNRA SCUBA divers, which covered each retrieved structure with a rigid plastic crate perforated on each side and internally lined with a 100 μm nylon net, in order to avoid the escape of vagile benthic organisms.
2. The structures located in 2015 and recovered in 2016 (1 year), 2017 (2 years) and 2018 (3 years) were recovered and stored at a temperature of -20°C to be transported to Italy, where they were disassembled and processed. Each individual plate was appropriately photographed, from both sides, scraped and homogenized to form sub-samples that were subsequently stored in ethanol at -20°C. However, during the recovery of the first pair of structures (2016) and one of the second (2017), these crates malfunctioned and thus no analyses on the vagile component of the community inhabiting the ARMS could be performed. For the fifth-year structures, one pair located in 2016 and recovered in 2021 and the other pair located in 2017 and recovered in 2022, processing took place directly in Antarctica. The entire recovered structures were then covered in sterile plastic bags and preserved at -20°C until processing.
3. The samples were sorted, acquired by the Italian National Antarctic Museum (MNA, section Genoa) and directly stored in ethanol (96%) or at -20°C. to be identified later.
4. Most of the records were identified by one researcher, using original descriptions and taxonomic keys and online portal World Registry of Marine Species (WoRMS) to confirm acceptance of species names. The identification was often supported by taking pictures at the SEM photos and combining stack images of the analyzed specimens, particularly with the bryozoa phylum. For this taxon, a small portion of the colony of less than 1 cm was taken and treated with sodium hypochlorite (NaClO) for 10 minutes and washed with ethanol (EtOH) at different concentrations 70%, 90% and 100%. When identification was inconclusive, only genus or family names were assigned. The samples were deposited in the biological collection of the MNA. All data were uploaded to the GBIF portal.

N/A

1. Tubuliporidae
   rank: family
2. Celleporidae
   rank: family
3. Gymnolaemata
   rank: class
4. Odontasteridae
   rank: family
5. Bugulidae
   rank: family
6. Stenolaemata
   rank: class
7. Lichenoporidae
   rank: family
8. Beaniidae
   rank: family
9. Asteriidae
   rank: family
10. Serpulidae
    rank: family
11. Microporidae
    rank: family
12. Terebellidae
    rank: family
13. Animalia
    rank: kingdom
14. Terebellida
    rank: order
15. Sabellida
    rank: order
16. Romancheinidae
    rank: family
17. Annelida
    rank: phylum
18. Polychaeta
    rank: class
19. Forcipulatida
    rank: order
20. Valvatida
    rank: order
21. Cheilostomatida
    rank: order
22. Asteroidea
    rank: class
23. Cyclostomatida
    rank: order
24. Bryozoa
    rank: phylum
25. Echinodermata
    rank: phylum

Autonomous Reef Monitoring Structures are located at 500 m to the Italian research base "Mario Zucchelli" (Terra Nova Bay, Ross Sea), in Tethys Bay, at a 25 m of depth.