A pioneer morphological and genetic study of the intertidal fauna of the Gerlache Strait (Antarctic Peninsula)

19 pages, 3 figures, 2 tables, supplementary information https://doi.org/10.1007/s10661-023-11066-3.-- Data availability: All genetic data, as well as photographs of voucher specimens, can be publicly accessed and downloaded on boldsystems.org, under the “INTGS” project (Intertidal fauna from the Gerlache Strait). Occurrence data can be found on the Global Biodiversity Information Facility (GBIF, B121 dataset) using the following link: https://doi.org/10.15468/56bv6z. Additional data, tables and figures are also provided as Supplementary materials. The specimens used in this study are hosted at the Université Libre de Bruxelles (ULB, Brussels, Belgium) – Laboratoire de Biologie Marine

The underexplored intertidal ecosystems of Antarctica are facing rapid changes in important environmental factors. Associated with temperature increase, reduction in coastal ice will soon expose new ice-free areas that will be colonized by local or distant biota. To enable detection of future changes in faunal composition, a biodiversity baseline is urgently required. Here, we evaluated intertidal faunal diversity at 13 locations around the Gerlache Strait (western Antarctic Peninsula), using a combination of a quadrat approach, morphological identification and genetic characterization. Our data highlight a community structure comprising four generally distributed and highly abundant species (the flatworm Obrimoposthia wandeli, the bivalve Kidderia subquadrata, and the gastropods Laevilitorina umbilicata and Laevilitorina caliginosa) as well as 79 rarer and less widely encountered species. The most abundant species thrive in the intertidal zone due to their ability to either survive overwinter in situ or to rapidly colonize this zone when conditions allow. In addition, we confirmed the presence of multiple trophic levels at nearly all locations, suggesting that complex inter-specific interactions occur within these communities. Diversity indices contrasted between sampling locations (from 3 to 32 species) and multivariate approaches identified three main groups. This confirms the importance of environmental heterogeneity in shaping diversity patterns within the investigated area. Finally, we provide the first genetic and photographic baseline of the Antarctic intertidal fauna (106 sequences, 137 macrophotographs), as well as preliminary insights on the biogeography of several species. Taken together, these results provide a timely catalyst to assess the diversity and to inform studies of the potential resilience of these intertidal communities

This work was supported by the ‘Refugia and Ecosystem Tolerance in the Southern Ocean’ project (RECTO; BR/154/A1/RECTO) funded by the ‘Belgian Science Policy Office’ (BELSPO). [...] The B121 expedition was funded by the Federation Wallonia-Brussels, the Fund for Scientific Research (FNRS), the Research Foundation – Flanders (FWO), the Leopold 3 Fund for the exploration and conservation of Nature and the Royal Belgian Society for Zoology. David Bauman was funded by the Belgian American Educational Foundation (BAEF) and the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 895799. Henrik Christiansen was funded by the BELSPO project COPE (B2/191/P1/COPE). Blanca Figuerola received funding from the Beatriu de Pinós program (2019-BP-00183), funded by the Secretary of Universities and Research (Government of Catalonia) and the European Union's Horizon 2020 program under the Marie Skłodowska-Curie grant agreement No. 801370. Peter Convey was supported by NERC core funding to the BAS ‘Biodiversity, Evolution and Adaptation’ Team

With the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S)

Peer reviewed