IMIS - Marine Onderzoeksgroepen

To this end, they set out to explore the ecosystems of the continental shelf along the WAP and associated islands using National Geographic’s deep-sea cameras to capture high quality imagery of areas of the Antarctic sea floor and the associated fauna, which have been comparatively less well explored. This bi-national expedition was conducted on the Chilean Navy vessel, the OPV-83 Marinero Fuentealba, with scientists from both countries national Antarctic Institutes. In order to study the continental shelf faunal biodiversity of Antarctica , baited cameras were deployed at 20 locations along ~ 500 km of the Western Antarctic Peninsula (WAP) at depths from 90 to 797 m.
National Geographic’s deep-sea cameras were used to quantify marine life along the shelf of the WAP. These systems consist of high definition cameras (Sony Handycam FDR-AX33 4K Ultra-High Definition video with a 20.6 megapixel still image capability) in a 33-cm diameter borosilicate glass sphere that is rated to ~7,000 m depth. Viewing area per frame for the cameras is ca. 17 m2, depending on the steepness of the slope where the camera lands. Cameras were baited with ~ 1 kg of frozen sardines and deployed for ~ three hrs. Lighting at depth was achieved through a high-intensity LED array. Depth gauging was accomplished using an internal logging pressure sensor. The cameras were weighted with a 12-kg locally procured biodegradable sandbag weight with a descent rate of ~1 m s-1. At the programmed time, sandbag weights were automatically released allowing the cameras to return to the surface. A total of 20 camera deployments were conducted in January 2019 in the study area, which were aggregated in three major areas: King George/25 de Mayo Island (KG, n=5), Deception Island (DEC, n=3), and along the Western Antarctic Peninsula (WAP, n=12). Video footage was annotated for taxa present (identified to the lowest possible taxonomic level) and the maximum number of individuals of a given taxon per video frame (MaxN). Frequency of occurrence (Freq. occ. %) for each taxon observed was calculated as the percentage of incidence across all deployments. Taxa were classified as VME taxa based on CCAMLR. The substrata for each camera deployment were classified into standard geological categories consisting of mud, pebble, cobble, and boulder. Seafloor type was defined by the approximate percent cover of the two most prevalent substrata in each habitat patch. The first type was the substratum accounting for ≥ 50% of the patch, and the second most prevalent substratum accounting for an additional ≥ 30% of the patch.