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Heterogeneity in the abyssal plains: A case study in the Bering Sea

Cite this dataset

Sigwart, Julia et al. (2022). Heterogeneity in the abyssal plains: A case study in the Bering Sea [Dataset]. Dryad.


The abyssal plains are vast areas without large-scale topography that occupy much of the ocean floor. Ecological research in these superficially homogenous regions benefits increasingly from non-destructive visual sampling of epifaunal organisms with imaging technology. We analysed images from ultra high-definition towed camera transects at depths around 3500 m across three stations 100–130 km apart in the Bering Sea to ask whether the density and distribution of visible epifauna indicated any substantial heterogeneity. We identified 71 different megafaunal taxa, of which 24 occurred at only one station. Measurements of the two most abundant faunal elements, the holothurian Elpidia minutissima and xenophyophores, indicated significant differences in local densities and patchy aggregations that were strikingly dissimilar among stations. One station was dominated by xenophyophores, one was relatively depauperate in both target taxa as well as other identified megafauna, and the third station was dominated by Elpidia. This is an unexpected level of variation at relatively small spatial scales (~100 km), within comparable transects in a well-mixed oceanic basin, reinforcing the emerging view that abyssal habitats contain landscape heterogeneity at similar spatial scales to terrestrial continental realms.


The dataset contains images and metadata for three deep-sea sampling stations collected via towed camera system.

This study was conducted on board the German research vessel R/V SONNE during the ‘AleutBio’ expedition (cruise SO293, July-September 2022), which aimed to systematically investigate the biodiversity, biogeography, and evolution of deep-sea fauna across all size classes in the Bering Sea and Aleutian Trench. The scientific party on board included taxonomic expertise for most major animal groups. Seafloor imaging was undertaken using the Ocean Floor Observation System (OFOS), a towed camera on-board R/V SONNE. This system is equipped with a Full-HD video camera and a 45-megapixel mirrorless camera with a resolution of 8192 x 5464 pixels (Canon EOS R5), as well as a tether-management system to maximise stability. A complementary flash set accompanies the still camera, which requires an average of 10 s to charge between shots. In addition, three laser-points arranged in a triangle and separated by 40 cm distances provide a scale, calibrated for the still camera.


Federal Ministry of Education and Research, Award: 03G0293A