First High‐Resolution Benthic Habitat Map From the Greenland Shelf (Disko Bay Pilot Study). Issue 11 (26th October 2021)

• Record Type: Journal Article
• Authors: Krawczyk, D. W.; Zinglersen, K. B.; Al‐Hamdani, Z.; Yesson, C.; Blicher, M. E.; Arboe, N. H.; Jensen, J. B.; Wagnholt, J. N.; Hansen, F.; Rödel, L.‐G.
• Is Part Of: Journal of geophysical research. Volume 126:Issue 11(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-10-26
• Subjects: benthic habitat -- Greenland -- mapping -- multibeam -- seafloor -- shrimp; Oceanography -- Periodicals; 551.4605
• DOI: 10.1029/2020JC017087
• Languages: English
• ISSNs: 2169-9275

Abstract

Abstract: A healthy ocean where marine habitats and ecosystems are mapped and protected is one of the UN's Sustainable Development Goals to sustainably use marine resources. Our study presents the first high‐resolution benthic habitat map from Greenland integrating analyses of multibeam bathymetry and backscatter data, and ground‐truth data including video sled, drop camera and day grab. The pilot area of 30 × 20 km is located on the continental shelf in central Disko Bay, West Greenland and all data were collected in a single, 10‐day survey. Multibeam bathymetry data were gridded to a 10 × 10 m resolution, whereas backscatter mosaic was built from a 1 × 1 m grid cell to obtain higher resolution manifestation of seafloor properties. Ground‐truth data consisted of 14 video transects, 17 drop camera deployments, and 17 sediment samples. Our results were verified with the published shallow seismic and vibrocore data from the Disko Bay region to link the geological background with the sedimentary environment. We distinguished five physical habitats in the area, based on the distribution of sediment types, water depth with general water masses and morphology. In addition, numerous gas seeps alongside pockmarks were observed in the area, as well as recent iceberg ploughmarks. The identified habitats were associated with two basic communities of benthic fauna, linked primarily to the distribution of sediments and representing hard bottom habitats (sessile fauna) and soft bottom habitats (shrimp/polychaetes). Our study is the first step toward mapping the entire seafloor of Disko Bay to provide a scientific context for the management of seafloor and marine resources. Plain Language Summary: Distribution of benthic habitats is an important element in understanding the function and services of the marine ecosystems. A well‐founded knowledge of the marine bio environment is crucial for sustainable use of marine resources and Greenland economy is highly dependent on marine resources. Our pilot study presents a pioneer benthic habitat map from glaciated shelf of central West Greenland, Disko Bay. We chose a small area of 600 km 2 in a c . 30 × 20 km box which is characterized by a complex hydrography, geodiversity and rich marine biodiversity including rare observations of Vulnerable Marine Ecosystem indicator species. This area was mapped in high‐resolution with multibeam echo sounder and ground‐truth stations using underwater imagery and physical samples. Five benthic habitats were identified based on classifying data on water depth, seafloor topography, and sediment types. These habitats were represented by two biotopes, (1) attached fauna, such as sponges, soft corals, and sea lilies and (2) shrimp with tubeworms. Our first high‐resolution benthic habitat model may have an important future application in seafloor management plans to sustainably use the oceans and marine resources in Greenland. Key Points: Central Disko Bay pilot area was mapped in high‐resolution with multibeam and ground‐truth stations Five benthic habitats were identified focusing on bathymetry, seafloor topography, and sediments Two benthic communities (sessile fauna and shrimp/polychaetes) were associated with sediment types