Physical oceanography during G. O. Sars cruise GS2018108 to an Arctic deep-sea sponge ground in 2018 ...

• Main Author: Hanz, Ulrike
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2021
• Subjects: Deep-sea Sponge Grounds Ecosystems of the North Atlantic SponGES; North Atlantic
• Online Access: https://dx.doi.org/10.1594/pangaea.927946; https://doi.pangaea.de/10.1594/PANGAEA.927946

Deep-sea sponge grounds are hotspots of benthic biomass and diversity. To date, very limited data exists on the range of environmental conditions in areas containing deep-sea sponge grounds and which factors are driving their distribution and sustenance. We investigated oceanographic conditions at a deep-sea sponge ground located on an Arctic Mid-Ocean Ridge seamount. Hydrodynamic measurements were performed along CTD transects and a lander was deployed within the sponge ground that recorded near-bottom physical properties as well as vertical fluxes of organic matter over an annual cycle. The data demonstrate that the sponge ground is found at water temperatures of -0.5 to 1 °C and is situated at the interface between two water masses at only 0.7° equatorward of the turning point latitude of semidiurnal lunar internal tides. Internal waves supported by vertical density stratification interact with the seamount topography and produce turbulent mixing as well as resuspension of organic matter with temporarily ...