A new study from the Christian-Albrechts-Universität zu Kiel (CAU) investigates crater-like depressions on the seabed, so-called pockmarks. Previous research has been assuming that they are caused by rising gases and liquids. However, the study published in Communications Earth & Environment proposes an alternative assumption: Instead of gases and liquids, vertebrates may be the key to explaining pockmarks. Dr. Jasper Hoffmann from the Alfred Wegener institute, Helmholtz centre for polar and marine research (AWI), was part of this project. The University of Veterinary Medicine Hannover and the Leibniz Institute for Baltic Sea Research Warnemünde were also involved.
The study by the Kiel Marine Science Center at CAU shows that the pockmarks originate from pits dug into the seabed by marine mammals in search of food. This insight was gained through a comprehensive analysis using geological surveys, geophysical sonar measurements, vertebrate behavioral and food biology, satellite interpretation, and oceanographic analyses. The project involved a team of researchers from a variety of disciplines. The findings can be used, among other things, to optimize marine environmental protection.
The study’s explanation begins with sand eels, small, long fish that burrow into the seabed. They serve as a food source for harbor porpoises. Because sand eels live in the sediment, the porpoises have to dig through the seabed in search of food. This creates pits from which the pockmarks form over time as they are scoured out.
More information:
https://www.uni-kiel.de/en/details/news/312-pits-vertebrates-seafloor
Original publication:
Schneider von Deimling, J., Hoffmann, J., Geersen, J., Koschinski, S., Lohrberg, A., Gilles, A., Belkin, I., Böttner, C., Papenmeier, S., Krastel, S.: Millions of seafloor pits, not pockmarks, induced by vertebrates in the North Sea. Commun Earth Environ (2023). DOI: 10.1038/s43247-023-01102-y