A vast icefish breeding colony discovered in the Antarctic

• Published in: Current Biology
• Main Authors: Purser, Autun, Hehemann, Laura, Boehringer, Lilian, Tippenhauer, Sandra, Wege, Mia, Bornemann, Horst, Pineda-Metz, Santiago E.A., Flintrop, Clara M., Koch, Florian, Hellmer, Hartmut H., Burkhardt-Holm, Patricia, Janout, Markus, Werner, Ellen, Glemser, Barbara, Balaguer, Jenna, Rogge, Andreas, Holtappels, Moritz, Wenzhoefer, Frank
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2022
• Subjects: Breeding; Icefish; Southern Weddell Sea; Antarctica; Colony; Jonah's icefish (Neopagetopsis ionah); Antarctic; Arctic; Filchner Trough; Southern Ocean; The Antarctic; Weddell; Weddell Sea; Antarc*; Weddell Seals
• Online Access: http://hdl.handle.net/2263/90796; https://doi.org/10.1016/j.cub.2021.12.022

A breeding colony of notothenioid icefish (Neopagetopsis ionah, Nybelin 1947) of globally unprecedented extent has been discovered in the southern Weddell Sea, Antarctica. The colony was estimated to cover at least 240 km2 of the eastern flank of the Filchner Trough, comprised of fish nests at a density of 0.26 nests per square meter, representing an estimated total of 60 million active nests and associated fish biomass of >60,000 tonnes. The majority of nests were each occupied by 1 adult fish guarding 1,735 eggs (±433 SD). Bottom water temperatures measured across the nesting colony were up to 2 C warmer than the surrounding bottom waters, indicating a spatial correlation between the modified Warm Deep Water (mWDW) upflow onto the Weddell Shelf and the active nesting area. Historical and concurrently collected seal movement data indicate that this concentrated fish biomass may be utilized by predators such as Weddell seals (Leptonychotes weddellii, Lesson 1826). Numerous degraded fish carcasses within and near the nesting colony suggest that, in death as well as life, these fish provide input for local food webs and influence local biogeochemical processing. To our knowledge, the area surveyed harbors the most spatially expansive continuous fish breeding colony discovered to date globally at any depth, as well as an exceptionally high Antarctic seafloor biomass. This discovery provides support for the establishment of a regional marine protected area in the Southern Ocean under the Convention on the Conservation of Antarctic Marine Living Resources (CCAMLR) umbrella. AWI grants; the H2020 project INTAROS (Integrated Arctic Observation System; the PACES (Polar Regions and Coasts in a Changing Earth System) Program of the Helmholtz Association. https://www.journals.elsevier.com/current-biology am2023 Mammal Research Institute Zoology and Entomology