Abstract
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.
| Originalsprog | Engelsk |
|---|---|
| Tidsskrift | Current Biology |
| Vol/bind | 32 |
| Udgave nummer | 4 |
| Sider (fra-til) | 842-850.e4 |
| ISSN | 0960-9822 |
| DOI | |
| Status | Udgivet - 28. feb. 2022 |
Bibliografisk note
Funding Information:We are grateful to the crew of RV Polarstern for their support during PS124, which made this discovery possible, and the active discussion among the onboard scientific party on this unusual finding. Ulrich K?pnick is thanked for support with the ship winch operation. Simon Dreutter is thanked for his advice on OFOBS side scan processing. Axel Nordhausen, Matthias Monsees, and Henning Schroeder are thanked for their assistance with mooring design and deployment. Christian Konrad is thanked for assistance with particle size distribution analysis. We also thank Dr. Stefan Hain (AWI), Dr. Mark Belchier (British Antarctic Survey, UK), Dr. Steve Parker (National Institute of Water and Atmospheric Research Ltd [NIWA], NZL), and Andrew Stewart (Museum of New Zealand, [NZL]) for their help in confirming the species identification and their comments on the draft manuscript. The following AWI grant nos. are acknowledged for supporting the various onboard research groups working on this topic: AWI_PS124_01, AWI_PS124_02, AWI_PS124_03, AWI_PS124_04, AWI_PS124_05, AWI_PS124_06, AWI_PS124_10, AWI_PS124_11, and AWI_PS124_13. We acknowledge funding by the H2020 project INTAROS (Integrated Arctic Observation System; grant no. 727890) and the PACES (Polar Regions and Coasts in a Changing Earth System) Program of the Helmholtz Association. C.M.F. was funded via the AWI strategy fund project ?Climate change impact on ecosystem structure and the efficiency of the biological carbon pump for Antarctic diatom- and Phaeocystis-dominated phytoplankton communities (EcoPump).? The funders played no role in the content of this manuscript. A.P. L.H. L.B. E.W. and F.W. ran the OFOBS, collecting all acoustic, image, and positioning data. A.P. and L.B. characterized and quantified all nests imaged during the study. L.B. quantified egg abundances. L.H. L.B. and E.W. analyzed the OFOBS acoustic data. S.T. M.J. and H.H.H. provided the MicroCAT temperature sensor and collated the oceanographic data. H.B. and M.W. tagged the Weddell seals during COSMUS. M.W. integrated the new data with published data on seal activity in the area and analyzed it. C.M.F. and B.G. deployed the drift traps and analyzed the particle size and amphipod data. A.R. collected and analyzed the UVP5 particle data. F.K. and J.B. collected and analyzed the Chlorophyll a and primary production data. S.E.A.P.M. P.B.H. and A.P. analyzed the image and video data for fauna analysis. M.H. coordinated the benthic research program of the COSMUS expedition, in association with H.H.H, expedition leader. F.W. was group leader of the benthic imaging team and coordinated this study. A.P. prepared the manuscript with input and approval of all co-authors. The authors declare no competing interests. One or more of the authors of this paper self-identifies as a member of the LGBTQ+ community.
Funding Information:
We are grateful to the crew of RV Polarstern for their support during PS124, which made this discovery possible, and the active discussion among the onboard scientific party on this unusual finding. Ulrich Köpnick is thanked for support with the ship winch operation. Simon Dreutter is thanked for his advice on OFOBS side scan processing. Axel Nordhausen, Matthias Monsees, and Henning Schroeder are thanked for their assistance with mooring design and deployment. Christian Konrad is thanked for assistance with particle size distribution analysis. We also thank Dr. Stefan Hain (AWI), Dr. Mark Belchier (British Antarctic Survey, UK), Dr. Steve Parker (National Institute of Water and Atmospheric Research Ltd [NIWA], NZL), and Andrew Stewart (Museum of New Zealand, [NZL]) for their help in confirming the species identification and their comments on the draft manuscript. The following AWI grant nos. are acknowledged for supporting the various onboard research groups working on this topic: AWI_PS124_01 , AWI_PS124_02 , AWI_PS124_03 , AWI_PS124_04 , AWI_PS124_05 , AWI_PS124_06 , AWI_PS124_10 , AWI_PS124_11 , and AWI_PS124_13 . We acknowledge funding by the H2020 project INTAROS (Integrated Arctic Observation System; grant no. 727890 ) and the PACES (Polar Regions and Coasts in a Changing Earth System) Program of the Helmholtz Association . C.M.F. was funded via the AWI strategy fund project “Climate change impact on ecosystem structure and the efficiency of the biological carbon pump for Antarctic diatom- and Phaeocystis-dominated phytoplankton communities (EcoPump).” The funders played no role in the content of this manuscript.
Publisher Copyright:
© 2021 The Authors