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'Sinking dead' - how zooplankton carcasses contribute to particulate organic carbon flux in the subantarctic Southern Ocean


Halfter, S and Cavan, EL and Butterworth, P and Swadling, KM and Boyd, PW, 'Sinking dead' - how zooplankton carcasses contribute to particulate organic carbon flux in the subantarctic Southern Ocean, Limnology and Oceanography, 67, (1) pp. 13-25. ISSN 0024-3590 (2022) [Refereed Article]

Copyright Statement

2021 The Authors. Limnology and Oceanography published by Wiley Periodicals LLC on behalf of Association for the Sciences of Limnology and Oceanography.

DOI: doi:10.1002/lno.11971


Zooplankton carcasses are an important, yet understudied, pathway of the biological gravitational pump. To understand their contribution to the downward carbon flux in the subantarctic, carcasses of the copepod Neocalanus tonsus were analyzed for carbon content, microbial remineralization rates, and sinking velocities. In addition, the sensitivity of carcass flux to varying mortality, microbial turnover, and sinking velocity rates was analyzed and compared to carbon flux measurements from sediment traps. Microbial decomposition rates (between 0.02 and 0.16 d−1) were comparable to those of marine snow, highlighting the importance of carcasses as microbial hotspots. High sinking velocities (730  182 m d−1) suggest that particulate organic carbon flux to the deep ocean is substantial. Carcass flux is sensitive to a change in sinking velocity but appears less sensitive to fluctuations in microbial decomposition rate. More research on zooplankton mortality and the factors that influence carcass sinking through the water column is needed to quantify the carcass-mediated carbon export and enable their inclusion in marine ecosystem and biogeochemical models.

Item Details

Item Type:Refereed Article
Keywords:zooplankton carcass, biological carbon pump, microbial decomposition
Research Division:Biological Sciences
Research Group:Zoology
Research Field:Invertebrate biology
Objective Division:Environmental Management
Objective Group:Management of Antarctic and Southern Ocean environments
Objective Field:Antarctic and Southern Ocean oceanic processes
UTAS Author:Halfter, S (Ms Svenja Halfter)
UTAS Author:Butterworth, P (Dr Philip Butterworth)
UTAS Author:Swadling, KM (Associate Professor Kerrie Swadling)
UTAS Author:Boyd, PW (Professor Philip Boyd)
ID Code:148529
Year Published:2022
Web of Science® Times Cited:5
Deposited By:Ecology and Biodiversity
Deposited On:2022-01-20
Last Modified:2022-10-13

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