The appendicularian Oikopleura dioica can enhance carbon export in a high CO 2 ocean.

Autor: Taucher J; GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany., Lechtenbörger AK; GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany., Bouquet JM; Department of Biological Sciences, University of Bergen, Bergen, Norway.; Michael Sars Centre for Marine Molecular Biology, University of Bergen, Bergen, Norway., Spisla C; GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany., Boxhammer T; GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany., Minutolo F; GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany.; Institute of Carbon Cycles, Helmholtz-Centre Hereon, Geesthacht, Germany., Bach LT; Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, Australia., Lohbeck KT; Limnological Institute, University of Konstanz, Konstanz, Germany., Sswat M; GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany., Dörner I; GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany., Ismar-Rebitz SMH; GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany., Thompson EM; Department of Biological Sciences, University of Bergen, Bergen, Norway.; Michael Sars Centre for Marine Molecular Biology, University of Bergen, Bergen, Norway., Riebesell U; GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany.
Jazyk: angličtina
Zdroj: Global change biology [Glob Chang Biol] 2024 Jan; Vol. 30 (1), pp. e17020. Date of Electronic Publication: 2023 Nov 10.
DOI: 10.1111/gcb.17020
Abstrakt: Gelatinous zooplankton are increasingly recognized to play a key role in the ocean's biological carbon pump. Appendicularians, a class of pelagic tunicates, are among the most abundant gelatinous plankton in the ocean, but it is an open question how their contribution to carbon export might change in the future. Here, we conducted an experiment with large volume in situ mesocosms (~55-60 m 3 and 21 m depth) to investigate how ocean acidification (OA) extreme events affect food web structure and carbon export in a natural plankton community, particularly focusing on the keystone species Oikopleura dioica, a globally abundant appendicularian. We found a profound influence of O. dioica on vertical carbon fluxes, particularly during a short but intense bloom period in the high CO 2 treatment, during which carbon export was 42%-64% higher than under ambient conditions. This elevated flux was mostly driven by an almost twofold increase in O. dioica biomass under high CO 2 . This rapid population increase was linked to enhanced fecundity (+20%) that likely resulted from physiological benefits of low pH conditions. The resulting competitive advantage of O. dioica resulted in enhanced grazing on phytoplankton and transfer of this consumed biomass into sinking particles. Using a simple carbon flux model for O. dioica, we estimate that high CO 2 doubled the carbon flux of discarded mucous houses and fecal pellets, accounting for up to 39% of total carbon export from the ecosystem during the bloom. Considering the wide geographic distribution of O. dioica, our findings suggest that appendicularians may become an increasingly important vector of carbon export with ongoing OA.
(© 2023 The Authors. Global Change Biology published by John Wiley & Sons Ltd.)
Databáze: MEDLINE
Externí odkaz: