Impact of aggregate-colonizing copepods on the biological carbon pump in a high-latitude fjord

Zooplankton consumption of sinking aggregates affects the quality and quantity of organic carbon exported to the deep ocean. Increasing laboratory evidence shows that small particle-associated copepods impact the flux attenuation by feeding on sinking particles, but this has not been quantified in s...

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Bibliographic Details
Published in:Limnology and Oceanography
Main Authors: Svensen, Camilla, Iversen, Morten, Norrbin, Maria Fredrika, Möller, Klas Ove, Wiedmann, Ingrid, Skardhamar, Jofrid, Barth-Jensen, Coralie Marie Christine, Kwasniewski, Slawomir, Ormanczyk, Mateusz, Dąbrowska, Anna Maria, Koski, Marja
Format: Article in Journal/Newspaper
Language:English
Published: 2024
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Online Access:https://hdl.handle.net/11250/3152690
https://doi.org/10.1002/lno.12641
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Summary:Zooplankton consumption of sinking aggregates affects the quality and quantity of organic carbon exported to the deep ocean. Increasing laboratory evidence shows that small particle-associated copepods impact the flux attenuation by feeding on sinking particles, but this has not been quantified in situ. We investigated the impact of an abundant particle-colonizing copepod, Microsetella norvegica, on the attenuation of the vertical carbon flux in a sub-Arctic fjord. This study combines field measurements of vertical carbon flux, abundance, and size-distribution of marine snow and degradation rates of fecal pellets and algal aggregates. Female M. norvegica altered their feeding behavior when exposed to aggregates, and ingestion rates were 0.20 μg C ind.−1 d−1 on marine snow and 0.11 μg C ind.−1 d−1 on intact krill fecal pellets, corresponding to 48% and 26% of the females' body carbon mass. Due to high sea surface abundance of up to ~ 50 ind. L−1, the population of M. norvegica had the potential to account for almost all the carbon removal in the upper 50 m of the water column, depending on the type of the aggregate. Our observations highlight the potential importance of abundant small-sized copepods for biogeochemical cycles through their impact on export flux and its attenuation in the twilight zone. publishedVersion