Krill faecal pellets drive hidden pulses of particulate organic carbon in the marginal ice zone

The biological carbon pump drives a flux of particulate organic carbon (POC) through the ocean and affects atmospheric levels of carbon dioxide. Short term, episodic flux events are hard to capture with current observational techniques and may thus be underrepresented in POC flux estimates. We model the potential hidden flux of POC originating from Antarctic krill, whose swarming behaviour could result in a major conduit of carbon to depth through their rapid exploitation of phytoplankton blooms and bulk egestion of rapidly sinking faecal pellets (FPs). Our model results suggest a seasonal krill FP export flux of 0.039 GT C across the Southern Ocean marginal ice zone, corresponding to 17–61% (mean 35%) of current satellite-derived export estimates for this zone. The magnitude of our conservatively estimated flux highlights the important role of large, swarming macrozooplankton in POC export and, the need to incorporate such processes more mechanistically to improve model projections.


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Authors: Belcher, Anna ORCIDORCID record for Anna Belcher, Henson, Stephanie ORCIDORCID record for Stephanie Henson, Manno, Clara ORCIDORCID record for Clara Manno, Hill, Simeon ORCIDORCID record for Simeon Hill, Atkinson, A, Thorpe, Sally ORCIDORCID record for Sally Thorpe, Fretwell, Peter ORCIDORCID record for Peter Fretwell, Ireland, Louise ORCIDORCID record for Louise Ireland, Tarling, Geraint ORCIDORCID record for Geraint Tarling

On this site: Anna Belcher, Clara Manno, Geraint Tarling, Louise Ireland, Peter Fretwell, Sally Thorpe, Simeon Hill
21 February, 2019
Nature Communications / 10
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