Phosphorus limitation and heat stress decrease calcification in Emiliania huxleyi

Gerecht, AC; Šupraha, L; Langer, G; Henderiks, J. 2018 Phosphorus limitation and heat stress decrease calcification in Emiliania huxleyi. Biogeosciences, 15 (3). 833-845. https://doi.org/10.5194/bg-15-833-2018

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Official URL: https://doi.org/10.5194/bg-15-833-2018

Abstract/Summary

Calcifying haptophytes (coccolithophores) sequester carbon in the form of organic and inorganic cellular components (coccoliths). We examined the effect of phosphorus (P) limitation and heat stress on particulate organic and inorganic carbon (calcite) production in the coccolithophore Emiliania huxleyi. Both environmental stressors are related to rising CO2 levels and affect carbon production in marine microalgae, which in turn impacts biogeochemical cycling. Using semi-continuous cultures, we show that P limitation and heat stress decrease the calcification rate in E. huxleyi. However, using batch cultures, we show that different culturing approaches (batch versus semi-continuous) induce different physiologies. This affects the ratio of particulate inorganic (PIC) to organic carbon (POC) and complicates general predictions on the effect of P limitation on the PIC = POC ratio. We found heat stress to increase P requirements in E. huxleyi, possibly leading to lower standing stocks in a warmer ocean, especially if this is linked to lower nutrient input. In summary, the predicted rise in global temperature and resulting decrease in nutrient availability may decrease CO2 sequestration by E. huxleyi through lower overall carbon production. Additionally, the export of carbon may be diminished by a decrease in calcification and a weaker coccolith ballasting effect.

Item Type: Publication - Article
Divisions: Marine Biological Association of the UK > Mechanisms underlying biogeochemical and ecological processes > Cell and Molecular Programme
Depositing User: Barbara Bultmann
Date made live: 23 Mar 2018 13:17
Last Modified: 25 Apr 2020 09:59
URI: http://plymsea.ac.uk/id/eprint/7854

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