MEPS 173:305-308 (1998)  -  doi:10.3354/meps173305

Calcium carbonate production of a dense population of the brittle star Ophiothrix fragilis (Echinodermata: Ophiuroidea): role in the carbon cycle of a temperate coastal ecosystem

A. Migné1,*, D. Davoult1,**, J.-P. Gattuso2

1Station Marine de Wimereux, Université de Lille 1, EP 1750 CNRS, BP 80, F-62930 Wimereux, France
2Observatoire Océanologique, UPRES-A 7076 CNRS-UPMC, BP 28, F-06234 Villefranche-sur-mer Cedex, France
*Present address: Laboratoire d'Hydrobiologie, Université Paris VI, 12 rue Cuvier, F-75005 Paris, France
**Addressee for correspondence. E-mail:

ABSTRACT: The production of calcium carbonate by a dense Ophiothrix fragilis population was calculated in order to investigate its role in the carbon budget of a temperate coastal ecosystem (Dover Strait, eastern English Channel). Production, calculated using monthly data of population density, demographic structure and a size/CaCO3 conversion, was 682 g CaCO3 m-2 yr-1. Assuming that the molar ratio of CO2 released to CaCO3 precipitated varied with temperature between 0.66 and 0.73, this production would result in the release of 4.8 mol CO2 m-2 yr-1. This calculation reinforces the suggestion that this coastal system is a source of CO2 to the atmosphere.

KEY WORDS: CO2 flux · CaCO3 production · Ophiuroid · Coastal ecosystem · Temperate sea

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