Biogeochemical implications of calcification and secondary production of a population of the brittle star Acrocnida brachiata in a temperate coastal ecosystem
[en] The production of organic matter and calcium carbonate by a population of the brittle star Acrocnida brachiata (Echinodermata) was calculated using demographic structure, population density, and relations between the size and the ash-free dry weight (AFDW) or the calcimass. During a two-year survey in the Bay of Seine (English Channel, France), one of the four major estuaries affecting the biogeochemical cycling of elements in the southern bight of the North Sea, benthic production of this species amounted to 40.3 g.m-2.yr-1 for AFDW and 80.0 g.m-2.yr-1 for CaCO3. Respiration, based on secondary production, was estimated to be 736 mmol CO2.m-2.yr-1. Using the molar ratio () of CO2 released to CaCO3 precipitated, this biogenic precipitation of calcium carbonate would result in an additional release of 617 mmol CO2.m-2.yr-1. The results of the present study demonstrate that marine calcification should be considered as a significant source of CO2 to seawater and thus a potential source of CO2 to the atmosphere, emphasizing the important role of the biomineralization and dissolution in the carbon budget of temperate coastal ecosystems. This additional biogenic source of CO2 could increase in the future in two ways: firstly, as a positive feedback of to the rising pCO2 and, secondly, as a positive response to the availability of nutrients due to eutrophication.
Harlay, Jérôme ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Océanographie chimique
Gentil, Franck; Station Biologique de Roscoff, UMR 7127 - Equipe Ecologie Benthique Université Pierre et Marie Curie (Paris VI), Place Georges Teissier BP 74, F-29682 Roscoff cedex (France)
Davoult, Dominique; Station Biologique de Roscoff, UMR 7127 - Equipe Ecologie Benthique Université Pierre et Marie Curie (Paris VI), Place Georges Teissier BP 74, F-29682 Roscoff cedex (France)
Language :
English
Title :
Biogeochemical implications of calcification and secondary production of a population of the brittle star Acrocnida brachiata in a temperate coastal ecosystem
Publication date :
10 May 2004
Event name :
The Ocean in a High-CO2 World - International Symposium