An integrated ecosystem approach for assessing the potential role of cultivated bivalve shells as part of the carbon trading system

• Published in: Marine ecology. Progress series (Halstenbek) 2015-01, Vol.518, p.281-287
• Main Authors: Filgueira, R., Byron, C. J., Comeau, L. A., Costa-Pierce, B., Cranford, P. J., Ferreira, J. G., Grant, J., Guyondet, T., Jansen, H. M., Landry, T., McKindsey, C. W., Petersen, J. K., Reid, G. K., Robinson, S. M. C., Smaal, A., Sonier, R., Strand, Ø., Strohmeier, T.
• Format: Article
• Language: English
• Subjects: aquaculture; AS WE SEE IT; Bivalvia; carrying-capacity; coastal embayment; culture; dynamics; farms; growth; light limitation; Marine; mussel mytilus-edulis; oyster reefs
• ISSN: 0171-8630; 1616-1599
• DOI: 10.3354/meps11048

The role of bivalve mariculture in the CO₂ cycle has been commonly evaluated as the balance between respiration, shell calcium carbonate sequestration and CO₂ release during biogenic calcification. However, this approach neglects the ecosystem implications of cultivating bivalves at high densities, e.g. the impact on phytoplankton dynamics and benthic–pelagic coupling, which can significantly contribute to the CO₂ cycle. Therefore, an ecosystem approach that accounts for the trophic interactions of bivalve aquaculture, including dissolved and particulate organic and inorganic carbon cycling, is needed to provide a rigorous assessment of the role of bivalve mariculture in the CO₂ cycle. On the other hand, the discussion about the inclusion of shells of cultured bivalves into the carbon trading system should be framed within the context of ecosystem goods and services. Humans culture bivalves with the aim of producing food, not sequestering CO₂ in their shells, therefore the main ecosystem good provided by bivalve aquaculture is meat production, and shells should be considered as by-products of this human activity. This reasoning provides justification for dividing up respired CO₂ between meat and shell when constructing a specific bivalve CO₂ budget for potential use of bivalve shells in the carbon trading system. Thus, an integrated ecosystem approach, as well as an understanding of the ecosystems goods and services of bivalve aquaculture, are 2 essential requisites for providing a reliable assessment of the role of bivalve shells in the CO₂ cycle.