What is the contribution of mussel farming to greenhouse gas emissions? A combined empirical and life cycle assessment approach

Mussel farming is an important industry for the Blue Economy. Apart from being a key food source, farmed mussels can also be a tool to combat eutrophication.

With its projected growth, it is vital for managers to have a holistic understanding of the sustainability of mussel farming. One glaring gap of knowledge is to what extent mussel farming contributes to greenhouse gas (GHG) emissions.

Present assessments do not consider methane (CH4) and nitrous oxide (N2O) fluxes to the atmosphere from mussel farms, despite the potential to impact GHG emission.

Farming activities increase the transport of organic matter to the sediments below and sediment-to-water fluxes of CH4, while bivalves are known to harbour CH4 and N2O producing bacterial symbionts. However, there is today no available quantification of how much GHGs reach the atmosphere due to mussel farming.

This project aims to address this knowledge gap to deliver a number of outcomes important from a scientific and management perspective, namely: a) High resolution quantification of CH4 and N2O sea-air fluxes from mussel farms, b) Quantification and partitioning of the sources of such emissions; c) Evaluation of the impact of these emissions on the climate footprint of the industry.

The proposed project includes collaboration with scientists from molecular and benthic ecology, and biogeochemistry that will improve our understanding of mussel farming consequences to climate change and potential mitigation measures.