Influence of mussel aquaculture on benthic oxygen fluxes in a coastal upwelling system (Ria de Vigo, NW Iberia)

Oceans Sciences Meeting, 28 February-4 March 2022, virtual eventThe high primary production of the NW Iberian coastal upwelling supports high mussel production in this area. In fact, the Rias Baixas, four coastal embayments located in this region, are the largest mussel producers in Europe. The high mussel filter feeding activity results in a large production of faeces and pseudofaeces that are deposited at the benthic surface. This large loading of mussel biodeposits increases benthic remineralization. However, this type of aquaculture may be affected by climate change. Based on this, the objective of this ongoing study is to quantify the impact of intense mussel aquaculture on benthic remineralization by measuring benthic oxygen fluxes with the non-invasive Aquatic Eddy Covariance (AEC) technique. Two AEC systems were deployed concurrently below a mussel raft and in an adjacent reference location during the upwelling season (June to August, 2021). Benthic oxygen uptake under the mussel raft was approximately two times higher than at the reference location. This result emphasizes the impact mussel aquaculture can have on the oxygen dynamics and carbon cycling. Keywords: Coastal upwelling, Benthic oxygen fluxes, Aquatic Eddy Covariance, Mussel raftN