Benthic oxygen uptake in coastal mussel farms is enhanced by organic bio-deposition and can trigger hypoxic or anoxic conditions. Despite this, previous studies have determined benthic oxygen uptake under simulated conditions using traditional flux methods, overlooking the dynamic nature of coastal regions that can affect oxygen exchanges with processes occurring on different time scales. In this study, tidal variability of benthic oxygen fluxes in a mussel farm was examined using the aquatic eddy covariance (AEC) technique. Four deployments were conducted during neap and spring tides in the Ría de Vigo (NW Spain). Two AEC systems were concurrently deployed, one on each side of a mussel raft to measure benthic oxygen fluxes during tidal ebbs and floods. During neap tides, significantly higher oxygen flux was observed during floods (mean ± SD = -64 ± 34 mmol m