Evaluating　the　distribution　and　sea-air　fluxes　of　dissolved　methane　(CH4)　in　mariculture　areas　is　important　for　understanding　how　aquaculture　contributes　to　regional　CH4　emissions　into　the　atmosphere.Seasonal　field　surveys　conducted　in　2023　were　used　to　analyze　the　temporal　and　spatial　variation　of　CH4　concentrations　in　surface　water　and　CH4　air-sea　flux　in　a　typical　aquaculture　system　in　Sansha　Bay,　Fujian　Province.The　results　showed　that　dissolved　CH4　concentrations　ranged　from　9.91　to　609.22　nmol/L,　with　corresponding　air-sea　fluxes　between　3.46　to　1　188.15　μmol/(m2·d).Temporally,　the　CH4　air-sea　fluxes　were　higher　in　summer　and　autumn　compared　to　spring　and　winter.Spatially,　CH4　concentrations　and　air-sea　fluxes　decreased　consistently　from　the　estuary　to　the　bay　mouth,　with　the　highest　values　in　the　estuarine　aquaculture　area　and　the　lowest　in　the　bay　mouth　aquaculture　area.Correlation　analysis　showed　that　aquacultural　activities　and　terrestrial　runoff　inputs　contributed　to　the　spatiotemporal　distribution　of　CH4　concentrations　within　the　bay.In　the　macroalgae　cultivation　zones,　CH4　production　and　emissions　during　farming　periods　were　significantly　lower　than　during　non-farming　periods.Additionally,　the　residual　feed　and　feces　generated　by　fish　in　cages　may　result　in　increased　CH4　emissions.Notably,　CH4　emissions　peaked　in　summer,　due　to　enhanced　aquaculture　activities　and　runoff　inputs　during　the　wet　season.Future　work　should　focus　on　investigating　CH4　air-sea　fluxes　in　mariculture　areas　to　provide　scientific　support　for　CH4　control　and　emission　reduction　in　aquaculture.　©　2024　Science　China　Press.　All　rights　reserved.