Microplastics in biota and surface seawater from tropical aquaculture area in Hainan, China

•First report on microplastics pollution in aquaculture area in Hainan, South China.•Microplastics were widely distributed and mostly in the form of foam.•The gastrointestinal tract has more microplastics than the gills in many fish species.•There is a high correlation between microplastic types of biota and surface seawater.