Green tides are harmful phenomena refering to fast growth and vast accumulated biomass of green macroalgae, which often occur in estuaries, inner bays, lagoons and on urbanized seacoasts in different scales. This kind of phenomena has increased over the past four decades all over the world. Species forming green tides are mainly Ulvaceae, especially Ulva. They often become abnormally free-floating instead of normally attached during the occurence of green tides. Our government has raise concerns about the Y...