Macroalgae occasionally flows into the water intakes of coastal industrial facilities, causing blockage. Therefore, we conducted a unit acreage sampling and a diving survey for macroalgae near a power plant on the coast of the Bohai Sea to investigate the dominant species and to clarify their temporal and spatial distributions. The dominant species were green algae; Enteromorpha linza, Ulva pertusa, brown algae; Sargassum thunbergia, Punctaria latifolia, and red algae Ceramium kondoi, Gelidium sp.. Green and brown algae accounted for about 80% of the total in the studied area. The Dazuizi (DZZ) area, where gravels and reefs are widely dispersed, was clarified to be the primary macroalgae habitat, with a biomass of 0.7 kg/m2 and a total weight of 837.1 t, which was about 20 times of the Jiangshidi (JSD) area. The significant increase in macroalgae began in May when the water temperature reached about 15°C and peaked around June. In July, the water temperature raised above 25°C; the macroalgae began to decline. From the GLM analysis, it was cleared that the biomass of green algae was affected remarkably by the environmental factors relative to the other algae.
