Green algae tides degrade the marine environments in which they occur and are
a consequence of the anthropogenic nutrients input. On the main tourist beach of Gran Roque Island
(Francisco de Miranda Insular Territory, Venezuela) the excessive accumulation of macroalgae is considered
alarming, for this reason samples were taken in May 2023 to determine its specific composition. The algae
were preserved in 4% formalin and studied with a stereoscopic magnifier, using taxonomic keys for their
identification. We found a total of 22 species: 11 Rhodophyta, 10 Chlorophyta and 1 Ochrophyta. The
most dominance seaweed was Chaetomorpha linum, being the first time in Venezuela that an arrival of
this specie has been reported. The adequate management of domestic effluents, the elimination of surplus macroalgae and the monitory of seaweed accumulation constitute the appropriate strategy to control the
presence of C. linum on this island, can be used this species to detecting the marine waters qualit
