Seaweed biomass is washed ashore on beaches causing recreational problems for local inhabitants and tourists. The management of marine waste in Latvia is not well developed. Brown algae Fucus vesiculosus is one of the most abundant seaweed in Latvia. The chemical composition of brown algae Fucus vesiculosus, collected from the Gulf of Riga, was evaluated. Algae contain higher amounts of both macroelements (490 – 21500 ppm; P, K, Ca, Mg, Na, Fe, Mn) and trace elements (0.11 – 930 ppm; Zn, Cu, Cr, Pb, Sr, As, Cd, Se) than terrestrial plants. The obtained composition was used to describe the potential uses of seaweed. Food, pharmacy and bioenergy were considered as potentially the best sectors for macroalgae use. Due to high levels of heavy metals in seaweed, it is not recommended to use F. vesiculosus from Gulf of Riga as a food. The best potential use is found to be using it as biomass feed to obtain biogas.