[Sargassum enters the scene].

This work is written as a brief reflection that reviews the evolution of the biological phenomenon associated with the appearance of large masses of floating brown algae called sargassum, explores the social responses as well, perception in the media and in the tourism sector they derive as an impact of these upheavals. The entire Caribbean, and the area of Quintana Roo in Mexico, have experienced this kind of plant invasion, like a plague whose causes are unclear, but its effects on the beaches have caused a discredit to the landscape and therefore a discouragement to the bathers and visitors of those crystalline waters. The text presents public policy arguments and explains the causes associated with impacts of human activities that have directly or indirectly influenced this phenomenon to be a novelty and possibly a constant presence since 2011.