The rise of stinky washed up sargassum seaweed in the Caribbean is a big problem for animals and tourism and is being made worse by nutrient pollution from deforested parts of the Amazon River. In the British Virgin Islands, the layer of seaweed is two meters thick. In Punta Cana, the clear water has turned brown. Barbados recently declared a national emergency and Mexico has even called in the navy to restore the beauty of tourist hub Cancun. Until this pollution stops, scientists have given the smelly Caribbean seaweed patches a name: the Great Atlantic Sargassum Belt (GASB).