Scientists warn of ‘regime shift’ as seaweed blooms expand worldwide

Sargassum, a seaweed-like algae, surrounds a boat in Bahia La Media Luna, near Akumal in Quintana Roo state, Mexico. File picture: Eduardo Verdugo/AP

Scientists have warned of a potential “regime shift” in the oceans, as the rapid growth of huge mats of seaweed appears to be driven by global heating and excessive enrichment of waters from farming run-off and other pollutants.

Over the past two decades, seaweed blooms have expanded by a staggering 13.4% a year in the tropical Atlantic and western Pacific, with the most dramatic increases occurring after 2008, according to researchers at the University of South Florida.