SAN JUAN, Puerto Rico (AP) — Near-record amounts of seaweed are smothering Caribbean coasts from Puerto Rico to Barbados, killing fish and other wildlife, choking tourism and releasing stinky, noxious gases.

More than 24 million tons of sargassum blanketed the Atlantic in June, shattering the all-time record, set in 2018, by 20%, according to the University of South Florida’s Optical Oceanography Lab.

And unusually large amounts of the brown algae have drifted into the Caribbean Sea.

Scientists say the possible explanations include a rise in water temperatures as a result of climate change and nitrogen-laden fertilizer and sewage nourishing the algae.