May 02, 2016

An 'Impossible' Coral Reef System Discovered at Amazon River Mouth



Sometimes science is a treasure hunt, and the only clues you have to guide you are a hand-drawn map and a brief, 40-year-old scientific paper that suggests something amazing might be found somewhere under the ocean. And then you go look, and you actually find that something amazing.

A recent paper published in the journal Science Advances describes the discovery of a 600-mile-long (966-kilometer-long) coral reef system in the Atlantic Ocean, under the muddy plume of the Amazon River. It was overlooked for so long because corals reefs are generally known for preferring shallow, clear water, and conditions at the mouth of the Amazon have more commonly been described as "turbid" or even "goopy."

"You don't really look for things unless you think it's possible they could be there," says oceanographer Patricia Yager of the University of Georgia, one of the principal investigators on the study.

In 2012, Yager and her research team received funding to go to the mouth of the Amazon to study how the nutrient-rich plume of the world's largest river affects the ocean. In order to study the plume, she had to get permission from the Brazilian Navy, who required that she bring on several Brazilian scientists as collaborators. One of these was a reef ecologist named Rodrigo Moura, from the Federal University of Rio de Janeiro.

"At the planning meeting for this cruise we were going to take around the mouth of the Amazon, I sat next to Rodrigo," says Yager. "When he told me what he did, I was a little confused. 'You're a reef ecologist? What are you going to do on this cruise?' It's really muddy out there, you know.' He smiled and handed me a paper from 1977. It's only about four pages long with a hand-drawn map. It said they found reef fish and sponges out there. The dot on the map where this stuff was found turned out to be about 20 miles across when I put it into Google Maps, but we decided to just take a look around."
Moura spent the cruise reading the conditions of the sea floor until he found a spot hard enough to support a coral reef. There, the team put a dredge down in the water and pulled up a sample of what was underneath the boat.

"When they pulled up the dredge and brought it on board, I was flabbergasted," says Yager. "It wasn't anything you'd imagine was down there. We pulled up some of the most amazing things I've ever seen on an expedition: coral, colorful sponges, fish, brittle stars."

By Jessica Shields
With many thanks to How Stuff Works 



See also
Newly Discovered Victorian Reef 'Teeming With Life'
Chile Creates Largest Marine Reserve in the Americas