The mouth of the Amazon has revealed a deep dark secret to a group of Brazilian and American scientists this year. Brazil’s southern coastline has the only known reef system in the South Atlantic, but a new discovery adds 600 miles of sponge and coral reef in Brazil’s northern region.
A reef has been discovered where the world’s largest river empties its monumental and muddy discharge into the ocean. The discovery was reported in Science Advances on April 22, 2016.
Update: Celebrating The Year of the Reef
During 2018 we are celebrating The International Year of The Reef. Over the next few months we will increase the frequency of our articles on the world’s coral reef ecosystems. We will include current news on the health of reefs and the worldwide efforts to maintain and restore them. In addition, we will republish a variety of our past, but still very pertinent and helpful articles on coral reefs. Our hope is that this effort will focus more attention on these very important issues.
A Mystery Solved
Patricia Yager, an oceanographer from the University of Georgia, accompanied by 30 Brazilian oceanographers, was in the region to investigate how the muddy plumes of the Amazon affected the ocean’s ability to absorb carbon dioxide. (The Atlantis is known for its work as the support vessel used in the discovery of the wreck of the Titanic.)
One of the assembled scientists, Rodrigo Moura wanted to look for a potential reef he had read about in a 1977 research paper Reef Fishes Over Sponge Bottoms Off the Mouth of the Amazon River. (photo – Researchers aboard the Atlantis study coral dredge contents, Patricia Yager)
The Reef Covers 3600 Square Miles
It seemed an outrageous hypothesis considering the Amazon releases a muddy plume that spreads out into the ocean, often blocking out sunlight from reaching the ocean floor. But during the 2 ½ week voyage the RV Atlantis’ dredge brought up sponges, corals, fish and seastars, indicating there really is a reef – and it covers some 3600 square miles off Brazil’s Maranhão State up to southern French Guiana.
The Reef Ecosystem varies greatly depending on Sunlight
Subsequent research voyages have shown that assemblage of this newly discovered reef ecosystem varies, depending upon how much of the Amazon’s plume the area is subjected to during the year. Impacted by the plume only 3 months of the year, the southern section gets more sun and looks more like a traditionally colorful coral reef. The northern section is shielded by the plume half the year and features sponges and carnivorous marine life.
The discovery adds to the scientific understanding of the different types of conditions that coral reefs can tolerate, such as the muddy Amazonian plumes. Unfortunately, this new reef is under threat by the oil industry. The Brazilian government has already sold 80 permits for oil exploration, and drilling is already producing oil at 20 of the sites. Find out more at The Atlantic
Related Blue Ocean Articles on Coral Reefs:
A Coral Reef To Die For!
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