Scientists have discovered a huge 3,600 sq mile (9,300 sq km) coral reef system below the muddy waters off the mouth of the Amazon river.
The reef ranges from about 30-120m deep and stretches from French Guiana to Brazil’s Maranhão state.
“We found a reef where the textbooks said there shouldn’t be one,” said Fabiano Thompson, a co-author of the study published on Friday in the journal Science.
The mouth of one of the world’s largest rivers is an unlikely place for a coral reef. The Amazon accounts for a whopping 20 percent of the world’s river-to-ocean discharge, and the tremendous muddy plume it produces in the Atlantic can be seen from space.
This makes the reef important to study, the scientists say in their article, because it could illuminate how tropical reefs respond “to suboptimal and marginal reef-building conditions.”
The reef appears to be thriving. The carbonate structure, which functions as a waterway passage for fish and other marine life, is home to a big colony of sponges and other creatures that thrive in low-light waters.
The researchers have so far found over 60 species of sponges, 73 species of fish, spiny lobsters, stars and much other reef life.
Although, the unique reef is already in danger because of oil drilling, the scientists say.
“In the past decade, a total of 80 exploratory blocks have been acquired for oil drilling in the study region, 20 of which are already producing,” the article reads.