The Atlantic (the magazine, not the ocean) just located a giant reef no one knew existed near the mouth of the Amazon River:
A team of Brazilian and American scientists have discovered a new sponge and coral reef more than 600 miles long (1,000 kilometers), located at the mouth of the Amazon River. The reef appears to sprawl across more than 3,600 square miles of ocean floor at the edge of the South American continental shelf, from the southern tip of French Guiana to Brazil’s Maranha?o State.
The discovery, announced Thursday in the journal Science, was more than three decades in the making. Patricia Yager, a professor of oceanography and climate change at the University of Georgia, and the sole American researcher on the project, wasn’t even in the area to look for reefs, at first. Her project was supposed to use the RV Atlantis to investigate how the Amazonian plume affects the ocean’s absorption of carbon dioxide. (The Atlantis is the “host vessel” of the deep-water submarine Alvin, the same craft that discovered the wreck of the Titanic.) But one of the senior Brazilian scientists, Rodrigo Moura, said that he wanted to use their time on the vessel to look for a reef he thought might be in the region.
(Yager’s expedition was repeatedly denied access to the mouth of the Amazon by the Brazilian government, so she had added Brazilian oceanographers to the cruise in hopes of securing its approval.)
“I kind of chuckled when Rodrigo first approached me about looking for reefs. I mean, it’s kind of dark, it’s muddy—it’s the Amazon River,” Yager told me. “But he pulls out this paper from 1977, saying these researchers had managed to catch a few fish that would indicate reefs are there. He said, ‘Let’s see if we can find these.’”
Part of what surprised the researchers is that the reef could exist at all, because all the gunk in the Amazonian plume often sheltered it from the sun. Later cruises by Moura and other Brazilian researchers have indicated that the reef’s biology varies depending on its location. The southern section is only covered by the plume three months of the year, so its environs can complete more photosynthesis. (Most corals live in symbiotic relationships with photosynthetic algae that inhabit their pores.) The southern section contains more staghorns and other colorful corals, “much more what you might imagine a coral reef would look like,” says Yager. The north section, dominated by sponges and carnivorous creatures, is shielded from sunlight by the muddy plume more than half of the year.