Equatorial waters near the mouth of the Amazon are some of the muddiest in the world, with vast quantities of sediment washed thousands of miles down the river and swept hundreds of miles out to sea. This indicates that there was previously little evidence of an active reef there, because corals mostly thrive in clear, sunlit, salt water.
This reef however, appears to be thriving below the freshwater 'plume,' or outflow, of the Amazon. Compared to many other reefs, the scientists say, it is is relatively “impoverished”. Nevertheless, they found fish, spiny lobsters, stars and several other examples of reef life.
A professor of oceanography and climate change at the University of Georgia said:
"I was flabbergasted, as were the rest of the 30 oceanographers. Traditionally, our understanding of reefs has focused on tropical shallow coral reefs which harbour biodiversity that rivals tropical rainforests."
But the reef, is said to be in grave danger. According to sources, the Brazilian government has sold 80 blocks for oil exploration and drilling at the mouth of the Amazon and 20 of these are already producing oil – some, it is thought, right on top of the reef.