First off, i find it highly unlikely that this was not well known to local mariners. The depth is not that exceptional. What it to be understood though is that our continental shelf can now be mapped in fine detail and that the apparent geology can be identified. I will go much further and insist that it must be done.
All pre - Pleistocene Nonconformity humanity ( Pre 12900 BP ) lived on this shelf and we need to identify as much as possible. The actual flooding of this shelf then took thousands of years until fairly recently or around three thousand years ago. there will be scattered ruins as as already being identified.
Understand that the scholarly community has been literally blind to this pressing reality even to the extent of ignoring even the well proven last fifty feet or so. Only now are they getting serious about the whole Doggar Bank which is the size of France. Then how about the Equally large Bahamas Bank? Neither demanded subsidence in order to create their present flooded condition.
Scientists just discovered a 1,000-km-long coral reef at the mouth of the Amazon
Whoa. Just whoa.
FIONA MACDONALD
22 APR 2016
http://www.sciencealert.com/scientists-just-discovered-a-1-000-km-coral-reef-at-the-mouth-of-the-amazon
An international team of researchers has discovered a 1,000-km (600-mile) long coral reef sitting at the murky, muddy mouth of the Amazon river, according to new reports.
The incredible discovery proves that no matter how well we think we've mapped the surface of our planet, there are still secrets left for us to discover. In this case, a huge, flourishing sponge and coral reef that appears to stretch from the southern tip of French Guiana all the way to the state of Maranhão in Brazil.
The announcement also comes at a time when we're running incredibly low on hope for coral reefs everywhere - just this week scientists admitted that 93 percent of the Great Barrier Reef has now been bleached, and large portions might not recover. So the discovery of a new reef is welcome news. But how the hell did it go so long without anyone spotting it?
The reef was able to remain hidden so well because the mouth of the Amazon is, to be frank, a little bit of a mess. Out of all the water that flows from Earth's rivers into Earth's oceans every day, roughly one-fifth of that water pours out here, at the mouth of the Amazon.
With that, come nutrients, waste, and organic matter collected along the river's 6,992 km (4,344 mile) winding journey through the rainforests and farmlands of South America. And by the time it reaches the water, it bring a whole lot of mud and triggers plenty of algae blooms, both of which cloud the water of the flume.
"I kind of chuckled when [Brazilian oceanographer Rodrigo Moura] first approached me about looking for reefs. I mean, it’s kind of dark, it’s muddy - it’s the Amazon River," one of the researchers involved, Patricia Yager, told Robinson Meyer over at The Atlantic.
"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.'"
The paper in question, from almost 40 years ago, described species of reef fishes and sponges being dredged up from the mouth of the Amazon - and these species were unique to the tropical flora and fauna you'd find in the islands of the Caribbean.
But since then, no one had really given it much thought - after all, given our general understanding of coral reefs, would you expect to find any under here?
The 'Meeting of Waters' where the sandy waters of the Amazon's Slimões River meet the darker waters of the Rio Negro. Image: guentermanaus/Shutterstock.com
Yager wasn't even there to look for the reefs. She was using the RV Atlantis to look into how Amazonian plume was affecting carbon dioxide absorption in the ocean. But to get approval to study the mouth of the Amazon she needed to get some Brazilian oceanographers involved, and one of those, Rodrigo Moura, asked for her help looking for the reef while they were there.
To everyone's surprise, when the put down the dredger, it came up with sponges, stars, and fish. "I was flabbergasted, as were the rest of the 30 oceanographers," Yager told The Atlantic.
The discovery makes the reef the most northernmost known in Brazil, Meyer reports.
What was most surprising is the fact that the reef can exist at all, given the fact that all the mud in the Amazonian plume keeps it sheltered from the Sun most of the time. But return trips by Moura and other Brazilian scientists have suggested that the biology of the reef changes depending on its location, and how much Sun it gets.
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 colourful 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.
There still isn't a whole lot of info about the new reef - the discovery is due to be published in Science, so for now we only have The Atlantic's report to go off.
But Rebecca Albright, an oceanographer and coral researcher from the Carnegie Institute for Science, who wasn't involved in this study, confirmed to the publication that the find is a pretty big deal.
"Traditionally, our understanding of reefs has focused on tropical shallow coral reefs which harbour biodiversity that rivals tropical rainforests," she said. "The new Amazonian reef system described in this paper is another example of a marginal reef that we didn't previously know existed."
Read more about the discovery over at The Atlantic, and we'll update the story with the link to the paper as soon as it comes out.
Shining Light on Brazil’s Secret Coral Reef
The massive, previously unstudied reef is unlike any other known on Earth image: http://thumbs.media.smithsonianmag.com//filer/b7/40/b7400e3a-9d02-4baf-9c56-b2be2e0a122c/researchers.jpg__800x600_q85_crop.jpg
Researchers sort through finds recovered from trawling in the central section of the Amazon reef. (F. Moraes, Instituto de Pesquisas Jardim Botânico do Rio de Janeiro)
By Rachel Nuwer
3 hours ago
Ask anyone to picture a coral reef and they almost certainly think of sun-dappled aquatic communities in clear, turquoise waters. While that is the norm for the majority of the world’s reefs, there are striking exceptions—one of which can be found in the muddy waters off northern Brazil’s coast, where the Amazon River meets the sea.
Researchers previously had a vague idea of the reef’s existence, but until now they had no inkling of just how large and diverse it truly is. The most extensive study to date, published today in Science Advances, reveals that the reef covers an area larger than Delaware—some 3,600-square miles, stretching from the French Guiana border to Brazil’s Maranhão State—and likely supports many species previously unknown to science. The reef is so odd, in fact, that its discoverers believe it may constitute an entirely new type of ecological community.
“This is something totally new and different from what is present in any other part of the globe,” says Fabiano Thompson, an oceanographer at the Universidade Federal do Rio de Janeiro in Brazil. “But until now, it’s been almost completely overlooked.”
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. “You wouldn’t expect to have gigantic reefs there, because the water is full of sediment and there’s nearly no light or oxygen,” Thompson says.
But in the 1950s, a U.S. ship collected a few sponges there, which suggested something bigger could be below. Another group in the 1977 found reef fish and sponges in an area near the mouth of the Amazon, as did a few scattered teams of researchers in the 1990s, including one headed by Rodrigo Moura, lead author of the new study and a marine biologist at the Universidade Federal do Rio de Janeiro. Except for a 2015 study that examined a small area in the reef’s northern stretches, however, no one had followed up on those findings.
“Until now, only 0.001 percent of the total area was covered, because people had only sampled a few points,” Thompson says. That can probably be explained by how difficult the reef is to access: It is situated at depths ranging from 160 to over 320 feet, and the sea there is very rough.
In late 2012, Thompson and his team, mostly Brazilian researchers along with one American, began surveys of the reef system, conducting a second mission in 2014. They used sonar instruments to map the reefs, along with metal dredges and trawls to collect samples. While those destructive methods are not ideal, Thompson says they were necessary for collecting initial evidence of the reef’s presence and identifying the species that live there. In the future, remotely operated vehicles equipped with cameras and lights could be employed.
The researchers discovered that the reef sits at depths below the Amazon’s large plume of muddy fresh water. The pH, salinity and amount of sedimentation and light that characterize the habitat, though, are drastically different compared with what is found at other reefs around the world.
More species turned up in the sunnier central and southern waters than in the more sediment-rich northern ones, which are closer to the Amazon. But the Brazilian reef, overall, had lower biodiversity than the Great Barrier Reef and other traditional coral reefs, which host a quarter of all marine species.
One striking feature of the reef was its high densities of rhodoliths, a type of red algae that is often confused with coral because of its calcium carbonate structure and bright colors. These tennis ball-shaped organisms often covered the Brazilian reef floor. Sponges were the other major component of the reef system, with 61 species found. The team also counted 73 fish species, 35 algae, 26 soft corals, 12 stony corals and more.
Carbonate fragments, with pink patches of live algae (Moura et al., Scientific Advances)
Of the sponges, the team found 29 specimens that they have yet to identify and suspect constitute new species. They also uncovered unique microbes that seem to base their metabolism not on light but on minerals and chemicals such as ammonia, nitrogen and sulfur. Identifying and better understanding those species will require further taxonomic study, which is now underway. But the team believes there is enough evidence to recognize Brazil’s reef as a unique ecosystem. “The oceanographic conditions, unique metabolic features and the new biodiversity allow us to argue that this system is a new biome,” Thompson says.
Walter Goldberg, a coral biologist at Florida International University, who was not involved in the study, says the new research “greatly expands” what is known about Brazil’s reef system.
Carlos Daniel Perez, a marine biologist at the Universidade Federal de Pernambuco in Vitoria de Santo Antao in Brazil, who also was not involved in the work, adds that the Brazilian reef may serve as a corridor for species that span the Caribbean and South Atlantic. Studies such as this one, he says, are critical for identifying those important areas and designing environmental management protocols to protect them.
Thompson and his colleagues agree that reef’s uniqueness warrants protection—especially in light of the fact that major oil and gas companies are exploring areas nearby for drilling. The researchers also point out that the reef probably plays an important role in sustaining fisheries that local communities depend on.
There is much left to be discovered. Though this study represents the largest survey ever conducted of the reef, it covered only about 10 percent of the entire system. “We have only rough map, not a very fine one,” Thompson says says. “We still have another [3,240-square miles] to describe.”
Read more: http://www.smithsonianmag.com/science-nature/shining-light-brazils-secret-coral-reef-180958872/#xQTKV4q2BsmECazo.99
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