Archive for 07/05/2011

Bo Petersen –

Sally Robinson sees it getting worse. More of the coral has lost color every time she dives the Freddy Day shipwreck.

“We’ve been seeing it for six years,” said Robinson, of Charleston Scuba. Coral whitening, or bleaching, occurs when the algae that feed the coral die. It’s deadly not only to the coral but to swarms of young fish and marine life that depend on it — one of every four species in the ocean.

The shipwreck 18 miles out from Charleston is the farthest north that coral bleaching has been found, and it was unheard of here before Robinson came across it in 2005. Bleaching has already wiped out half or more of the living coral in the Florida keys.

If it were only the coral, that would be bad enough. But in a part of the Atlantic considered relatively healthy and rich in sea life, the coral is only the tip of it. The water is getting more fished, more dumped in, warmer and more acidic. Along the heavily developed Grand Strand coast, hypoxic “dead zones” are showing up, spots where there’s just not enough oxygen left in the water for fish to breathe.

Trophy fish and prize catches like bluefin tuna have gotten scarce. The long, laden strings of fish catches are historic photos; the catch is now smaller in size and fewer. Jellyfish seem profuse. Invasive tropical species like lionfish are moving in.

“I can remember when Charleston Harbor got to 82 degrees and we all gasped,” Robinson said. “Last year it got to 89 degrees. Yesterday it was 86 degrees. There’s a lot of things out there that leave people scratching their heads, anecdotal things.”

Full story…

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Nature Geoscience –

World demand for rare-earth elements and the metal yttrium—which are crucial for novel electronic equipment and green-energy technologies—is increasing rapidly.

Several types of seafloor sediment harbour high concentrations of these elements. However, seafloor sediments have not been regarded as a rare-earth element and yttrium resource, because data on the spatial distribution of these deposits are insufficient.

Here, we report measurements of the elemental composition of over 2,000 seafloor sediments, sampled at depth intervals of around one metre, at 78 sites that cover a large part of the Pacific Ocean.

We show that deep-sea mud contains high concentrations of rare-earth elements and yttrium at numerous sites throughout the eastern South and central North Pacific.

We estimate that an area of just one square kilometre, surrounding one of the sampling sites, could provide one-fifth of the current annual world consumption of these elements.

Uptake of rare-earth elements and yttrium by mineral phases such as hydrothermal iron-oxyhydroxides and phillipsite seems to be responsible for their high concentration.

We show that rare-earth elements and yttrium are readily recovered from the mud by simple acid leaching, and suggest that deep-sea mud constitutes a highly promising huge resource for these elements.