Dependency drives Conservation of Earth's Coral Reefs

Credit: IUCN

More than 275 million people are dependent on coral reefs for food, coastal protection and livelihoods.

Paul Snelgrove at TED: A census of the ocean

Oceanographer Paul Snelgrove shares the results of a ten-year project with one goal: to take a census of all the life in the oceans. He shares amazing photos of some of the surprising finds of the Census of Marine Life.

Paul Snelgrove led the group that pulled together the findings of the Census of Marine Life -- synthesizing 10 years and 540 expeditions into a book of wonders. Full bio »

Giant Red Crabs invade the Antartic Abyss

Huge crabs more than a metre across have invaded the Antarctic abyss, wiped out the local wildlife and now threaten to ruin ecosystems that have evolved over 14 million years.

Three years ago, researchers predicted that as the deep waters of the Southern Ocean warmed, king crabs would invade Antarctica within 100 years.

But video taken by a remotely operated submersible shows that more than a million Neolithodes yaldwyni have already colonised Palmer Deep, a basin that forms a hollow in the Antarctic Peninsula continental shelf.

They are laying waste to the landscape. Video footage taken by the submersible shows how the crabs prod, probe, gash and puncture delicate sediments with the tips of their long legs.

"This is likely to alter sediment processes, such as the rate at which organic matter is buried, which will affect the diversity of animal communities living in the sediments," says Craig Smith of the University of Hawaii at Manoa, whose team discovered the scarlet invaders.

Hungry invaders

The crabs also appear to have a voracious appetite. Echinoderms – sea urchins, sea lilies, sea cucumbers, starfish and brittle stars – have vanished from occupied areas, and the number of species in colonised areas is just a quarter of that in areas that have escaped the invasion.

"[Echinoderms] constitute a significant proportion of the large animals on the seafloor in many Antarctic shelf habitats," says Smith.

The crabs come from further north and moved in as Antarctic waters have warmed, probably swept into Palmer Deep as larvae in warm ocean currents. 

They now occupy the deepest regions of Palmer Deep, between 1400 and 950 metres. In 1982, the minimum temperature there was 1.2 °C – too cold for king crabs – but by last year it had risen to a balmier 1.47 °C.

Melting ice sheets tend to make shallower waters in Antarctica cooler than deeper ones. There were no king crabs at depths of 850 metres or less, suggesting that these waters are still too cold for them. But with waters warming so rapidly, they could spread to regions as shallow as 400 metres within as little as 20 years, says Smith.

Gulf Oil Spill: Marine pollution Surveillance Report

In the satellite image from April 27 at 12:05 p.m. CDT the MODIS image showed that the oil slick was continuing to emanate from the spill location. Individual slicks lay just north of 29 degrees and zero minutes north, where they have been noted in the days before.

Oil had spread further east and the edge of the slick passed 87 degrees and 30 minutes west compared to the MODIS image taken on April 26. The April 26 satellite image came from NASA's Aqua satellite.

On April 29, the MODIS image on the Terra satellite captured a natural-color image of the oil slick just off the Louisiana coast. The oil slick appeared as dull gray interlocking comma shapes, one opaque and the other nearly transparent. The northwestern tip of the oil slick almost touches the Mississippi Delta.

Deepwater Horizon had more than120 crew aboard and contained an estimated to 17,000 barrels of oil (700,000 gallons) of number two fuel oil or marine diesel fuel.

Today, April 30, NOAA declared the Deepwater Horizon incident "a Spill of National Significance (SONS)." A SONS is defined as, "a spill that, due to its severity, size, location, actual or potential impact on the public health and welfare or the environment, or the necessary response effort, is so complex that it requires extraordinary coordination of federal, state, local, and responsible party resources to contain and clean up the discharge" and allows greater federal involvement.

NOAA's estimated release rate of oil spilling into the Gulf is estimated at 5,000 barrels (210,000 gallons) per day based on surface observations and reports of a newly discovered leak in the damaged piping on the sea floor.

NOAA reported on April 29 that dispersants are still being aggressively applied to the oil spill and over 100,000 gallons have been applied. NOAA's test burn late yesterday was successful and approximately 100 barrels of oil were burned in about 45 minutes. NOAA is flying planes over the area and using NASA satellite imagery from the Terra and Aqua satellites to monitor the spill.