This video is called King Crabs Invade Antarctica.
From Discovery News:
King Crabs Invade Antarctic Waters
A warmer Antarctica makes a hospitable home for these crabs, endangering an entire ecosystem that has no defenses against them.
By Eric Niiler
Tue Feb 8, 2011 07:00 AM ET
* Shell-crushing king crab are expanding their kingdoms into the Antarctic peninsula.
* Creatures living there for tens of millions of years have no defenses against these crustaceans.
* Warmer waters are facilitating the crabs’ advancement.
McMURDO STATION, Antarctica — Warming waters along the Antarctic peninsula have opened the door to shell-crushing king crabs that threaten a unique ecosystem on the seafloor, according to new research by a U.S.-Sweden team of marine researchers.
On a two-month voyage of the Swedish icebreaker Oden and U.S. research vessel Nathaniel B. Palmer, marine biologists collected digital images of hundreds of crabs moving closer to the shallow coastal waters that have been protected from predators with pincers for more than 40 million years. They are the same kind of deep-water crabs with big red claws that you might find at the seafood counter.
“Along the western Antarctica peninsula we have found large populations over like 30 miles of transects. It was quite impressive,” said Sven Thatje, an evolutionary biologist at the University of Southampton in England and chief scientist on the cruise.
Finding crabs on the bottom of the ocean isn’t that big a deal. But here in Antarctica, crabs haven’t lived in coastal waters for the past 40 million years. Until now, it’s been too cold.
Bottom-dwelling creatures like mussels, brittle stars and sea urchins have not developed any defenses. They have thinner shells, for example. For the same reason, filter feeders, like clams and worms, burrow underground in most regions. The lack of predators has led to a thick canopy of sorts, much like a submarine jungle comprised of flowery feather stars, tube worms and squirming sea spiders.
During an interview on board the Oden just after it docked at the main U.S. base in Antarctica, Thatje described how the crabs are moving closer to an ecosystem with no defenses.
“The Antarctic shelf communities are quite unique,” Thatje said. “This is the result of tens of millions of years of evolution in isolation.”
To explore this underwater world, Thatje and his team of U.S. and Swedish scientists towed an autonomous underwater vehicle (AUV) that scanned the seafloor with a digital camera. Along the way, they encountered thick packs of ice, rough seas and lots of feeding whales.
Even though Thatje predicted the crab invasion several years ago in a research paper, he was surprised at seeing so many so quickly.
“The pace of changes that we are observing here in the Antarctic, which is the remotest continent on this planet, is quite frightening,” he said.
What’s happened is that the waters around the Antarctic peninsula have begun to get warmer. The air temperature has jumped 6 degrees Celsius (10.8 degrees Fahrenheit) since the 1950s, while the average ocean temperature has increased by 1 degree Celsius (1.8 degrees Fahrenheit) over the same time.
That change in water temperature has lowered a physiological barrier that has kept the crabs in check. Crabs are unable to process magnesium in their blood below a certain temperature, and the result is a narcotic effect on the crabs’ movement. Magnesium is a mineral that they absorb from the surrounding sea water. Scientists say that barrier may soon fall, as global climate change continues to impact wildlife at the polar regions.
The crab research team will spend the next few months analyzing 120,000 images taken of the seafloor by the AUV, which was designed and operated by the Woods Hole Oceanographic Institution. They want to know whether the crabs will invade and leave, or permanently colonize the shallow areas. Will their presence destroy the existing community or simply alter it?
Previous cruises had only spotted one or two crabs, but now scientists are seeing entire populations, according to Rich Aronson, lead investigator in the crab project and a professor of biology at the Florida Institute of Technology. The crabs are moving from the deep ocean, up the continental slope to the shallower shelf areas.
“As the surface waters warm up, that will make it possible to come running over the top and raise hell with the bottom communities,” Aronson said.
Unlike most areas of the world, the shallower waters on the Antarctic continental shelf are actually slightly colder than the deeper waters of the Southern Ocean. That’s because of a clockwise current of water called the Antarctic circumpolar current. That flow of cold water keeps Antarctic marine life — especially the bottom-dwelling creatures — isolated. There are no sharks, rays or fish with bony jaws, for example, Aronson explained, in Antarctica.
“If you look at the warming trends on the peninsula, you would expect that the crabs would come back in 40 or 50 years,” Aronson said from his office in Melbourne, Fla. “But boom, they’re already here. This is the last pristine marine system on Earth and it could get destroyed.”
King crabs invade Antarctica: here.
Penguins beware: Voracious 1m-wide red crabs invade Antarctica: here.
Guardian: Warming Arctic brings invasion of southern species: here.
In a world first, the sex life of Antarctic Krill in the wild has been caught on camera revealing the shrimp-like creatures are able to mate deeper in the ocean than previously thought: here.
Creatures from the Arctic abyss – video. The Census of Marine Life is bringing to light extraordinary microscopic creatures never before seen by human eyes, dredged from their world of permanent darkness, freezing temperatures and crushing pressure: here.
Antarctic researchers funded by the U.S. National Science Foundation (NSF) may need to throw on another blanket at night to ward off the chill. But Thursday’s agreement to lease a Russian icebreaker to help resupply NSF’s logistics hub at McMurdo Station should otherwise allow the agency to avoid any major curtailments to its Antarctic research schedule for the 2011-12 winter season: here.
Sea Urchins Turning into Cannibals: Discovery News: here.
August 2011. New research by scientists in the Department of Biology at the University of York shows that species have responded to climate change up to three times faster than previously appreciated. These results are published in the latest issue of the leading scientific journal Science: here.
Oldest Spider Crabs Discovered in Fossil Reef: here.
Using risk assessments, like those used for setting occupational safety limits in the workplace, researchers determined the winners and losers of climate change in the Antarctic. They show that marine animals associated with sea ice for food or breeding, such as some whales and penguins, are most at risk from the effects of climate change, while seafloor predators and open-water feeding animals like starfish and jellyfish will benefit from the opening up of new habitat: here.
- Antarctica braces for influx of invasive species (newswatch.nationalgeographic.com)
- Polar research: Trouble bares its claws (nature.com)
- There Goes the Ecosystem: Alien Animals Invade Antarctica (blogs.smithsonianmag.com)
- King Crabs Poised to Wipe Out Rare Antarctic Ecosystem of Invertebrates (scientificamerican.com)
- Research station on skis withstands Antarctic ice and snow (phys.org)
- Giant crabs invade Antarctic abysss (infocult.typepad.com)
- Life Found Deep Under Antarctic Ice For First Time? (news.nationalgeographic.com)
- Antarctic blue whale new research (dearkitty1.wordpress.com)
- Wales News: Now open – the Antarctic post office run by two Welshmen (walesonline.co.uk)