Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Antarctic marine life under threat from warming seas

18.02.2008
Predatory crabs and fish are poised to return to warming Antarctic waters for the first time in millions of years, threatening the shallow marine ecosystems surrounding Antarctica.

Antarctic marine communities resemble the primeval waters of millions years ago because modern predators - crabs and fish - are missing.

But this is about to change. 'The crabs are on the doorstep. They are sitting in deep water only a couple of hundred bathymetric metres away from the slightly cooler shallow water in the Antarctic shelf environment,' says Dr Sven Thatje of the National Oceanography Centre, Southampton (NOCS).

Predators like the shell-cracking crabs that dominate bottom communities in temperate and tropical waters have been shut out of Antarctica because it is too cold for them.

'Crabs have a problem in cold water,' says Dr Thatje, a biologist at the University of Southampton's School of Ocean and Earth Science, based at NOCS, 'They cannot flush magnesium out of their blood. So when they are already moving slowly because of the cold, the magnesium acts as a narcotic causing them to pass out and die.' Released from the dangers of predation, filter feeders such as brittlestars thrive in dense populations. Giant sea spiders and marine woodlice share the ocean bottom with fish that have antifreeze proteins in their blood.

Dr Thatje is discussing his findings at a science meeting of the American Association for the Advancement of Science (AAAS) in Boston today Under Thin Ice: Global Warming and Predatory Invasion of the Antarctic Seas (19.00 hours GMT 15th February 2008) with colleagues, Rich Aronson of the Dauphin Island Sea Lab in Alabama and Cheryl Wilga of the University of Rhode Island. Along with scientists from the British Antarctic Survey, BAS, the team studied the benthic communities living in different habitats around Antarctica.

'Antarctic marine communities are functionally Paleozoic - typical of around 250 million years ago,' says paleobiologist Rich Aronson. 'If the crabs' invasion succeeds, they will devastate Antarctica's spectacular Paleozoic-type fauna and fundamentally alter its ecological relationships.'

In January 2007 Dr Sven Thatje and a group of ocean biologists from NOCS and BAS discovered crabs massing in deeper slightly warmer waters, ready to move into the Antarctic shallows should they warm up sufficiently.

Understanding the changes of the past may help scientists to determine how a rise in temperatures may further transform this continent. In a report to be published in Ecology Life Hung By A Thread: Endurance of Antarctic Fauna In Glacial Periods, Sven Thatje reveals that harsh conditions during the Ice Ages pushed Antarctic life to the limit. With ice coverage ten times thicker than today's, the extreme climate conditions in Antarctica during past Ice Ages were so severe that animals were forced into migration to avoid extinction.

He and colleagues from BAS, and the Alfred Wegner Institute, Germany found that larger animals such as penguins, whales and seals were dependent upon areas of open water in the ice known as polynyas. These polynyas acted as vital oases providing access to food such as krill.

Dr Thatje said: 'The existence of open water was essential for the survival of marine plants - the base of the food web. Reduced to such refuges much of today's life in the high Antarctic would have hung by a thread. Limited resources restricted the abundance and productivity of both terrestrial and marine life.'

Sarah Watts | alfa
Further information:
http://www.soton.ac.uk/mediacentre/
http://www.aaas.org/news/press_room/

More articles from Ecology, The Environment and Conservation:

nachricht Scientists on the road to discovering impact of urban road dust
18.01.2018 | University of Alberta

nachricht Gran Chaco: Biodiversity at High Risk
17.01.2018 | Humboldt-Universität zu Berlin

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Artificial agent designs quantum experiments

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.

We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Let the good tubes roll

19.01.2018 | Materials Sciences

How cancer metastasis happens: Researchers reveal a key mechanism

19.01.2018 | Health and Medicine

Meteoritic stardust unlocks timing of supernova dust formation

19.01.2018 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>