Antarctic seas richer in life than Galapagos Islands, study claims

A British Antarctic Survey study has revealed over 1,200 marine species around the South Orkney islands

James Randerson, guardian.co.uk The Guardian 1 Dec 08;

Seas surrounding an archipelago near the tip of the Antarctic peninsula are richer in animal life than the Galapagos Islands, challenging the notion that warm seas in tropical zones are higher in biodiversity, scientists claimed today.
Much less is known about the South Orkney islands than the tropical islands that helped to shape Charles Darwin's thoughts about natural selection on his Beagle voyage. But according to a new study published today by the Journal of Biogeography, the sea around them is teeming with a huge variety of life. The survey disproves the notion that the waters in chilly polar regions have a much poorer variety of fauna.

"There has been a long-held belief that the tropics are rich and the polar regions are poor and mid-latitudes are somewhere in between," said Dr David Barnes at the British Antarctic Survey, who led the study, part of the international Census of Marine Life. "This is the first time we've been able to actually look at the fauna of a polar archipelago – it is not actually that poor at all."

Barnes said the reason for carrying out the survey was to give a baseline from which changes in biodiversity due to global warming can be judged. "This is in the part of the world with fastest change in terms of temperature," he said.

The Antarctic peninsula has already experienced warming of 3C over the past 50 years. "If you don't know what the fauna is at any one point it is very difficult to detect either species moving in or species moving out", he added.

The survey recorded 1,224 species in 50 different biological classes. The team discovered five new species and one genus - the biological category that is higher than species - that was new to science. The new species are all sea mosses (bryozoans) or isopods (woodlouse-like animals) but they have not been given names yet.

The team also scoured reports from scientific expeditions and the scientific literature going back decades to find every mention of species observed in the region in a bid to create the most complete and authoritative list of creatures that have ever been found there.

But studying the sea creatures off the South Orkneys is not for the faint hearted - and a far cry from the balmy waters around the Galapagos. Barnes's team had to brave biting winds that frequently stopped them from working.

And while diving in the freezing waters, they had to keep an eye out for potential attacks by orcas and leopard seals. If either predator came near they had to stop diving by climbing onto the British Antarctic Survey's Royal research vessel James Clark Ross or scrambling to shore.

"Although that sounds dramatic, weather is a far bigger issue," said Barnes. "It stops us working far more and makes our work far more hazardous ... Sometimes it's much warmer under the water - it's only minus one and a half [degrees]!"

Once underwater though the view is spectacular. "," said Barnes, who has dived extensively on coral reefs and all over the world.

"I don't think I've been anywhere where you can see so many different types of major groups of animals all in one place.

"You would have to swim quite a long way in the UK or maybe cover hundreds of metres in a coral reef to see so many types of animals that you can see in a very small space at the polar regions."

He said that the marine environment off the South Orkneys is also pristine and free from invasive species. "It is literally the only place in the world where you can dive and not see alien species. Everything you can see in front of you is native to Antarctica."

None of the trawls of the ocean depths brought up any plastic waste – something expected anywhere else in the world. The only human crafted item the team did uncover was a piece of lead shot that was probably fired by whalers who used the South Orkneys as a base at the turn of the last century.

The team's survey covered all realms of sea life. As well as diving in the shallows they also trawled the sea bottom to a depth of 1,500m using nets and employed a special sled that when dragged across the bottom could collect even very tiny creatures. Its sieve held everything bigger than 0.3mm.

Other team members combed the intertidal zone of the islands to survey life in rock pools and living on the shore.

Antarctic more diverse than Galapagos Islands, claim British scientists
The freezing islands of the Antarctic are home to more species of animals than the Galapagos, according to the first inventory of life in the region.

Richard Alleyne, The Telegraph 1 Dec 08;

A team from the British Antarctic Survey and University of Hamburg spent seven weeks studying life on the South Orkney Islands, near the tip of the Antarctic Peninsula.

The survey - which saw experts combing the land and using trawling nets up to 1,500 metres long in waters around the island - revealed an area "rich in biodiversity".

Some 1,224 marine and land species were recorded, including sea urchins, free-swimming worms, crustaceans, molluscs, mites and birds.

After checking 100 years of study data five were found to be new to science and a third new to the area, with 1,026 marine creatures, 821 of which living on the seabed.

Scientists believe the study provides an important benchmark to monitor future environmental change in the area.

Antarctic ocean temperatures have risen by 1C and atmospheric temperatures by 2.5C in the last 50 years, making it one of the most rapidly warming areas on the planet.

Dr David Barnes, lead author at the Cambridge-based British Antarctic Survey (BAS), has revealed his findings in the Journal of Biogeography.

He said: "If we are to understand how these animals will respond to future change, a starting point like this is really important.

"This is the first time anybody has done an inventory like this in the polar regions. It's part of the Census of Marine Life (COML) an international effort to assess and explain the diversity and distribution of marine life in the world's oceans."

Stefanie Kaiser, co-author from University of Hamburg said: "We never knew there were so many different species on and around these islands.

"This abundance of life was completely unexpected for a location in the polar regions, previously perceived to be poor in biodiversity."

The research team of 23 scientists from five research institutes spent seven weeks on the BAS Royal Research Ship James Clark Ross in 2006 as part of the COML.

COML is a ten year program started in 2000 to assess diversity, distribution and abundance of marine organisms in the world's oceans.

The team sampled seven areas of ocean at three different depths - 200m, 500m, 1000m, 1500m - four areas on land, and dived at three islands.

While the sea was less rich than in Hawaii, Caribbean Islands or the Canaries, it had more known species than many temperate and tropical regions including the Galapagos.

The Galapagos are a chain of 13 large islands and 100 small islets, located on the equator around 600 miles off the coast of South America.

Only five are inhabited by people with an approximate population of 18,000. Of the known marine and land species, many are unique to the island.

The Islands are famous for their highly diverse ecosystems and unique geological composition which helped inspire Charles Darwin's Theory of Evolution.

Antarctic islands surpass Galapagos for biodiversity
Tamsin Osborne, New Scientist 1 Dec 08;

A group of isolated Antarctic islands have proved to be unexpectedly rich in life. The first comprehensive biodiversity survey of the South Orkney Islands, near the tip of the Antarctic Peninsula, has revealed that they are home to more species of sea and land animals than the Galapagos.

See a gallery of South Orkney animals

The findings raise the issue of what sort of impact climate change - already hitting the Antarctic hard - will have on this rich biodiversity.

Researchers from the British Antarctic Survey and the University of Hamburg, Germany, carried out the survey using a combination of trawl nets, sampling as deep as 1500m, and scuba divers. The team found over 1200 species, a third of which were not thought to live in the region. They also identified five new species.

The majority of animals were found in the sea, with most living on the seabed.

These findings go against the traditional view that biodiversity declines away from the tropics and towards the polar regions, says lead researcher David Barnes of the British Antarctic Survey.

"Our paper makes the point that if you go right the way across different animal groups rather than taking one specific animal group, which is what most biodiversity studies do, then you get a much better perspective of real biodiversity," he says. "This is the first place in either polar region, not just the Antarctic, where we've actually got a biodiversity across all groups."

Previous research has shown that Antarctic waters harbour a surprising diversity of plankton and larvae and that deep-sea life in the Southern Ocean is similarly rich. But the new study is the first to look at all animals on land as well as in the seas.

"As the sea gets warmer, then temperate species will move into Antarctica and Antarctic species will shift further south or into colder regions," says Barnes. "The South Orkney Islands is the one place where we have a real possibility of detecting new things arriving and things leaving."

Jon Copley, a marine ecologist at the University of Southampton, UK, agrees. "The starting point for any conservation strategy has got to be knowing what you've got to conserve," he says, "and this study provides a very valuable baseline in that regard."

While biodiversity in this region may not decrease as a result of the warming, says Barnes, it is likely that the changes in species composition will result in an overall loss in the Earth's biodiversity.

"All that it will take is for a few things to alter," says Barnes. "It is only a matter of time."

Journal reference: Journal of Biogeography, DOI: 10.1111/j.1365-2699.2008.02030.x