Scientists have determined that at least 235 species live in both polar seas despite the 8,000 miles (13,000 km) between the ends of the Earth.
How some of the creatures wound up at the top and bottom of the planet is a mystery. Distance and habitat divisions - such as warm water between the two regions - are among the things that can separate creatures and lead to new species. A DNA analysis is underway to confirm if the like species are in fact identical, the researchers announced today.The researchers also found evidence that cold water species are moving toward the poles to escape rising ocean temperatures. The project has also returned dramatic photos of species as wide-ranging as ice-loving sand fleas and an antifreeze Antarctic fish that can withstand temperatures that would freeze other fish.
Among the beasts that call both polar seas home are marathon migrators such as grey whales and birds. But the researchers, working on the ongoing Census of Marine Life, also found bipolar worms, crustaceans, and angelic snail-like pteropods.
"The polar seas, far from being biological deserts, teem with an amazing quantity and variety of life," said Ian Poiner, chair of the Census Scientific Steering Committee for the project.
Biologists from several nations have for the past two years worked on the census, at times braving 48-foot (16-meter) waves and frigid conditions.
"Only through the cooperation of 500 people from more than 25 countries could the daunting environmental challenges be overcome to produce research of such unprecedented scale and importance," Poiner said. "And humanity is only starting to understand the nature of these regions."
The team estimates there are 7,500 animals in the Antarctic and 5,500 in the Arctic, and the total number of marine life species known globally is about 250,000. That number may eventually rise to about a million, scientists say. In general, other scientists have said they do not know how many species exist on Earth. The National Science Foundation estimates there could be anywhere from 5 million to 100 million species of life on the planet, but science has only identified about 2 million.
One result of the sea-life census: Researchers are beginning to understand how the polar seas act as incubators for life that sometimes ventures away from the poles as sea temperatures rise and fall over the eons. Last year they discovered that several octopus types have repeatedly colonized the deep sea, each migration coinciding with retreating Antarctic ice over 30 million years.
The scientists now theorize that the Antarctic regularly refreshes the world's oceans with many new creatures, including different varieties of sea spiders, isopods (crustaceans related to shrimp and crabs), and more. They believe the new species evolve when expansions of ice cloister around the south polar region; when the ice retreats, creatures radiate northward along the same pathways followed by the octopuses.
Meanwhile, the census finds smaller marine species are replacing larger ones in some Arctic waters. The reasons are unclear but the implications for the Arctic food web may be profound, the scientists said.
More photos: Rich Life Under the Sea
Study: 'Astonishing richness' in polar sea species
Michael Casey, Associated Press 16 Feb 09;
BANGKOK, Thailand – The polar oceans are not biological deserts after all.
A marine census released Monday documented 7,500 species in the Antarctic and 5,500 in the Arctic, including several hundred that researchers believe could be new to science.
"The textbooks have said there is less diversity at the poles than the tropics, but we found astonishing richness of marine life in the Antarctic and Arctic oceans," said Victoria Wadley, a researcher from the Australian Antarctic Division who took part in the Antarctic survey. "We are rewriting the textbooks."
In one of the biggest surprises, researchers said they discovered dozens of species common to both polar seas — separated by nearly 7,000 miles (11,000 kilometers). Now they have to figure out how they separated.
"We probably know more about deep space than we do about the deep polar oceans in our own backyard," said Gilly Llewellyn, leader of the oceans program for the environmental group WWF-Australia. She did not take part in the survey. "This critical research is helping reveal the amazing biodiversity of the polar regions."
Most of the new discoveries were simpler life forms known as invertebrates, or animals without backbones.
Researchers found scores of sea spider species that were as big as a human hand, and tiny, shrimp-like crustaceans in the Arctic basin that live at a depth of 9,850 feet (3,000 meters).
The survey is one of several projects of the Census of Marine Life, an international effort to catalog all life in the oceans. The 10-year census, scheduled for final publication in 2010, is supported by governments, divisions of the United Nations and private conservation organizations.
The survey — which included over 500 polar researchers from 25 countries — took place during International Polar Year which ran in 2007-2008.
Researchers endured up to 48-foot (16-meter) waves on their trip to the Antarctic, while their colleagues in the Arctic worked under the watchful eye of a security guard hired to protect them from polar bears.
New technology also helped make the expeditions more efficient and productive than in the past. Researchers used cell-phone-like tracking devices to record the Arctic migration of narwhals, a whale with a long twisted tooth, and remotely operated submersibles to reach several miles (kilometers) down into the oceans to study delicate marine animals that are impossible to collect.
As many as 235 species were found in both polar seas, including five whale species, six sea birds and nearly 100 species of crustaceans.
"We think of the Arctic and Antarctic as similar habitats but they are separated by great distances," said University of Alaska Fairbanks plankton ecologist Russ Hopcroft, who took part in the Arctic survey.
"So finding species at both ends of the Earth — some of which don't have a known connection in between — raises a whole bunch of evolutionary questions," he said.
Hopcroft and other polar researchers will now try to determine how long these species have been separated and whether they have drifted apart genetically.
David Barnes, of the British Antarctic Survey, said there a number of possibilities to explain how similar species live so far apart.
Some may have traveled along the deep-sea currents that link the poles or may have thrived during the height of the last ice age about 20,000 years ago when the polar environment was expanded and the two habitats were closer.
Hopcroft and Barnes cautioned that more work needs to be done to confirm whether the 235 species are indeed the same or differ genetically.
"Painstaking work by geneticists investigating both nuclear and mitochondrial genes will only be able to confirm this," Barnes said in an e-mail interview. "It may be they separated sometime ago but similar selective pressures have meant they have not changed much."
Creatures in both Arctic, Antarctic puzzle experts
Alister Doyle, Reuters 15 Feb 09;
OSLO (Reuters) - At least 235 types of cold-loving creatures thrive in both Arctic and Antarctic seas, puzzling scientists about how they got to both ends of the earth, a study showed on Sunday.
Until now, the warm tropics have been seen as a barrier keeping polar bears in the Arctic separate from penguins in the Antarctic. Only a few creatures have been known from both polar regions, such as long-migrating grey whales or Arctic terns.
"At least 235 species live in both polar seas despite an 11,000-km (6,835 miles) distance in between," according to the Census of Marine Life, a decade-long international project to map the world's oceans with results due in October 2010.
Species living at both poles include cold-water worms, crustaceans, sea cucumbers and snail-like pteropods. They make up two percent of the 7,500 Antarctic and 5,500 Arctic animals known to date, out of a global total estimated at up to 250,000.
"The Arctic and Antarctic are much more alike than we thought," Ron O'Dor, senior scientist of the census, told Reuters. Genetic studies were being carried out to confirm that the 235 species were identical.
The findings, along with a discovery that the frigid seas teem with life, raise questions about where common polar species "originated and how they wound up at both ends of the earth," the census said in a statement.
Among theories were that larvae of some species could be swept northwards from Antarctica by chill currents along the deep floor of the Atlantic Ocean -- away from warm surface waters in the tropics that would kill them.
GO NORTH
"Animals can be dispersed over such long distances at the deep sea floor," Julian Gutt of the Alfred Wegener Institute in Germany, a senior member of the census, told Reuters. "The most likely direction is from the Antarctic."
He said, however, that he knew of no finds of cold-loving species in the depths near the equator to back up the theory.
Ice Ages may have helped species disperse.
During Ice Ages, Antarctica's ice smothered surrounding seas and caused new northbound currents that could have carried species such as sea spiders or crustaceans known as isopods. Genetic studies have traced many types of octopus to an Antarctic ancestor.
Among other findings, researchers said smaller marine species of copepods, a sort of crustacean, were replacing larger ones in some Arctic waters, perhaps because of shifts linked to global warming.
"A change in these few species might impact the whole food system," Rolf Gradinger of the University of Alaska said. The larger copepods were key food for creatures such as whales and seabirds.
Among bizarre creatures, one of the Antarctic ice fish known as Chionodraco hamatus can withstand temperatures that would freeze the blood of other fish.
The census is seeking to lay down a benchmark for judging long-term shifts in the oceans. The U.N. General Assembly has asked for regular assessments of the oceans to gauge the impact of pollution, over-fishing and climate change.
(Editing by Janet Lawrence)
Ice oceans 'are not poles apart'
Mark Kinver, BBC News 15 Feb 09;
At least 235 marine species are living in both polar regions, despite being 12,000km apart, a census has found.
Scientists were surprised to find the same species of "swimming snails" at both poles, raising questions about how they evolved and became so dispersed.
The census, involving 500 researchers from more than 25 nations, was carried out during International Polar Year.
The findings form part of the global Census of Marine Life (CoML) report, which will be published in 2010.
"Some of the more obvious species like birds and whales migrate between the poles on an annual basis," explained Ron O'Dor, CoML's co-senior scientist.
But he added the presence of smaller creatures, such as worms living in mud, sea cucumbers and "swimming snails", at both locations had particularly interested researchers on the project.
'Conveyor belt'
One of the swimming snails, or sea butterflies, found in the icy waters of both the Arctic and Antarctic was Cliona limacina .
The creature feeds on Limacina helicina , which is another swimming snail found in the waters of both poles.
Dr O'Dor said that although there was 12,000km separating the two habitats, it did not create a huge barrier for marine wildlife, as a mountain range does for terrestrial species.
"The oceans are a mixing ground," he told BBC News. "There are all kinds of currents that allow things to move around."
He also added that the temperature differences in the oceans did not vary enough to act as a thermal barrier.
"The deep ocean at the poles falls as low as -1C (30F), but the deep ocean at the equator might not get above 4C (39F).
"There is continuity in the ocean as a result of the major current systems, which we call the 'conveyor belt'; a lot of these animals have egg and larvae stages that can get transferred in this water."
'Barcode of life'
Dr O'Dor said that part of the CoML's work included examining organisms' genetic information, which would help the scientists to identify any differences between the seemingly identical species.
"The traditional approach was to describe an organism's physical features, so if these organisms lived in very similar habitats, did very similar jobs and ate similar food, then they often looked very alike even if they came from different origins.
"So we are also working very closely with the Barcode of Life team at the University of Guelph (Canada), and we hope that by 2010 that we will have about 90% of marine species barcoded."
The project aims to develop DNA barcoding as a global standard for identifying species using key genetic markers - much like a shop barcode uniquely identifies a retail product.
"It's a new way to mark or classify things," Dr O'Dor observed.
"Even though organisms look exactly the same and have been identified as being the same type by traditional methods, genetic information can reveal them to be a sub-species or different populations."
COML, which began back in 2000, carried out 17 regional censuses involving more than 2,000 scientists from 82 nations.
Currently, the census teams are collating and examining the data collected by the various surveys, ahead of the publication in October 2010 of the first global Census of Marine Life.
Global warming 'changing balance' of marine life in polar seas
Scientists involved in the most comprehensive study of life in the oceans ever conducted have documented changes in species distribution in the polar regions as warmer oceans spur migration
Jessica Aldred, guardian.co.uk 15 Feb 09;
Global warming is changing the distribution, abundance and diversity of marine life in the polar seas with "profound" implications for creatures further up the food chain, according to scientists involved in the most comprehensive study of life in the oceans ever conducted.
Researchers from the Arctic Ocean Diversity (Arcod) project have documented rising numbers of warm-water crustaceans in the seas around Norway's Svalbard Islands. Arcod is part of the Census of Marine Life, a huge 10-year project involving researchers in more than 80 nations that aims to chart the diversity, distribution and abundance of life in the oceans.
They say an increasing number of these species are extending their range towards the poles as previously cold waters between Norway and the North Pole become warmer and more hospitable.
The team, led by Dr Rolf Gradinger, from the University of Alaska, also collected evidence from the polar Chukchi Sea, between Russia and Alaska, which showed that at least three species have extended their range northwards by up to 500km. The most notable is the snow crab, which has crossed the Bering Strait and is occurring in the Chukchi Sea for the first time.
"This is an example of a general trend we are observing where water is warming further north and making this region more suitable for southerly species," Gradinger said.
The Census is a huge 10-year project involving researchers in more than 80 nations that aims to chart the diversity, distribution and abundance of life in the oceans.
The team also found that smaller species are replacing larger ones in some Arctic waters, a shift which could have profound implications further up the food chain.
"We are finding two smaller species of plankton. This difference in size is big enough to cause a problem for the breeding populations of birds and whales as they will be forced to eat smaller species that has less energy content."
Gradinger's team of scientists from the University of Alaska and the Shirshov Institute of Oceanology in Moscow has collected its findings over five years. Their research has been released in conjunction with another survey from the Census of Antarctic Marine Life (CAML) following a series of expeditions during International Polar Year 2007-08. Both projects will contribute data on polar regions to the global Census of Marine Life, which is due to be released in 2010.
"In oceanographical terms these [Arctic] changes are huge," said Gradinger. "A change in temperature of just a few degrees will see the loss of sea ice cover and with it the sea ice algae, small animals and crustaceans which depend on it. By 2050 the arctic oceans may be ice free, we will lose these animals and that will have implications further up the food chain."
"From an Arctic perspective it's not only about an increase in temperature, it's a complete change in the ecosystem - salinity, ice melt, flow, currents - all of these together will have an impact."
The Antarctic team also reported evidence that some species of pteropods - snail-like species also known as sea butterflies - are moving further towards the pole. "It is similar to the Arctic – animals adapted to cold water environments are having to head to the poles to keep to colder climes as northern waters warm," said Dr Julian Gutt of the CAML.
By comparing notes, Arcod and CAML scientists found that at least 235 species live in both polar regions despite being 6,800 miles (11,000km) apart. Marine life that both poles share includes grey whales, birds, worms, crustaceans and pteropods. Scientists say the discovery opens a host of future research questions over where they originated and how they ended up at opposite ends of the earth.
Another major finding from the 18 research expeditions conducted by CAML during 2007-08 has revealed that life on the seafloor around the Antarctic continent forms a single bioregion - not separate ecosystems, as previously thought. Sampling from 1m locations around the 5,300 miles (8,500km) of Antarctic seafloor - or benthos - has also confirmed that the system is united by a single high-speed current.
"These findings are a major part of new information because so little was really known historically about these regions," said Ron O'Dor, the chief scientist of the census.
Gradinger added: "It's extremely difficult to get information from polar seas because we don't have good historical data. But we must collect data now to evaluate the impact of climate change and the use of the seas for tourism, fishing and shipping. With the warming of Arctic commercial exploitation might increase and therefore it's important to document what species are occurring currently."
Scientists from around the world have been involved in 17 different marine projects that will inform the census, a 10-year project that will provide a snapshot of life in the world's oceans.
The Earth's ice oceans have already revealed some secrets that have excited scientists. Last year at team of British Antarctic Survey scientists working on the census found that 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.
In February last year, giant sea creatures, including sea spiders the size of dinner plates and jellyfish with six-metre long tentacles, were found by Australian scientists working on a census project in the deep waters around Antarctica.