wild places | wild happenings | wild news
make a difference for our wild places

home | links | search the site
  all articles latest | past | articles by topics | search wildnews
wild news on wildsingapore
  National Geographic 16 May 07
Bizarre New Deep-Sea Creatures Found Off Antarctica
Helen Scales for National Geographic News

Yahoo News 16 May 07
'Treasure trove' of new species deep in Antarctic ocean
by Marlowe Hood

BBC 16 May 07
Antarctic 'treasure trove' found
By Rebecca Morelle Science reporter, BBC News

PlanetArk 17 May 07
Marine Species Suggest Antarctic 'Cradle of Life'
Story by Maggie Fox, Health and Science Editor

WASHINGTON - Carnivorous sponges, 585 new species of crustaceans and hundreds of new worms have been discovered in the dark waters around Antarctica, suggesting these depths may have been the source of much marine life, European researchers reported on Wednesday.

The team, who scooped samples from as deep as 20,000 feet (6,348 metres), found unexpectedly rich diversity of animal life.

Many belong to species found around the world, notably in the Arctic, while others appear to be unique to the deepest Antarctic waters, the researchers reported in the journal Nature.

The unique species tend to be the kind that do not spread easily, which suggests the deep, cold southern oceans may have been the source of many types of marine life, the researchers conclude.

"The Antarctic deep sea is potentially the cradle of life of the global marine species. Our research results challenge suggestions that the deep sea diversity in the Southern Ocean is poor," said Angelika Brandt of the Zoological Institute and Zoological Museum at Germany's University of Hamburg.

"We now have a better understanding in the evolution of the marine species and how they can adapt to changes in climate and environments," Brandt, who led the expedition, said in a statement.

Among the new creatures they documented are a gourd-shaped carnivorous sponge called Chondrocladia; free-swimming worms and 674 species of isopod, a diverse order of crustaceans that includes woodlice, also commonly called pillbugs, sea lice or sea centipedes. Of the isopod crustaceans, 585 species had never been seen before.

Between 2002 and 2005, researchers sampled water and the sediment from 2,500 to 20,000 feet (774 metres to 6,348 metres) in the deep Weddell Sea and adjacent areas.

Their catch was surprisingly rich. "What was once thought to be a featureless abyss is in fact a dynamic, variable and biologically rich environment," Katrin Linse, a marine biologist from the British Antarctic Survey, said in a statement.

The researchers said the Weddell Sea is an important source of deep water for the rest of the ocean. Species can enter the depths of the Weddell sea from shallower continental shelves.

Animals that spread easily, such as the single-celled Foraminifera, were similar to those found in other oceans. "The isopods, ostracods (seed shrimp) and nematodes, which are poor dispersers, include many species currently known only from the Southern Ocean," the researchers wrote.

Yahoo News 16 May 07
'Treasure trove' of new species deep in Antarctic ocean
by Marlowe Hood

The lightless depths of the Antarctic's Southern Ocean harbor a unexpectedly diverse " treasure trove" of marine life, including more than 700 previously unknown species, according to a study released Wednesday.

A series of expeditions over three years collected samples of fauna living up to six kilometers (four miles) below the surface of the Weddell Sea, a poorly understood region that supplies much of the deep water circulating in the world's oceans.

Angelika Brandt, a marine biologist at the Zoological Museum of Hamburg and lead author of the study, said the consortium of international researchers were greatly surprise by what they found.

"We were astonished by the number of new species, and expected to find the same patterns" of low biodiversity reported in the oceans around the North Pole, she told AFP in an interview.

Most of the new life forms discovered were isopods, a vast order of crustaceans ranging in size from microscopic to nearly 30 centimetres (10-inches) long. Of 674 species cataloged, more than 80 percent had never been previously identified.

The expeditions also turned up 160 species of snail-like gastropods and bivalves, along with 76 types of sponges, 17 of them new to science.

"What was once thought to be a featureless abyss is in fact a dynamic, variable and biologically rich environment," said Katrin Linse, one of 21 co-authors of the study, published in the British journal Nature.

"Finding this extraordinary treasure trove of marine life is our first step to understanding the complex relationships between the deep ocean" and the distribution of fauna, she added.

Brandt was especially struck by a tiny amoeboid, epistominella exigua, that seems to thrive at depths below 6000 meters (20,000 feet) as well as in much shallower waters, showing "a previously unsuspected ability to adapt to a wide range of pressures."

Earlier studies had predicted that the Antarctic depths would be as bereft of marine life as the deep Arctic seas.

There are two possible explanations for the dramatic difference between the polar ecosystems, explained Brandt. One is that the Arctic is very young.

"In the Antarctic, marine life has had at least 20 million years available for evolution, whereas the time was much shorter in the Arctic," she said.

The other reason, which does not exclude the first, relates to the Southern Sea's critical role in the circulation of deep water through the world's oceans. The movement of massive quantities of water through the areas investigated "might nourish animals better than in any other deep sea," she said.

BBC 16 May 07
Antarctic 'treasure trove' found
By Rebecca Morelle Science reporter, BBC News

An extraordinarily diverse array of marine life has been discovered in the deep, dark waters around Antarctica.

Scientists have found more than 700 new species of marine creatures in seas once thought too hostile to sustain such rich biodiversity.

Groups of carnivorous sponges, free-swimming worms, crustaceans and molluscs were collected. The findings, published in the journal Nature, could provide insights into the evolution of ocean life in this area.

Dr Katrin Linse, an author of the paper and a marine biologist from British Antarctic Survey (BAS), said: "What was once thought to be a featureless abyss is in fact a dynamic, variable and biologically rich environment.

"Finding this extraordinary treasure trove of marine life is our first step to understanding the complex relationships between the deep ocean and distribution of marine life."

New to science

The research formed part of the Andeep (Antarctic benthic deep-sea biodiversity) project, which is the first comprehensive study of Antarctic marine life. It is designed to fill the "knowledge vacuum" that surrounds the fauna that inhabit the deeper parts of the Southern Ocean.

During three research expeditions that took place between 2002 and 2005, an international team collected tens of thousands of specimens from the Weddell Sea, from depths of between 774 and 6,348m (2,539-20,826ft).

The samples were taken from diverse settings, including the continental slope, the abyssal plain and channel levees.

The researchers found the area to be teeming with lifeforms; well over 1,000 species were recovered, and many were completely new to science. For example, they spotted 674 species of isopod (a diverse order of crustaceans), most of which had never previously been described; more than 200 polychaete species (marine worms), 81 of which were found to be new species; and 76 sponges, 17 of which had previously been unknown.

Lead author of the paper, Angelika Brandt, who is based at the Zoological Institute and Zoological Museum, University of Hamburg, Germany, said: "I initiated the Andeep project because such a vast area of the Southern Ocean had never been explored.

"We thought we might find some novel species, but previous research had suggested deep- sea diversity this far south would be poor, so we were very surprised to find such enormous diversity."

The findings could help to shed light on the evolution of ocean life in this area, Professor Brandt told the BBC News website.

By comparing the species that are found in the deep-sea and those found in the shallower waters surrounding Antarctica, scientists will be able to better understand how climate and the environment these animals live in drove past evolutionary changes.

National Geographic 16 May 07
Bizarre New Deep-Sea Creatures Found Off Antarctica
Helen Scales for National Geographic News

A treasure trove of more than 700 new species has been uncovered in the dark depths of oceans surrounding Antarctica, researchers report.

Heart-shaped sea urchins, carnivorous sponges, and giant sea spiders the size of dinner plates are among the surprising discoveries brought up from the seafloor about 2,300 to 19,700 feet (700 to 6,000 meters) beneath the Antarctic waves.

"We were astonished by the enormous biodiversity we found in many groups of species," said study lead author Angelika Brandt, a marine biologist at the University of Hamburg in Germany.

"We used to think that, with decreasing nutrient and food availability, there might cause a decrease in biodiversity toward the Poles," Brandt said. "There were a lot of species we hadn't seen before, because so little was known before we started," said study co-author Brigitte Ebbe, a marine biologist at the German Centre for Marine Biodiversity Research in Willhelmshaven.

The research was part of the Antarctic Benthic Deep-Sea Biodiversity Project, or ANDEEP. An international team of researchers from 14 organizations embarked on three ANDEEP expeditions between 2002 and 2005 on the German research vessel Polarstern in the Weddell Sea, east of the Antarctic Peninsula. (See a map of the region.)

The project has made a major contribution to the Census of Marine Life (CoML) programme, a global collaboration among thousands of researchers who aim to make a detailed record of all ocean life by 2010.

Astounding Diversity

"In other oceans the number of species drops the deeper you go," said study co-author Katrin Linse, a marine biologist at the British Antarctic Survey. "But in the Southern Ocean we found the opposite trend."

The Southern Ocean includes the Indian, Atlantic, and Pacific Oceans surrounding Antarctica.

Around 300 species of isopod, a diverse group of marine crustaceans related to garden wood lice, live in the shallow Antarctic waters. However, they look different from wood lice. One common family of isopods can even swim.

"With the deep-sea samples, suddenly the number of isopods rocketed up to at least a thousand," co-author Linse said.

In addition to the wealth of species found in the oceans near Antarctica, lead author Brandt noted the deepest part of the seafloor, farther north, revealed even more isopod species, from 60 to 70 degrees south latitude.

Most of the new species are very small—less than 0.2 inches (about 5 mm)—and nearly all are ghostly white. "It's so deep and dark down there, you dont need any color," said co-author Linse.

Deep-Sea DNA

The ANDEEP cruises were also the first to look at the DNA of the Southern Ocean's deep- sea species.

"The great advantage in the Antarctic is that the water column is cold all the way up," said Brandt, "so we can bring material up on deck and extract DNA before it becomes damaged by heat."

The study revealed that similar-looking specimens of foraminifera, single-celled amoeba- like creatures found at the North and South Poles, are genetically the same species—a shock to scientists.

Even more surprising, said Brandt, was the discovery of a much stronger gene flow in foraminifera from the Antarctic to the Arctic, but not vice versa.

That's because deep Antarctic water flows northward, supplying much of the deep water in other world oceans.

The study appears in tomorrow's issue of the journal Nature.

Assumptions

Shattered Colin Summerhayes, executive director of Scientific Committee on Antarctic Research ( SCAR), was not involved in the study. He noted that the Ecology of the Antarctic Sea Ice Zone project, another recently- completed program, also turned up high biodiversity under Antarctic sea ice.

"We now see that the notion of a latitudinal decrease in biodiversity towards the South Pole is rubbish," Summerhayes said. "This current study confirms the trend we found in communities beneath the sea ice."
links
Related articles on Global marine issues
about the site | email ria
  News articles are reproduced for non-profit educational purposes.
 

website©ria tan 2003 www.wildsingapore.com