Posts Tagged ‘british antarctic survey’

Invasive Species Carried Steadily in the Antarctic

May 9, 2011

Softpedia news, April 29th, 2011 – original article here

Antarctica was until recently the most pristine continent in the world, but that situation is currently changing. Research scientists, tourists, and just about anyone who sets foot around the South Pole, are carrying bacteria and other organisms that are not indigenous to this area.

For all intents and purposes, we are promoting an invasion that could see the establishing of new species in this clean habitat. While the harsh conditions in Antarctica will take care of most intruders, there are those that will undoubtedly survive.

Some microorganisms are known for being able to survive in space for prolonged periods of time, so they can surely endure in a bit of ice, scientists say. The same holds true for plant seeds that are being involuntarily and steadily carried on the Southern Continent.

 The main risk with invasive species is that they tend to overtake a new habitat by killing off indigenous species. The latter spent millions of years adapting to their environment, and achieving an ecosystemic balance, only to have it all taken away by opportunistic organisms.

“We are still at the stage when Antarctica has fewer than 10 non-native species, none of which have become invasive. Unless we take steps now to minimize the risk of introduction, who knows what will happen,” says expert Kevin Hughes.

The investigator, who holds an appointment as an environmental scientist at the British Antarctic Survey (BAS), analyzed some 11,250 pieces of fresh produce in a new study. Together with colleagues, he was trying to determine how many new organisms make their way in the Antarctic via this route.

Experts found 56 invertebrates, which included aphids, butterflies, spiders and snails. Large amounts of soil were discovered on many produce, and more than a quarter of all were rotten due to microbes.

“Are these numbers surprising, or does it mean this is likely to be a problem? It’s pretty hard to say,” comments Daniel Simberloff, an expert who was not a part of the new research.

“The upshot is that there’s just enough people going to some parts of Antarctica nowadays that lots of organisms are carried there,” adds the scientist, who is a professor at the University of Tennessee in Knoxville.

“I have to think this isn’t good, and some subset of them are going to pose environmental problems,” he goes on to say, quoted by LiveScience.

“To be quite honest, the only way we are going to stop the introduction of nonnative species is to stop going to Antarctica, to cut off all the pathways. What we can do is try and minimize the risk of introduction and we can do that by relatively simple steps,” Hughes adds further.

Penguin Colony in the Antarctic Disappears

March 5, 2011

Softpedia News, March 5th, 2011 Original article here

Map 2: Emperor Island, Dion Islands, ASPA No. 107: topographic map. Map specifications: Projection: Lambert Conformal Conic; Standard parallels: 1st 67° 0' 00" W; 2nd 68° 00' 00"S; Central Meridian: 68° 42' 30" W; Latitude of Origin: 68° 00' 00" S; Spheroid: WGS84; Datum: Mean sea level. Horizontal accuracy: ± 1.5 m; Vertical accuracy ±1 m (best accuracy of the control points); Vertical contour interval 5 m (index contour interval 15m).

Biologists have documented the first instance of what they call the global warming-induced disappearance of an animal colony. The experts can no longer find even the smallest traces of a small colony of penguins that once lived on an island off the coasts of Antarctica.

It has been proposed a long time ago that penguins would be among the most affected species when climate change finally struck, right alongside other ice-dependent animals, like polar bears.

But no one documented an actual case of that happening until now. Experts believe that the emperor penguin colony disappeared because of dwindling sea ices around their home island.

The island in question is located off the West Antarctic Peninsula, which is one of the areas that lost the most ice due to the warming climate. Without the shelfs to provide them with support and food, the penguins most likely could not secure enough to eat.

When the Emperor Island colony was first discovered in 1948, it featured about 150 breeding pairs of penguins. An 1978 report showed a sharp decline in numbers, while a 2009 aerial survey found the entire island deserted.

One of the biggest unknowns in this study is whether the penguins died off, or just relocated to a more hospitable environment, says lead researcher Philip Trathan. He holds an appointment as a conservation biologist as the British Antarctic Survey (BAS), LiveScience reports.

An explanation could be that fewer and fewer emperor penguins returned to this location over the years. The animals live for about 20 years, and they tend to return yearly to the site where they hatched.

Over time, it could be that more and more parents from the Emperor Island colony laid their eggs elsewhere. As such, the new generation did not return to the former colony, because they did not know where it was, and had no connection to it.

On the other hand, the researchers did find a connection to climate change and rising temperatures. “The one site in Antarctica where we have seen really big changes is the West Antarctic Peninsula,” Trathan explains in the February 28 issue of the journal PLoS ONE.

Ices in this region were observed over the past two decades forming about 54 days later than normal, and melting some 31 days earlier. This may have also contributed to the decline of the penguin colony. These birds are completely reliant on ice for most of their activities.

The BAS team admits that more studies are required to establish a clear cause for the penguins’ disappearance. “We need to look at more colonies so we can reduce the uncertainty. With the first report, there is a high degree of uncertainty,” the BAS team leader concludes.

Surveyor seals reveal secrets of Antarctic depths

November 7, 2010

Original article at  New Scientist
05 November 2010 by Kate Ravilious

Ocean explorers (Image: D. Costa)

Seals are helping to map the ocean floor around Antarctica. And they are proving their worth: they have already revealed new features on the sea bed that could help researchers explain the rapid melting of ice in recent years.

Knowing the shape of the ocean floor is important because underwater mountains and valleys help to shape ocean circulation, which influences ice cover and production at the surface.

Normally such mapping is carried out by echo sounding, whereby the depth of the sea is calculated by timing how long it takes for sound waves to travel from a ship to the sea bed and back again. But the most of the sea and ocean beds around Antarctica remain unmapped because the thick ice that covers much of the region is impassable for ships.

So Daniel Costa, a marine biologist at the University of California, Santa Cruz, glued electronic depth sensors onto the heads of 57 elephant seals and tracked their movements in the Bellingshausen Sea off the Antarctic Peninsula between 2005 and 2009.

Ideal seals

“Seals are ideal because they go places where no one else has gone, and they don’t need a battery to drive them,” says Costa.

By tracking seals in previously well-mapped regions, Costa and his colleagues showed they dived all the way to the sea floor around 30 per cent of the time.

Next they analysed the maximum depths of seal dives in unmapped regions, to trace the contours of the sea bed to the west of the Antarctic Peninsula.

“We found that the troughs that cut across the continental shelf from the deep ocean to the coast are deeper and straighter than shown on existing maps,” says Laurie Padman, an oceanographer at Earth and Space Research, a non-profit research institute in Corvallis, Oregon.

In particular, the data revealed that troughs leading towards the Wilkins ice shelf were 600 to 200 metres deeper than previously thought. Such troughs act as conduits for warm water, so the greater depth may help to explain the dramatic collapse of the ice shelf in 2008.

The researchers are planning similar work in other areas around both Antarctica and the Arctic. “It is a cheap and very powerful technique,” saysPaul Holland, an ocean modeller from the British Antarctic Survey in Cambridge, UK, who was not involved in the study.

Journal reference: Geophysical Research Letters, DOI: 10.1029/2010gl044921

Antarctic Garbage Patch Coming?

June 29, 2010


You’ve heard about the Pacific garbage patch and the Atlantic garbage patch, each a sobering sign of how when we throw things away, they don’t go “away” — they often go into the sea, where they remain for a long, long time.

Much of the global ocean remains uncharted in terms of pollution, but unfortunately the more we look, the more we find. And now even the most remote, pristine waters on the planet — the coastal seas of Antarctica — are being invaded by plastic debris.

In a series of surveys conducted during the austral summer of 2007-2008, researchers at the British Antarctic Survey and Greenpeace trawled the region, skimming surface waters and digging into the seabed. Even in the exceedingly remote Davis and Durmont D’Urville seas they found errant fishing buoys and a plastic cup. Plastic packaging was found floating in the Amundsen Sea (see map).

It doesn’t sound like much, but finding trash in the far corners of the planet is a worrying sign. The research team, led by David Barnes of the British Antarctic Survey, believe the debris they found represents the leading edge of a tide of man-made refuse that is just now starting to make its way into the most secluded parts of our oceans.

If there’s good news, it’s this: sledges dragged along the seafloor turned up a healthy, vibrant Antarctic ecosystem, and nothing else. Plastic bits are ubiquitous in beach sands and coastal sediments throughout much of the world, but the reach of humanity’s profound plastic habit and throw-away culture has so far failed to reach the bottom of these southern seas.

The researchers, though, have a gloomy outlook for what they might find in a future trip to the region. In a letter to the journal Marine Environmental Research, they write:

The seabeds immediately surrounding continental Antarctica are probably the last environments on the planet yet to be reached by plastics, but with pieces floating into the surface of the Amundsen Sea this seems likely to change soon. Our knowledge now touches every sea, but so does our legacy of lost and discarded plastic.

Original article here

Ice and Silence: Extreme Working for the British Antarctic Survey

April 19, 2010

by Paul Torode and Rich Burt – BAS 31/Mar/2010

It’s not often you get to climb inside an iceberg. Held in the vice-like grip of the surrounding sea ice, the frozen colossus facing us was split by a deep crack. The bottom of the vertical cavern had at some stage flooded with seawater and refrozen. We jumped a sinister gash of open water and climbed inside the ‘berg.

Earlier, we’d left our skidoos and field camp and had to abseil the ice cliffs to reach the sea ice: now we were inside the iceberg itself, awestruck by the azure glassy hardness and the immensity of it all. Soft powder snow adorned the entrance of the cavern, and crystals festooned the ‘roof’ high above our heads. As we descended the wondrous symmetry of the two ice walls eventually met in a hairline crack. Outside it was -40°C – our breath frosted heavily on our clothing and our crampons bit aggressively into the ice. In a matter of weeks this ‘berg would break free of the ice and drift into immeasurable seas.

I’ve seen some pretty unusual sights, working as a Field Assistant for the British Antarctic Survey (BAS). Seals swimming under the ice you’re standing on. Powder snow so deep your skidoo leaves a trench behind you. Frozen landscapes of implausible tranquillity take your breath away. I’m one of a team whose job is to support scientists going ‘deep field’ to investigate big questions like climate change. Antarctica is arguably the Earth’s greatest natural laboratory and an early warning system for global change.

BAS operates five research stations, five planes and two ships. During the short summer months life is pretty hectic for everyone. As a Field Assistant, you spend a great deal of time off-station and get to experience the continent more than most.

In summer, before going deep field, I assist the pilot to load and fuel the Twin Otter aircraft before clambering on board. I often get to sit up front as ‘co-pilot’. Watching the plane take off and leave as we set up a remote field camp is a defining moment for any Field Assistant or scientist. For two months we might work from a static camp, or travel by paired skidoo and sledge, linked together by thick rope for safety in crevassed areas. It’s a heavyweight, ‘belt-and-braces’ expedition. Once the orange pyramid tent is firmly pitched, we brew up, crack a big bar of chocolate and enjoy the most comfortable camping imaginable.

In winter days when you’re confined to the station there’s all the maintenance work on field equipment. Servicing field kit takes time in the cold, dark and windy Antarctic winter. But when weather relents there’s great enthusiasm for recreational trips that give groups a chance to have a break from station life and learn valuable field skills. It’s often these trips that the most vivid memories of the Antarctic are formed. Which brings me back to that iceberg!

Paul Torode for the British Antarctic Survey

Original article with many more beautiful pictures and more information here