Study Shows Southern Ocean Saturated with Carbon Dioxide

May 18, 2007 — By Deborah Zabarenko, Reuters

WASHINGTON -- The Southern Ocean around Antarctica is so loaded with carbon dioxide that it can barely absorb any more, so more of the gas will stay in the atmosphere to warm up the planet, scientists reported Thursday.

Human activity is the main culprit, said researcher Corinne Le Quere, who called the finding very alarming.

The phenomenon wasn't expected to be apparent for decades, Le Quere said in a telephone interview from the University of East Anglia in Britain.

"We thought we would be able to detect these only the second half of this century, say 2050 or so," she said. But data from 1981 through 2004 show the sink is already full of carbon dioxide. "So I find this really quite alarming."

The Southern Ocean is one of the world's biggest reservoirs of carbon, known as a carbon sink. When carbon is in a sink -- whether it's an ocean or a forest, both of which can lock up carbon dioxide -- it stays out of the atmosphere and does not contribute to global warming.

The new research, published in the latest edition of the journal Science, indicates that the Southern Ocean has been saturated with carbon dioxide at least since the 1980s.

This is significant because the Southern Ocean accounts for 15 percent of the global carbon sink, Le Quere said.

GLOBAL WARMING SPURS WINDS

Increased winds over the last half-century are to blame for the change, Le Quere said. These winds blend the carbon dioxide throughout the Southern Ocean, mixing the naturally occurring carbon that usually stays deep down with the human-caused carbon.

When natural carbon is brought up to the surface by the winds, it is harder for the Southern Ocean to accommodate more human-generated carbon, which comes from factories, coal-fired power plants and petroleum-powered motor vehicle exhaust.

The winds themselves are caused by two separate human factors.

First, the human-spawned ozone depletion in the upper atmosphere over the Southern Ocean has created large changes in temperature throughout the atmosphere, Le Quere said.

Second, the uneven nature of global warming has produced higher temperatures in the northern parts of the world than in the south, which has also made the winds accelerate in the Southern Ocean.

"Since the beginning of the industrial revolution the world's oceans have absorbed about a quarter of the 500 gigatons (500 billion tons) of carbon emitted into the atmosphere by humans," Chris Rapley of the British Antarctic Survey said in a statement.

"The possibility that in a warmer world the Southern Ocean -- the strongest ocean sink -- is weakening is a cause for concern," Rapley said.

Another sign of warming in the Antarctic was reported Tuesday by NASA, which found vast areas of snow melted on the southern continent in 2005 in a process that may accelerate invisible melting deep beneath the surface.

Source: Reuters

Experts Find Turtles Are Drawn to Light Sticks

May 09, 2007 — By Associated Press

CHAPEL HILL, N.C. -- Endangered loggerhead turtles snared by longline fishermen may be inadvertently lured to the hooks because of an attraction to light sticks designed to attract tuna and swordfish, researchers said.

Scientists at the University of North Carolina at Chapel Hill found in lab experiments that young loggerhead turtles will swim toward lights similar to those used by fishermen to attract big fish.

"Juvenile turtles are indiscriminate eaters and bite nearly everything small that they encounter," said Ken Lohmann, a UNC biology professor whose expertise is turtle navigation.

Lohmann recommended that longline fishermen direct the lights, designed to mimic the nighttime luminescence of squid, toward the bottom of the ocean. Turtles spend most of their time near the surface.

"The fish are found at much greater depths," Lohmann said. "If the lights are shaded so that the lights are directed downward, the turtles may not see them."

He also suggested that fishermen switch to colors of light that turtles can't detect.

Lohmann conducted the study with John Wang, a graduate who is now a research associate at the University of Hawaii and National Marine Fisheries.

Inadvertent turtle catches have long been a concern, said David Bernhart, chief of protected resources for National Marine Fisheries in the Southeast region.

U.S. longline fishermen working in the Atlantic have had to use circle hooks since 2004 to limit inadvertent catches, a change Bernhart said reduced the number of turtles captured by 50 percent.

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Information from: The News & Observer, http://www.newsobserver.com

Empty Nets as Tide Turns on Asia's Fishermen

May 14, 2007 — By Jalil Hamid, Reuters

KUALA MUDA, Malaysia -- The old adage 'there are plenty more fish in the sea' no longer rings true for Malaysian fisherman Shafie Said.

"These days, we have to go farther offshore and into deeper waters to fish," said Shafie, aged 39, his face weather beaten after 16 years sailing tropical waters in the Andaman Sea, off the coast of northwest Malaysia.

"Sometimes we return empty handed," Shafie said sadly.

It is a story told across Asia by millions of fishermen who ply the region's seas to bring home their main, and often only, source of income.

A staple in Asia with its extensive coastlines and poor populations, seafood provides up to 70 percent of the animal protein intake of most Asians.

But the tide is turning as fish stocks in Asia have declined by 70 percent in the past 25 years, says Stephen Hall, head of WorldFish, a non-profit research body based in northern Malaysia.

"We are taking far too many fishes out of the sea and not leaving enough there to grow and re-generate," Hall said at his seaside office on the Malaysian resort island of Penang.

Compounding the problem is global warming, which will bring rising sea levels, higher sea-surface temperatures, higher salinity and greater weather extremes from droughts to storms.

Scientists predict mean sea levels will rise by 10-90 cm (4-35 inches) over this century, with most estimates in the range of 30-50 cm (12-20 inches).

"This will likely damage or destroy many coastal ecosystems such as mangroves and salt marshes, which are essential to maintaining many wild fish stocks," explained a WorldFish report.

Warming seas are changing fish migration patterns with some fish heading south and others moving north, damaging entire ecosystems and affecting reproduction and replenishment rates.

Scientists in Australia are already warning of a massive decline in fish along the country's eastern seaboard with marine life such as yellow-fin tuna and stinging jellyfish moving towards Antarctica as sea waters warm.

"It's not a disaster for the ones that can move south. It is for the ones that can't move south," Dr Alistair Hobday, the lead author of a recent report from the CSIRO, Australia's premier scientific institution, told Reuters recently.

FAVOURITE FOOD

Researchers say the implications of the global overfishing crisis are greater for Asia than any other part of the world. Fish is a vital part of food security, employment and income in the region.

But while the number of fish in the sea is dropping dramatically, the demand for fish is rising as populations grow.

The Asian Development Bank has predicted that demand for fish in Asia will continue to rise, reaching 69 million tonnes by 2010 and accounting for 60 per cent of the world demand for fish for human consumption, compared to 53 per cent in 1990.

China with its 1.3 billion population and growing affluence is expanding its fish consumption, especially for expensive reef fish sold live at restaurants.

In the Philippines, a major source of reef fish, 90 percent of fish stocks have been depleted, conservation group WWF said. Divers report seeing lifeless reefs in areas that were once teeming with fish.

Last December, Philippine authorities rescued more than 1,000 endangered humphead wrasse from poachers. The reef fish, which can sell for as much as $200 per kilo, are adored by diners in China because their large lips are considered a delicacy.

In India, turtles get caught up in their thousands in trawler nets and nesting sites such as Devi -- where tens of thousands of Olive Ridley turtles would nest in a single night -- are becoming devoid of turtles.

A shark species called "Karat hangar" has already vanished off the coast of Bangladesh along with sea-horses and other fish.

FISHERMEN'S LIVELIHOOD AT RISK

And it's not just the environment that is at risk.

Fishermen in Asia and across the Indian Ocean in Africa are economically vulnerable to the decline in fish stocks, which directly affects their livelihoods, local economies and diet.

Poor and often uneducated, many are unaware of the need to help marine life rejuvenate by throwing back immature fish and avoiding catching turtles and other sea creatures in nets.

"Fishers need to reduce their reliance on narrow resources by learning to exploit a broader range of species and pursue alternative sources of income and fish production such as marine and aquaculture," Hall explained.

But teaching the world's estimated 29 million fishermen about sustainable fishing is an enormous task, especially as many live in countries where education systems are poor, poverty endemic and where there is little investment in aquaculture projects.

WorldFish suggests governments enforce tighter controls over fishing such as ceilings on the number of boats allowed to operate in certain areas and institute a vessel registration system. But enforcing such a system may be close to impossible.

Another solution is expanding fish farms in Asia. But these require significant investment as well as a successful campaign to convince fishermen to change their lifestyles from plying the seas for fish to raising them in ponds on land.

Bangladesh, one of the most impoverished countries in the world, relies on fish for about 80 percent of its national animal protein intake. Yet the fish are disappearing, leaving Bangladeshi fishermen baffled and their incomes dropping.

"Many fish species have vanished and our prime catch of silvery Hisha is also dwindling," said fisherman Suleman Miah.

"The golden days of fishing are gone. (Additional reporting by Anis Ahmed in Dhaka)

Source: Reuters