Archive for 07/07/2011

Lee Dye – 

A small shark that’s as nasty as it is fearless, attacking everything from Navy submarines to killer whales, has been blamed for its first clearly documented attack on a live human being.

A so-called cookiecutter shark, which was probably a little more than a foot long, took a chunk out of the leg of a distance swimmer who was trying to make a nighttime swim from the island of Hawaii to Maui.

The attack occurred 90 minutes after sunset March 16, 2009, but has just recently been documented by scientists in Hawaii and Florida.

Despite their reputation, sharks historically have not posed a widespread danger to people. Only two other cases involving attacks on humans by cookiecutter sharks have been widely accepted by experts, but both those attacks were on human cadavers, one a drowning victim and the other a suicide.

While this is the best evidence yet for attacks on live humans, there are several other cases that are highly suspicious.

So, are we in for another Jaws? Maybe not, because the cookiecutter shark, so named because it gouges horrific pockets of flesh from its prey, feeds at night in deep tropical waters where it is not likely to encounter humans.

But this case is so spooky that the director of the International Shark Attack File at the Florida Museum of Natural History thinks people ought to at least be aware the nature of this predator.

“It’s not as scary as ‘Jaws,’ but it’s very different from any other kind of attack we have [in the file] because of the size of the shark and the modus operandi,” George Burgess, director of the file, said in releasing the study.

It is to be published in an upcoming edition of the journal Pacific Science.

Full story…

Novinite –

The Black Sea used to be a freshwater lake turned into a salt-water sea, Columbia University Professor William Ryan announced in Bulgaria.

Ryan participated in a scientific expedition headed by Prof. Petko Dimitrov, the director of the Underwater Archaeology unit of the Oceanology Institute at the Bulgarian Academy of Sciences, which started to explore the ancient coastline of the Black Sea on June 27, 2011.

The 18-member team of scientists sailed 80 miles along the Bulgarian coast to Turkey in the Akademik ship of the Oceanology Institute of the Bulgarian Academy of Scientists.

According to Ryan, the expedition has found evidence that in the past the Black Sea experienced a sudden influx of salted water, a cataclysm that he described as an “environmental catastrophe”, as cited by BTA, and that changed tremendously the environment of the Black Sea.

Samples that the scientists extracted from the Black Sea bottom indicate that layers of sand sealed with slime. A total of 27 drillings were made during the expedition, which funded by Bulgarian Scientific Research Fund.

The scientists who took part in the expedition believe that there was an abrupt change in the fauna of the Black Sea basin. Ryan pointed out that after the last Ice Age, the water from glaciers flew into the Black Sea, the Caspian and the Aral Sea.

Full story…

Remy Melina – 

Gray whales managed to survive many cycles of global cooling and warming over the past few million years by changing their migratory habits and broadening their feeding styles, according to a new study.

The oldest gray whale fossils date back 2.5 million years, and since then, the Earth has gone through more than 40 major cycles of warming and cooling. The California, or eastern, gray whale is one of two surviving populations of gray whale and can be traced back about 150,000 to 200,000 years.

Gray whales appear to have “a lot more evolutionary plasticity than anyone imagined,” said study author and evolutionary biologist David Lindberg of the University of California, Berkeley.

After studying California gray whales’ responses to climate change over the past 120,000 years, the researchers suggest that gray whales survived previous climate changes by broadening their feeding styles.

Gray whales were once thought to feed only by suctioning seafloor sediment and filtering out worms and amphipods, but some gray whales now eat herring and krill as well, just like their baleen whale relatives such as the humpback.

The migration habits of gray whales proved to be flexible as well, with one group preferring to stop migrating altogether and remain off Vancouver Island in Canada year-round.

Full story…

Milton Osborne –

Unlike the Three Gorges dam on the Yangtze, dams on the Mekong River seldom attract Australian attention. Yet a planned dam at Xayaburi on the Mekong in Laos has become central to a debate about the river’s future, while the dams China has already built on its section of the river are a subject of long-standing controversy.

Matters have not yet reached the point captured in Mark Twain’s quip that “whiskey is for drinking, water is for fighting over,” but disagreements among the six countries through which the Mekong flows – China, Burma, Laos, Thailand, Cambodia and Vietnam – have become sharp and could become sharper.

With the exception of Burma, each state has its own view of how the Mekong can be exploited.

Since the 1980s, China has brought four hydro-electric dams on its section of the Mekong into commission, is currently building another and has plans to construct at least three more by 2030. One of the operational dams at Xiaowan is the second-biggest constructed in China and it, with the other completed dams, will soon be able to alter the flow of the Mekong, reducing floods downstream in the wet seasons and preventing the river from falling too sharply in the dry.

These seem desirable developments, but this is misleading. Floods play a positive role, particularly in spreading sediment over the downstream agricultural areas, most notably in Vietnam’s Mekong Delta. Altering the Mekong’s flow will negatively affect fish catches since fish spawning is linked to existing pattern of flood and retreat.

Though it may be some years before the full effects of China’s dams are apparent, there is no doubt many will be negative. But dams below China would, if built, have an almost immediate and dangerous effect in a region that is home to 60 million people in the Lower Mekong Basin.

Full story…

Chris Morris – 

Derek Hatfield has always known about the loneliness of the long-distance sailor, but he’s never felt as alone as he does these days when racing over the vast, empty expanses of our dying oceans.

Hatfield recently completed his second successful race around the world, sprinting to a third place finish in the grueling VELUX 5 Oceans competition, a solo round-the-world ocean race that is held every four years.

But the last eight months have been an eye-opener for the New Brunswick-born sailor when it comes to the state of the world’s oceans.

Streaking across the open waters in a sleek, 60-foot yacht that affords him a unique, close-up view of marine life, he has been troubled by what he is not seeing.

“You don’t see the fish, you don’t see the turtles, you don’t see the birds,” Hatfield said in an interview from Nova Scotia, where he now lives.

“Along the coast you will see the odd humpback whale but it is getting more and more rare. Last year I did a transatlantic race and I didn’t see one whale in the whole 15 days of racing across the North Atlantic. Not one whale! . . . The oceans are dying and they’re dying very quickly.”

He especially misses the company of dolphins.

Hatfield, who has been making long sea voyages since the early 1990s, says he always used to stop what he was doing when dolphins showed up to race beside the bow of the boat or follow behind.

“It is much lonelier without them,” he says.

“They’re such an intelligent animal and such great company, especially when you’re out there by yourself. Now it’s a rare sight.”

Around the world, even here in New Brunswick on the Bay of Fundy, people who live, work and play on the water are reporting significant changes in marine ecosystems.

Full story…

BBC News – 

The Dorset coastline saw more scuba diving accidents than anywhere else in the country, it has emerged.

Portland Coastguard dealt with 41 separate diving incidents in 2010, three times the national average. The incidents included three deaths.

The coastguard said the Dorset coastline is one of the most popular diving locations in UK waters.

Inadequate training, such as people not learning to dive in unclear waters, was also highlighted by the coastguard.

Visibility off the coast of Dorset can be 3m, compared to 30m in the Red Sea.

Cindy Rodaway, dive liaison officer for Portland Coastguard, said: “Divers now tend to do their courses abroad when they’re on holiday, then come straight back to the UK, from warm, clear waters, then jumping into cold, murky water and doing a 20m dive off a boat.
Decompression sickness

“Then they get panicky, their buoyancy isn’t controlled and they have a rapid ascent.”

Rapid ascent is the biggest risk to a scuba diver.

The pressure underwater changes the way gases are ingested into the bloodstream, so divers have to re-surface very gradually from the deep to avoid getting Decompression Sickness – otherwise known as the Bends.

It can be lethal – but Alan Clarke, from Dibden Purlieu, is one diver who survived it.

An underlying heart condition stopped Mr Clarke’s body decompressing correctly during an ascent.

He said: “I lost total feeling in my left hand and then all of a sudden the feeling came back, the room swam and I had completely double vision.”

Full story…

The Peninsula – 

Scientists warned yesterday that water off the famed beaches of the Indian holiday state of Goa was unfit for bathing and fishing due to high levels of bacteria from untreated sewage.

The National Institute of Oceanography, which is based in the former Portuguese colony, said the level of faecal coliform bacteria off the coast of Goa and in its rivers was higher than the international benchmark.

“For safe bathing and international standards it should be 100 CFU (colony forming units) per 100 millilitres but now it has touched 190” in some areas, said NIO scientist Dr N Ramaiah.

Ramaiah said coastal waters tested by the scientists were generally above the limit, but the problem was most acute in the basins of Goa’s two main rivers, the Mandovi and Zuari.

A colony forming unit is used in microbiology to measure the number of viable bacteria. Faecal coliform bacteria can be a product of human or animal waste but also storm water run-off or plant material.

Tourism officials expressed alarm at the findings, given the state’s dependence on foreign visitors. Around 400,000 overseas tourists flock to Goa each year, with its long, sandy beaches a major draw.

“If there is such a phenomenon then it is a matter of concern,” said state tourism director Swapnil Naik, who had yet to see the NIO report.

The findings come after a six-year assessment of water quality off the Konkan coast in western India, where the tiny state of Goa is found.

Scientists compared levels of faecal coliform bacteria in Goa’s water with overall Indian levels and those from the US Environmental Protection Agency.

“Almost all the sewage released in the rivers is untreated. Even one gram of stools contains millions and millions of coliform bacteria. So when it is present in water naturally the count goes up,” said Ramaiah.

The chairman of the Goa State Pollution Control Board, Simon de Souza, said the direct discharge of untreated sewage into the state’s rivers or ocean was rare.

“But there are so many residential areas along the water bodies whose sewage might have been flowing into them,” he said.

Full story…