Scubaism

Exploring life in the North Atlantic Ocean at various depths of 800 to 3,500 metres, a team of 31 scientists are returning from a five-week scientific expedition which has surfaced a wealth of new information and insights, stunning images and marine life specimens, with one species thought to be new to science.

The international team arrived in Scotland following the expedition along the Mid-Atlantic Ridge (MAR) between Iceland and the Azores on board the £40 million royal research ship, the Royal Research Ship, James Cook. Professor Monty Priede, Director of the University’s highly-acclaimed Oceanlab, said: “It is like surveying a new continent half way between America and Europe. We can recognise the creatures, but familiar ones are absent and unusual ones are common. We are finding species that are rare or unknown elsewhere in the world.”

The team of scientists mapped over 1,500 square miles, exploring the deep sea creatures living in the depths of the Mid-Atlantic Ridge. They used the latest technology to learn more about what is living in this remote and relatively unexplored deep-sea environment using remotely operated vehicles equipped with digital cameras. Trawls, traps and corers have brought back thousands of specimens for study back in the laboratory.

Professor Priede said: “We are trying to imagine what the north Atlantic would be like without the ridge that literally cuts it in half, as we think it has a major effect on ocean currents, productivity and biodiversity of the North Atlantic Ocean.

The aim of the voyage is to contribute to the wider MAR-ECO project studying biodiversity along mid-ocean ridges and to the global Census research programme. Census of Marine Life is a 10-year global scientific initiative to assess and explain the diversity, distribution and abundance of life in the oceans. The team already think they may have discovered a new species of Ostracod (or seed shrimp) that was found swarming in large numbers on the western side of the ridge. Specimens are on their way to experts in Southampton where world-renowned expert, Professor Martin Angel, will ultimately determine whether this is a new species, describe it and allocate a name.

Dr Steven Wilson, Director of Science & Innovation for the Natural Environment Research Council, said: “The Mid-Atlantic Ridge is still relatively unexplored so this voyage will have played a vital role in expanding our knowledge of the biodiversity of the region.”

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In one report, appearing in the journal Hydrobiologia, a team of international scientists documented two giant bluefins tagged within minutes of each other off the coast of Ireland. The two fish swam to opposite sides of the Atlantic Ocean—ending up more than 3,000 miles (5,000 kilometers) apart.

One of the fish traveled 3,730 miles (6,000 kilometers) southwest to waters about 186 miles (300 kilometers) northeast of Cuba. The other remained in the eastern Atlantic and moved off the coasts of Portugal.

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A New Mexico Tech scientist believes he has found a way to head off dangerous climate change. Oliver Wingenter said the idea is simple — fertilize the ocean so that more plankton can grow. Plankton growing in the ocean emits a gas known as dimethyl sulfide, or DMS, that once in the atmosphere, helps spur cloud formation. That, in turn, would cool the planet and offset some of the global warming caused by human emitted greenhouse gases, he said.

Wingenter said his idea has been a tough sell, and it has been a struggle to win funding to further pursue the research. But as Earth inches toward a climate tipping point of runaway warming, Wingenter said his technique could be used to buy time to make societal changes necessary to cut greenhouse gas emissions.

He and a pair of colleagues published the information last month in the scientific journal Atmospheric Environment. Wingenter said he came up with idea while spending seven weeks at sea in early 2002, collecting atmospheric data as part of a major climate change research experiment.

At the time, DMS and cloud formation were the furthest thing from the scientists’ minds. They were trying to see if fertilizing plankton in the planet’s southern oceans could slow down global warming in an entirely different way — by coaxing the ocean plankton to gobble greenhouse gases out of the atmosphere.

Greenhouse gases, primarily carbon dioxide coming out of the tailpipes of cars and exhaust stacks of factories, are changing Earth’s climate, most scientists agree. But the potential for using plankton to scrub greenhouse gases out of the atmosphere remains uncertain.

In pursuing his idea, Wingenter is entering a scientific political minefield known as geo-engineering. The most widely discussed geo-engineering proposal involves a fleet of jets spewing aerosols that would deflect the sun’s rays, cooling the planet in the process. Other suggestions include launching giant mirrors into space to block some of the sun’s light.

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A massive ocean circulation pattern that plays a crucial role in shaping the world’s climate may not have been slowing down over the last few decades as scientists previously believed, according to a study released Thursday. The perceived slowdown had been considered alarming support for computer predictions that global warming would disrupt the planet’s heat regulation.

In a single year of measurements, published in today’s issue of the journal Science, the scientists found enough normal variation in the pattern to suggest that previous studies were premature in asserting a long-term trend. “We can’t strictly say they are wrong, but we can have an alternative explanation,” said coauthor Torsten O. Kanzow, an oceanographer at the National Oceanography Centre in Southampton, England.

The ocean flow, known as the meridional overturning circulation, has been a focus of global warming debates. The Gulf Stream is perhaps its best-known such current. Often called the “ocean conveyor belt,” the pattern carries tropical Atlantic water north. Along the way, the water emits heat, warming North America and Europe. Current theories hold that slower circulation would impair the ocean’s uptake of carbon dioxide and its transport of heat from the tropics.

A previous study on the meridional overturning circulation was based on data collected by ships in 1957, 1981, 1992, 1998 and 2004 that showed a gradually declining flow. It was the first evidence of such a slowdown, and though computer models had predicted one — projecting a flow reduction of about 25% during this century — scientists had not expected it so soon. But because the data points were snapshots in time and not part of a complete record, oceanographers tended to view the analysis with skepticism.

“You could convince yourself that this indicated a trend,” said William E. Johns, an oceanographer at the University of Miami and a coauthor of the new study. “But it could also be a lot of wiggles that happened on shorter time scales.”

The researchers had no definite explanation for the wide variation in flow, but Kanzow surmised that the dynamics of wave movements, eddies and currents that interfere with the circulation pattern could be more influential than previously thought. Despite their own findings, many of the researchers believe that a slowdown is occurring. But they lack proof.

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When the first four-legged animals sprouted fingers and toes, they took an ancient genetic recipe and simply extended the cooking time, say University of Florida scientists writing in Wednesday’s issue of the journal PLoS One. Even sharks — which have existed for more than half a billion years — have the recipe for fingers in their genetic cookbook — not to eat them, but to grow them.

Previous work suggested that the transition from fins to limbs involved the addition of a late phase of gene activity during embryonic development, something thought to be absent during the development of fish fins. The finding shows what was thought to be a relatively recent evolutionary innovation existed eons earlier than previously believed, shedding light on how life on Earth developed and potentially providing insight for scientists seeking ways to cure human birth defects, which affect about 150,000 infants annually in the United States.

Researchers say the same genes that produced ancient fins likely enlarged their role about 365 million years ago in amphibians struggling to adapt to swamps and terrestrial living, creating a distinct burst of development and more versatile appendages.

Using molecular markers to study the formation of skeletal cartilage in embryos of the spotted catshark, UF scientists isolated and tracked the activity of Hox genes, a group of genes that control how and where body parts develop in all animals, including people. They discovered a phase of gene expression in sharks that was thought until recently to occur only when digits began to form in limbed animals.

Why, then, don’t sharks have fingers? Renata Freitas and GuangJun Zhang, co-authors of the paper and graduate students in the zoology department of the College of Liberal Arts and Sciences, speculate that sharks and many other types of fish do not form more dramatic appendages during this late phase of Hox gene expression because it occurs briefly and only in a narrow band of cells, compared with the more extended time frame and larger anatomical area needed to prefigure the hand and foot in limbed animals.

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Reef-building corals may be more resilient against climate change than scientists had previously thought. Researchers have discovered that some species are able to survive an increase in seawater acidity, even though it strips the individual coral polyps of their protective calcium carbonate skeletons. This may be good news for individual polyps, but it doesn’t change the gloomy outlook for reef ecosystems.

As atmospheric carbon dioxide levels continue to rise, so do the levels of dissolved carbon dioxide in sea water. This leads to an increase in ocean-borne carbonic acid, which is capable of dissolving calcium carbonate. “This is a major problem for corals,” says Maoz Fine, a marine zoologist at Bar-Ilan University in Israel. “Essentially, acidification leads to naked coral.”

Researchers estimates that ocean surface pH could decrease from 8.2 to 7.8 by the end of this century — more acidic than it has been for the past 20 million years.

Fine set out to study the effects of this ocean acidification on two species of Mediterranean coral, Oculina patagonica and Madracis pharencis.

He subjected specimens in the lab to increasingly acidic conditions. It didn’t take long for the colonies in the most acidic environments — those with pH levels as low as 7.3 — to show remarkable changes; within a few weeks, their calcium carbonate skeletons had started to dissolve and the polyps became entirely exposed, he and a colleague report in Science.

Surprisingly, the polyps seemed to fare well under these conditions, growing up to three times their original size and reproducing unhindered. “No one expected that corals could survive such low pH,” says Fine.

Equally remarkable is that the coral colony transformed from an interdependent collective into completely self-reliant organisms. Under normal conditions, coral polyps are connected by a tissue called the coenosarc, which enables them to share nutrients and spread out energy demands throughout the colony. “Corals are like a kibbutz,” explains Fine. “All members are equal and share everything; if one polyp hunts plankton, it shares it among the community.”But in the most acidic environments, the polyps withdrew their coenosarcs and proceeded to fend for themselves.

It is the first time researchers have seen this kind of response. Fine says the acid-induced changes are so radical that several of his colleagues were unable to identify the two relatively common species. “Our students — everyone we showed — thought we were joking.”

Once pH levels were returned to normal, the polyps quickly reverted back to their original state, rebuilding their skeletons, shrinking to their original size and restoring their kibbutz-like colony.

Fine is quick to point out that his findings contain no good news for the future of coral reefs, or the fish that depend on them for protection and food. “We have to remember that while coral polyps may survive, reefs won’t,” he says.

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Sharks change their blood volume depending on the saltiness of the water they’re swimming in, according to new research. So sharks must continuously regulate their blood and other body-fluid volumes as water salinity changes.

Although sharks absorb water through their gills, they may also drink seawater and expel shark urine to keep their systems in sync with their environment.

Gary Anderson, an assistant professor of biological sciences at Canada’s University of Manitoba said “Without appropriate regulation of body fluid volumes, physiological systems, such as the cardiovascular and renal systems, would not function optimally and therefore the animal would suffer as a result.”

Shark blood consists of cells and plasma, a protein, water and a mineral-containing substance. Anderson and his team say that sharks in low salt or freshwater environments have much higher blood volumes than sharks in salty water. When shark plasma amounts rise, their cell counts remains the same, so sharks in fresh water essentially develop watery blood in response to certain surroundings.

The researchers analysed earlier studies and data on bull sharks, bamboo sharks, several dogfish and other shark, ray and skate species. They conclude that sharks accomplish blood and fluid volume changes through at least five processes.

The first involves water entry through the shark’s permeable gills. But sometimes the absorption is not enough to sustain the shark.

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Staff at a German marine centre have turned to Justin Timberlake in a bid to get their shy sharks in the mood for mating.

The marine predators were so slow in the romantic stakes that, as an experiment, Sea Life staff began piping music into the sharks’ aquariums for two hours a day to stir their libidos.

And the tunes seem to have had the desired effect, with 50 eggs discovered at the end of the four-week experiment, the Independent reported.

Among the top shark love ballads were Justin Timberlake’s Rock Your Body, Push It by Salt-n-Pepper, Joe Cocker’s You Can Leave Your Hat On, and Traumschiff by James Last. But Britney Spears elicited no reaction from the discerning sea creatures.

The experiment was conducted by 10 Sea Life centres in Germany after the country’s captive breeding program began to lag.

The experiment followed a research project six years ago at the Rowland Institute in Cambridge, Massachusetts, which showed fish processed music in a similar way to humans and appreciated different melodies and tunes.

In Konstanz and Dresden, staff and tourists watched the sharks follow each other and bite each other on their fins. At the Timmendorfer Strand aquarium, the sharks reportedly “danced” to the tunes of Joe Cocker.

Jenz Hirzing from Sea Life Timmendorf said: “The study gives us and scientists the chance to investigate how much influence music can really have on sharks and their mating behaviour”.

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Coral reefs in the Indian and Pacific Oceans are dying off much quicker than previously thought, a new study shows. For the last two decades, Indo-Pacific reefs have shrunk by 1 percent each year—a loss equivalent to nearly 600 square miles (1,553 square kilometers). That makes the rate of reef loss about twice the rate of tropical rain forest loss.

The study is the first to conduct a regional, long-term assessment of coral reef health in the Indo-Pacific region, which is home to 75 percent of the world’s coral reefs and the greatest diversity of coral and fish.

Researchers compiled more than 6,000 underwater surveys, which were conducted between 1968 and 2004, in ten subregions of the Indo-Pacific. These included Indonesia, the Philippines, and Australia’s Great Barrier Reef.

Each survey measured the percentage of seafloor covered of hard corals—a key indicator of reef health.

Marine ecologists from the University of North Carolina found that hard-coral cover on Indo-Pacific reefs currently averages 22 percent of the seafloor —a much lower figure than expected. The percentage is also surprisingly consistent across the region.

The widespread declines may be due to regional or global stressors such as increased sea temperatures, which trigger coral bleaching, said the researchers.

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Scientists claim to have discovered a remote spot in the eastern North Pacific, which they say, serves as a mating ground for the Great Whites. Scientists, had at first, nicknamed the spot 1,553 miles west of the Baja Peninsula, the ‘great white cafe’ because they suspected sharks could go there to feed. But, as lead author Kevin Weng, who conducted the study at Stanford University with project leader Barbara Block, said, there is a potential wrench in that theory.

“It’s just not an area that a shark would logically go to from California to find something to eat. No seals or sea lions are there and it’s not a hot area for whales either,” said Weng, now a researcher at the University of Hawaii at Manoa.

To test their theory, Weng and his team tagged three great whites and then analyzed the satellite telemetry information. Findings revealed that the sharks migrated long distances seasonally from the coast of California to Hawaii and to the offshore area.

During the migration they occasionally dove 3,000 feet or more, possibly to “read” geomagnetic, compass-like information emitted from Earth’s crust. However, at the remote spot, they dove more often. On average they dove every 10 minutes, 1,000 feet down.

Weng believes the sharks could be diving to “sniff” for mates.

“Smells in the ocean are layered horizontally. So if you dump any kind of odorous thing into the ocean - an apple pie, a dead horse, or a female shark - its fragrance will end up within a horizontal plane. When the sharks repeatedly dive, they could be passing up and down through these layers…(for) olfactory cues,” said Weng.

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