Scubaism

A Canadian study suggests Orca whales, may continue to suffer the effects of polychlorinated biphenyl, or PCB, contamination for decades.

The study by Brendan Hickie, Peter Ross and colleagues at Canada’s Institute of Ocean Sciences determined orcas, also known as killer whales, are the most PCB-contaminated creatures on Earth.

Scientists are now trying to discover how current declines in environmental PCBs might affect orcas throughout an exceptionally long life expectancy, which ranges up to 90 years for females and 50 years for males.

The researchers used mathematical models and measurements of PCBs in salmon — orcas’ favorite food — and ocean floor cores to recreate a PCB exposure history to estimate PCB concentrations in killer whales. It concluded the threatened northern population of 230 animals will likely face health risks until at least 2030, while the endangered southern population of 85 orcas might face such risks until at least 2063.

PCBs make whales more vulnerable to infectious disease, impair reproduction, and impede normal growth and development, the researchers said.

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For obvious reasons, scientists long have thought that salt water couldn’t be burned. So when an Erie man announced he’d ignited salt water with the radio-frequency generator he’d invented, some thought it a was a hoax.

John Kanzius, a Washington County native, tried to desalinate seawater with a generator he developed to treat cancer, and it caused a flash in the test tube. Within days, he had the salt water in the test tube burning like a candle, as long as it was exposed to radio frequencies.

His discovery has spawned scientific interest in using the world’s most abundant substance as clean fuel, among other uses.

Rustum Roy, a Penn State University chemist, held a demonstration last week at the university’s Materials Research Laboratory in State College, to confirm what he’d witnessed weeks before in an Erie lab.

Dr. Roy said the salt water isn’t burning per se, despite appearances. The radio frequency actually weakens bonds holding together the constituents of salt water — sodium chloride, hydrogen and oxygen — and releases the hydrogen, which, once ignited, burns continuously when exposed to the RF energy field. Mr. Kanzius said an independent source measured the flame’s temperature, which exceeds 3,000 degrees Fahrenheit, reflecting an enormous energy output.

But researching its potential will take time and money, he said. One immediate question is energy efficiency: The energy the RF generator uses vs. the energy output from burning hydrogen.

Mr. Kanzius’ discovery was an accident. He developed the RF generator as a novel cancer treatment. His research in targeting cancer cells with metallic nanoparticles then destroying them with radio-frequency is proceeding at the University of Pittsburgh Medical Center and at the University of Texas’ MD Anderson Cancer Center in Houston.

While Mr. Kanzius was demonstrating how his generator heated nanoparticles, someone noted condensation inside the test tube and suggested he try using his equipment to desalinate water.

So, Mr. Kanzius said, he put sea water in a test tube, then trained his machine on it, producing an unexpected spark. In time he and laboratory owners struck a match and ignited the water, which continued burning as long as it remained in the radio-frequency field.

During several trials, heat from burning hydrogen grew hot enough to melt the test tube, he said. Dr. Roy’s tests on the machine last week provided further evidence that the process is releasing and burning hydrogen from the water. Tests on different water solutions and concentrations produced various temperatures and flame colors.

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How much damage can a slow big ship do? For her doctorate project, Regina Campbell-Malone of the Woods Hole Oceanographic Institution has compressed and stressed whalebone to determine just how much it can take.

“With most problems you break them down to the simplest components possible,” she explained. “You look at bone at the tissue level to see what a small bone sample will do. It turns out the shape of the whole bone doesn’t matter so much. It’s the weakest part of the bone that’s going to break.”

Applying engineering and mathematics enable her to extrapolate from that tiny lab sample to a 500-pound bone in real life. “Another project is running a model ship into a model whale on a computer,” noted Campbell-Malone. “We’ve been working on that for three years now. There is a grad student at UNH who took measurements of a specific whale and a specific ship and put these into a computer.”

That model allows a researcher to sail at different ship speeds and clip the whale at varied angles. “Those are the two ways of looking at it — at the scale of whale bone and tissue and the full scale geometry of collision,” Campbell-Malone declared.

She has taken option one. When a dead 50-foot female right whale named Stumpy washed ashore in North Carolina three years ago, she had her chance to get a bone. “We saw one-third of the animals killed by blunt trauma had broken jaws. And we’ve never seen a right whale skeleton that had a healed jawbone,” she said. “So it’s more than likely that this injury causes death.” So it was the jaw they collected.

“We did a full necropsy and brought the [493 pound] jawbone back to Woods Hole and kept it in a freezer. We pulled it out and weighed it and used a wood corer to take samples of bone. We made many samples,” recalled Campbell-Malone.

The result is the amount of stress (force per unit area) that would break the bone. What consumes her now is translating the lab data to the physical reality of the full-size jaw. The computer will match that with potential forces up to that delivered by a 300,000-ton oil tanker.

“Thinking about the worst case; maximum impact would be from a perpendicular strike. Then it depends on how fast you are going and the mass of the ship,” Campbell-Malone said.

Her bones have all been squashed. What does it take to break a right whale? Ask her come January when the analysis is done. “NOAA is looking at the first biomechanical data on whether the speed restrictions and slowing down when there are right whales around is going to help,” Campbell-Malone said. “The data are still out as to how right whales are responding, but I think the answer is yes, speed restrictions will help.”
Some believe a slow ship just means more time for a collision. But Campbell-Malone has seen a right whale avoid electronic gear trailing behind a vessel. “Given the appropriate amount of time, they can interpret the world around them and choose a course of action,” she said. “They interpret natural signals that say ‘this is a good place to eat’. They interpret sounds from other right whales a decide whether to join or avoid them. We know they have the capability of responding to stimuli. This may include vessels – the jury is still out.”

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A decade-old photograph wasn’t enough, so marine biologist Marc Hughes grabbed his chance the next time he saw the strange fish in an underwater lava tube cave off the Big Island. In a flash, he slipped the droopy mouthed, eel-like fish into a pocket of his scuba outfit.

Now, the six-inch fish is being heralded by Bishop Museum tropical fish expert John E. Randall as a new species in the genus Grammonus. Other Grammonus species are found in waters from Japan to South Asia, the Gulf of Aden and even the Mediterranean.

But Randall says Hughes’ fish, which the biologist first photographed in 1998, is a unique species. The brownish fish has fins along its rear that make it look similar to an eel, and its mouth is turned down like a grumpy old man.

Randall says he and Hughes are preparing a scientific paper on the fish in the process aimed at getting it recognized and bestowing a name on the species.

One unusual characteristic of the fish is that it gives birth to live young, like some freshwater fish, such as guppies, Randall told West Hawaii Today, which first reported the find in its Saturday edition. He said it also has a system of pores along its body that allow it to sense and slight water movement.

“It’s an interesting feature, and probably one used to detect the presence of predators and hunt for prey because it is a completely dark environment,” he said. “The fish has to rely upon its sense of movement rather than sight.” Randall said other divers have probably seen the fish but they didn’t know what to look at.

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Exotic creatures that live at deep-sea vents will not be immune to the effects of climate change, a UK scientist says.

It was thought that life at these fiercely hot volcanic fissures was so independent from the world above that the habitat would prove a safe haven. But new work finds that some of the animals are reliant on food sources from sea surface level, which could be affected by a change in climate.

Jon Copley, a marine biologist at the University of Southampton, who carried out the research, said: “These vents support lush islands of deep-sea life which is nourished by mineral-rich waters gushing out of the vents. “Thanks to this chemical energy source, these places seemed to be independent of the sunlit world above.” But Dr Copley has discovered this is not the case.He discovered that the creatures at this cold seep had a seasonal reproductive cycle. “The females spawn their eggs in autumn, brood them on the back legs during winter and they hatch out their young in early spring,” explained Dr Copley.

While seasonality in deep-sea creatures that live away from vents is connected to the availability of food sources, the vent’s shrimps have access to a plentiful food source all year round. “We believe the answer lies in the shrimps’ larvae,” Dr Copley said.

The team found that the larvae were leaving the vents and drifting to neighbouring vents where they completed their metamorphosis. “During that journey, they are feeding on material that is sinking down from the sunlit surface waters - and that food supply varies seasonally depending on where you are in the ocean,” explained Dr Copley. The adults were timing their reproduction to coincide with the point when there would be the most food for their offspring during their travels, he added.

Dr Copley said that this pattern has now been found in other shrimp species and mussels at volcanic vents. The biologist believes the finding could have wider implications. He said: “I used to think that what goes on in these vent environments was pretty much quarantined from what goes on in the sunlit world. “But this link suggests that changes to the life in sunlit waters can be communicated though to life in these remote corners of the ocean floor.

“If climate change were to alter life in surface waters, our work suggests that potentially such changes could be communicated to the ocean floor.” Other global catastrophes, such as an asteroid slamming into the Earth, would have a similar effect, he said.

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American and Canadian scientists have found evidence that fishes living in coral-reef habitats undergo higher rates of diversification than similar groups living in other habitats. The biologists examined the DNA of 67 species of tetraodontiform fishes (pufferfishes and their allies) and compared them with a series of fossils.

The authors found that tetraodontiform lineages associated wih reef habitats generally experience greater rates of diversification than nonreef-associated lineages.

In addition, the authors found that the pattern of diversification is complex and does not suggest an ancient reef-fish association, but coincides with reef diversifiacation and marine provincialization during the late Oligocene (about 25 million years ago).

The authors argue that this increase in diversification rate is due in part to the ecological opportunities provided by the unique and complex reef habitat, and in part by major paleoclimatic events that have increased diversification rates in reef clades by fragmenting reef biotas.

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Moray eels have a unique way of feeding reminiscent of a science fiction thriller, researchers at UC Davis have discovered. After seizing prey in its jaws, a second set of jaws located in the moray’s throat reaches forward into the mouth, grabs the food and carries it back to the esophagus for swallowing.

Rita Mehta, a postdoctoral researcher in the Section of Evolution and Ecology at UC Davis used a high-speed digital camera to film eels feeding in the laboratory, and was able to capture the rapid movement of these secondary pharyngeal jaws. She also used X-ray and other imaging equipment at the UC Davis School of Veterinary Medicine to work out how the jaws could move.

More than 200 species of moray eels are found in tropical waters worldwide, often living in holes in rocks and coral reefs. In the wild, they can reach 10 feet in length.

Most fish feed by suction. When it comes upon food or prey, the fish rapidly expands its mouth cavity, sucking in water and the food with it. Some fish feed by overtaking prey with their mouth open or grabbing it in their jaws, but most of those fish then use suction to move the food from the mouth to the esophagus.

But moray eels have little ability to generate suction through their mouths, Mehta found. Instead, they first grasp food with their powerful, toothsome outer jaws. Then the pharyngeal jaws, armed with large, curved teeth, reach forward and seize it. At the same time, the outer jaws release the prey and the pharyngeal jaws bring it back for swallowing. The whole process takes just fractions of a second.

Other fish are known to have pharyngeal jaws that can grind or crush food, but “nothing this spectacular,” said Peter Wainwright, professor of evolution and ecology at UC Davis and co-author with Mehta on the paper. Only the moray eel seems to have a second, mobile set of jaws that can reach forward and grab prey.

At rest, the pharyngeal jaws sit behind the eel’s skull. When they reach forward, they move almost the length of the animal’s skull, but do not protrude beyond the powerful outer jaws. The arrangement means that if the eel can sink in a few teeth to hold its prey, it can secure its meal with the pharyngeal jaws, the researchers note.

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Now, two evolutionary biologists at the University of California, Berkeley, claim that, just as bats developed sonar to chase flying insects through the darkness, dolphins and other toothed whales also developed sonar to chase schools of squid swimming at night at the surface.

Because squid migrate to deeper, darker waters during the day, however, toothed whales eventually perfected an exquisite echolocation system that allows them to follow the squid down to that “refrigerator in the deep, where food is available day or night, 24/7,” said evolutionary biologist David Lindberg, UC Berkeley professor of integrative biology and coauthor of a new paper on the evolution of echolocation in toothed whales published online July 23 in advance of its publication in the European journal Lethaia.

“When the early toothed whales began to cross the open ocean, they found this incredibly rich source of food surfacing around them every night, bumping into them,” said Lindberg, former director and now a curator in UC Berkeley’s Museum of Paleontology. “This set the stage for the evolution of the more sophisticated biosonar system that their descendents use today to hunt squids at depth.”

Lindberg and coauthor Nick Pyenson, a graduate student in the UC Berkeley Department of Integrative Biology and at the Museum of Paleontology, reconstructed this scenario after looking at both whale evolution and the evolution of cephalopods like squid and nautiloids - relatives of today’s chambered nautilus - and relating this to the biology of living whales and cephalopods.

All toothed whales, or odontocetes, echolocate. The baleen whales, which sieve krill from the ocean and have no teeth, do not. The largest of the toothed whales, the sperm whale, grows up to 60 feet long and dives to 3,000 meters - nearly two miles - in search of squid. Though poorly known because they live entirely in the deep ocean, the many species of the beaked whale dive nearly as deep. Belugas and narwhals descend beyond 1,000 meters, while members of the dolphin family - porpoises, killer whales and pilot whales, for example - all can dive below the 200-meter mark where sunlight is reduced to darkness.

According to Pyenson, who focuses on the evolution of whales, the first whales entered the ocean from land about 45 million years ago, and apparently did not echolocate. Their fossil skeletons do not have the scooped forehead of today’s echolocating whales, which cups a fatty melon-shaped ball that is thought to act as a lens to focus clicking noises.

Skulls with the first hints of a concave forehead and potential sound-generating bone structures arose about 32 million years ago, Pyenson said, by which time whales presumably had spread throughout the oceans. Whales had developed underwater hearing by about 40 million years ago.

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The shark’s ability to inflict killer damage on anything it grabs, however, probably is due to saw-like teeth and not the amount of bite force, researchers say. Once a great white clamps down on a prey with its razor-sharp teeth, the shark often shakes the catch from side to side to initiate a sawing action.

Daniel Huber, a biologist at the University of Tampa in Florida, examined an eight-foot (2.4-meter) great white shark that had died after becoming entangled in nets off the coast of Australia. Huber and his colleagues dissected the shark’s head and took several measurements, including the size and placement of the jaw muscles.

“We are figuring out in three dimensions the leverage of all of these jaw muscles,” Huber told LiveScience. The jaws work like a set of pliers, where pliers with long handles would let you grab an item with more force than pliers with short handles.

From this data, the researchers are developing a 3-D digital recreation of the shark and a computer simulation of a full-force bite. They will compare the final force estimate with those from tiger and bull sharks, which, along with the great white, are responsible for most shark attacks on humans.

“The white has the narrowest head of the three, so it has less space for jaw muscles,” Huber said. “Consequently, we’re expecting that it will have a lower bite force on a pound-for-pound basis.”

But great whites would still top the charts as savviest hunters and most adept at capturing prey. “Much of the damage inflicted by white sharks is due to their teeth, and not necessarily to the force,” Huber said.

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Six Italian scuba divers are set to live underwater for two weeks at a depth of fifteen metres (49 feet), in an effort to demonstrate it is possible for human beings to colonise the sea-bed, according to organisers.

The divers, in teams of two, will be assigned one of three “diving bells” as their private room where they will go through their daily routine, from physiological needs to medical monitoring.

“What we want to do is live with the sea life without altering the ecosystem,” said Corrado Costanzo, the Underwater House Project’s medical coordinator.

Organisers say the underwater house complex will be largely self-sufficient. Energy to the complex will be provided by solar panels on the water’s surface. Sweet water will be obtained by desalinising sea water.

The diving bells will be anchored to the sea bed using 100-thousand kilogrammes (220,462 pounds) of ballast and 14 kilometres (8.7 miles) of cables and hoses. A fourth diving bell will be used as a common room where at set hours they will have to cook, eat, take care of their underwater gear and manage their limited resources during the 336-hour-long mission.

“I think I’ll take a book with me, a frisbee, we are going to bring playing cards, and an MP3 player, if I can find a waterproof model. I’ll try to spend time as well as possible,” diver Luca Giordani told AP Television News.

Another team member, Isabella Moreschi, said the six divers had formed a good relationship over the preparation period. “The other guys, the other divers are so united, we met during medical checks in this period and we have been creating a nice and funny team. I think we won’t have problems supporting each other,” she said.

The six divers will have to provide for their own food, as well as perform monitoring tasks in the sea water. They will spend 70 per cent of their time in the water using especially made diving suits and full face breathing masks.

The divers will take to the water on Saturday on the island of Ponza, off the Italian coast near Rome.

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