Scubaism

So far this year, the Nha Trang Oceanography Institute has artificially produced nearly 4,000 clown anemone fish (Amphiprion percula). Some 3,000 fishes have been released into the sea and the rest exported to France. Dr. Ha Le Thi Loc from the institute’s Aquacultural Technology Department revealed the above information.

This species of fish lives in coral reefs in tropical seas and they live in symbiosis with sea-anemones. Vietnam currently has ten varieties of clownfish.

In 2002, scientists at the Nha Trang Oceanography Institute began to artificially produce this species of fish without the presence of sea-anemones. The survival rate of one-month-old fishes is quite high, from 40.59% to 85.42%. However, the institute currently produces Amphiprion frenatus Brevoort only. Scientists are completing artificial reproduction technology of this species of fish and they plan to finish this job by 2008.

So far this year, aiming to replenish the aquatic resources of Vietnam’s sea, the institute released 2,000 artificially-reproduced clownfish in Hon Mun and 1,000 in Van Phong Bay off the central province of Khanh Hoa. In mid August 2007, the institute exported around 1,000 fishes.

In recent years, the demand for ornamental fish has been soaring, resulting in the overexploitation of ornamental fish in nature. A survey in 1999 showed that around 160,000 ornamental sea fishes were caught each month on average.

The research of the artificial reproduction of clownfish is considered a measure to reduce the exploitation of nature and be a source of supply of ornamental fish for the local and foreign markets.

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A giant mountain of mud found under the Indian Ocean’s Nicobar Islands is being closely monitored by geologists who fear a tsunami could be triggered by a massive landslide.

Smith Dharmasarojana, chairman of the National Disaster Warning Centre Committee, said the geologists from India recently discovered the giant mud mountain, and some parts of it measured more than seven kilometres high. He conceded there was little information on the mud formation but it is widely believed it was formed by sediment transported by rivers for over a thousand years accumulating under the sea.

The mud mountain is only 400 km from Phuket, he said. ”If a tsunami happens, it will definitely affect Thailand,” said Mr Smith, adding that mud-triggered tsunamis had occurred in Canada and Australia.

According to Mr Smith, a team of Thai and German marine geologists found four smaller mud mountains only 200 km from Phuket island during a survey last year. The team surveyed the seabed for 1,500 sq km at a depth of 1,000 to 2,800 metres. The finds are less scary compared to the one near the Nicobar Islands.

However, Mr Smith said he will ask for a budget of over 100 million baht from the cabinet to set up two additional buoys in international waters in an attempt to boost the efficiency of the tsunami early warning system. They will be placed about 200 km from Thai territorial waters.

Meanwhile, Anond Snidvongs, Chulalongkorn University’s geologist on the research team, agreed with Mr Smith, saying his comments were based on existing information. But he said it is too early to say if Thailand is at risk of a tsunami if the mud mountain collapses.

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Join National Geographic Emerging Explorer Dr. Enric Sala and National Geographic photographer Brian Skerry on the first of three expeditions to explore and document the uninhabited coral reef atolls of the Line Islands, one of the most remote places in the ocean.

http://ngm.typepad.com/virgin_reefs/

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Pet owners who flush used cat litter down the lavatory may be responsible for the deaths of whales, dolphins and porpoises around Britain’s coast, according to academics and public health experts.

They have found evidence of a common parasite in dead marine mammals and say family cats could be be the unwitting source. Cats are essential to the life cycle of toxoplasma gondii, which can infect most mammals and birds but only as part of the food chain.

The possible link to dolphin deaths has been raised by staff from Swansea and Glamorgan universities and the National Public Health Service for Wales in a letter to the Veterinary Record. They say that in California concern that cat faeces have contributed to sea otter deaths has led to disposal warnings on bags of cat litter. But little is known about infection in marine species around Britain.

Blood samples from dead stranded cetaceans revealed infection in one in 70 harbour porpoises, in six of 21 common dolphins and in the only hump-backed whale tested. Nearly one in eight Swansea University and health service employees admitted flushing cat litter away.

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A team of scientists will spend the next several months creating a detailed map of Australia’s coastline to identify areas most at risk to sea level rises. GeoScience Australia and the Australian Greenhouse Office have commissioned the project which is expected to be finished by February.

University of Tasmania researchers will bring together land form maps that already exist and develop an electronic map of the entire coastline, showing areas that are most vulnerable. The map will play a major role in a national study by the greenhouse office, looking at where coastal infrastructure and ecosystems are most at risk to climate change.

Geomorphologist Chris Sharples says it is the first time the information will enable researchers to easily compare and analyse different areas of Australia’s coastline. “We’ve got one consistent solid set of coastal information for Australia, which makes it much more simple to go about the job of identifying which parts of the coast are sensitive and how to respond to that,” he said.

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How did an electronic tag placed in a salmon at a hatchery in Washington end up in the stomach of a bird found 7,700 miles away in New Zealand?

At the National Oceanic & Atmospheric Administration (NOAA) Northwest Fisheries Science Center (NWFSC) in Seattle, scientists said a juvenile steelhead at the Ringold Hatchery in Franklin County, north of Pasco, was tagged in September 2004 and released into the Columbia River in April 2005.

The fish’s tag indicated the steelhead passed through the Bonneville Dam in May 2005. Two years later, the tag was found in the stomach of a muttonbird (formerly known as the sooty shearwater) in New Zealand.

“The most likely scenario is that the young salmon was caught and consumed by an adult sooty shearwater at the mouth of the Columbia River sometime in the summer of 2005. The tag then remained in the bird’s stomach for over 16 months until it was regurgitated to feed young chicks early in 2007,” explained John Ferguson, director of the NWFSC’s Fish Ecology Division.

Scientists said they’ll work with colleagues in New Zealand and conduct research to find out if any more salmon tags have been taken there by sooty shearwater birds feeding on the Columbia River.

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To protect consumers from getting ripped off, scientists at the University of Bologna have developed : skipjack, yellowfin and bigeye.Fishmongers sometimes get caught labeling, for example, skipjack tuna as more expensive yellowtail. Consumer advocates or government agencies could use the new procedure to spot check canned or frozen fish and keep the vendors honest.

In a paper that appeared on the Journal of Agricultural and Food Chemistry website, Aldo Roda and his team described the quality-control procedure and explained how it was developed. The researchers noted that similar tests could be used to check for traces of endangered animal flesh in food products.

To develop the test, Roda and his colleagues used a computer program to look for slight differences in a gene carried by the three types of tuna that are most popular in Italy. Using that information, they designed three short and unique DNA molecules called primers — one for each species.

Performing the test is simple. Mix DNA from some suspicious seafood with the three unique primers and put them in a gene-copying machine. Since each primer corresponds to a different type of fish, identifying the correct species is as simple as checking to see which primers became much longer. That can be done with a very inexpensive method called gel electrophoresis — an experiment that just about every biochemistry student learns before graduating from college.

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Walter Golet of the University of New Hampshire’s Large Pelagics Research Lab partnered with veteran tuna grader Robert Campbell at the Yankee Fisherman’s Co-op in Seakbrook, N.H. to analyze the quality of 3,082 Atlantic bluefin tuna (Thunnus thynnus). “In a drawer, he had two or three notebooks with every fish he graded in the last 14 years, from 1991 — 2004,” says Golet.

Specifically, Golet and co-authors analyzed the fat and oil content and shape of the tuna. “Fat content is in high demand for the market, because that’s what makes the meat taste good,” he says.

Beyond the tekkamaki, however, fat content is a valuable indicator of the overall health condition of the bluefin. Highly migratory, traveling from their spawning grounds to the Gulf of Maine and possibly across the Atlantic, Atlantic bluefin have high metabolisms and energetic needs.

In 1991, he found, the probability of landing a C+ fish (A being the highest grade) was 16 percent and 9 percent for August and September, respectively. By 2004, the probability increased to 68 percent and 76 percent in the C+ category for August and September, respectively. He also found that the bluefin are leaner on arrival to the Gulf of Maine; the probability of catching a poor quality fish (grade C or worse) in June 1991 was 30% compared with 70% in 2004. Good quality fish, such as B or better, now comprise less than one percent of the commercial catch at this New Hampshire cooperative.

Now that the researchers have documented the decline of bluefin quality, they’re looking into the reasons behind it. One obvious cause would be a decline in their food supply; bluefin are voracious predators with a high metabolism. “Bluefin will eat just about anything — sponges, seahorses, dogfish — but according to recent studies, up to 60 percent of their prey is comprised of Atlantic herring,” says Golet, noting that herring, along with mackerel and bluefish, is tuna health food, providing maximum energy to these long-distance swimmers.

Since stock assessments indicate that herring abundance is at historically high levels, however, the researchers wonder if perhaps the herring themselves have experienced a decline in quality, or if they have dispersed into smaller schools, requiring greater energy output: Bluefin have to swim farther for each meal.

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Scientists are investigating the mysterious disappearance of more than 5,000 common seals from Britain’s coastline. Zoologists from the University of St Andrews are so concerned about the catastrophic slump in population that they are carrying out the first complete survey of Scotland’s common seal population, home to 80 per cent of the British total.

Two teams of researchers will spend the next two weeks flying over the coast in helicopters using military-specification thermal imaging technology to pinpoint seals. Flying at up to 90 knots and 700ft above the sea, they expect to cover about 55 miles of coast every hour but are limiting their flying to several hours either side of low tide - the best time to view seals. The thermal imager can detect a seal up to two miles away, showing it as a little white blob on a sand bank or rock.

The seals will be counted as they appear, but the footage will also be recorded so that the findings can be double-checked. Both teams set out last week, one beginning at Berwick-upon-Tweed in England and working its way around the east and north Scottish coasts, the other starting in the Solway Firth and following the West Coast. They are expected to converge in the Outer Hebrides this month.

Callan Duck, senior research zoologist at the university’s sea mammal research unit, said that the slump in population was a “mystery”. The decision to map the entire population in one go was prompted by a routine survey of Orkney and Shetland last summer showing that numbers had dropped by up to 45 per cent over the previous five years, he said. The population had crashed to 7,277, compared with 12,635 in 2001.

Mr Duck said: “We want to find out what the reasons are for that decline, and if that decline is continuing. We also want to find out if the decline is limited to the East Coast of Scotland or if it is also happening on the West Coast.”

He said: “It’s possible that seals are being shot, though if people do shoot seals the carcasses are usually found and folk haven’t been finding carcasses in great numbers. It could be disease, but again there would be carcasses.” He said that the big rise in the grey seal population may be a factor. Both species rely for food on sand eels, which have declined sharply over the past few years. Mr Duck said that, in his view, there was no single reason for the slump in the common seal population.

Ailsa Hall, another team member, said: “It’s baffling. It could be killer whales, it could be changes in the environment, it could be pollutants in the water, it could be shooting. We just don’t know.”

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Winter, an Atlantic Bottlenose Dolphin, is a playful two-year-old. She was found off the coast of Florida, caught in a crab trap. When she arrived at the Clearwater Marine Aquarium, CMA CEO David Yates said her condition was critical.

Winter survived, but she lost her tail and was left with merely a stump. “She’s had to adapt to how to swim without a tail, which no dolphin has ever done in captivity. We didn’t know if she could do that,” he said.

Winter’s swimming style changed from up and down to side to side. Veterinarians were concerned that this unusual swimming form might alter the long-term health of her spine. The vets, therefore, began to explore designing a prosthetic tail for Winter.

Kevin Carroll, vice-president of prosthetics at Hanger Orthopedic Group, Inc., contacted Winter’s caretakers after he got word of the need for a prosthetic tail, and he offered his services. However, Carroll didn’t realize how large a project it would be.

“I came straight down, saw Winter (and) felt really sorry for her. And I came in and I said, ‘OK, we’ll fit her little tail. Not a big deal.’ Little did I know it was going to take a year and a half to do,” Carroll said.

Designing a prosthetic for a dolphin was a trickier process than Carroll anticipated. He said, “With a person, when we fit a socket on them, we have one long, solid bone. We don’t have to have the socket moving in every direction. With a dolphin, it needs to move along with her full spine.”

Casts are used to monitor Winter’s growth and body shape. The casts are also able to provide the mold for Winter’s new prosthetic. Carroll noted that it is important for Winter to be able to adapt to having a new tail. “We can’t just put a prosthetic on and walk out the door. We have to slowly introduce the prosthetic,” he said.

Teaching Winter how to use the prosthetic device also presents a challenge. Carroll will have to aide her in learning how to once again swim up and down like a typical dolphin.

The last step is to attach the actual tail. That’s still a few months away, but Winter’s caretaking team is incredibly excited to get her back to full strength. “It’s going to be powerful seeing her coming out of the water with that tail,” Carroll said. “I know she’s going to do it. We’re really looking forward to that.”

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