domingo, 16 de diciembre de 2012

Coral sperm bank offers last ditch hope for restoring health of reefs

Coconut Island, HI - Just before sunset, on the campus of the Hawaii Institute of Marine Biology, Mary Hagedorn waited for her mushroom corals to spawn.

As corals go, Fungia is fairly reliable, usually releasing its sperm and eggs two days after the full moon, but this time they were late.

Eventually, as Dr Hagedorn and her assistant watched, one coral tightened its mouth and seemed to exhale, propelling a cloud of sperm into its bath and the water bubbled like hot oatmeal.

A reproductive physiologist with the Smithsonian Institution, Dr Hagedorn, 57, is building what is essentially a sperm bank for the world's corals. She hopes her collection - gathered in recent years from corals in Hawaii, the Caribbean and Australia - will someday be used to restore, and even rebuild, damaged reefs.

She estimates that she has frozen 1 trillion coral sperm, enough to fertilise 500 million to 1 billion eggs. In addition, there are 3 billion frozen embryonic cells; some have characteristics of stem cells, meaning they may have the potential to grow into adult corals.

Dr Hagedorn's collection is the only one of its kind. While corals can reproduce asexually - that is, fragments of coral can grow into clones of their parents - Dr Hagedorn points out that only sexual reproduction maintains genetic diversity within populations, and with it a species' capacity to survive and adapt to change.

For corals, the number of likely partners is shrinking. As climate change warms the oceans, corals are becoming more vulnerable to disease and bleaching.

In recent years, bleaching events have grown from local curiosities to global phenomena and, in some cases, are so severe and long-lasting that the corals cannot recover. Meanwhile, rising carbon dioxide levels are acidifying the oceans, inhibiting the growth of coral skeletons and weakening the bones of reefs.

In the central and western parts of the Pacific Ocean the extent of living coral is thought to have shrunk by half between the early 1980s and 2003. If this decline continues, almost all of the world's reefs will be on their way to oblivion by 2050.

Dr Hagedorn supports traditional conservation strategies, such as marine refuges, but is preparing for their failure. While she freezes coral sperm and eggs for future use, colleagues are refining techniques for raising coral in captivity and for reintroducing young corals to their natural habitats.

But she and her colleagues have to struggle to raise money for her efforts, which are often seen as a distraction from the more immediate job of habitat protection.

Last northern autumn, she and a group of colleagues travelled to Australia at the invitation of the Australian Institute of Marine Science. Using techniques developed by Dr Hagedorn, they froze sperm and cells from colonies of Acropora tenuis and Acropora millepora, two of the roughly 400 coral species native to the Great Barrier Reef.

viernes, 14 de diciembre de 2012

Researchers monitor red tides in Chesapeake Bay

Gloucester Point, VA — Researchers at the Virginia Institute of Marine Science continue to monitor the algal blooms that have been discoloring Chesapeake Bay waters during the last few weeks. These "red tides" occur in the lower Bay every summer, but have appeared earlier and across a wider area than in years past, likely due to last winter's warmth and this summer's heat.

Red tides are caused by dense blooms of tiny marine plants called algae that contain reddish pigment. Algae are normal components of all aquatic environments, but can produce what is known as a "harmful algal bloom" or "HAB" when they bloom in significant numbers and generate toxic byproducts. HABs can be harmful to both marine organisms and human health.

Professor Kim Reece, a member of Virginia's Harmful Algal Bloom Task Force, is the focal point for HAB research and monitoring at VIMS. Reece, fellow VIMS professor Wolfgang Vogelbein, and other colleagues at VIMS partner with representatives from the Virginia Department of Health, the Marine Resources Commission, the Department of Environmental Quality, and Old Dominion University to track the appearance of algal blooms within Virginia waters and to determine whether the bloom organisms pose any threat to marine life or human health.

There is currently no evidence of harm from the recent blooms, which were first observed in early to mid-July. Study of samples taken in the York River near VIMS' Gloucester Point campus show that they comprise dense aggregations of Cochlodinium polykrikoides, a single-celled marine dinoflagellate.

Reece says "Blooms of this and closely related species may harm oyster larvae and other marine life, and are associated with fish kills and economic loss in Japan and Korea, but we've had no reports of any of these effects in local waters this year." Fish and crab kills reported in the Bay during Cochlodinium blooms in previous years are likely due to low levels of dissolved oxygen, which are associated with blooms of many different species and occur when the algal cells die, sink, and decay.

Virginia residents who have observed a patch of water that is colored red or mahogany and are concerned should contact Virginia's toll-free Harmful Algal Bloom hotline at (888) 238-6154.

Algal blooms are not uncommon in lower Chesapeake Bay during the spring and summer. Algae respond to the same conditions that encourage plant growth on land, and thus are most likely to form blooms when waters are warm and nutrient rich. Excess nutrients from farms and yards, sewage treatment plants, and the burning of fossil fuels are one of the biggest challenges facing the Bay.

"There are three main ingredients for an algal bloom," explains Reece. "Warm waters that favor rapid growth of algal cells, abundant nutrients to fertilize that growth, and wind and tidal-driven currents to confine the cells into a dense aggregation. Our recent heat and rains provide ideal conditions for bloom formation, so we'll continue to monitor whether the ongoing blooms become a cause for any concern."

Real-time monitoring of algal blooms is not an easy task, as it involves developing and applying DNA tests to rapidly identify -- from among a huge variety of mostly benign microorganisms -- the particular algal species that have been observed to produce toxins. Development of these molecular DNA assays is a prime focus of Reece's research at VIMS.

Monitoring also requires daily collection of water samples from all across lower Chesapeake Bay. Analysis of these samples at VIMS shows that Cochlodinium is currently blooming in the York, James, Elizabeth, and Lafayette rivers; Mobjack Bay; and near the mouth of the Bay in the vicinity of the Hampton Roads Bridge Tunnel.

miércoles, 12 de diciembre de 2012

Divided dolphin societies merge for first time

Sydney, NSW - Two become one: the unification of these two socially distinct groups of bottlenose dolphin demonstrates the intelligence and social adaptability of the species.

A unique social division among a population of bottlenose dolphins in Australia's Moreton Bay has ended, according to a new study. The dolphins lived as two distinct groups that rarely interacted, one of which foraged on trawler bycatch.

But scientists think that a ban on fishing boats from key areas has brought the two groups together. They believe these socially flexible mammals have united to hunt for new food sources. The findings are published in the journal Animal Behaviour.

Bottlenose dolphins have large brains and quickly learn new behaviours. Using a wide range of sounds to communicate with other members of the group, or "pod", they have been observed showing remarkable individual and social intelligence:

The Moreton Bay dolphins were thought to be the only recorded example of a single population that consisted of groups that were not associating with each other in a split dubbed "the parting of the pods". But since the study that discovered the rift, trawlers have been banned from designated areas of the bay leading to a 50% reduction in the fishing effort.

A key area of the bay to the south, where the social split was observed by the previous study, has been protected. The changes gave scientists a unique opportunity to observe the adaptability of dolphin society. The "trawler" dolphins from Moreton Bay had previously fed on the bycatch from boats while the "non-trawlers" found other sources of food.

"There's never been really any experiments looking at social structure... where you can compare what it was like before and what it is like now," said Dr Ina Ansmann, marine vertebrate ecologist, University of Queensland, and the study's lead author.

Analysing how the population interacted before and after trawling meant the team could assess how the dolphins' social network had changed. "The dolphins had basically re-arranged their whole social system after trawling disappeared so they're now actually interacting again," Dr Ansmann told BBC Nature.

The scientists identified individual dolphins by the marks on their dorsal fin and recorded which animals were associating with which.

"Each dolphin has small injuries like nicks and notches, cuts and things like that on the fin so they all have a very unique looking dorsal fin." This technique meant that Dr Ansmann could observe changes in behaviour, in some cases down to the individual dolphins which had been studied in the 1990s to reveal the original division.

The "trawler" dolphins of Moreton Bay benefited from the bycatch thrown back from fishing boats "Presumably they're sharing information, co-operating and things like that." One of those males is now fully integrated into a single community.

Dolphins operate in what is called a fission-fusion society, forming groups and then splitting up to form different groups. Through complex communication and social intelligence, bottlenose dolphins often work as a team when hunting for food and Dr Ansmann believes this may be what lies behind the unification.

"When relying on natural food sources I guess it's more important for them to interact with others, or to learn from others, or to co-operate with others to get to these food sources," she said. The results suggest that a flexible social structure may be an important factor in how dolphins exploit a wide range of resources in the marine environment.

lunes, 10 de diciembre de 2012

A whale of a hearing system

New York, NY - Kina, a false killer whale, was the focus of a study about how marine mammals hear. A group of scientists led by marine biologist Paul Nachtigall discovered whales can "close" their ears, decreasing their sensitivity to loud noises underwater.

Scientists have long known that man-made, underwater noises – from engines, sonars, weapons testing, and such industrial tools as air guns used in oil and gas exploration – are deafening whales and other sea mammals. The Navy estimates that loud booms from just its underwater listening devices, mainly sonar, result in temporary or permanent hearing loss for more than a quarter-million sea creatures every year, a number that is rising.

Now, scientists have discovered that whales can decrease the sensitivity of their hearing to protect their ears from loud noise. Humans tend to do this with index fingers; scientists haven't pinpointed how whales do it, but they have seen the first evidence of the behavior.

"It's equivalent to plugging your ears when a jet flies over," said Paul E. Nachtigall, a marine biologist at the University of Hawaii who led the discovery team. "It's like a volume control."

The finding, while preliminary, is already raising hopes for the development of warning signals that would alert whales, dolphins and other sea mammals to auditory danger.

Peter Madsen, a professor of marine biology at Aarhus University in Denmark, said he applauded the Hawaiian team for its "elegant study" and the promise of innovative ways of "getting at some of the noise problems." But he cautioned against letting the discovery slow global efforts to reduce the oceanic roar, which would aid the beleaguered sea mammals more directly.

The noise threat arises because of the basic properties of seawater. Typically, light can travel for hundreds of feet through ocean water before diminishing to nothingness. But sound can travel for hundreds of miles.

The world's oceans have been getting noisier as companies and governments expand their undersea activities. Researchers have linked the growing racket to deafness, tissue damage, mass strandings and disorientation in creatures that rely on hearing to navigate, find food and care for their young. The danger has long been a political football.

In 2008, the Supreme Court heard a lawsuit by the National Resources Defense Council against the Navy over ocean noise; the court ruled that naval vessels had the right to test sonar systems for hunting submarines. But environmentalists saw a tacit victory in getting the nation's highest court even to consider the health of sea mammals in a debate over national security.

The latest development took place at a research facility off Oahu – at an island where the opening shots of "Gilligan's Island" were filmed. Scientists there are studying how dolphins and toothed whales hear. In nature, the mammals emit sounds and listen for returning echoes in a sensory behavior known as echolocation. In captivity, scientists taught the creatures to wear suction-cup electrodes, which revealed the patterns of brainwaves involved in hearing.

The discovery came in steps. First, Nachtigall and his team found that the animals could adjust their hearing in response to their own loud sounds of echolocation, mainly sharp clicks. The scientists then wondered if they could also protect their ears from incoming blasts.

The team focused on a false killer whale named Kina and sought to teach her a conditioned behavior similar to how Pavlov taught dogs to salivate upon hearing a bell.

First, the scientists played a gentle tone repeatedly. Then they followed the gentle pulse with a loud sound. After a few trials, the warning signal alone caused Kina to decrease the sensitivity of her hearing.

"It shows promise as a way to mitigate the effects of loud sounds," said Nachtigall, founding director of the Marine Mammal Research Program at the University of Hawaii. "People are generally very excited about it."

In May, Nachtigall and his colleagues presented the findings to acoustic scientists and groups meeting in Hong Kong, including the Acoustical Society of America. The team cited the protective deafening as a potential way to help sea mammals cope with noisy blasts from naval sonars, civilian air guns and other equipment.

In the future, the team plans to expand the research to other species in captivity and ultimately to animals in the wild.

"We have a problem in the world," Nachtigall said of the oceanic roar. "And we think the animals can learn this response very rapidly."

Scientists unconnected to the mammal research called it important.

"It's a big deal," said Vincent M. Janik, a prominent marine biologist at the University of St. Andrews in Scotland. In an email, he said it revealed a rare ability among the planet's creatures.

Carl Safina, president of the Blue Ocean Institute, a conservation group in Cold Spring Harbor, N.Y., called the discovery a potential window into what sea mammals may already do on some occasions to protect their hearing.

"I've sometimes wondered why these high intensity sounds don't cause problems all the time," he said in an interview. "Maybe it's that, once the animals hear something very loud, they can adjust their hearing – dial it down and protect themselves."

Scientists say the extraordinary hearing of sea mammals evolved to compensate for poor visibility beneath the waves and to take advantage of the unique qualities of seawater. Sound travels five times faster than in air and undergoes far less diminishment.

The heads of whales and dolphins are mazes of resonant chambers and acoustic lenses that give the animals not only extraordinary hearing but complex voices. The distinctive songs of humpback whales appear to be sung exclusively by males seeking mates.

In recent decades, scientists have linked the human cacophony to reductions in mammalian vocalization, which suggests declines in foraging and breeding. And the problem is poised to get worse: In May, the Navy disclosed draft environmental impact statements (Atlantic and Pacific operations) that said planned expansions could raise the annual hearing losses among sea mammals to more than 1 million.

Zak Smith, a lawyer with the Natural Resources Defense Council, recently called the new estimates "staggering." A question of science, Nachtigall said, is whether the levels of protective deafening found in Kina can be increased. The team plans to study the auditory response in such species as bottlenose dolphins and beluga whales before trying it on wild populations.

The big political hurdle is financing, he said. Federal support for the sea mammal research has declined in recent years, and industry is only starting to show interest in the finding.

"I'm pulling in money where I can," he remarked. Nachtigall said the research was costly because sea mammals need high levels of care.

But he called it revealing and rewarding. "When it comes to whales and sound," Nachtigall said, "we're just starting to understand."

lunes, 22 de octubre de 2012

A 10-fold rise in Marine Protected Areas has been recorded over a decade.

Hyderabad, UK - A 10-fold rise in Marine Protected Areas has been recorded over a decade.

A report to a UN meeting on biodiversity in Hyderabad reports that more than 8.3 million sq km - 2.3% of the global ocean area - is now protected.

The percentage is small but the rapid growth in recent times leads to hope that the world will hit its target of 10% protected by 2020.

This would have looked most unlikely prospect just a few years ago.

The aspiration was agreed by the Convention on Biological Diversity in 2004 with a target date of 2012. Progress was so slow at first that the target was slipped to 2020 - with some researchers forecasting it would not be reached until mid-century.

But recently there have been huge additions - like Marine Protected Areas (MPAs) in the UK-controlled Chagos archipelago and US-controlled uninhabited territories in the mid-Pacific.

The Cook Islands recently announced a 1.1 million sq km MPA - that is four times the area of the UK land mass. New Caledonia's is even bigger - 1.4 million sq km.

Australia has added a further 2.7 million sq km to its listing of the Great Barrier Reef. Now 28 countries have designated MPAs of more than 10%.

But these statistics may not be quite so impressive as they appear as most of them are far distant from people who would be likely to over-exploit them.

And a recent paper on the demise of the Barrier Reef demonstrates that declaring an area protected does not necessarily shield it from distant influences like over-nutrification.

Mark Spalding from the Nature Conservancy, lead author of the report, told BBC News: "This is great news in the sense that the prospect looked so hopeless until recently. We really should manage to meet the 10% target now.

"But we have to ask whether the targets in themselves are enough - or whether governments need to be smarter to ensure that they're protecting the very most important areas.

"I don't want to knock any of the MPAs but some appear to be easy wins, where you could stick a pin on a map and maybe send a patrol vessel. We need more than that."

Dr Spalding said it was vital now for nations to concentrate efforts on MPAs near heavily-populated coastlines where marine resources were most at risk.

The UK government has been accused of dragging its feet after postponing by a year the introduction of MPAs around the coast of England.

sábado, 20 de octubre de 2012

Passionate opinions voiced at NOAA hearing on 'taking' of beluga whales

Silver Spring, Md. - Passionate statements from aquarium officials and environmental activists alike over the importation of beluga whales resounded in a crowded but quiet meeting room at the National Oceanic and Atmospheric Administration Science Center Friday.
The issue at hand was the Atlanta-based Georgia Aquarium's application for a permit to import 18 beluga whales from Russia. While the Georgia Aquarium is seeking to import the whales, they would go to multiple destinations - possibly including several SeaWorld locations as well as Mystic Aquarium, which currently houses four beluga whales, also known as white whales.
The Marine Mammal Protection Act of 1972 prohibits the "take or import" of marine mammals but includes an exception for animals kept for educational public display or scientific research. NOAA officials held Friday's hearing as part of the process of gathering public comment before making a final decision, which is expected to be issued early next year.
NOAA regulations require only a 30-day public comment period prior to review of such an application, but the comment period for this particular application was extended to 60 days due to increased public interest.
The controversy over the permit request centers around whether these whales are truly being kept for educational purposes, and whether they are being imported in what the Marine Mammal Protection Act defines as a humane manner - or, in the words of the statute, a "method of taking which involves the least possible degree of pain and suffering practicable to the mammal involved."
Naomi Rose, a senior scientist with The Humane Society of the United States, questioned whether the belugas would be transported in a humane manner. Although aquarium officials said that they believed stress associated with capture and transport is short-lived, Rose said her organization disagrees.
"The most likely cause (of death in captive belugas), in my opinion, is chronic stress," she said, citing research conducted at Mystic Aquarium linking transportation and high levels of stress in beluga whales.
The Georgia Aquarium's chief veterinarian, Greg Bossart, sought to emphasize his enterprise's concern for the belugas' welfare and described its medical facilities as one of the largest and most modern aquarium hospitals in the world. Georgia Aquarium's Correll Center includes a surgery suite and a pathology room, along with water quality and diagnostic labs. Bossart also said that the belugas received regular, comprehensive medical exams as well as daily exams from their trainers.
Other objections to the permit request came from scientists and activists who do not consider the exhibits at Georgia Aquarium and SeaWorld parks "educational." Lori Marino, a neuroscientist who studies dolphin and whale intelligence at the Kimmela Center for Animal Advocacy, contended that no one was actually being educated at these locations.
"Theme parks publish material that is often false and misleading on dolphin and whale intelligence," she charged, adding that she believes these organizations downplay the animals' intelligence to rationalize keeping them in captivity.
Marino also described a course at Georgia Aquarium that was marketed as an "animal behavior" class, but which she regarded as a course in "animal husbandry."
But no shortage of educators lined up to defend the Georgia Aquarium, as school principals, teachers, and university professors from the Atlanta region praised the aquarium's beluga exhibit. They were enthusiastic about the hands-on nature of the aquarium, saying that students learned more by actually observing the animals rather than by listening to a lecture.
"With the aquarium, we can make every teacher's words come to life," declared Brian Davis, vice president of education and training at the Georgia Aquarium.

jueves, 18 de octubre de 2012

Misterio en Florida por un globo ocular gigante

Del tamaño de una bola de softbol, los especialistas están a la espera de los análisis genéticos para determinar a qué especie marina pertenece el gran ojo azul

El hallazgo del globo ocular gigante en una playa del sur de Florida ha causado alboroto en internet y en la comunidad de estudio de la biología marina.

El enorme globo ocular azul podría ser el de un calamar de aguas profundas o de un pez espada grande, dijo Heather Bracken-Grissom, profesora asistente en el Programa de Ciencia Marina de la Universidad Internacional de Florida en Miami.
Un hombre encontró el gran ojo cuando paseaba por la mañana en Pompano Beach justo al norte de Fort Lauderdale. Se puso en contacto con funcionarios estatales de vida silvestre, quienes tomaron posesión del globo ocular del tamaño de una bola de softbol.

Bracken-Grissom comentó que tan pronto como llegaron las fotografías el jueves a internet, comenzó a conversar con sus colegas. "Cada vez que algo extraño y demencial es arrastrado a la playa, resulta definitivamente interesante", agregó.

La profesora y sus colegas llegaron a la conclusión de que el cristalino y pupila del globo ocular son similares en forma a los del calamar de aguas profundas. Señaló que el globo ocular de esta especie puede ser tan grande como un balón de softbol y puede dislocarse fácilmente.

El misterio probablemente no se resolverá sino hasta que se terminen los análisis en el Instituto de Investigación de Vida Silvestre y pesca de Florida en St. Petersburg. "Va a ser muy interesante ver qué muestra el análisis genético", dijo Bracken-Grissom.

Añadió que la noticia sobre el globo ocular gigante viajó rápidamente; incluso familiares de California le llamaron por teléfono para preguntarle su opinión. "Algo como esto emociona mucho al público en relación con el misterioso reino del océano", señaló.

martes, 16 de octubre de 2012

Red tide affects Sarasota and Charlotte Beaches

A large red tide bloom, about 12 miles long and six miles wide, is lingering off the Charlotte-Sarasota County coastline and killing fish.

Mote Marine Laboratory publishes a twice-daily beach report that details whether dead fish are on the beach and whether lifeguards or other sentinels are feeling respiratory irritation from red tide.

Statwide red tide sampling results are published online every Friday by the FWRI.

As dead fish began washing ashore on beaches in Englewood this week, hotel owners and tourism officials were hopeful that the problem would not worsen or spread. But more dead fish are likely to land on the region's southern beaches in the coming days, as the bloom creeps north about six to nine miles offshore and winds shift, scientists predicted.

"So far we've been very lucky," said Virginia Haley, president of Visit Sarasota County, noting that "this is generally the time of year when we're going to have problems."

September and October are the most common months for red tide blooms, caused by toxic algae. Almost exactly a year ago a similar red tide bloom sporadically washed dead fish ashore from Venice to Naples for several weeks. A major bloom with widespread, lingering fish kills has not occurred in Southwest Florida since early 2007. Most years bring red tide blooms and fish kills to some part of the region.

Red tide naturally occurs in the Gulf of Mexico. Occasionally conditions allow the algae to accumulate in large numbers, creating a bloom that is deadly for fish, marine mammals, sea turtles and other sea life.

The bloom's toxins also can become airborne, causing significant breathing problems for people with asthma or other respiratory diseases. The toxins also cause healthy people to cough or sniffle.

As of midweek, the red tide effects were limited to southern Sarasota and Charlotte counties. No dead fish or bad air quality were reported on beaches north of Venice.

"There has been no indication of red tide yet, so we have not disturbed our guests and residents about it," said Edward Braunlich, general manager of Hyatt Siesta Key Beach. If the bloom reaches Siesta Key shores this week, Braunlich said precautionary literature will be given to each hotel guest.

Scientists at Mote Marine Laboratory, the University of South Florida and the state Fish and Wildlife Conservation Commission are monitoring the bloom to track its dimensions and location.

Underwater robots that test for the algae will be deployed in a joint experiment between Mote and USF next week, said Jason Lenes, research associate for the Center for Prediction of Red Tides at USF.

He said a cold front sweeping through the region pushed the bloom toward the coast and will shift winds northward after it passes. The change is likely to cause more fish to land on beaches.

"Right now that main patch, the chunk of it, is heading straight north, slightly toward the coast," Lenes said, referring to the red tide outlook for the next three days.

Scientists cannot predict whether the bloom will grow or where it will move beyond about three days, Lenes said.

Sarasota County crews are cleaning up dead fish along Blind Pass and Manasota Key in Englewood, said Curt Preisser, a county spokesman.

In the meantime Mote Marine scientists are "watching beach conditions like hawks," said Barbara Kirkpatrick, senior scientist with the research laboratory in Sarasota.

Scientists will continue to take water samples along the coast this week, concentrating additional effort on Charlotte Harbor.

domingo, 14 de octubre de 2012

Ecologists Start New Antarctic Season

Bozeman, MT — Montana State University ecologists who are about to return to Antarctica for another season had to adapt to dramatic changes in the sea ice last year.

Now they have published a paper that says the Weddell seals they monitor had to deal with some dramatic changes in ice in recent years, too. In fact, the seals handled the adverse conditions well and suffered less than the Emperor penguins in that region.

The paper was published Sept. 26 in the international journal, Proceedings of the Royal Society B: Biological Sciences. Lead author was Thierry Chambert, a doctoral student supervised by co-authors Bob Garrott and Jay Rotella in the MSU ecology department. Rotella and Garrott have just received a National Science Foundation grant for $867,272 that will extend their long-term study by five more years.

Last year, the researchers encountered unusually thin ice that was three feet thick instead of the usual 12 to 16 feet, Garrott said. Large cracks and active breaks threatened snowmobile travel. As a result, the faculty members and students moved their base camp to a safer spot and set up emergency camps around their study area. When they couldn't cross the ice on snowmobiles, they flew by helicopter.

In the course of their work, Rotella said the researchers saw how the Weddell seals faced their own challenges from massive icebergs that broke off and dramatically changed sea-ice conditions in a number of recent years.

Using data from 29 years, the team was able to compare seal numbers, as well as rates of pup production and adult survival, from before, during, and after the iceberg event, to learn how the seals fared. The number of seals they observed and the number of pups that were born during the peak of the iceberg event were down to unprecedented low numbers, but monitoring showed that, "the seals, in fact, handled the event quite well," Rotella said.

He explained that the seals were able to maintain high survival rates by lowering their breeding efforts during the years of iceberg presence. They tended to avoid breeding colonies when sea-ice conditions were particularly unfavorable.

The Emperor penguins, however, continued their normal activities during the worst of the iceberg event. The result was dramatic with dying penguins, as well as breeding failures, Rotella said. He noted that moving ice crushed eggs and even some adults at the peak of the iceberg event. Exhaustion and starvation might also have been an issue for penguins that walked across the ice from open water to their nesting colonies.

"These results reveal that, depending on their ecology, different species can suffer different impacts from an extreme environmental disturbance," said Rotella, the new leader of the Weddell seal study.

"The results also reveal the importance of having long-term data to evaluate possible effects," Rotella continued. "Without the data, we couldn't have known whether this extreme environmental event had extreme consequences for the seals or not. Fortunately for the seals, it did not. We learned that the seals were quite capable of riding out the massive changes in ice conditions as long as they didn't persist too long."

Rotella said the relationship between thinner ice and icebergs is outside of his field of expertise, but he said that ice provides protection from predators like orcas and leopard seals. It also serves as a platform for Weddell seals in the first few weeks of their lives when they have little fat for staying warm in the water and can't swim well yet. When the ice is thinner, predators have better access to the breeding areas used by penguins and Weddell seals for rearing their young. It is also easier for storms to shatter the ice sheets and for the area to have open water.

No one knows what this season will bring for sea-ice conditions, but the MSU researchers said they hope it isn't a repeat of last year.

"That was very challenging," Garrott said. "We really don't know what the ice conditions are like this year until we get down there."

This year's field season will run from about Oct. 10 to mid-December, with Rotella going down for the first half of the season and Garrott for the second half. Mary Lynn Price, a video journalist who has joined the group for the past two seasons, will be there for three weeks in the middle, with her stay overlapping Rotella's and Garrott's.

Price will again produce a variety of videos and other materials that will be available to the public.

This will be the 45th season for the study that Garrott and Rotella took over around 2001 from Don Siniff at the University of Minnesota. Initiated by Siniff, the study is one of the longer running animal population studies and the longest marine mammal study in the southern hemisphere. It not only focuses on changes in the Weddell seal population, but it yields broader information about the workings of the marine environment. The study incorporates information on sea ice, fish, ecosystem dynamics, climate change, and even the Antarctic toothfish, which is marketed in U.S. restaurants as Chilean sea bass.

The MSU study concentrates on pups and adult breeding females that live in the Ross Sea, which is the most pristine ocean left in the world and the only marine system whose top predators -- including the Weddell seal -- still flourish.

The researchers start the season by weighing and tagging every pup when it's about two days old. Later in the season, they visit every colony in their study, collecting genetic samples and recording every tag they find. Weddell seals are relatively gentle for being a top predator in the ecosystem, but they can weigh over 1,000 pounds and have a set of teeth like a bear's, Garrott has said in the past.

viernes, 12 de octubre de 2012

It's not too late for Coral reefs

Fort Lauderdale, FL — Coral reefs -- ecosystems of incredible environmental and economic value -- are showing evidence of significant degradation, but do not have to be doomed. We can make a difference.

Once plentiful, coral reefs worldwide and locally have been ravaged by a number of stresses, including global threats like rising sea temperatures and ocean acidification, and local threats like pollution, overfishing and coastal development. An estimated 25-30 percent of the world's coral reefs are already severely degraded or lost, and another very high percentage are in danger of greater impact or worse. Some even predict reefs could be essentially wiped out within a human generation unless action is taken.

The coral reef issue is not only an environmental problem, but an economic one. The United Nations estimates globally, coral reefs generate over $172 billion per year from the services they provide including tourism, recreation and fisheries. In South Florida alone, where 84 percent of the nation's reefs are located, reef ecosystems have been shown to generate over $6 billion in annual economic contributions and more than 71,000 jobs.

In July, hundreds of scientists joined in a consensus statement written at the recently held 12th International Coral Reef Symposium in Cairns Australia, stating: "Across the globe, these problems cause a loss of reef resources of enormous economic and cultural value. A concerted effort to preserve reefs for the future demands action at global levels, but also will benefit hugely from continued local protection."

Is there good news for the posterity of reefs? There can be. Research is allowing greater understanding about how reefs response to threats. Consequently, there are clear steps that must be taken to ameliorate stresses. Some of these are easy fixes that include stopping overfishing, controlling pollution and establishing marine protected areas. Others, like the rising ocean temperatures that are causing coral bleaching or the increasing acidity in our oceans, are more complex.

Research can also help us learn how to restore these valuable reefs. This includes raising corals in places where larvae and juveniles are nurtured in a relatively safe environment before being moved to a location where we can hope to restore a coral population.

Offshore coral nurseries are showing tremendous potential for restoration. A corollary, and less studied technique, is to grow corals under more controlled conditions in on-land nurseries where they are less subject to stress and variation. These specimens can then be transplanted back to degraded reefs that need a kick start. It's a fairly new idea -- and one among others that we hope will lead to increasing the tools for restoring coral reefs.

Because coral nurseries can play a significant role in restoration, we are expanding our grow-out facilities. With our new reef research facility, the Center of Excellence for Coral Reef Ecosystems Research in Hollywood, Fla., we will triple the size of our land-based coral nursery operation. Our offshore nursery research area with thousands of corals will continue its efforts. We'll use state-of-the-art facilities to study coral stressors in a controlled environment in order to better understand the impacts of these threats and how to better take corrective actions.

There are many unanswered research questions: What size of coral best survives transplantation? When is the optimum time to conduct the transplantation? What genetic strains and mix of a single species will have greatest survivorship? How are the most appropriate species for restoration? How long does it take to restore a reef?

Coral reefs are the rainforests of the sea. And like the Amazonian rainforest that's facing extreme degradation, reefs are disappearing at an alarming rate. We are embarking on a critical mission to understand and restore reef ecosystems. It's a mission that must be accomplished.

miércoles, 10 de octubre de 2012

Why is It illegal ti ride a manatee?

Tampa, FL - Anyone looking for cheap thrills and a quick brush with nature should reconsider thoughts of riding a manatee. As a Florida woman is learning, multiple federal and state laws can be swiftly wielded in defense of the vulnerable sea cow.

Ana Gloria Garcia Gutierrez, 52, accused of riding a manatee in a waterway in Pinellas County over the weekend, turned herself in after authorities on her trail released photos that appear to show her mid-ride.

The Florida Manatee Sanctuary Act outlaws riding or touching the slow-moving marine mammals. And while Gutierrez wasn't immediately charged, her alleged crime is punishable by a $500 fine or a jail term of up to 60 days, according to the Tampa Bay Times.

There was no immediate indication that federal charges would be pressed, but Gutierrez's alleged offense also would violate the Marine Mammal Protection Act and the U.S. Endangered Species Act, under which she could be subject to thousands of dollars in additional fines for harassing a protected species.

Such penalties may seem outsized for a joy ride on a thick-skinned manatee, which was not thought to have been physically injured in the encounter. But authorities' refusal to regard Gutierrez's alleged crime as harmless whimsy is perhaps acknowledgement that human interactions with manatees are precisely what threaten to end the endangered animal's existence.

The same easygoing and curious nature that would likely predispose a manatee to taking on a human passenger seems to contribute to the species' vulnerability to being mowed down by passing speed boats. [Manatee Mystery: Why Can't They Avoid Speedboats?]

About 87 Florida manatees are killed by humans every year, according to the U.S. Fish and Wildlife Service, most of them dying in boat collisions. And with an estimated Florida population of 3,800 manatees, 87 is a grave number.

Coastal development, which has altered and destroyed manatee habitat, also threatens the species.

Swimmers seeking a visceral interaction with a non-manatee marine mammal, take note: Riding a dolphin — the gazelle to the manatee's cow — also violates federal law.

lunes, 8 de octubre de 2012

Lakes React Differently to Warmer Climate

Lund, SWEDEN — A future warmer climate will produce different effects in different lakes. Researchers from Lund University in Sweden have now been able to explain that the effects of climate change depend on what organisms are dominant in the lake. Algal blooms will increase, especially of toxic blue-green algae.

The study in question has been carried out by a group of researchers at the Department of Biology at Lund University. The research team is specifically focusing on predictions regarding how our water resources will be like in the future, in terms of drinking water, recreation, fishing and biodiversity. They have now published findings on the impact of a warmer climate on lakes in the journal Nature Climate Change.

"The most interesting and unexpected result from the study is that the reaction to climate change will vary between lakes; this has been observed previously but has puzzled researchers. We have shown that the variation is dependent on what organisms are dominant in the lake," says Lars-Anders Hansson, Professor of Aquatic Ecology at Lund University.

In lakes without fish, a warmer climate will lead to clear water without algal blooms. However, the results will be different in lakes containing fish. There, the warmer climate will benefit the fish, which will eat up large quantities of crustaceans (zooplankton). These crustaceans keep the algae in check. When the number of crustaceans falls, the algae will be free to multiply, and algal blooms will increase.

"Since most lakes close to humans contain fish and are also already eutrophicated, we can expect to have to deal with algal blooms even more in the future," says Lars-Anders Hansson.

Conditions will be particularly favourable for the development of blue-green algae, and this is an even greater cause for concern, in the view of Lars-Anders Hansson. Blue-green algae, also known as cyanobacteria, are the type of algae that cause the most problems in lakes and oceans because they form very strong and often toxic algal blooms.

The researchers already know that climate change is expected to lead to a rise in temperatures of 2-5o C within the lifetime of the coming generation. An increase in leaching of humus-rich water from land and forests is also expected, which will at least double the brownness of the lake water.

"We know that we are going to see a change in the climate, but we are also seeing other major environmental changes taking place, for example 'brownification'. This means that we have several simultaneous changes that will interact and possibly create synergies," says Lars-Anders Hansson.

In the Future Water research project, a large experiment has been set up based on these conditions, in order to study what impact they may have on organisms and water quality in the future.

sábado, 6 de octubre de 2012

Life Cycle of blue-crab parasite unraveled

Gloucester Point, VA — Professor Jeff Shields and colleagues at the Virginia Institute of Marine Science have succeeded in their 15-year effort to unravel the life history of Hematodinium, a single-celled parasite that afflicts blue crabs and is of growing concern to aquaculture operations and wild fisheries around the world.

Knowledge of the parasite's complex life cycle -- gained by rearing of successive generations across a full year in a VIMS laboratory -- will help guide efforts to understand the transmission of Hematodinium within crab populations and shrimp farms, and to develop best practices for the handling of animals within Virginia's fishery for wild-caught blue crabs.

"Describing the entire life cycle of Hematodinium was an important breakthrough for us," says Shields. "Having all stages in culture means we can now really start picking the life cycle apart to learn what the organism does and how it functions."

One important finding, says Shields, is "that we now know that the development time in culture is around 40-50 days. That matches well with cycles of infection that we see in the field, which we think occur in relation to molting in the blue crab."

"We also now realize that the parasite is a broad host generalist," he adds. "That's important to know for both modeling and management. You can't just fish the blue crabs out of an area and expect to get rid of the pathogen, as it's also present in a number of other host species, including amphipods, fiddler crabs, spider crabs, mud crabs, and other swimming crabs."

The team's achievement -- funded in part by a 5-year grant from the National Science Foundation -- was reported in the journal Parasitology, with Dr. Caiwen Li as lead author. Li authored the paper while a post-doctoral researcher in Shield's Crustacean Diseases Laboratory on the VIMS campus in Gloucester Point; he is now a professor at the Chinese Academy of Sciences' Institute of Oceanology in Qingdao, China.

Hematodinium was first reported from the Eastern Seaboard in the mid-1970s, and first noted in Virginia's blue crabs in the early 1990s. During disease outbreaks, crab mortality can reach 50% in crab pots, and 75% in shedding facilities for soft-shell crabs on Virginia's Eastern Shore. Infections are generally fatal with crabs dying from energy depletion or disruption of bodily tissues. The disease is not harmful to humans.

Dr. Hamish Small­, an assistant research scientist in the Shield's Lab at VIMS, began his career studying Hematodinium in lobsters in his native Scotland. He says, "Hematodinium infections are now increasing in frequency and are being encountered in new hosts and locations worldwide."

Crab growers in China reported their first case of Hematodinium in 2004; and, in 2008, other Chinese growers reported a Hematodinium outbreak in shrimp -- the first time the disease has been noted in this popular aquaculture organism.

The Chinese outbreaks are of concern not only in China, but in the U.S. and other nations as well. NOAA's most recent report on U.S. fisheries notes that more than 90% of the 4.7 billion pounds of seafood consumed in the U.S. in 2011 was imported, with shrimp the most popular item. Moreover, almost half the imports come from aquaculture, with China -- the world's largest aquaculture grower -- producing 32 million metric tons of cultured seafood in 2008.

In a recent theme issue of the Journal of Invertebrate Pathology, Small, Shields, and a host of other crustacean-disease experts from across the globe raise concerns about Hematodinium's growing threat, and its movement between wild and farmed populations. They note that the parasite likely entered the Chinese crab and shrimp farms though the filling of ponds using nearby coastal waters, and caution that it is just as likely to move in the opposite direction -- with transmission from the fertile breeding grounds of crowded crab and shrimp ponds back into wild populations and fisheries.

In a review of Hematodinium's global diversity and distribution -- published as part of the same theme issue -- Small writes "Hematodinium infections have the potential to significantly impact wild host crustacean populations and associated fisheries." In another theme-issue article, Shields notes that Hematodinium may cause more than $500,000 in losses per year to blue crab fishery in Virginia.

Hematodinium most commonly infects younger crabs, with researchers reporting prevalence levels of 50 to 70% among juvenile blue crabs from Virginia's seaside bays. "Infections are most prevalent in saltier waters," says Shields. "You get very high prevalence of infection on the Eastern Shore, and in coastal bays along the entire East Coast of the U.S. It affects the smaller fisheries in the coastal bays."

Shields and his colleagues suspect that the parasite also has a significant indirect impact on the larger blue-crab fishery within Chesapeake Bay, with untold losses due to the death of young crabs before they can complete their migration from coastal spawning grounds into freshwater tributaries where they might otherwise grow big enough to harvest.

"The crabs have to come through high-salinity waters as juveniles," says Shields, "where we find a very high prevalence of the disease. We suspect that Hematodinium induces a fairly high mortality load on the juvenile crabs as they are moving into the Bay. Imagine a harvest with 50% more crabs and the effect of the parasite becomes quite clear."

Recent laboratory experiments by Shields and graduate student Anna Coffey help explain the parasite's inability to survive in fresher waters. Their findings, reported in the June issue of the Journal of Parasitology, show that Hematodinium can develop within the body tissues of blue crabs living in low-salinity conditions, but that the parasite's spores are incapable of transmission in this environment.

"Infected crabs can move into low-salinity waters," says Shields, "but any parasites they release can't survive long enough to infect new crab hosts."

Knowledge of Hematodinium's life cycle and routes of transmission suggests several preventive measures to reduce the parasite's impact on aquaculture operations and wild fisheries.

"Most of our recommendations for the wild fishery involve changes in capture and processing methods," says Shields. "There are low-cost preventative measures to not only stop the spread of disease but to improve the harvest from the soft-shell industry."

Measures to prevent the spread of Hematodinium and other crustacean diseases in aquaculture include isolating ponds from nearby water bodies, stocking ponds with larvae from disease-free hatcheries or from adult crustaceans that have been certified as disease-free, educating farmers about best-management practices, and avoiding the practice of rearing several species together in a single pond, which can encourage transmission of parasites between susceptible crustaceans.

The next frontier in Hematodinium research -- under active pursuit at VIMS with collaborator Professor Kim Reece -- is to improve understanding of the parasite's genetics, so that researchers can more accurately and quickly distinguish between related species and track their interactions as they spread and mingle via ocean currents, natural movements of their hosts, and human activities such as shipping and aquaculture.

"It's difficult to tell different species of Hematodinium apart based just on their external appearance," says Small. "Genetic tools will allow us to more readily compare characteristics like virulence, transmission routes, and potential hosts among different isolates or species."

"The combination of genetic tools with life-cycle studies will make for a powerful approach to understanding this group of parasites," says Shields.

jueves, 27 de septiembre de 2012

Japan Escalates Politically Motivated Attacks Upon Eco-Hero Captain Paul Watson and Sea Shepherd

Captain Paul Watson
FRIDAY HARBOR, Wash. — September 16, 2012 — Interpol reports it has issued a second `red notice' to its member nations for Captain Paul Watson — iconic marine conservationist and founder of Sea Shepherd Conservation Society, and focus of the hit docu-reality TV series "Whale Wars." This notice was issued at Japan's request and was clearly filed in retribution for the eco-hero and his nonprofit's successful interventions against Japanese whaling in an established, internationally designated whale sanctuary.

Captain Watson's first `red notice' was issued in August at Costa Rica's request after he was arrested in Frankfurt on May 13 on a 10-year-old warrant from Costa Rica while en route to Cannes, France. He forfeited his bail and departed Germany on approximately July 22 after being held there under house arrest for 70 days, and is now in an undisclosed location. Captain Watson was being detained in Germany for extradition to Costa Rica for a previously alleged "violation of ship traffic," which reportedly occurred during the 2002 filming of the award-winning documentary, "Sharkwater." The so-called "violation" occurred during the course of Captain Watson enforcing the law at the request of the Guatemalan government against illegal shark-finners whom just the year prior had been charged and found guilty of the same crime.

According to Interpol, Captain Watson is being sought for prosecution by Japan on charges of `Breaking into the Vessel, Damage to Property, Forcible Obstruction of Business, and Injury' pertaining to two incidents that occurred in the Antarctic Ocean in February 2010 against a Japanese whaling ship. However, the extradition `red notice' from Japan is based solely on the testimony of a former Sea Shepherd associate in a plea bargain deal he made to avoid serving prison time in Japan. In essence, Japan, who has been after Captain Watson for years, found a turncoat in the former associate, who swapped his own head for Captain Watson's.

According to legal counsel for Captain Watson, filing for this `red notice' with Interpol on the heels of Costa Rica's request absolutely confirms the organization's strong suspicions that, due to Sea Shepherd's sweeping success in protecting whales in the Southern Ocean Whale Sanctuary, Japan is also behind the Costa Rican warrant to have Captain Watson extradited.

"News of the filing of the requested `red notice' from Japan does not come as a surprise," said Susan Hartland, Administrative Director of Sea Shepherd. "This is simply indicative of the lengths to which Japan will go to plunder our oceans. We have been expecting this for weeks and our legal counsel is already challenging these retaliatory, politically motivated, bogus charges to get them dismissed," she added.

Hartland went on: "None of these charges held up in court when Japan's Institute for Cetacean Research (ICR), a front for the nation's commercial whaling endeavors, tried to bring suit against Sea Shepherd in the U.S. In fact, the judge ruled against them in the preliminary injunction in February. The Japanese whalers sliced the Ady Gil vessel in half and almost killed six of our volunteer crew and have never had to answer for any of those actions, yet they dare accuse Sea Shepherd of wrongdoing."

Sea Shepherd has challenged Japan in the Antarctic Whale Sanctuary for eight seasons and is currently preparing to head to Antarctica for a ninth year with a bigger and stronger fleet than ever before, which includes a new vessel. "The Japanese whalers are sorely mistaken if they think another `red notice' is going to stand in the way of Sea Shepherd's defense of the whales this season," Hartland said. "It will in no way impact Sea Shepherd's next Antarctic campaign, Operation Zero Tolerance, whose goal it is to send the whaling fleet home with zero kills."

• An Interpol `red notice' is not an international arrest warrant. It merely heightens awareness of the Japanese warrant in the form of a notice to its member nations. Member nations may or may not abide by the notice at their discretion; it is not a warrant in itself.

• The specific incident relating to the Japanese warrant relates to an incident in 2010 when former crew member Pete Bethune boarded a Japanese whaling vessel to confront the captain who sliced his ship the Ady Gil, operating on behalf of Sea Shepherd, in two, despite Captain Watson's advice to Bethune not to do so. The impact injured a cameraman, nearly drowned the other crew members, and destroyed a $1.5 million dollar vessel, for which Japan has not even been questioned.

• The specific incident relating to the Costa Rican warrant took place in Guatemalan waters in 2002, when Sea Shepherd encountered an illegal shark-finning operation run by the Costa Rican vessel, the Varadero I. On order of Guatemalan authorities, Sea Shepherd instructed the crew of the Varadero I to cease their shark-finning activities and head back to port to be prosecuted. While escorting the Varadero I back to port, the tables were turned and a Guatemalan gunboat was dispatched to intercept the Sea Shepherd crew. To avoid the Guatemalan gunboat, Sea Shepherd then set sail for Costa Rica, where the crew uncovered even more illegal shark-finning activities in the form of dried shark fins by the thousands on the roofs of industrial buildings.

About Captain Paul Watson

Sea Shepherd Founder and President Captain Paul Watson is a world renowned, respected leader in environmental issues. He was a co-founder of Greenpeace, has won countless awards for his decades of conservation work, and in 2000 was named one of Time Magazine's Top 20 Environmental Heroes of the 20th Century.

About Sea Shepherd Conservation Society

Established in 1977, Sea Shepherd Conservation Society (SSCS) is an international non-profit conservation organization whose mission is to end the destruction of habitat and slaughter of wildlife in the world's oceans in order to conserve and protect ecosystems and species. Sea Shepherd uses innovative direct-action tactics to investigate, document, and take action when necessary to expose and confront illegal activities on the high seas. By safeguarding the biodiversity of our delicately balanced oceanic ecosystems, Sea Shepherd works to ensure their survival for future generations. Visit for more information.

lunes, 24 de septiembre de 2012

An international research team, led by Institute of Oceanology of Chinese Academy of Sciences and BGI

Shenzhen, CHINA – An international research team, led by Institute of Oceanology of Chinese Academy of Sciences and BGI, has completed the sequencing, assembly and analysis of Pacific oyster (Crassostrea gigas) genome—the first mollusk genome to be sequenced—that will help to fill a void in our understanding of the species-rich but poorly explored mollusc family. The study, published online today in Nature, reveals the unique adaptations of oysters to highly stressful environment and the complexity mechanism of shell formation.

"The accomplishment is a major breakthrough in the international Conchological research, with great advancement in the fields of Conchology and Marine Biology." said, Professor Fusui Zhang, Academician of Chinese Academy of Sciences, and a well-known Chinese Scientist of Conchology, "The study will provide valuable resources for studying the biology and genetic improvement of molluscs and other marine species. "

Oysters are a soft-bodied invertebrate with a double-hinged shell, which make up an essential part of many aquatic ecosystems. They have a global distribution and for many years they have much higher annual production than any other freshwater or marine organisms. In addition to its economic and ecological importance, the unique biological characteristics of oyster make it an important model for studying marine adaptations, inducing a great deal of biological and genomics research. The completed sequencing of oyster genome will provide a new horizon into understanding its natural mechanisms such as the adaptations to environmental stresses and shell formation, better exploration of marine gene resource, , among others.

Unlike many mammals and social insects, oyster as well as many other marine invertebrates is known to be highly polymorphism, which is a challenge for de novo assembling based on current strategies. In this study, researchers sequenced and assembled the Pacific oyster genome using a combination of short reads and a "Divide and Conquer" fosmid-pooling strategy. This is a novel approach developed by BGI, which can be used to study the genomes with high level of heterozygosity and/or repetitive sequences. After data process, the assembled oyster genome size is about 559 Mb, with a total of ~28,000 genes.

Based on the genomic and transcriptomic analysis results, researchers uncovered an extensive set of genes that allow oysters to adapt and cope with environmental stresses, such as temperature variation and changes in salinity, air exposure and heavy metals. For example, the expansion of heat shock protein 70 (HSP 70) may help explain why Pacific oyster can tolerate high temperatures as HSP family is expanded and highly expressed when in high temperature. The expansion of inhibitors of apoptosis proteins (IAPs), along with other findings, suggested that a powerful anti-apoptosis system exists and may be critical for oyster's amazing endurance to air exposure and other stresses. One notable finding on development is that the oyster Hox gene cluster was broken, and there are unusual gene losses and expansions of the TALE and PRD classes. Hox genes are essential and play critical important role in body plan, the Hox clusters are found to be more conserved in many organisms.

Researchers found paralogs might have the function to change the gene expression for better coping with the stresses. This result suggested that expansion and selective retention of duplicated defense-related genes are probably important to oyster's adaptation. Moreover, many immune-related genes were highly expressed in the digestive gland of the oyster, which indicated its digestive system was an important first-line defense organ against pathogens for the filter-feeder. The shell provides a strong protection against predation and desiccation in sessile marine animals such as oysters.

At present, two models have been proposed for molluscan shell formation, but neither of them is accurate enough. In this study, by sequencing the peptides in the shell, researchers identified 259 shell proteins, and further analysis revealed that shell formation was a far more complex process than previously thought. They found many diverse proteins may play important roles in matrix construction and modification. The typical ECM proteins such as Laminin and some collagens were highly expressed in shells, suggesting that shell matrix has similarities to the ECM of animal connective tissues and basal lamina. Hemocytes may mediate fibronectin (FN)-like fibril formation in the shell matrix as they do in ECM. Furthermore, the functional diversity of proteins showed that the cells and exosome may participate in the shell formation.

Xiaodong Fang, Primary Investigator of this project at BGI, said, "The assembly approach of Oyster genome opens a new way for researchers to better crack the genomes with high-heterozygosity and high-polymorphism. The Oyster genome sheds insights into the comprehensive understanding of mollusc genomes or even lophotrochozoa genomes at the whole genome-wide level, with focuses on the studies of diversity, evolutionary adaptive mechanisms, developmental biology as well as genomics-assisted breeding."

sábado, 22 de septiembre de 2012

the Arctic continues to shrink during this century

Seattle, WA — As sea ice in the Arctic continues to shrink during this century, more than two thirds of the area with sufficient snow cover for ringed seals to reproduce also will disappear, challenging their survival, scientists report in a new study.

The ringed seal, currently under consideration for threatened species listing, builds caves to rear its young in snow drifts on sea ice. Snow depths must be on average at least 20 centimeters, or 8 inches, to enable drifts deep enough to support the caves.

"It's an absolute condition they need," said Cecilia Bitz, an associate professor of atmospheric sciences at the University of Washington. She's a co-author of the study, published in the journal Geophysical Research Letters.

But without sea ice, the platform that allows the snow to pile up disappears, ultimately reducing the area where the seals can raise their pups.

Bitz typically focuses on studying the area and thickness of sea ice. "But when a seal biologist telephoned and asked what our climate models predict for snow depth on the ice, I said, 'I have no idea,'" she said. "We had never looked."

That biologist was co-author Brendan Kelly of the National Science Foundation and he was curious about the snow depth trend because he was contributing to a governmental report in response to the petition to list the seals as threatened.

The researchers, including lead author and UW atmospheric sciences graduate student Paul Hezel, found that snowfall patterns will change during this century but the most important factor in determining snow depth on the ice will be the disappearance of the sea ice.

"The snowfall rate increases slightly in the middle of winter by the end of the century," Hezel said. However, at the same time sea ice is expected to start forming later in the year than it does now. The slightly heavier snowfall in the winter won't compensate for the fact that in the fall -- which is also when it snows the heaviest -- snow will drop into the ocean instead of piling up on the ice.

The researchers anticipate that the area of the Arctic that accumulates at least 20 centimeters of snow will decrease by almost 70 percent this century. With insufficient snow depth, caves won't hold up.

Other climate changes threaten those caves, too. For instance, the snow will melt earlier in the year than it does now, so it's possible the caves won't last until the young seals are old enough to venture out on their own. In addition, more precipitation will fall as rain, which soaks into the snow and can cause caves to collapse.

The research is important for more than just the ringed seals. "There are many other reasons to study snow cover," Hezel said. "It has a huge thermodynamic impact on the thickness of the ice."

Snow on sea ice in fall and winter acts like a blanket that slows the release of heat from the relatively warm ocean into the atmosphere. That means deeper snow tempers sea ice growth.

In the spring, snow has a different impact on the ice. Since snow is more reflective than ice, it creates a cooling effect on the surface. "So the presence of snow helps sustain the icepack into spring time," Hezel said.

To produce the study, the scientists examined 10 different climate models, looking at historic and future changes of things like sea ice area, precipitation, snowfall and snow depth on sea ice. The resulting prediction for declining snow depth on sea ice this century agreed across all of the models.

The new research comes too late to be cited in the report about ringed seals that was written by the National Oceanic and Atmospheric Administration in response to the petition to list the ringed seal as threatened. However, it confirms results that were based on a single model that Bitz provided for the report two years ago. NOAA expects to issue its final decision soon.

jueves, 20 de septiembre de 2012

A man who survived while adrift in the Pacific for 106 days

KIRIBATI - A man who survived while adrift in the Pacific for 106 days is crediting a shark for helping to save his life.

Toakai Teitoi, 41, a policeman from the Central Pacific island nation of Kiribati, had been traveling with his brother-in-law on what was supposed to be a short voyage, beginning May 27, from the Kiribati capital of Tarawa to his home island of Maiana.

But the mariners decided to fish along the way, and fell asleep during the night. When they awoke they were far at sea and adrift in their 15-foot wooden vessel. They soon ran out of fuel, and were short on water.

"We had food, but the problem was we had nothing to drink," Teitoi told Agence France-Presse news service.

Dehydration was severe. Falaile, the 52-year-old brother-in-law, died on July 4. That night, Teitoi slept next to him, "like at a funeral," before an emotional burial at sea the next morning.

Teitoi shared scant details of the ordeal after arriving in Majuro, in the Marshall Islands, on Saturday. He said he prayed the night Falaile died, and the next day a storm arrived and, over the next several days, he was able to fill two five-gallon containers with fresh water.

Days and weeks passed, however, and Teitoi, a father of six, did not know whether he'd live or die. He subsisted mostly on fish and protected himself against the searing tropical sun by curling up in a small, covered portion of the bow.

It was on the afternoon of Sept. 11 that he awoke to the sound of scratching against his boat. A six-foot shark was circling the boat and, Teitoi said, bumping against its hull.

"He was guiding me to a fishing boat," Teitoi said. "I looked up and there was the stern of a ship and I could see crew with binoculars looking at me."

The first thing he asked for after he was plucked from the water was a cigarette, or "a smoke." He was given food and juice and his rescuers continued to fish for several days before delivering him to Majuro.

Teitoi, who seemed in good health, said he booked flights back to his home island, adding, "I'll never go by boat again."

The record for drifting at sea is believed to be held by two fishermen, also from Kiribati, who were at sea for 177 days before coming ashore in Samoa in 1992.

domingo, 9 de septiembre de 2012

The new DNA-method

Copenhagen, DENMARK — Danish researchers at University of Copenhagen lead the way for future monitoring of marine biodiversity and resources by using DNA traces in seawater samples to keep track of fish and whales in the oceans. A half litre of seawater can contain evidence of local fish and whale faunas and combat traditional fishing methods. Their results are now published in the international scientific journal PLOS ONE.

"The new DNA-method means that we can keep better track of life beneath the surface of the oceans around the world, and better monitor and protect ocean biodiversity and resources," says PhD student Philip Francis Thomsen from the Centre for GeoGenetics, Natural History Museum of Denmark, University of Copenhagen.

Marine ecosystems worldwide are under threat with many fish species and populations suffering from human over-exploitation, which greatly impacts global biodiversity, economy and human health. Today, marine fish are largely surveyed using selective and invasive methods mostly limited to commercial species, and restricted to areas with favourable conditions.

However, researchers at Centre for GeoGenetics now lead the way for future monitoring of marine biodiversity. They have shown that seawater contains DNA from animals such as fish and whales. The species leave behind a trace of DNA that reveals their presence in the ocean based on water samples of just half a litre.

The development of the novel DNA monitoring approach was accomplished by PhD student Philip Francis Thomsen and Master's student Jos Kielgast from the Centre for GeoGenetics headed by Professor Eske Willerslev. In December last year, they showed that small freshwater samples contain DNA from several different threatened animals, and after having published these results they began to focus on seawater. Here it also proved possible to obtain DNA directly from the water, which originated from local species living in the area.

"We analysed seawater samples specifically for fish DNA and we were very surprised when the results started to show up on the screen. We ended up with DNA from 15 different fish species in water samples of just a half litre. We found DNA from both small and large fish, as well as both common species and rare guests. Cod, herring, eel, plaice, pilchard and many more have all left a DNA trace in the seawater," says Philip Francis Thomsen.

In the other study the researchers showed that it is also possible to obtain DNA from harbour porpoise in small water samples taken in the sea, so the approach is not only limited to fish, but can also track large marine mammals.

The study also compares the new DNA method with existing methods traditionally used for monitoring fish such as trawl and pots. Here, the DNA method proved as good as or mostly better than existing methods. Moreover, the DNA method has a big advantage that it can be performed virtually anywhere without impacting the local habitat -- it just requires a sample of water. Associate Professor and fish expert Peter Rask Møller from the National History Museum of Denmark, who also participated in the study, is optimistic.

"The new DNA method has very interesting perspectives for monitoring marine fish. We always keep our eyes open for new methods to describe marine fish biodiversity in an efficient and standardised way. Here, I look very much forward to follow the DNA method in the future, and I think it could be very useful to employ in oceans around the world," says Peter Rask Møller.

The researchers also see great perspectives in the method for estimating fish stocks in the future.