Friday, September 30, 2011

Zoologger: The amphibious fish that mates with itself

From New Scientist: Zoologger: The amphibious fish that mates with itself

Species: Kryptolebias marmoratus

Habitat: Mangrove swamps on the east coast of North and South America

Faced with the inevitability of death, some people draw up a "bucket list": a checklist of things they plan to do, like learning a musical instrument or visiting the Grand Canyon. The Bucketlist website collates these ideas, including such gems as "play chicken with a train and lose". Yet nowhere on the site has anyone expressed a desire to have sex with themselves while living in a tree.

This shows a deplorable lack of initiative, because it wouldn't even be a world first. The mangrove killifish is way ahead of us. It lives in pools that are prone to drying up, so it can also live on land for months at a time – often inside hollowed-out logs – where it survives by breathing through its skin. It's also one of only two vertebrates – the other being the closely-related ocellated rivulus – that can self-fertilise.

These abilities give rise to a peculiar society made up of groups of clones that compete with each other for survival.

Fishy business
Plenty of animals are hermaphrodites, with both male and female sexual organs. But they still tend to mate with others to mix their genes up a bit.

Mangrove killifish don't tend to bother. Adults have both ovaries and testes, so when they want to reproduce they release sperm and eggs simultaneously. After the eggs are fertilised, they lay them in gravel.

Constant self-fertilising means the fish lose any genetic variation. Mangrove killifish that have self-fertilised for just a few generations become homozygous: that is, they have two identical copies of every gene. So within each population, there are a few groups of genetically identical killifish, each cloned from a different ancestor.

Having said that, some populations do have a few males. And though self-fertilisation is the norm for the hermaphrodites, they do occasionally mate with a male. That allows different clonal groups to trade genes, using males as middlemen. The killifish in these populations are not homozygous – they have two different versions of some of their genes.

Personable clones
Nevertheless, most of the time there aren't any males, just groups of hermaphrodite clones. These groups can be quite different, for instance having differing sex ratios, growth rates and numbers of offspring.

Mathew Edenbrow and Darren Croft of the University of Exeter in the UK wondered if the groups also differed in their personalities: for instance, how willing they were to explore new places.

One idea is that the "life history" decisions an animal makes, like when to reproduce, help determine its personality. But when Edenbrow and Croft monitored 120 young fish as they hatched and grew to adulthood, they couldn't find any correlations between life history and personality.

Instead they found that the young killifish were remarkably malleable, with each individual changing its behaviour substantially as it grew up. "They're not constrained in their personality expression," Edenbrow says. He speculates that the young fish are learning from their experiences and shaping their personalities accordingly.

But not all of the fish were so flexible. Edenbrow and Croft looked at six clone groups and found that some were more malleable than others. That could give them an advantage: faced with a changeable environment, they may cope better than their stuck-in-the-mud cousins.

Given that the clone groups must compete with each other, do animals within each group work together? We don't know yet: Croft says it's not even clear if clones can recognise each other. But closely related animals are more likely to cooperate – think of worker ants in a nest, all descended from the same queen – and clones are as closely-related as you can get.

Journal reference: Animal Behaviour, DOI: 10.1016/j.anbehav.2011.07.003

UW dog tracks Orca scat and contributes to a number of new studies

From My Fox Spokane: UW dog tracks Orca scat and contributes to a number of new studies

SEATTLE—
Labradors are natural born hunting dogs, but what Tucker is retrieving is a little out of the ordinary.

The research team from the University of Washington is in the San Juan Islands tracking Orca poop. Samples they've collected so far show our Southern Resident Killer Whales don't have enough to eat.

"The fact that there is less food means they have to metabolize their fat and then the toxicants are released into their bodies," researcher Deborah Giles said. "It's a bad deal. Last year we lost two males that were just coming into that time when they could have been helping with the gene pool."

Research shows one stressor impacting the Orcas is the noise of boat engines which interferes with the sonar they use to hunt and communicate.

Another threat was recently discovered in a study by NOAA, led by Dr. Michael Ford.

The study shows the Orcas in J, K and L pod are inbreeding, a circumstance that can cause a host of health issues in whales, just as it does in humans.

"You expect to see problems with the immune system, robustness of the genetic code and the ability to reproduce and be fertile," Orca Relief president Mark Anderson said.

Inbreeding isn't something we can do much about, so researchers are working twice as hard to get a handle on problems that can be prevented and learn more about how boat noise and pursuit impacts the whales' well being. In fact, the National Marine Fisheries Service is conducting a new study on the issue right now.

"We have a tagging project and there are some suction cup tags our science center will put on the whales. It will record the sound level that the whales are hearing and that will give us a better indication not only what sounds the boats make but how the whales are receiving that sound," Lynn Barre with NMFS said.

In another project, Soundwatch, a non-profit group that educates boaters on whale watching guidelines, are working with Tucker and his team tracking the number of boats near the Orcas. The UW crew collects scat and cross references the day and time with Soundwatch to measure increased stress levels of the whales in the presence of a lot of boats.

"Physiologically if they’re having stressors coming from vessel activities we want to know that so we can alleviate that by having some new guidelines and laws. It would be a good indicator and we’re really happy to partner with them," Kari Koski said.

Thursday, September 29, 2011

Undersea cable laid for 'transformative' ocean observatory


From KPLU.com: Undersea cable laid for 'transformative' ocean observatory
This spring there was a big volcanic eruption in the Pacific Northwest. If you missed it, you're not alone. It happened under the ocean off the northern Oregon coast.

However, all this week [Sept 8-15) a University of Washington research ship has been streaming live video via satellite of lava flows in the undersea crater. In a couple years, 24/7 video coverage of the ocean floor will be made possible by a new underwater fiber optic cable.

"This is big deal," says UW oceanography professor John Delaney. "Suddenly the ocean is going to be accessible to people. We can't take them all out there deep in the ocean, but we can bring the ocean to them."

Wiring the ocean
Delaney is describing his baby ... a very expensive and ambitious high-tech baby. He is one of the driving forces behind an effort to wire the Pacific Ocean off the Oregon and Washington coasts for science.

Delaney says the vision for this cable and instrument array dates back twenty years.

"I think I was complaining to a friend in a bar, probably in San Francisco."

Delaney recalls bemoaning the expense and difficulty of gathering data in the deep ocean. Then the conversation turned to new undersea fiber optic cables.

"'Bingo!' We said, let's do something about this," Delaney recalls. "That was a long time ago."

Laying cable
Now the vision is becoming reality. A commercial-cable laying ship has just finished spooling out 560 miles of fiber optic cable. One strand starts from Pacific City, Ore., goes out to the edge of the continental shelf and then loops down toward Newport. Another line heads far out to sea to an underwater volcano.

Scientists plan to attach dozens and dozens of instruments to the cables. Seismometers could give us a better idea about the offshore earthquake threat. Other sensors will track fish migration, ocean acidification, weather trends and dissolved oxygen, just to name a few.

Underwater microphones could capture whale calls, like hard-to-find blue whales.

Delaney says the undersea network is designed to funnel a fire hose of open source, real time data to the internet around the clock.

"So people that are interested – and I'm hoping it will be a growing number of people – will have the ability to tap into what we're doing," he says. "They'll be able to watch over our shoulders electronically as we discover things, as we make mistakes."

Spying on the volcano
One of the cool things to eavesdrop on might be an undersea volcano called the Axial Seamount. It is 300 miles out in the ocean due west of Astoria. Delaney is out there right now with co-chief scientist Debbie Kelley. They're scouting hydrothermal vents to wire up.

"Many people now think the volcanoes on the seafloor are where life originated on the planet," Kelley explains. "One of the things we're going to see later on the dive are these vents called snowblower vents, which is where there is warm water issuing out of the seafloor at about 30 degrees Centigrade. With it, it is entraining novel microorganisms."

This summer, Oregon State University scientists and engineers are also on the water, testing instrument packages and buoys that will connect in part to the fiber optic network.

OSU Professor Bob Collier says it's fair to say the data array will "revolutionize" oceanography.

"With this cable we really are able to provide a whole new way of looking at the ocean, which we honestly have never had before," he says.

The OSU and UW pieces fall under the umbrella of a larger project with locations in other oceans. It's called the Ocean Observatories Initiative. U.S. taxpayers are paying for the whole thing through the National Science Foundation.

Construction of the regional underwater cable network is budgeted for $153 million. It'll be in full service in 2014.

Research Vessel Polarstern At North Pole; 'Not More Interesting Than Other Places In The Arctic'

From Underwater Times: Research Vessel Polarstern At North Pole; 'Not More Interesting Than Other Places In The Arctic'
North Pole -- On August 22, 2011, at exactly 9.42 a.m., the research icebreaker Polarstern of the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association reached the North Pole. The aim of the current expedition is to document changes in the far north. The researchers on board are conducting an extensive investigation program in the water, ice, and air at the northernmost point on the Earth. The little sea ice cover makes the route via the pole to the investigation area in the Canadian Arctic possible.

Sea ice not only plays a role in the selection of the route, but is above all a major research focal point. How thick is the ice and how old? To what extent has it been deformed by pressure – is there snow or puddles of melting water on it? Satellite measurements supply some ice information, but measurements are still required on site to be able to interpret these data correctly. Light energy causes the ice to melt and heats up the water in the summer months. The warming of the Arctic and the related changes in heat and gas exchange processes between the ocean, sea ice, and atmosphere are the paramount focus of the investigations. The oceanic currents that exchange water masses with the Atlantic and the Pacific are also undergoing change. Redistribution of the freshwater input from rivers into the Arctic Ocean is one of the factors that influence these oceanic currents.

Light is the source of energy for tiny algae that live in and under the ice and form the basis of the food web in the Arctic Ocean. Biologists classify species and determine the number of algae as well as the small and larger animals that feed on them. The researchers follow the path taken by the organisms from the water surface to the seafloor, where the remains end up as organic substance at a depth of thousands of meters after the organisms die.

These deposits on the seafloor permit conclusions to be drawn on how living conditions were in the course of the Earth's history. After all, the sediments and the animal and plant remains they contain are up to several million years old. Following the expedition, sediment cores will be analyzed in the laboratory. To improve the models of the Earth's climate history, chemists, physicists and oceanographers additionally examine the environmental conditions in the present-day oceans. They draw conclusions on how fast organic substance is transformed and relocated as a result of altered current conditions.

All 55 scientists and technicians from six countries on board the Polarstern have a common goal: studying the changes in the Arctic. This is also reflected in the name of the expedition "TransArc – Trans-Arctic survey of the Arctic Ocean in transition". The researchers have been investigating their questions jointly with the 43 crew members since the Polarstern left the port of Tromsø (Norway) on 5 August. The first ice floes appeared on 8 August. Since 9 August the Polarstern has been sailing through dense pack ice on the route along 60° East in temperatures of around 0° C. At first it was predominantly one-year-old sea ice, now older and consequently thicker ice floes appear.

"From a scientific point of view the North Pole is not more interesting than other places in the Arctic," reports Prof. Ursula Schauer from on board the Polarstern. The oceanographer at the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association is the chief scientist of the expedition. "The expected changes are rather minor here. However, the northern part of the Canadian sector of the Arctic still numbers among the least researched regions on the globe because of the dense pack ice."

Schauer was in the central Arctic the last time in 2007 and is now experiencing a similarly small ice cover as the year that went down in the annals as the one with the lowest extent of sea ice since the beginning of satellite measurements in 1979. Initial measurements of the ice thickness confirm this: in 2011 as well as in 2007 the most frequently occurring ice thickness was 0.9 metres. As a comparison, the most frequently measured ice thickness in 2001 was around 2 metres. In that year the extent of the ice cover at the end of the melting period corresponded roughly to the long-term mean.

The Polarstern is at the North Pole for the third time in its history. On September 7, 1991, it was one of the first two conventionally driven ships to sail there, along with the Swedish research icebreaker Oden. Almost exactly ten years later, on 6 September 2001, it carried out a joint expedition at the North Pole together with the American research icebreaker Healy.

After the investigations at the North Pole and subsequently in the Canadian Basin the vessel will head for the Siberian Sea. The researchers want to study the oceanic circulation from the deep sea to the shallow shelf seas and habitats from the ice edge to the ice-free ocean. The Polarstern is expected to return to its homeport of Bremerhaven on 7 October.

Wednesday, September 28, 2011

Researchers: Dolphin 'Conching' May Be Spreading To Others 'Before Our Very Eyes'


From Underwater Times: Researchers: Dolphin 'Conching' May Be Spreading To Others 'Before Our Very Eyes'
PERTH, Australia -- Researchers from Murdoch University believe a recently documented method of fishing may be spreading throughout a population of dolphins.

Indo-Pacific bottlenose dolphins (Tursiops aduncus) in Shark Bay were photographed engaging in 'conching' in 2007 and 2009.

The dolphins would trap small fish in large conch shells with their rostrums (beaks), then bring the shells to the surface and shake them, causing the water to drain out and the fish to fall into their mouths.

Murdoch Cetacean Research Unit Researcher Simon Allen says this previously rarely witnessed phenomenon might be on the increase, suggesting that the technique is spreading.

"In the last four months alone, the research team have seen and photographed the behavior no less than six times, possibly even seven.

"If – and that is a big if – we are witnessing the horizontal spread of this behavior, then I would assume that it spreads by an associate of a 'conching' dolphin closely observing the behavior and then imitating it," Mr Allen said.

"It is a tantalizing possibility that this behavior could spread before our very eyes – over a field season or two – and that we could track that spread."

The prospect of observing a learned behavior spreading through a population over a short period of time is exciting in itself, but the behavior also raises new questions about how exactly dolphins engage in conching.

"As yet, we don't know if dolphins simply pursue fish into the 'refuge' of the large, empty conch/bailer shells or whether they actually manipulate the shells prior – perhaps turning them over so that the opening is facing up in order to make them 'appealing' to fish as a place to hide from the jaws of death," Mr Allen said.

"If we were to set up a few shells – opening down – in a known location and either witness dolphins turning them over, see evidence of them having been turned over when we weren't around, or better still get some video footage of dolphins manipulating them in some way, then that would be priceless, since that implies forward planning on the dolphins' part.

"I wouldn't be too surprised to find such cunning and devilish ploys being adopted by Shark Bay's bottlenose dolphins."

Until such observations are recorded though, Mr Allen says it is too early to rush to any conclusions.

Members of the Murdoch Cetacean Unit, with colleagues from the University of Zurich, spend roughly four months of the year studying western Shark Bay's dolphin population in the field.

The Unit operates with the assistance of a partnership with Shark Bay Resources, who provide accommodation, office space and mess facilities for the research teams.

To read more about whale and dolphin research at Murdoch University, please visit: www.mucru.org

Maine: Five Foot Long Skull Found in Lake

From Eabi TV 5: Five Foot Long Skull Found in Lake
Rockwood - The pace of life at Moosehead Lake just sort of bobs along, offering views that are, at the very least, consistent.

"You see fish, you know, you see old bottles from the Kineo," said Lynn Stade.

But on a recent trip, Stade and his family swam right into a mystery waiting for them on the lake's floor.

"I thought, oh my god, it looks like a prehistoric monster."

Or what used to be one.

Stretching five feet and smelling nothing like the catch of the day should, it was hauled back by Stade's family to a nearby home in Rockwood.

"To me it's either a whale that survived in the lake all these years. It's a phenomenon. I don't know what it is," said Stade.

That's why they called local newspaper owner, Busta Koppenhaver, to help them get some answers.

"Left a message that said next time you come up bring your camera. I thought we were talking about a two headed chicken, or a humongous sized bees nest, I wasn't sure."

But Koppenhaver thought it was worth of a full page spread asking readers to guess what it is.

"A lot of locals insist that it's a moose's skull. I see no resemblance of a moose there. I've seen moose skulls before. They have teeth, for one thing."

And researchers at the University of Maine agreed, telling us that based on pictures, they believe it's the skull of a Minke Whale that was most likely dumped in the lake.

"I don't see foul play," said Koppenhaver.

He would like to believe that the skull's story runs much deeper than that.

"It would be fun to think that it is a prehistoric creature that lived in the lake. It would be fun to think that it was ET."

And however shallow his theories, it's clear that this family's summer trip has created a ripple effect amidst the calm and quiet of Moosehead Lake.

Monday, September 26, 2011

BBC Set To Premiere 'The Woman Who Swims With Killer Whales', Detailing Dr. Ingrid Visser's Orca Research

From Underwater Times: BBC Set To Premiere 'The Woman Who Swims With Killer Whales', Detailing Dr. Ingrid Visser's Orca Research
Most would consider it madness to enter the water with them, but New Zealander, Ingrid Visser thinks differently. She is the only scientist in the world to swim with the species – called Orca by some, and officially named Orcinus Orca (from the Latin for 'from the world of the dead').

Her maverick approach has revolutionized our understanding of these extraordinary creatures – and uncovered a trend which threatens their existence. Swimming alone along New Zealand's 9,000 miles of spectacular coast, she's become an expert on a unique band of shark and ray-hunting Killer Whales.

Recently Ingrid has noticed a worrying trend. An already critically-endangered population of about 200 is no longer increasing and, worse, 2010 saw an unusual number of deaths. THE WOMAN WHO SWIMS WITH KILLER WHALES charts Ingrid's one-woman mission to find out what's going on her disturbing discoveries about the health of our oceans.

Breaking research unveiled in the film reveals that:



New Zealand's orca test positive to hundreds of different pollutants, including industrial chemicals like PCBs, the long-banned pesticide DDT and flame retardants – a largely unregulated group of chemicals which have been shown to affect fertility in animals and humans.


The pollutant levels found in New Zealand's orca make them amongst the most polluted creatures in the southern hemisphere


The levels are likely to be exerting a negative effect on orca reproduction, immunity and growth.

The film also shows that the problems facing New Zealand's killer whales are mirrored around the world, including that in some marine places, levels of flame retardants are doubling every three to four years. Research suggests many of the pollutants found in the Orca are also in humans.

For more information on Dr. Visser's work, see the www.orcaresearch.org/.

Ancient Whale Skulls And Directional Hearing: A Twisted Tale; 'Not Related To Echolocation'

From Underwater Times: Ancient Whale Skulls And Directional Hearing: A Twisted Tale; 'Not Related To Echolocation'
ANN ARBOR, Michigan -- Skewed skulls may have helped early whales discriminate the direction of sounds in water and are not solely, as previously thought, a later adaptation related to echolocation. University of Michigan researchers report the finding in a paper to be published online in the Proceedings of the National Academy of Sciences during the week of Aug. 22.

Asymmetric skulls are a well-known characteristic of the modern whale group known as odontocetes (toothed whales). These whales also have highly modified nasal structures with which they produce high-frequency sounds for echolocation---a sort of biological sonar used to navigate and find food. The other modern whale group, mysticetes (baleen whales), has symmetrical skulls and does not echolocate.

These observations led scientists to believe that archaeocetes---the extinct, ancient whales that gave rise to all modern whales---had symmetrical skulls, and that asymmetry later developed in toothed whales in concert with echolocation. But a new analysis of archaeocete skulls by U-M postdoctoral fellow Julia Fahlke and coauthors shows that asymmetry evolved much earlier, as part of a suite of traits linked to directional hearing in water.

"This means that the initial asymmetry in whales is not related to echolocation," said Fahlke, who is working with Philip Gingerich, an internationally recognized authority on whale evolution, at the U-M Museum of Paleontology.

When Fahlke first began working with Gingerich, who is the Ermine Cowles Case Collegiate Professor of Paleontology and professor of geological sciences, ecology and evolutionary biology and anthropology, she intended to study a completely different aspect of whale evolution: tooth form and function.

"Modern whales don't chew their food," Fahlke said. "Toothed whales just bite it and swallow it, and baleen whales filter feed. But archaeocetes have characteristic wear patterns on their teeth that show that they've been chewing their food." By studying those wear patterns, she hoped to piece together how and what early whales ate and how their eating habits changed over time. She started by studying the skull of Basilosaurus, a serpent-like, predatory whale that lived 37 million years ago, using a three-dimensional digital model generated from CT scans of the fossil that were acquired at the U-M Medical School Department of Radiology.

The actual skull on which the model was based was noticeably asymmetrical, but Fahlke and colleagues at first dismissed the irregularity.

"We thought, like everybody else before us, that this might have happened during burial and fossilization," Fahlke said. "Under pressure from sediments, fossils oftentimes deform." To correct for the deformation, coauthor Aaron Wood, a former U-M postdoctoral researcher who is now at the University of Florida, straightened out the skull in the digital model. But when Fahlke began working with the "corrected" model, the jaws just didn't fit together right. Frustrated, she stared at a cast of the actual skull, puzzling over the problem.

"Finally it dawned on me: Maybe archaeocete skulls really were asymmetrical," Fahlke said. She didn't have to go far to explore that idea; the U-M Museum of Paleontology houses one of the world's largest and most complete archaeocete fossil collections. Fahlke began examining archaeocete skulls, and to her astonishment, "they all showed the same kind of asymmetry---a leftward bend when you look at them from the top down," she said.

To study the asymmetry in a more rigorous way, Fahlke and colleagues selected six well-preserved skulls that showed no signs of artificial deformation and measured those skulls' deviation from a straight line drawn from snout to back of skull. For comparison, they made similar measurements of the decidedly symmetrical skulls of artiodactyls, the group of terrestrial mammals from which whales evolved.

"Taken together, the six skulls deviate significantly from symmetry," Fahlke said. "Taken individually, four of them deviate significantly." The other two appear asymmetrical, but their measurements fall within the range of the symmetrical comparative sample.

"This shows that asymmetry existed much earlier than previously thought---before the baleen whales and toothed whales split," Fahlke said. "This means that the earliest baleen whales must have had asymmetrical skulls, which later became symmetrical."

The authors also show in their paper that archaeocete asymmetry is a three-dimensional torsion, or twist that affects the whole skull, rather than only a two-dimensional bend. Interestingly, archaeocetes have structures similar to those that are known in toothed whales to function in directional hearing in water: fat bodies in their lower jaws that guide sound waves to the ears, and an area of bone on the outside of each lower jaw thin enough to vibrate and transmit sound waves into the fat body. This adaptation, along with the acoustic isolation of the ear region from the rest of the skull, appears to have evolved in concert with asymmetry.

The link between asymmetry and directional hearing is not unique to whales, Fahlke said.

"Owls have asymmetrical ear openings, which help them decompose complex sounds and interpret differences and space and time, so that they can discriminate the rustling of leaves around them from the rustling of a mouse on the ground," Fahlke said. "Such ability would also be helpful when you're trying to detect prey in the water, so we interpret that the same kind of mechanism was operating for archaeocetes."

Rare crab makes appearance at Cornish aquarium


From BBC News Cornwall: Rare crab makes appearance at Cornish aquarium
A rare type of spider crab, which has not been seen in Cornwall since 1912, is making an appearance at a north Cornwall aquarium.

The tiny 'gibb's spider crab' was donated to Newquay's Blue Reef Aquarium earlier this summer by a fisherman.

The creature is so rare a marine life expert was needed to identify it.

Matt Slater, curator at the aquarium, said the only records they had of such a crab dated back to "Edwardian and Victorian times".

Photos of the crustacean were sent to Cornish marine life expert Dr Paul Gainey who identified it.

Mr Slater said: "It's hardly surprising that we weren't able to find out much about it, apparently it's incredibly rare.

"There are 13 records but all are during Edwardian and Victorian times when the crabs were caught in trawl nets."

Mr Slater said the crab was "only about the size of a thumbnail".

Thursday, September 22, 2011

Eco-Labeled Seafood Is Not Always What It Seems; 'The Results Are Not Exactly Shocking'

From Underwater Times.com: Eco-Labeled Seafood Is Not Always What It Seems; 'The Results Are Not Exactly Shocking'
Clemson, South Carolina -- When you buy what looks to be a nice piece of certified sustainable fish at the supermarket, you'd like to think that's exactly what you're getting. Unfortunately, things aren't always what they seem, according to researchers who have analyzed DNA isolated from store-bought, eco-labeled Chilean sea bass and report their findings in the August 23 issue of Current Biology, a Cell Press publication.

"We found that, for fish purchased in US groceries, not all those labeled as MSC-certified Chilean sea bass are actually MSC-certified Chilean sea bass," said Peter Marko of Clemson University. MSC stands for the Marine Stewardship Council, an international organization dedicated to recognizing and rewarding sustainable fishing.

In the case of Chilean sea bass, MSC certification labels should indicate that a fish was harvested from the only recognized sustainable Chilean sea bass fishery, a population living in waters surrounding the sub-Antarctic island of South Georgia and a nearby plateau called Shag Rocks, Marko explained.

In fact, some of the fish that his team purchased turned out to be other species entirely. Of those that were Chilean sea bass, some 15 percent were genetically distinct from fish collected previously from the certified fishery. One sample carried a haplotype (defined as a combination of genetic variants in cellular components known as mitochondria) that has only been found on the other side of the globe, in the southern Indian Ocean. Other haplotypes that the researchers uncovered amongst fish marked with an MSC-certified label commonly trace to South American waters, and still others had never been recorded before in previous genetic surveys.

"The simplest explanation for this result is that other species plus Chilean sea bass from other, uncertified fisheries are being added to the supply chain for MSC-certified Chilean sea bass," Marko said. Although unexpected, "the results are not exactly shocking," given widespread mislabeling in the seafood industry and potential profits to be made.

It isn't clear who is responsible for the misleading labels, given that fish pass through many hands from the time they are caught to the time they are purchased.

"There is no question that organizations like the Marine Stewardship Council are trying their best to guide consumers to sustainably harvested seafood, but it is currently difficult to guarantee the geographic origins of fish," Marko said. He added that the MSC has been working on ways to confirm fishes' origins, and the new study may serve as a model for how to go about that.

The only thing it seems that concerned consumers can really do for now is keep Chilean sea bass off their dinner menus. "At a grocery or on a plate in a restaurant, Chilean sea bass from South Georgia looks the same as Chilean sea bass from other parts of the world," Marko said.

Wednesday, September 21, 2011

DPD deploys underwater from combat rubber raiding crafts

From Marines.mil: DPD deploys underwater from combat rubber raiding crafts
8/19/2011 By Lance Cpl. Mark W. Stroud, Marine Corps Bases Japan
CAMP SCHWAB, OKINAWA, Japan — Marines with 3rd Reconnaissance Battalion executed a series of submerged movements off the beaches of Camp Schwab using diver propulsion devices Aug. 9.

The DPD is a battery-powered vehicle capable of carrying two divers and their gear while submersed out of sight.

“The (DPD) is the Marine Reconnaissance’s miniature submarine, if you will,” said Petty Officer 1st Class Donald R. Miner, medical deep sea diver, 3rd Recon. Bn., 3rd Marine Division, III Marine Expeditionary Force. “It allows them to transit long distances using minimal amounts of energy and O2 on their diving rigs.”

According to Miner, the training consisted of a series of submerged movements between checkpoints marked by large buoys, designed to improve the divers’ underwater navigation skills as well as familiarize them with the DPD.

The Marines first had to complete dive training to be eligible for the follow-up DPD training.

“They qualify Marine combat divers at dive school and come out here, and we sustain them and grow them as diving supervisors and DPD pilots,” said Miner.

“The course is roughly seven days long start to finish and includes night dives. Once they are qualified on the DPD, they will get together as platoons and do sustainment training, which would basically be a navigation dive like this or a (simulated mission),” Miner added.

During combat operations, the Marines use the device for covert insertions onto beaches and shorelines.

“They would be able to take the DPDs and insert into a hostile environment quietly and covertly … do reconnaissance on an enemy position or even potentially attack the enemy,” said Miner.

The device allows Marines to conserve their energy during tactical operations as DPDs do the work of propelling them and their gear ashore, said Petty Officer 1st Class, Gregory S. Early, Navy diver, 3rd Recon Bn.

Marines are trained to cache the device out of sight once they have reached their objective and return to the device after actions-on-objectives for extraction, said Miner.

“It is designed to be cached and stowed underwater, or it can be carried and buried on the beach if they want to,” said Miner.

Due to the size of the DPD, it is easily deployable from a broad range of platforms, said Early.

The DPD demonstrated this flexibility during the training evolution when it was deployed from a combat rubber raiding craft.

The Marines will continue training with the DPD here and abroad.

“We will be going (abroad) in January and doing this course again with (a partner) combat-diver unit,” said Early. “At that point, we will work together with (our partners). They will insert into shore, stow the DPD, go over the beach, recon a target, take pictures of it and return.”

The end goal is to ensure Marines can proficentley use the DPD.

“We train them and get them qualified to perform these jobs without us, so they can go execute missions (independently),” said Early.

The DPD provides the Marines with another tool for covert insertions, helping them execute their reconnaissance mission.

“It is a very small portion of what the Marines do as a whole, but this type of capability is what keeps the enemy at bay,” said Miner.

Would Sea Shepherd reimburse donations if they lose case, Fish & Fish asks

This article is from Aug 21, 2011. I hadn't been paying attention to the Sea Shepherd case but will cover it as "retro news". Seems kind of silly to me - people donate money which will has to be paid by lawyers in a legal case - how can Sea Shepherd reimburse money which they no longer have because they've spent it on lawyers????

From Times of Malta: Would Sea Shepherd reimburse donations if they lose case, Fish & Fish asks

Should the Sea Shepherd lose the court case initiated by Maltese company Fish & Fish Ltd, would they reimburse the £520,000 donated to enable the organisation to free the Steve Irwin, Fish & Fish asked this afternoon.

In a statement, the organisation said it was licenced to operate a blue fin tuna farm by ICCAT and the Maltese government.

In June last year, members of the Sea Shepherd pounced on a cage containing a catch of live blue fin tuna being towed to Malta, purchased by Fish & Fish from a number of fishermen.

During this incident, the ship Steve Irwin "deliberately and repeatedly" rammed the cage and deployed dinghies and divers to tear open one of the cages.

As a result a good part of the catch was lost.

The company is now proceeding in the London Court against the Sea Shepherd to collect damages.

Whilst acknowledging that the matter was still sub judice, contrary to what Paul Watson was saying the catch was perfectly legal, Fish & Fish said.

"It was carried out during the fishing season in conformity with all applicable regulations.

"It is in any case clear that Paul Watson has no authority to judge the legality or otherwise of catches.

"Contrary to what he imagines, he has no right to inspect cargoes or vessels and if he thinks that something is not in order he should approach the authorities...

"On the contrary the Steve Irwin fled when they thought that patrol boats were on their way."

Fish & Fish said this was a highly dangerous confrontation on the high seas in which lives could have been lost.

"It was a wanton act of unprovoked aggression, totally irresponsible and without any legal basis whatsoever."

It said that as a result one of the company's crew members was grievously injured and a catch was ruined.

Fish & Fish decided to commence judicial proceedings for redress and sought to obtain security for the claim.

"The arrest of the Steve Irwin was necessary because it was increasingly becoming apparent that a judgment against the Sea Shepherd would not be enforceable given the lack of suitable assets.

"In July the company became aware that the Steve Irwin would be stopping at Lerwick in Scotland and therefore asked the Scottish court to issue a warrant of arrest on the vessel in security of the claim which being made in London.
"The Scottish Court accepted this request and rejected a further request by the Sea Shepherd Conservation Society to free the ship without providing security." Eventually, the Court ordered the Sea Shepherd to place a £520,000, which, according to Captain Watson was funded entirely by donations, Fish & Fish said.

"The question which arises at this point is whether the Sea Shepherds will return these donations if they lose the case?"

Tuesday, September 20, 2011

Gulf of Mexico makes dramatic comeback from Deepwater Horizon oil spill

From Al.com (Alabama): Gulf of Mexico makes dramatic comeback from Deepwater Horizon oil spill
by Michael C. Bolton
As I watched the ghastly photos and videos of the unfolding Deepwater Horizon oil spill last year, I told anyone who would listen that the Gulf of Mexico would never recover in our lifetimes.

I assumed that there would never again be fishing as we know it. I also assumed that the rich bounty that the Gulf produces would not be edible for decades.

Some scientist I am, huh?

There is more and more evidence that Mother Nature is a dang good cleaning lady. The recovery of the Gulf of Mexico has been nothing less than dramatic.

The recent Alabama Deep Sea Rodeo provided the opportunity for many different species of fish to be tested. The U.S. Food and Drug Administration (FDA) had a team of researchers and scientists on hand at the rodeo to collect tissue samples from the fish that were caught all the way from Florida to Louisiana waters.

The group was looking for the bad stuff such as Polycyclic Aromatic Hydrocarbons that cause all kinds of problems including being carcinogenic in some cases. The group also looked for any chemicals found in the dispersants sprayed on the oil slicks.

The group conducted tests of 942 tissue samples during and after the rodeo. The group stayed on Dauphin Island following the rodeo and tested oyster and shrimp, too.

FDA officials say the tests showed that the fish, shrimp and oysters were every bit as safe to eat as they were prior to the spill. Minute but safe levels of several chemicals were found in the fish, oysters and shrimp, but all the tests were within limits of tissue samples prior to the oil spill. They were at levels that the FDA considers safe for human consumption.

FDA officials say the chemicals they found are part of the Gulf's normal environment. The Gulf was by no means pristine prior to the Deepwater Horizon oil spill. An estimated 20 million to 50 million gallons of crude oil leak into the Gulf each year.

No one is saying that the Deepwater Horizon oil spill caused no lasting effects on the Gulf. Still in question is whether the spill caused a loss of spawning seasons for many fish important to the Gulf. That likely won't be known for several years.

Many creatures in nature have a remarkable ability to bounce back from even the worst damage inflicted upon them. Scientists were well aware that fish and shellfish exposed to other oil spills have shown the ability to metabolize and excrete many contaminants. The magnitude of the Deepwater Horizon spill raised the question of how much is too much.

It is incredibly good news that the Gulf's inhabitants seemed to have shrugged off this enormous attack on their habitat.

This is no time to say everything is back to normal, though. The FDA will continue its testing and the Alabama Marine Resources Division is beginning a three-year seafood-testing program.

Newly Discovered Icelandic Current Could Change North Atlantic Climate Picture

From Underwater Times: Newly Discovered Icelandic Current Could Change North Atlantic Climate Picture
WOODS HOLE, Massachusetts -- An international team of researchers, including physical oceanographers from the Woods Hole Oceanographic Institution (WHOI), has confirmed the presence of a deep-reaching ocean circulation system off Iceland that could significantly influence the ocean's response to climate change in previously unforeseen ways.

The current, called the North Icelandic Jet (NIJ), contributes to a key component of the Atlantic Meridional Overturning Circulation (AMOC), also known as the "great ocean conveyor belt," which is critically important for regulating Earth's climate. As part of the planet's reciprocal relationship between ocean circulation and climate, this conveyor belt transports warm surface water to high latitudes where the water warms the air, then cools, sinks, and returns towards the equator as a deep flow.

Crucial to this warm-to-cold oceanographic choreography is the Denmark Strait Overflow Water (DSOW), the largest of the deep, overflow plumes that feed the lower limb of the conveyor belt and return the dense water south through gaps in the Greenland-Scotland Ridge.

For years it has been thought that the primary source of the Denmark Overflow is a current adjacent to Greenland known as the East Greenland Current. However, this view was recently called into question by two oceanographers from Iceland who discovered a deep current flowing southward along the continental slope of Iceland. They named the current the North Icelandic Jet and hypothesized that it formed a significant part of the overflow water.

Now, in a paper published in the Aug. 21 online issue of the journal Nature Geoscience, the team of researchers—including the two Icelanders who discovered it—has confirmed that the Icelandic Jet is not only a major contributor to the DSOW but "is the primary source of the densest overflow water."

"In our paper we present the first comprehensive measurements of the NIJ," said Robert S. Pickart of WHOI, one of the authors of the study. "Our data demonstrate that the NIJ indeed carries overflow water into Denmark Strait and is distinct from the East Greenland Current. We show that the NIJ constitutes approximately half of the total overflow transport and nearly all of the densest component.

The researchers used a numerical model to hypothesize where and how the NIJ is formed. "We've identified a new paradigm," he said. "We're hypothesizing a new, overturning loop" of warm water to cold.

The results, Pickart says, have "important ramifications" for ocean circulation's impact on climate. Climate specialists have been concerned that the conveyor belt is slowing down due to a rise in global temperatures. They suggest that increasing amounts of fresh water from melting ice and other warming-related phenomena are making their way into the northern North Atlantic, where it could freeze, which would prevent the water from sinking and decrease the need for the loop to deliver as much warm water as it does now. Eventually, this could lead to a colder climate in the northern hemisphere.

While this scenario is far from certain, it is critical that researchers understand the overturning process, he said, to be able to make accurate predictions about the future of climate and circulation interaction. "If a large fraction of the overflow water comes from the NIJ, then we need to re-think how quickly the warm-to-cold conversion of the AMOC occurs, as well as how this process might be altered under a warming climate," Pickart said.

"These results implicate local water mass transformation and exchange near Iceland as central contributors to the deep limb of the Atlantic Meridional Overturning Circulation, and raise new questions about how global ocean circulation will respond to future climate change," said Eric Itsweire, program director in the U.S. National Science Foundation (NSF)'s Division of Ocean Sciences, which funded the research.

The Research Council of Norway also funded the analysis of the data.

Pickart and a team of scientists from the U.S., Iceland, Norway, and the Netherlands are scheduled to embark on Aug. 22 on a cruise aboard the WHOI-operated R/V Knorr to collect new information on the overturning in the Iceland Sea.

"During our upcoming cruise on the Knorr we will, for the first time, deploy an array of year-long moorings across the entire Denmark Strait to quantify the NIJ and distinguish it from the East Greenland Current," Pickart said. "Then we will collect shipboard measurements in the Iceland Sea to the north of the mooring line to determine more precisely where and how the NIJ originates."

Open season on Russian Jaws declared

From RT.com: Open season on Russian Jaws declared
Following two recent incidents of shark attacks in the Russian Far East, the authorities in Primorye have come up with a straightforward solution and announced that local sharks will be dealt with by professional fishermen.
“We are planning to take out a number of fishing boats to catch sharks in the near future,” governor Sergey Darkin said today in a video address, Itar-Tass reports.

He also called upon locals and visitors to refrain from swimming in the sea along the entire coastline of the region, particularly stressing the danger of deeper waters.
According to the governor, three special operation group has been made up of local authorities, scientists, emergency response specialists and members of law-enforcement services.

The authorities are also planning to use Japan’s expertise in the area. Although Russian scientists have enough special knowledge to tackle the problem, there is an urgent need for special equipment.

“I think the only way is to capture this shark and there are several ways of doing that,” Konstantin Zgurovsky, head of the Marine Program at WWF Russia, told RT. “The crew can either use large fishing rods for big fish or very solid rope with several big hooks like this one. It’s perfectly suitable for catching a three or four-meter shark.”
Police boats and teams of the Emergencies Ministry are currently patrolling the coastline. No new cases of shark attacks have been reported so far.
The beaches along Russia’s Pacific coast are full of people this August, but those willing to go into water are few, despite the heat. Those who dare, remain in shallow waters.

Patrol boats are cruising along the coastline outside Vladivostok – Russia’s main city in the region – to warn people of potential danger. To add to the mood of anxiety, local authorities have reported a shoal of large sharks near the island of Russky, just a few kilometers from Vladivostok.
The first attack occurred on Wednesday about 50 meters off the coast in Telyakovsky Bay in southern Primorye, when a 25-year-old man lost both his forearms after being mauled by what is thought to be a four-meter-long Great White shark.

He was immediately taken to a hospital in the village of Slavyanka in a serious condition and underwent surgery. According to his doctors, the man’s life is not in danger and he will soon be transferred to Vladivostok for further treatment.
The second attack took place less than 24 hours after the first one. This time, a 16-year-old sustained serious injuries to his leg while diving for scallops. His wetsuit is thought to have saved him from more serious injuries.

The boy was hospitalized in Vladivostok and his life in not in danger. The medical staff say they will probably be able to save his leg.

Mekong dolphins on brink of extinction - WWF

From iol News: Mekong dolphins on brink of extinction - WWF
Tokyo - The Irrawaddy dolphin population in the Mekong River numbers roughly 85, with the survival of new calves very low, suggesting they are at high risk of extinction, environmental group WWF said on Wednesday.

The Irrawaddy dolphins live in a 190 km section of the Mekong between Kratie, Cambodia and the Khone Falls, which are on the border with Laos.

Fishing gear, especially gill nets, and illegal fishing methods involving explosions, poison and electricity all appear to be taking a toll, with surveys conducted from 2007 to 2010 showing the dolphin population slowly declining, the WWF added.

“Evidence is strong that very few young animals survive to adulthood, as older dolphins die off and are not replaced,” said Li Lifeng, director of WWR's Freshwater Programme, in a statement.

“This tiny population is at risk by its small size alone. With the added pressure of gill net entanglement and high calf mortality, we are really worried for the future of dolphins.”

Research also shows that the population of dolphins in a small transboundary pool on the Cambodia-Laos border may be as few as 7 or 8, the WWF added, despite the fact that Irrawaddy dolphins are protected by law in both nations.

The group called on Cambodia to establish a clear legal framework to protect dolphins, including steps such as banning gill nets if needed.

“Our best chance of saving this iconic species from extinction in the Mekong River is through joint conservation action,” Li said.

Dolphins once ranged from the Mekong delta in Vietnam up through the Tonle Sap in Cambodia, and then up tributaries into Laos, but they have been shot by soldiers and harvested for oil in the past.

Irrawaddy dolphins are found in coastal areas in South and Southeast Asia, and in three rivers: the Mekong, the Ayeyarwady in Myanmar, and the Mahakam in Indonesian Borneo.

Sunday, September 18, 2011

Otters return to every county in England

From BBC News: Otters return to every county in England
Two otters have been seen in Kent, signalling their return to every English county following efforts to save them from extinction.

Kent was the only county found without otters in a survey of rivers across England carried out by the Environment Agency (EA) last year.

Since then at least two otters have been spotted, with holts on the Medway and Eden rivers, the EA said.

A survey on the Ribble in Lancashire showed a 44% increase since 2008.

Otter numbers fell as a result of toxic pesticides, which damaged their health and reduced their supplies of fish. They had almost disappeared from England by the 1970s.

'Great success'

Improvements in water quality, along with legal protection, has helped their recovery.

"The recovery of otters from near-extinction shows how far we've come in controlling pollution and improving water quality," said the EA's national conservation manager, Alastair Driver.

"Rivers in England are the healthiest for over 20 years and otters, salmon and other wildlife are returning to many rivers for the first time since the Industrial Revolution.

"The fact that otters are now returning to Kent is the final piece in the jigsaw for otter recovery in England and is a symbol of great success for everybody involved in otter conservation."

The otter survey of England, which examined 3,327 river sites between July 2009 and March 2010, showed the number of places with evidence of otter life had increased tenfold in 30 years.

But recovery was slowest in the South East, with conservationists predicting otters may not be resident in Kent for another 10 years.

Their return was also a "fantastic reward" for efforts by the agency to improve water quality, said Mr Driver.

Human Feces Killing Corals In The Florida Keys

From Underwater Times: Human Feces Killing Corals In The Florida Keys
ATHENS, Georgia -- A research team from Rollins College in Florida and the University of Georgia has identified human sewage as the source of the coral-killing pathogen that causes white pox disease of Caribbean elkhorn coral. Once the most common coral in the Caribbean, elkhorn coral was listed for protection under the United States Endangered Species Act in 2006, largely due to white pox disease. The team's findings have just been published in the peer-reviewed open access journal PLoS ONE.

Kathryn P. Sutherland, associate professor of biology at Rollins College, and her research collaborators, Associate Professor of Environmental Health Science Erin K. Lipp and Professor of Ecology James W. Porter of the University of Georgia, have known since 2002 that the bacterium that killed coral was the same species as found in humans. "When we identified Serratia marcescens as the cause of white pox, we could only speculate that human waste was the source of the pathogen because the bacterium is also found in the waste of other animals," Sutherland said.

In order to determine a source for the pathogen, the research team collected and analyzed human samples from the wastewater treatment facility in Key West and samples from several other animals, such as Key deer and seagulls. While Serratia marcescens was found in these other animals, genetic analyses showed that only the strain from human sewage matched the strain found in white pox diseased corals on the reef. The final piece of the investigative puzzle was to show that this unique strain was pathogenic to corals.

With funding from Florida's Mote Marine Laboratory "Protect Our Reefs" grant program, Sutherland, Lipp and Porter conducted challenge experiments by inoculating fragments of coral with the strain found in both humans and corals to see if it would cause disease. The experiments were carried out in a laboratory in closed seawater tanks to eliminate any risk of infection to wild populations of corals.

"The strain caused disease in elkhorn coral in five days, so we now have definitive evidence that humans are a source of the pathogen that causes this devastating disease of corals," Sutherland said.

"These bacteria do not come from the ocean, they come from us," said Porter. Water-related activities in the Florida Keys generate more than $3 billion a year for Florida and the local economy. "We are killing the goose that lays the golden egg, and we've got the smoking gun to prove it," Porter said.

Serratia marcescens is also a pathogen of humans, causing respiratory, wound and urinary tract infections, meningitis, and pneumonia. Human diseases caused by this bacterium are most often associated with hospital-acquired infections of newborn infants and immune-compromised adults. This research reveals a new disease pathway, from humans to wildlife, which is the opposite of the traditional wildlife-to-human disease transmission model. The movement of pathogens from wildlife to humans is well documented—for example, bird flu or HIV—but the movement of disease-causing microbes from humans to marine invertebrates has never been shown before. This is the first time that a human disease has been shown to cause population declines of a marine invertebrate.

"Bacteria from humans kill corals—that's the bad news," said Porter. "But the good news is that we can solve this problem with advanced wastewater treatment facilities," like one recently completed in Key West. "This problem is not like hurricanes, which we can't control. We can do something about this one," he said. The entire Florida Keys is in the process of upgrading local wastewater treatment plants, and these measures will eliminate this source of the bacterium.

The Rollins College and University of Georgia collaborative research group is currently funded by a $2.2 million grant from the National Science Foundation to investigate the ecology of white pox disease in the Florida Keys. The five-year study will focus on mechanisms of transmission of the coral pathogen and the factors that drive the emergence and maintenance of white pox outbreaks, including water quality, climate variability and patterns of human population density. "We are concerned that disease incidence or severity may increase with rising temperatures," Lipp said, "reinforcing the importance of protecting near-shore water quality in a changing climate."

Tuesday, September 13, 2011

Soft Coral Builds Strong Reefs, Key To Health Of Oceans

From the Underwater Times: Soft Coral Builds Strong Reefs, Key To Health Of Oceans
TEL AVIV, Israel -- Scientists have long believed soft corals, one of the many endangered elements of marine life, are only minor contributors to the structure of coral reefs. But that's not true, says new research from Tel Aviv University — and the preservation of soft corals is essential to the health of our seas.

Joint research by Tel Aviv University and the Academia Sinica, the National Museum of Natural Science of Taiwan, and National Taiwan University has revealed that soft corals, like stony corals, are one of the central building blocks of a reef, says Prof. Yehuda Benayahu of TAU's Department of Zoology at the George S. Wise Faculty of Life Sciences. A new in-depth analysis of reefs in the South China Sea has revealed that massive parts of the reefs are actually made from cemented microscopic skeletal elements of soft corals termed sclerites.

The finding, which recently appeared in the journal Coral Reefs, challenges conventional knowledge about soft corals and makes their conservation a priority. Like whales, dolphins, and stony corals, soft corals are a critically important component of the marine environment, Prof. Benayahu insists.

Building a home from flesh and bone
Reefs are ecosystems derived from biological organisms. They predominantly consist of cemented stony corals made of calcium carbonate. In contrast, the tissues of soft corals contain sclerites, which look like tiny pins or porcupine needles. In the reefs of Kenting National Park, located in South Taiwan, the researchers discovered that large structures originally believed to be comprised of stony corals were actually deposits of sclerites that been cemented to each other by calcium carbonate over time.

Soft corals were once considered a mere veneer of reefs, says Prof. Benayahu, not unlike a living ocean carpet. Once a soft coral colony disintegrates, the sclerites, each less than 1 millimeter in size, were thought to scatter and simply accumulate on the sea bed along with shells, sea urchin spines, and other smaller materials. But in fact, they are integral throughout the reef ecosystem and provide a home for creatures such as fish, snails, algae and many others.

Outside of the marine environment, soft corals also work to protect our human habitat. Boulders and reef structures made of cemented soft coral sclerites that form near shores act as natural wave breakers, Prof. Benayahu says, protecting land against erosion by the sea or ocean during typhoons or cyclones.

Carbon dioxide burning through our oceans
Not only is soft coral widespread, especially throughout the Indo-Pacific reefs, but it is also extremely rich in biodiversity. The genus Sinularia, the soft coral used in reef building, is composed of about 170 species worldwide. This is more than any stony coral genus, including 130 species of staghorn corals, the most populous. Given its spread and diversity, the group is certainly understudied, Prof. Benayahu says.

Soft coral is in danger of being wiped out of the marine environment. One major culprit is the rising acidity of our oceans, caused by heightened levels of carbon dioxide, says Prof. Benayahu. "As burning oil dissolves into the sea water, the water becomes more acidic, which then dissolves calcareous materials," he warns, including corals whose skeletons are made of calcite.

Soft corals need not only to be protected, but also further studied to understand their role in the entire ecosystem. Questions such as the rate at which soft corals can form reefs, especially as they face environmental challenges such as temperature changes, water acidity, and rising sea levels, still linger.

This investigation was led by Dr. Ming-Shiou Jeng of the Academia Sinica's Biodiversity Research Center, along with colleagues from the National Museum of Natural Science in Taichung and National Taiwan University, Taipei.

First As Japanese Tsunami Picked Up By Radar

From the Underwater Times: First As Japanese Tsunami Picked Up By Radar
DAVIS, California -- The tsunami that devastated Japan on March 11 was picked up by high-frequency radar in California and Japan as it swept toward their coasts, according to U.S. and Japanese scientists. This is the first time that a tsunami has been observed by radar, raising the possibility of new early warning systems.

"It could be really useful in areas such as south-east Asia where there are huge areas of shallow continental shelf," said Professor John Largier, an oceanographer at the University of California, Davis, Bodega Marine Laboratory, and an author of a new paper describing the work. The paper appears this month in the journal Remote Sensing.

Largier and his colleagues have been using a high-frequency radar array at the Bodega Marine Lab to study ocean currents for the last 10 years. The Bodega lab is part of a network of coastal radar sites funded by the State of California for oceanographic research.

Largier, together with collaborators from Hokkaido and Kyoto universities in Japan and San Francisco State University, used data from radar sites at Bodega Bay, Trinidad, Calif., and two sites in Hokkaido, Japan, to look for the tsunami offshore.

The scientists found that the radar picks up not the actual tsunami wave — which is small in height while out at sea — but changes in currents as the wave passes.

The researchers found they could see the tsunami once it entered shallower coastal waters over the continental shelf. As the waves enter shallower water, they slow down, increase in height and decrease in wavelength until finally hitting the coast.

The continental shelf off the California coast is quite narrow, and approaches to the coast are already well-monitored by pressure gauges, Largier noted. But he said radar detection could be useful, for example, on the East Coast or in Southeast Asia, where there are wide expanses of shallow seas.

Monday, September 12, 2011

Poached Coral Finds New Purpose at Nova

From NBC Miami: Poached Coral Finds New Purpose at Nova
Once illegally poached, a $1 million haul of stolen coral is now helping educate South Floridians.

The coral, originally from the Solomon Islands near Australia, was delivered to Nova Southeastern University in Dania Beach by the U.S. Customs and Border Protection and U.S. Fish and Wildlife Service.

The coral was confiscated thanks to the way its shippers identified the contents on labels.

"It was paperwork that doomed this shipment because they were labeled as an endangered species in Florida and the Caribbean," explained professor Charles Messing.

Three of the 25 boxes have been unpacked so far, and already Professor Charles Messing said he's found coral that takes decades to grow -- and even a rare one called "blue denim coral."

"We have no idea how many different species there are in here because many of them are difficult to distinguish," Messing said.

Messing said on the street, the coral, most commonly used as home decor, is valued at nearly one million dollars. But instead of decorating with all of the once-living sea life, Messing said he will study them.

"We can cut them up and examine how old they are," Messing said. "They have growth rings like a tree."

Now, more people can learn from the coral, which will be displayed at museums and used in schools in both Miami-Dade and Broward counties.

New Pacific eel is a 'living fossil', scientists say

From BBC News: New Pacific eel is a 'living fossil', scientists say
A newly discovered eel that inhabits an undersea cave in the Pacific Ocean has been dubbed a "living fossil" because of its primitive features.

It is so distinct, scientists created a new taxonomic family to describe its relationship to other eels.

The US-Palauan-Japanese team say the eel's features suggest it has a long and independent evolutionary history stretching back 200m years.

Details appear in the journal Proceedings of the Royal Society B.

The animal used as the basis for the new study was an 18cm-long female, collected by one of the researchers during a dive at a 35m-deep cave in the Republic of Palau.

But the scientists also mention other examples of the new eel species in their research paper.

At first there was much discussion among the researchers about the animal's affinities. But genetic analysis confirmed that the fish was a "true" eel - albeit a primitive one.

"In some features it is more primitive than recent eels, and in others, even more primitive than the oldest known fossil eels, suggesting that it represents a 'living fossil' without a known fossil record," write the scientists.

In order to classify the new animal, the researchers had to create a new family, genus and species, bestowing on the animal the latin name Protoanguilla palau.

The team - including Masaki Miya from Chiba's Natural History Museum in Japan, Jiro Sakaue from the Southern Marine Laboratory in Palau and G David Johnson from the Smithsonian Institute in Washington DC - drew up a family tree of different eels, showing the relationships between them.

This allowed them to estimate when the ancestors of P. palau split away from other types of eel.

Their results suggest this new family has been evolving independently for the last 200m years, placing their origins in the early Mesozoic era, when dinosaurs were beginning their domination of the planet.

The researchers say the Protoanguilla lineage must have once been more widely distributed, because the undersea ridge where its cave home is located is between 60 and 70 million years old.

Friday, September 9, 2011

Department of Agriculture says Gulf seafood is safe

300 whole samples tested? Wow! That's a pretty extensive test for an area that covers thousands of square miles. Were they all tested in the same area, or was one whole fish sampled from each of 300 different areas?

Ridiculous!

The Florida Department of Agriculture and Consumer Services continued testing shows Gulf seafood is safe to eat, which is music to the ears of local seafood providers.

“It helps immensely,” Pete Blaylock, owner of Blaylock Seafood and Specialty Market told The Log Monday. “What I try and tell people is that our Gulf seafood is tested more now than it has been in the past 20 years.

Since last year’s Deepwater Horizon oil spill, the Department of Agriculture has screened hundreds of seafood samples from the Gulf of Mexico and found that Florida’s seafood hasn’t been affected by the spill.

Between August 2010 and June 2011, the department’s division of food safety tested nearly 300 seafood samples, ranging from fish, shrimp and oysters to crabs, lobsters and clams for possible contamination.

All of the samples were found to be “well below” the Food and Drug Administrations level of concern, according to a press release from the Department of Agriculture. Nearly half the samples were also tested for a component of Corexit, the dispersant dioctyl sulfosuccinate, which also came back “well below” the level of concern.

Agriculture Commissioner Adam Putnam has called this latest round of testing “aggressive.” Earlier this year he urged consumers “to put Florida seafood back on their plates and back into their diet.”

Restaurateur Dewey Destin said continued “vigorous testing” goes a long way to reassure people that local seafood is safe.

“It’s very important; otherwise people might be afraid to eat Gulf seafood,” said Destin.

The Department of Agriculture will continue to test Florida’s seafood over the next three years, as part of a $10 million funding agreement with BP and the state. The funds will be used to “enhance” laboratory capabilities to conduct further testing in an effort to “further restore public confidence” in Gulf seafood, the release states.

While concerns over the quality of local seafood might have died down since the oil spill, Destin said people are definitely “thinking about it.”

“You can’t blame them; they want to make sure it’s safe.”

Gulf fishermen find increasing number of sick fish

From 9WAFB: Gulf fishermen find increasing number of sick fish
BATON ROUGE, LA (WAFB) - Commercial fishermen in the Gulf are worried that their livelihood could be coming to a screeching halt.

It's been more than a year since the Deepwater Horizon oil rig explosion and fishermen are still finding sick fish.

Gulf fishermen are seeing increased numbers of fish with sores, fin rot and infections. Professors at LSU have analyzed many of the diseased fish and think they may know the cause.

"We think from chronic exposure to some environmental stresser and I think the likely assumption that it has something to do with the spill is there," said Dr. Jim Cowan, a professor of oceanography at LSU.

Scientists are working on a comprehensive study of the fish. They'll catch and examine thousands of fish and try to pinpoint hot spots for the infections.

Meanwhile, fishermen continue to worry whether there will be enough healthy fish left to sell.

Fish, coral from off-limits Hawaii come to Waikiki

From Seattle PI: Fish, coral from off-limits Hawaii come to Waikiki
HONOLULU (AP) — Hundreds of rare fish and coral pieces from one of the most remote parts of the planet have arrived in bustling Waikiki.

The Waikiki Aquarium's newest permanent exhibit, opening on Thursday, showcases specimens gathered from the pristine atolls of the Northwestern Hawaiian Islands — an area so well-protected it's generally off-limits to everyone but researchers and Native Hawaiians performing cultural rites.

It promises to be a special treat for scuba divers and fish enthusiasts only rarely able to see species like the white-and-black-colored masked angelfish or table corals — corals that spread out like tabletops around a central stem.

It should also appeal to those curious about the 1,200-mile long string of atolls so highly valued the United Nations named them a World Heritage Site last year and then-President George W. Bush designated them a marine national monument in 2006.

"Given the challenges in getting to the Northwestern Hawaiian Islands for the vast, vast majority of people, this will be their only chance to see a taste of some of the wonders that exist up there," said Andrew Rossiter, the aquarium's director.

The islands are all so small they're inhospitable to human settlement. But this has also meant people have mostly left them alone and in their natural condition.

The limited signs of human presence include ancient Hawaiian heiau, or shrines, lining the top of a ridge running along the spine of Mokumanamana island.

The Navy once had a base at Midway Atoll — the site of the famous 1942 battle between the U.S. and Japan that turned the tide of World War II — but turned the island over to the Fish and Wildlife Service for a wildlife refuge in 1993.

Today, the atolls have thriving coral reefs accounting for nearly 70 percent of all coral under U.S. jurisdiction. Experts say the robust reefs are what the rest of Hawaii's reefs looked like before they were damaged by coral mining, runoff from land, overfishing, and other human activity over the years.

Sharks — which have been overfished in many other parts of the world — are richly abundant there. Life also comes in unusual forms: 25 percent of the 7,000 marine species in the Northwestern Hawaiian Islands are found nowhere else in the world.

"This is a really, really unique place — nothing else like it in the world. And it's exactly how a coral reef should look, and this is how it was once around here," Rossiter said during an interview in his Honolulu office.

Fish and coral from the Northwestern Hawaiian Islands have been on display before, in limited circumstances. The Waikiki Aquarium has a small, existing exhibit, as does the National Oceanic and Atmospheric Administration's discovery center in Hilo on the Big Island.

But the aquarium's new display sets a new standard. The tank occupies about 10 percent of the aquarium's exhibit space, and will boast some 30 different fish species and 20 coral varieties. Altogether, the exhibit will feature 225 fish and 200 coral fragments.

The masked angelfish will allow researchers to observe how the unusual sex-changing fish behave and interact. Around the main Hawaiian islands the fish lives in deep water that's impractical for extended human observation. But scientists watching the aquarium tank may watch the fish for hours or days at a time.

The species is notable in part because they're all female when they're a certain size. Then one member of the group gets a little more aggressive, dominates the others, and changes its sex to male. The newly male fish uses the remaining females as his harem.

Scientists will not only be able to observe this process, but perhaps begin to understand why some of the fish change sex and others not, Rossiter said. The exhibit will have five to start with, and the aquarium will add four more by mid-September for a total of nine.

Aulani Wilhelm, superintendent of the Papahanaumokuakea Marine National Monument, said the aquarium is offering people a way to connect to a place that by necessity must be appreciated from afar.

"These are atolls, these are fragile places," Wilhelm said, noting even well-intentioned or well-regulated travel would inflict harm on the islands. "There's only so much visitation a place like that can handle before it's changed."

___

If You Go...

Northwestern Hawaiian Islands Exhibit: Stars Aug. 18 at the Waikiki Aquarium, 2777 Kalakaua Ave., Honolulu; www.waquarium.org or 808-923-9741. Adults, $9; children ages 13-17 and people with disabilities, $4; children ages 5-12, $2. Special rates for military and Hawaii residents. Open daily, 9 a.m.-4:30 p.m. except Christmas Day and Honolulu Marathon Sunday.

Wednesday, September 7, 2011

Seaweed suspected in French death (From 2009)

"'We want to know if in future we should take precautions to safeguard workers who collect or transport seaweed."

Well...gee....a horse dies, a man dies...I would think it would be easy to come to that conclusion immediately!


This story is a couple of years old but it was so interesting that I thought I'd share it.

From BBC News: Seaweed suspected in French death
French investigators are examining whether a lorry driver has become the first victim of a toxic seaweed that is clogging parts of the Brittany coast.

The driver died in July after carrying three truckloads of sea lettuce away from the beaches where it has been decaying, releasing poisonous gas.

His death was originally recorded as a heart attack but prosecutors want to know if it was linked to the seaweed.

France's PM warned of the health risk while visiting the beaches last month.

Francois Fillon announced that the government would pay for cleaning up the beaches polluted by the sea lettuce, Ulva lactuca.

Locals had raised the alarm after a horse, being ridden over the sands, collapsed and died. Its rider fell unconscious and had to be dragged off the algae-coated beach.

By then, the lorry driver had already died.

The 48-year-old driver had been working without a mask or gloves and died at the wheel of his vehicle when it crashed into a wall, reports Tim Finan in Brittany for the BBC.

The man had been part of the annual operation to remove 2,000 tonnes of rotting sea lettuce from the beaches at Binic.

His family have so far refused to allow an autopsy to establish the exact cause of his death, but on Monday the local prosecutor ordered a preliminary investigation.

Farming blamed

Christian Urvoy, the mayor of Binic, said: "'We want to know if in future we should take precautions to safeguard workers who collect or transport seaweed."

A spokesman for the local authorities has strongly denied they were aware of the death when Mr Fillon visited St-Michel-en-Greve in August.

Researchers from France's National Institute for Environmental Technology and Hazards (Ineris) have visited the same beach and found hydrogen sulphide in such concentration that it could be "deadly in few minutes".

Sea lettuce is harmless in the sea, but as it decomposes on the beach it releases the deadly gas.

Environmentalists say decades of misuse of Brittany's agricultural land is to blame for the explosion of algae, due to the high levels of nitrates used in fertilisers and excreted by the region's high concentration of livestock.

They have called for tighter controls on farming.

Seaweed survey finds rare sponge off coast of Norfolk

From BBC News England: Seaweed survey finds rare sponge off coast of Norfolk
A survey of seaweed on the coast of England has found a purple sponge off the Norfolk coast which has never been discovered in Britain before.

The Wildlife Trusts survey looked at the coasts of Essex, Sussex, Norfolk, Suffolk, Lincolnshire, Yorkshire, Durham and Northumberland.

The survey also found seaweed species new to the east coast of England, including the red seaweed.

The unknown purple sponge was found during dives off East Runton.

An unidentified sea-slug which is new to Norfolk was also found.

'Important finds'

Surveying the North Sea at a number of locations over a period of 10 days earlier this month, experts found in total some 131 types of seaweed, including four non-native species.

While starlet sea anemones, which are listed as a conservation priority in the UK, were seen along the Suffolk and Norfolk coast.

The survey focused on seaweed but the team of surveyors, which included marine biologists, volunteer divers, a botanist and a wild food expert, used the opportunity to look at other species in the relatively unexplored waters.

The information gathered from the research, along with a wildlife trusts scheme to analyse nature on the shoreline, could be used in the future to help identify areas of special importance for marine life above and below the sea surface.

Joan Edwards, head of living seas for the wildlife trusts, said: "This survey has thrown up some important finds.

"Although the main objective was to survey seaweed, the team took advantage of being in a relatively unexplored environment to survey other species, resulting in the sponge discovery off Norfolk.

"The samples and results are still awaiting full analysis. We have no doubt that once this is done they'll form a crucial part of our knowledge base around what's living in the North Sea off the east coast of England."

Alaskan fisheries advisor guilty of $100,000 in illegal fishing

From the Los Angeles Times: Alaskan fisheries advisor guilty of $100,000 in illegal fishing
In Alaska, fishing stories don't get much bigger than this one: Arne Fuglvog, who was U.S. Sen. Lisa Murkowski's top fisheries advisor and not long ago a top candidate to become head of the National Marine Fisheries Service, has pleaded guilty to illegal fishing -- $100,000 worth.

Fuglvog, a longtime commercial fisherman with years of service on the North Pacific Fishery Management Council, will probably land in prison for 10 months and have to pay $150,000 in fines and restitution, if U.S. District Judge Russel Holland goes with the plea deal during sentencing set for Nov. 18.

He had been Murkowski's top fisheries advisor since 2006, and one of the nation's most powerful players on fishing policy.

According to the federal charges, Fuglvog in 2005 took 63,000 pounds of sablefish --nearly twice what he was allowed to catch from the Western Yakutat area of the Gulf of Alaska -- and then falsified the records to suggest that half the fish had been caught in the central gulf.

Though Fuglvog and his crew might have caught the same amount of fish legally on a different day, cooking the books is a big deal in Alaska, which exports $1.6 billion of seafood a year and where access to fishing grounds is a matter of intense competition and debate.

The question on everyone's mind now is, what did Murkowski know, and when did she know it?

Though Fuglvog quietly signed a plea agreement with federal prosecutors April 8, Murkowski told the Anchorage Daily News her advisor didn't tell her about it until June 29; she didn't learn Fuglvog had already signed it, she said, until the plea deal was revealed publicly at the end of July -- when she accepted his resignation.

"Arne served Alaskans for the past five years on my staff and for over a decade before that in his public service work in fisheries," Murkowski said in a statement. "I thank him for his years of service, but he knows the importance and value of our fisheries, and he also knows what all fishermen understand: Fishing laws and regulations must be followed."

The Daily News, for its part, is skeptical. "Why didn't she know more?" the paper asked in an editorial.

"A United States senator has a fisheries aide about whom there are federal allegations of fisheries violations. At the least, Murkowski should have had Fuglvog tell her exactly what the allegations were and ask him flat out what he had done," it said. "You'd think a senator would make it crystal clear to every staff member that she would have to know about any criminal investigation of any of them."

An industry newsletter, Seafoodnews.com, points out that the critics of Fuglvog who apparently reported the purported violations initially to congressional critics of the National Marine Fisheries Service, rather than the authorities themselves, are undermining the controversial system of fishing quotas that have helped stabilize the industry.

"The larger question, and why Fuglvog matters, is that the case is being used to weaken the entire structure of U.S. fishing regulation. The fact that the detractors went immediately to the East Coast, rather than federal authorities, says volumes about what they thought was at stake," the newsletter said in an editorial.

"Fuglvog's guilty plea has given these critics a win: a live example that what they have alleged all along about the corruption ... the way in which people who benefit from the management system are in themselves cheaters, has one proven example where they are correct."

Fuglvog pleaded guilty to a misdemeanor violation of the Lacey Act, which combats trafficking in illegally taken wildlife, fish and plants.

Dreaded carp: Can they be stopped?

From the Minneapolis Star Tribune: Dreaded carp: Can they be stopped?
DNA from the invasive silver carp has been found at 22 sites in the St. Croix River, a development that has deepened despair about the imminent arrival of the notorious leaping fish and doubts that state and federal officials can do anything to stop it.

The Minnesota Department of Natural Resources announced Thursday that 22 of 50 water samples taken between St. Croix Falls and Franconia tested positive for silver carp DNA. The samples did not test positive for the other three species of Asian carp that are believed to moving upriver from Illinois, and another 50 samples from the Mississippi River were negative.

The results are not conclusive evidence that the fish are living and breeding in the St. Croix -- none has been found in the river -- or that they are absent from the Mississippi, DNR officials said. The DNA could have come from dead carp, live carp someone dumped in the river or fish pellets used in hatcheries.

Still, it ratchets up the fear considerably, they said.

"This is disappointing news," said DNR Commissioner Tom Landwehr.

The four species of Asian carp have caused enormous ecological damage in the Illinois and Missouri Rivers, where they are well established. The carp eat 40 percent of their body weight every day in plankton and bugs, squeezing out every other creature up the food chain, from sunnies to fish-eating birds.

"They become the most dominant organism in the system," said Byron Karns, a biologist with the National Park Service. "They topple the food chain."

Much national attention has focused on stopping the carp from moving into the Great Lakes through a shipping channel in Chicago, and five states -- Michigan, Minnesota, Ohio, Pennsylvania and Wisconsin -- have filed a federal lawsuit demanding the closure of the shipping channel.

The threat to Minnesota and Wisconsin waters has not attracted similar concern from federal agencies or Congress. That's partly because the Mississippi is a long river running through multiple states, managed by many federal agencies but with no one in charge, said Paul Labovitz, superintendent of the National Park Service's Mississippi National River and Recreation Area.

"It's like the invader of the body snatchers are at the door and we have no generals to fight back," said Mark Peterson, executive director of Audubon Minnesota.

Taken alone, the new DNA results are not likely to change that, officials said.

"We need a fish," Landwehr said Thursday.

So far, no silver carp have been caught in the St. Croix. Two bighead carp -- a cousin of the silver carp -- have been caught in the river, one in 1996 and another on April 18 of this year.

This month the DNR will contract with commercial fishermen to look for the carp up and down the St. Croix. As early as next week, DNR staff will be on the river with nets and boats outfitted with electric shocking capabilities to search for fish.

An Asian Carp Task Force brought together in January by National Park Service officials will also conduct more DNA testing in both rivers.

Meanwhile, the DNR will issue notices to anglers and boaters to keep an eye out for the silver carp, which can be hard to miss. The fish is known for its astonishing ability to leap 10 feet out of the water and even knock people out of their boats.

The far more difficult question is what to do if -- or when -- they find live carp. There is no surefire way to stop the fish.

In the short term, Landwehr said, the state will seek emergency authority to close the lock and dam at the Ford Bridge in Minneapolis.

Long-term, state and federal officials also said they will pursue a tool used elsewhere, an acoustic bubble barrier. The fish don't like the bubbles, and the acoustics can be changed to deter carp but not desirable fish.

But bubblers are not guaranteed to work, either. And just the material to construct one would cost $7 million, officials said. The only likely place on the Mississippi narrow enough for such a barrier would be at mouth of the St. Croix at Prescott, they said.

Another option is reconstruction of the Coon Rapids dam. The Legislature appropriated $16 million to carp-proof it this year. That could preserve the state's $4 billion recreational fishing industry north of the Twin Cities but would mean sacrificing the lower length of the Mississippi, including Lake Pepin, and the Minnesota River to carp invaders. And it could be only temporary. Some who have studied it say it would work for only 10 or 15 years and might not be adequate at times of high water.

The most effective solution is also the most politically difficult -- permanently closing the locks at the Ford Bridge or the St. Anthony Falls in downtown Minneapolis.

But that would require an act of Congress, and by the time that happens it might be too late.

"I don't think we need to wait to find the fish," said Peterson of the Audubon Society. "The fish are going to find us. It's just a matter of time."

Tuesday, September 6, 2011

Computer Simulation Says Arctic Ice Melt Could Pause For Several Years, Then Resume Again

From the Underwater Times: Computer Simulation Says Arctic Ice Melt Could Pause For Several Years, Then Resume Again
BOULDER, Colorado -- Although Arctic sea ice appears fated to melt as the climate continues to warm, the ice may temporarily stabilize or somewhat expand at times over the next few decades, new research indicates.

The computer modeling study, by scientists at the National Center for Atmospheric Research, reinforces previous findings by other research teams that the level of Arctic sea ice loss observed in recent decades cannot be explained by natural causes alone, and that the ice will eventually disappear during summer if climate change continues.

But in an unexpected new result, the NCAR research team found that Arctic ice under current climate conditions is as likely to expand as it is to contract for periods of up to about a decade.

"One of the results that surprised us all was the number of computer simulations that indicated a temporary halt to the loss of the ice," says NCAR scientist Jennifer Kay, the lead author. "The computer simulations suggest that we could see a 10-year period of stable ice or even an increase in the extent of the ice. Even though the observed ice loss has accelerated over the last decade, the fate of sea ice over the next decade depends not only on human activity but also on climate variability that cannot be predicted."

Kay explains that variations in atmospheric conditions such as wind patterns could, for example, temporarily halt the sea ice loss. Still, the ultimate fate of the ice in a warming world is clear.

"When you start looking at longer-term trends, 50 or 60 years, there's no escaping the loss of ice in the summer," Kay says.

Kay and her colleagues also ran computer simulations to answer a fundamental question: why did Arctic sea ice melt far more rapidly in the late 20th century than projected by computer models? By analyzing multiple realizations of the 20th century from a single climate model, they attribute approximately half the observed decline to human emissions of greenhouse gases, and the other half to climate variability.

These findings point to climate change and variability working together equally to accelerate the observed sea ice loss during the late 20th century.

The study appears this week in Geophysical Research Letters. It was funded by the National Science Foundation, NCAR's sponsor.

Rapid melt

Since accurate satellite measurements became available in 1979, the extent of summertime Arctic sea ice has shrunk by about one third. The ice returns each winter, but the extent shrank to a record low in September 2007 and is again extremely low this year, already setting a monthly record low for July. Whereas scientists warned just a few years ago that the Arctic could lose its summertime ice cover by the end of the century, some research has indicated that Arctic summers could be largely ice-free within the next several decades.

To simulate what is happening with the ice, the NCAR team used a newly updated version of one of the world's most powerful computer climate models. The software, known as the Community Climate System Model, was developed at NCAR in collaboration with scientists at multiple organizations and with funding by NSF and the Department of Energy.

The research team first evaluated whether the model was a credible tool for the study. By comparing the computer results with Arctic observations, they verified that, though the model has certain biases, it can capture observed late 20th century sea ice trends and the observed thickness and seasonal variations in the extent of the ice.

Kay and her colleagues then conducted a series of future simulations that looked at how Arctic sea ice was affected both by natural conditions and by the increased level of greenhouse gases in the atmosphere. The computer studies indicated that the year-to-year and decade-to-decade trends in the extent of sea ice are likely to fluctuate increasingly as temperatures warm and the ice thins.

"Over periods up to a decade, both positive and negative trends become more pronounced in a warming world," says NCAR scientist Marika Holland, a co-author of the study.

The simulations also indicated that Arctic sea ice is equally likely to expand or contract over short time periods under the climate conditions of the late 20th and early 21st century.

Although the Community Climate System Model simulations provide new insights, the paper cautions that more modeling studies and longer-term observations are needed to better understand the impacts of climate change and weather variability on Arctic ice.

The authors note that it is also difficult to disentangle the variability of weather systems and sea ice patterns from the ongoing impacts of human emissions of greenhouse gases.

"The changing Arctic climate is complicating matters," Kay says. "We can't measure natural variability now because, when temperatures warm and the ice thins, the ice variability changes and is not entirely natural."

The University Corporation for Atmospheric Research manages the National Center for Atmospheric Research under sponsorship by the National Science Foundation. Any opinions, findings and conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.