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Warmer, lower-oxygen oceans will shift marine habitats

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Rock crab habitats are predicted to shift away from warm temperatures at the equator and toward shallower, more oxygenated water.
Credit: J. MacCausland / U.S. Geological Survey

Modern mountain climbers typically carry tanks of oxygen to help them reach the summit. It’s the combination of physical exertion and lack of oxygen at high altitudes that creates one of the biggest challenges for mountaineers.

University of Washington researchers and collaborators have found that the same principle will apply to marine species under global warming. The warmer water temperatures will speed up the animals’ metabolic need for oxygen, as also happens during exercise, but the warmer water will hold less of the oxygen needed to fuel their bodies, similar to what happens at high altitudes.

The study, published June 5 in Science, finds that these changes will act together to push marine animals away from the equator. About two thirds of the respiratory stress due to climate change is caused by warmer temperatures, while the rest is because warmer water holds less dissolved gases.

“If your metabolism goes up, you need more food and you need more oxygen,” said lead author Curtis Deutsch, a UW associate professor of oceanography. “This means that aquatic animals could become oxygen-starved in the warmer future, even if oxygen doesn’t change. We know that oxygen levels in the ocean are going down now and will decrease more with climate warming.”

The study centered on four Atlantic Ocean species whose temperature and oxygen requirements are well known from lab tests: Atlantic cod that live in the open ocean; Atlantic rock crab that live in coastal waters; sharp snout seabream that live in the subtropical Atlantic and Mediterranean; and common eelpout, a bottom-dwelling fish that lives in shallow waters in high northern latitudes.

Deutsch used climate models to see how the projected temperature and oxygen levels by 2100 due to climate change would affect these four species’ ability to meet their future energy needs. If current emissions continue, the near-surface ocean is projected to warm by several degrees Celsius by the end of this century. Seawater at that temperature would hold 5-10 percent less oxygen than it does now.

Results show future rock crab habitat would be restricted to shallower water, hugging the more oxygenated surface. For all four species, the equator-ward part of the range would become uninhabitable because peak oxygen demand would become greater than the supply. Viable habitats would shift away from the equator, displacing from 14 percent to 26 percent of the current ranges.

The four animals were chosen because the effects of oxygen and temperature on their metabolism are well known, and because they live in diverse habitats. The authors believe the results are relevant for all marine species that rely on aquatic oxygen for an energy source.

“The Atlantic Ocean is relatively well oxygenated,” Deutsch said. “If there’s oxygen restriction in the Atlantic Ocean marine habitat, then it should be everywhere.”

Climate models predict that the northern Pacific Ocean’s relatively low oxygen levels will decline even further, making it the most vulnerable part of the ocean to habitat loss.

“For aquatic animals that are breathing water, warming temperatures create a real problem of limited oxygen supply versus elevated demand,” said co-author Raymond Huey, a UW professor of biology who has studied metabolism in land animals and in human mountain climbers.

“This simple metabolic index seems to correlate with the current distributions of marine organisms,” he said, “and that means that it gives you the power to predict how range limits are going to shift with warming.”

Previously, marine scientists thought about oxygen more in terms of extreme events that could cause regional die-offs of marine animals, also known as dead zones.

“We found that oxygen is also a day-to-day restriction on where species will live, outside of those extreme events,” Deutsch said. “Ranges will shift for other reasons, too, but I think the effect we’re describing will be part of the mix of what’s pushing species around in the future.”

Source: University of Washington

Originally published here: www.sciencedaily.com/releases/2015/06/150604162455.htm

 

Posted June 9th, 2015.

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Genetic analysis of the American eel helps explain its decline

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American Eels of the upper St. Lawrence grow slowly but attain larger sizes (top) compared with eels in coastal areas (bottom).
Credit: Guy Verreault/Current Biology 2015

The American eel has been a concern for the U.S. Fish and Wildlife Service since 2007, when it was first considered for, but failed to receive, Endangered Species Act protection. The numbers of these slender, slimy, ancient fish in freshwater areas have been decreasing rapidly due to dams, pollution, and overfishing, but scientists have been puzzled as to why the fish can’t recolonize. Now, a new look at eel genetics published on May 28 in Current Biology finds that there are differences between eels that feed in freshwater and eels that feed in brackish environments that were previously thought to be genetically interchangeable.

Both freshwater and brackish American eels are the same species, but they vary in size and have very different growth rates and life spans. Once a year, sexually mature eels from both groups migrate thousands of miles to spawn in the Sargasso Sea (located in the North Atlantic Ocean east of Bermuda). The offspring are carried off by the current to their new homes. It’s been thought that young American eels can detect whether they’ve ended up in brackish or freshwater habitats and acclimate accordingly. But this new study suggests that eels are predisposed to survive in these environments, depending on what genes they inherited.

“People have considered these differences in growth and age to be 100 percent due to phenotypic plasticity, independent of the genotype,” says lead author Scott Pavey, a postdoctoral fellow at the Integrated Biology Institute of Laval University in Quebec, Canada. “But what we found is that genes affect whether an eel can survive freshwater or brackish environments.” This helps explain why some conservation efforts to preserve the freshwater eel haven’t been successful, as more plentiful brackish eels cannot easily change their traits to survive in freshwater environments.

Pavey, in collaboration with ecologist Louis Bernatchez and colleagues, used new sequencing technologies to screen the eel genome in 45,000 places. The analysis identified 99 genes that differ between freshwater and brackish eels, including those associated with growth rate, heart development, and smell. It’s unknown whether this type of genetic differentiation exists in other, non-eel marine species with high levels of phenotypic plasticity.

The question remains, though, as to why eels would have such a strange approach to survival. The fish is considered evolutionarily ancient, so they must be doing something right. “It’s a different strategy, a kind of hedging your bets,” speculates Pavey. His team is now working to publish and release the entire genome of the eel. This will provide an important tool for other researchers to conduct similar studies on different aspects of eel ecology.

Source: Cell Press

Originally published here: www.sciencedaily.com/releases/2015/05/150528124204.htm

Posted May 29th, 2015.

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Iconic Indian fish on the brink of extinction

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Humpback Mahseer.

Credit: Bournemouth University

The legendary humpback Mahseer, one of the world’s most iconic freshwater fish, is on the brink of extinction according to scientists from Bournemouth University in the UK and St. Albert’s College in Kochi, India.

Ever since the publication of HS Thomas’s A Rod in India in 1873, this giant member of the carp family has been known to anglers around the globe as ‘one of the largest and hardest fighting freshwater fish in the world’. With its distribution having always been limited to South India’s River Cauvery basin, this fish is now believed to be so endangered it may be extinct in the wild within a generation.

Adrian Pinder of Bournemouth University and Dr Rajeev Raghavan of St. Albert’s College have been studying the ecology, taxonomy and conservation status of 17 species of mahseer which populate rivers throughout south and southeast Asia since 2010. Four of these species are already listed as ‘Endangered’ on the IUCN [International Union for Conservation of Nature] Red List. Along with co-author Dr Robert Britton, the paper, published in the international research journal Endangered Species Research, clearly demonstrates that the endemic humpbacked Mahseer is now of the brink of extinction having been replaced by non-native relatives (blue-finned Mahseer) which have been artificially bred and introduced to the river in the name of species conservation.

The paper acknowledges that many pressures are placed upon the fish of India’s rivers, including pollution; poaching (using dynamite and poisons); sand and gravel extraction; low river flows due to abstraction; and India’s continuing thirst for electricity, which has resulted in dozens of hydro-electric which restrict the ability of fish to migrate to their spawning grounds.

Against this backdrop of threats, this research suggests that the introduction of non-native Mahseer has acted as the catalyst which has had a catastrophic effect on the numbers of endemic Mahseer remaining in the River Cauvery and its tributaries.

Adrian Pinder said, “This research all stems from my interest as an angler, when as a boy I had read about this great fish. In 2010 I made my first trip the River Cauvery, where I realised the fish I was catching did not match the appearance of the iconic specimens I’d seen in historic photos.

“On returning to the UK, I interrogated the scientific literature and made contact with Dr Rajeev Raghavan based at St Albert’s College Kochi, to ask his opinion. Comparing photographs over the internet opened a can of worms and confirmed that very little was known about all of the Mahseer species found throughout south and south East Asia.

“As large monsoonal rivers are extremely difficult to survey, and angling was banned in all protected areas in India in 2012, I started to look for alternative data sources and discovered that the Galibore Fishing Camp [one of three former angling camps in the Karnataka jungle] had kept detailed angler catch records. This not only allowed us to analyse the temporal trends in population size over the previous 15 years but also form a detailed understanding of how the type and species of Mahseer had changed over time.”

In 2012 Adrian Pinder and Dr Raghavan set up the Mahseer Trust, an NGO working to protect Mahseer and its habitats. The Trust is now working with national and international stakeholders to educate and promote better informed fisheries management practices and to save the humpback Mahseer from extinction.

Adrian Pinder concluded, “The blue-finned Mahseer, is not native to the River Cauvery, yet our studies over the last two years have shown that they are now one of the most abundant fish in the river. Without a doubt, their success has been at the expense of the humpbacked Mahseer that historically occurred throughout the entire river catchment. Despite the positive intention of conservationists, this is clearly a conservation programme which has backfired. The state of confusion surrounding Mahseer taxonomy means the humpback Mahseer currently lacks a valid scientific name and could potentially go extinct before being named!”

“My current priority is on sourcing specimens of the endemic humpbacked Mahseer. If we are not already too late, obtaining DNA from this animal will allow us to name the fish and, based on our data, get it classified as ‘Critically endangered’ on the IUCN Red List. When you consider that the iconic Giant panda and tiger are classified as ‘endangered’ this puts things in context and demonstrates the urgency to act in sourcing native fish for culturing in local hatcheries.”

Source: Bournemouth University

Originally published here: www.sciencedaily.com/releases/2015/05/150514085703.htm

Posted May 26th, 2015.

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Clever fish around the coast of Mallorca Island avoid fishing lines

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A clever painted comber in its natural habitat at the coast of Mallorca.

Credit: Josep Alós

To avoid overfishing and aid in sustainable exploitation, the status of the fish stocks has to be monitored regularly. In many cases stock assessment is based on fishery-dependent data generated from fish markets or creel surveys. The assumption is: the lower the catches in a certain unit of time, the smaller the stock of fish should be. The scientists Dr. Josep Alós and Prof. Dr. Robert Arlinghaus from the German Leibniz-Institute of Freshwater Ecology and Inland Fisheries and the Humboldt-Universität zu Berlin have now shown that some fish species show enhanced gear-avoidance behavior in regions with high angling intensity compared to fish exposed to low levels of exploitation near marine protected areas. The consequence is the impression that there are less fish in the sea, which does not necessarily agree with underwater reality.

The coast of the Spanish Island Mallorca is a holiday paradise for sun worshippers and for those loving water sports. But few are aware of the exiting phenomena that happen below the water surface. Here, a competition between increasingly clever fishes and the catch-addicted fishers takes place. Within a project funded by the European Union, the Spanish scientist Josep Alós and the German-Spanish scientist Robert Arlinghaus from the German Leibniz-Institute of Freshwater Ecology and Inland Fisheries and the Humboldt-Universität zu Berlin have investigated the fish populations at the coast of Mallorca using novel mathematical models and monitoring methods . Their research aims at understanding the behavior of fish in response to recreational fisheries. Based on standardized angling catch methods in a study from 2013 the scientists concluded that marine protected areas host higher fish quantities and bigger fishes than sites with a high exploitation pressure. A follow-up study now released in the Canadian Journal of Aquatic Sciences, which used underwater video analysis in addition to angling as a method to quantify the fish stock, puts these former results into doubt. The reason for this: clever fishes that escape the pursuit of the anglers without a corresponding decline in fish stock levels.

More anglers means less painted comber on the hook

The research team investigated two fish species popular among recreational anglers along the Mediterranean Sea. Both have the same size and the same habitat but differ in their eating habits. The painted comber (Serranus scriba) show a carnivorous foraging mode and feeds on fish and small crustaceans while the annular sea bream (Diplodus annularis) lives on mobile algae and bivalves. The sea bream can afford to carefully examine the potential prey and takes its time moving around the baits, inspecting them and is generally less vulnerable to capture in comparison with the comber. By contrast, the comber evolved a carnivorous life-style: too much hesitation and the mobile prey is gone. As a result of this, the painted comber is much more aggressive towards baits than the annular sea bream in their natural habitats where fishing pressure is low, which makes the comber much more vulnerable to be harvested by the anglers.

The recent study by the researchers has now shown a starkly different behavior in sites where the fishing pressures is high. The researchers studied the behavioral responses towards baits in 54 different locations with the same habitat characteristics but different angling pressures. An autonomous underwater video recording was used to measure the behavior of the fish when they were exposed to baited hooks.

The researchers were amazed when finding a strong correlation between high fishing intensity and hook-avoidance behavior of painted comber: this species had starkly changed the behavior from aggressively attacking the baited hooks in the natural environments with low fishing pressure to being shy in exploited sites where they were able to recognize the fishing gear and avoid hooking. No such response was detected in the sea bream. The explanation may involve both genetic change towards increased shyness and learning to avoid future capture.

Less fish on the hooks does not necessarily mean less fish in the sea

Although the catch rates of comber in areas with high fishing intensity were half of those in low exploited and marine protected areas both sites showed similar fish densities as recorded by underwater video. Therefore, the benefits of marine protected areas previously determined by the same authors in 2013 were not supported by underwater video footage now. “These results suggest that recreational angling may contribute to patterns of hyper depletion in catch rates without a corresponding change in the fish population where catch rates declines stronger than the abundance of fishes,” the first author of the study, Josep Alós, comments. And further: “Reports on the dramatic decline of fish populations in the ocean which were only based on fishery-dependent data, for example data from the long-line fishery of tuna, cod or swordfish, could also have their cause in enhanced gear-avoidance behavior of those fishes. We have to rethink our monitoring of fish stocks and take the behavioral changes into account. Maybe some areas with high fishing intensity host more fish than we believe,” concludes study leader Robert Arlinghaus.

Story Source: Forschungsverbund Berlin e.V. (FVB)

Originally published here: www.sciencedaily.com/releases/2015/05/150520083129.htm

Posted May 20th, 2015.

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Deadly Sponges Snuffing-Out Coral Colonies

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Brain coral (Diploria labyrinthiformis) overgrown and smothered by the lavender branching sponge Aplysina cauliformis.

Joseph Pawlik, UNCW

It sounds like the plot of a B-movie, but researchers have determined that sponges in over-fished areas are using deadly tactics — such as smothering and toxic mucus — to kill coral colonies so that the sponges can grow on what’s left: skeletons.

The discovery shows how disruption of even just a few members of an ecosystem — in this case, tasty fish — can hurt many other organisms that live in the same area.

The problem, highlighted in the latest issue of the journal PeerJ, is particularly evident at Caribbean coral reefs, where the combined effects of warming seawater temperatures, storms, and diseases have already decimated populations of corals.

While coral looks sort of like an undersea plant, groupings actually consist of tiny marine creatures that live together within compact colonies. They usually grow slowly. Sponges, on the other hand, grow either quickly or more slowly, depending on the species.

“If the goal is to save the corals that build Caribbean reefs, we have to protect the angelfishes and parrotfishes that eat sponges,” lead author Tse-Lynn Loh, now a Postdoctoral Research Associate at the Haerther Center for Conservation and Research at Chicago’s Shedd Aquarium, said in a press release.

Loh and colleagues surveyed reefs from 12 countries across the Caribbean. The scientists compared 25 sites where fish abundance is very low (because of decades of intensive fish trapping) with 44 sites where fishes are plentiful (because they’ve been protected from fishermen).

Both fast and slow-growing sponges tended to dominate coral colonies at overfished sites, adversely impacting at least 25 percent of them. The damage was more than double the incidence of this seen at less-fished reefs. At the latter, angelfishes and parrotfishes munched on the sponges, helping to keep their dominant ways in check.

Even when the fish were around, slower-growing sponges still made a dent in coral colonies, since these sponges can unleash their arsenal of “weapons” that allow them to compete aggressively for reef real estate. In addition to the smothering tactics and toxic mucus, the sponges can kill coral by releasing other toxins and by shading out light.

In past studies, seaweed was also found to hurt coral, but the new research led to the surprising discovery that seaweeds were more abundant on reefs with greater numbers of fish. The outcome is contrary to the conventional wisdom that fishes eat seaweeds and keep them in check. It now looks like the relationship between seaweeds and fishes is more complicated than previously imagined.

Conservationists in earlier years based some of their claims about needed regulation of fishing at reefs on the idea that fish kept damaging seaweed under control. Now, there is convincing evidence that sponges, and perhaps not so much seaweed, are heavily impacted by over-fishing, which sets the stage for the sponges to kill and take over coral reefs.

“Caribbean nations can now base their fishing policy decisions on the clear connection between overfishing and sponge-smothered corals,” said co-author Joseph Pawlik of the University of North Carolina at Wilmington. “Coral conservation requires a healthy population of reef fishes.”

Author: Jennifer Viegas

Originally published here: http://news.discovery.com/earth/oceans/deadly-sponges-are-snuffing-out-coral-colonies-150427.htm

Posted May 18th, 2015.

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First In Fish: ‘Fully Warm-Blooded’ Moonfish Prowls The Deep Seas

NOAA Fisheries biologist Nick Wegner holds an opah caught during a research survey off the California coast. Researchers say the opah is the first fish known to be fully warm-blooded, circulating heated blood throughout its body.

NOAA Fisheries biologist Nick Wegner holds an opah caught during a research survey off the California coast. Researchers say the opah is the first fish known to be fully warm-blooded, circulating heated blood throughout its body.

Over decades of studying the oceans’ fishes, some species have been found to have partial warm-bloodedness. But scientists say the opah, or moonfish, circulates heated blood — and puts it to a competitive advantage.

“Nature has a way of surprising us with clever strategies where you least expect them,” according to NOAA Fisheries biologist Nicholas Wegner, who works in the Southwest Fisheries Science Center in La Jolla, Calif. In a news release about finding, Wegner said, “It’s hard to stay warm when you’re surrounded by cold water but the opah has figured it out.”

The opah is not a small animal; it’s roughly the size of a car tire and often weighs more than 100 pounds. In the past, it was often viewed as a fairly complacent dweller of water that’s hundreds of feet deep.

Now researchers say the opah also uses internal warmth to help it move quickly and efficiently — and kill prey such as squids and smaller fish. As the researchers describe in the journal Science, the fish relies on an internal heating system that seems to have been developed in frigid waters.

From the National Oceanic and Atmospheric Administration Fisheries:

“Satellite tracking showed opah spend most of their time at depths of 150 to 1,300 feet, without regularly surfacing. Their higher body temperature should increase their muscle output and capacity, boost their eye and brain function and help them resist the effects of cold on the heart and other organs, Wegner said.

“Fatty tissue surrounds the gills, heart and muscle tissue where the opah generates much of its internal heat, insulating them from the frigid water.”

Heat is generated from the opah’s large wing-like pectoral fins, which were previously thought only to help it swim fast enough to catch prey.

The agency’s researchers say they found an unexpected design tweak in the opah’s gills that sets it apart from other fish: a counter-current heat exchange in which blood vessels carrying warm blood are twined around vessels that are bringing oxygen — and cold temperatures — from the gills. The design helps the opah maintain endothermy (warm-bloodedness).

“The fish had an average muscle temperature about 5 degrees C (roughly 9 degrees Fahrenheit) above the surrounding water while swimming about 150 to 1,000 feet below the surface,” NOAA says.

Revelations about the opah’s blood temperature come after a moonfish was captured in a striking photograph off the California coast earlier this year, an encounter that was seen as part of a surge in opah sightings off the western U.S. coast.

Opah have more commonly been spotted in Hawaii — including at fish auctions.

Of the flavor, National Geographic has reported:

“Opah are unusual in that different parts of their body look and taste different, the biologist explains. The upper part of the fish looks like tuna and tastes like a cross between tuna and salmon, he says. But their pectoral muscles — the ones that power the fins on the side of the body — look and taste a bit like beef.”

Originally published here: http://www.npr.org/sections/thetwo-way/2015/05/15/407072979/first-in-fish-fully-warm-blooded-moonfish-prowls-the-deep-seas

Author: Bill Chappell

Posted May 18th, 2015.

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Cichlid Fish Display Extensive Social Interactions

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Neolamprologus pulcher (N. pulcher) is the breed of cichlid used in the study.

Credit: Dario Josi

A new study shows that cichlid fish reared in larger social groups from birth display a greater and more extensive range of social interactions, which continues into the later life of the fish. Researchers say this indicates the fish develop more attuned social behavior as a result of early environments.

The researchers also found that those fish raised in a more complex social environment have a different brain structure to those who experienced fewer group members in early life. If fish experienced the complex social environment for 2 month they had a larger hypothalamus: the area that contains most of the brain nodes of the ‘social behavior network’. They also had a larger ‘optic tectum’, which processes visual stimuli and could be related to the need to process more visual stimuli in larger groups, say researchers.

The brains of fish with enhanced social skills were not bigger overall than those reared in small groups; however, the ‘architecture’ within the brain was different.

“Our data suggests that, during development, relative brain parts change their size in response to environmental cues without affecting overall brain size: increasing certain parts forces others to decrease concurrently. These ‘plastic’ adjustments of brain architecture were still present long after the early stages of social interaction,” said study author Dr. Stefan Fischer, from Cambridge University’s Department of Zoology.

“Social animals need to develop social skills, which regulate social interactions, aggression and hierarchy formations within groups. Such skills are difficult and costly to develop, and only beneficial if the early social environment predicts a high number of social interactions continues to be critically important later in life,” he said.

For the study, published this week in the journal The American Naturalist, researchers used the Neolamprologus pulcher (N. Pulcher) breed of cichlid, primarily found in Lake Tanganyika — the great African freshwater lake that feeds into the Congo River.

N. Pulcher lives in family groups with up to 25 individuals, with one breeder pair and several helpers participating in territory defense and raising of offspring — known as ‘cooperative breeding’. To test for social skills, the researchers reared juvenile fish over two months with either three or nine adult group members, and observed all social behaviors at key experimental points.

These interactions included ‘lateral display’ — when one fish interrupts another by displaying their body side-on, sometimes as a mating ritual — as well as ramming, tail quivering, and ‘mouth fighting': a social display in which fish lock mouths to challenge each other over everything from food to mates.

Six month after this test phase, individual fish brains were measured to investigate the long term consequences of early group size on brain morphology, revealing differences in brain architecture.

The researchers say that one of the effects on social behavior in larger groups might be the perception of environmental risk. “In the wild, larger social groups of N. Pulcher represent a low-risk environment with enhanced juvenile survival. Being part of a larger, safer group may increase the motivation of juveniles to interact socially with siblings, enhancing the opportunities to acquire social skills,” said Fischer.

As perhaps with any social creature, Fischer points out that higher social competence and the ability to conform to social hierarchies may well stand the cichlids in good stead in later life:

“Group size for these fish stays relatively stable across the years, they have delayed dispersal. Remaining in a larger group means a better chance of survival. Fish reared in large groups showed more submissive and less aggressive behavior to big fish in the group, social behavior which greatly enhances the survival chances of smaller fish.”

Fischer added: “In highly social animals, such as cooperative breeders, almost all activities involve social interactions, where individuals need to adequately respond to social partners. In larger groups, these interactions are more common and individuals developing sophisticated social skills during childhood might highly benefit from them later in life.”

Source: University of Cambridge

Originally published here: www.sciencedaily.com/releases/2015/05/150507114048.htm

Posted May 15th, 2015.

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Some Like it Cold: Sea Anemones found in Antarctica

The Edwardsiela andrillae sea anemone measures less than 1 inch in length. (Credit: Courtesy Frank Rack, ANDRILL Science Management Office, University of Nebraska-Lincoln)

Using a camera-equipped robot to explore beneath the Ross Ice Shelf off Antarctica, scientists and engineers with the Antarctic Geological Drilling (ANDRILL) Program made an astonishing discovery.

Thousands upon thousands of small sea anemones were burrowed into the underside of the ice shelf, their tentacles protruding into frigid water like flowers on a ceiling.

“The pictures blew my mind,” said Marymegan Daly of Ohio State University, who studied the specimens retrieved by ANDRILL team members in Antarctica.

The new species, discovered in late December 2010, was publicly identified for the first time in a recent article in the journal PLoS ONE.

Though other sea anemones have been found in Antarctica, the newly discovered species is the first known to live in ice. They also live upside down, hanging from the ice, compared to other sea anemones that live on or in the sea floor.

The white anemones have been named Edwardsiella andrillae, in honor of the ANDRILL program. The discovery was “total serendipity,” said Frank Rack, executive director of the ANDRILL Science Management Office at the University of Nebraska-Lincoln and associate professor of Earth and atmospheric sciences at UNL.

“When we looked up at the bottom of the ice shelf, there they were,” he said.

Scientists had lowered the robot, a 4 1/2-foot cylinder equipped with two cameras, a side-mounted lateral camera and a forward-looking camera with a fish-eye lens, into a hole bored through the 270-meter-thick shelf of ice that extends more than 600 miles northward into the Ross Sea from the grounding zone of the West Antarctic Ice Sheet.

Their mission, financed by the National Science Foundation in the U.S. and the New Zealand Foundation for Research, was to learn more about the ocean currents beneath the ice shelf and provide environmental data for modeling the behavior of the ANDRILL drill string, Rack said. They didn’t expect to discover any organisms living in the ice, and surely not an entirely new species.

The discovery indicates that, even after 50 years of active U.S. research, more remains to be studied about the southernmost continent, said Scott Borg, head of the Antarctic Sciences Section in the NSF’s Division of Polar Programs.

“Just how the sea anemones create and maintain burrows in the bottom of the ice shelf, while that surface is actively melting, remains an intriguing mystery,” he said. “This goes to show how much more we have to learn about the Antarctic and how life there has adapted.”

Rack, who is U.S. principal investigator for the environmental surveys that were conducted as part of the international ANDRILL Coulman High project, had left the site just prior to the discovery. He was listening by radio when he heard the report from the robot deployment team — engineers Bob Zook, Paul Mahecek and Dustin Carroll — who began shouting as they saw the anemones, which appeared to glow in the camera’s light.

“They had found a whole new ecosystem that no one had ever seen before,” Rack said. “What started out as a engineering test of the remotely operated vehicle during its first deployment through a thick ice shelf turned into a significant and exciting biological discovery.”

In addition to the anemones, the scientists saw fish that routinely swam upside down, the ice shelf serving as the floor of their undersea world. They also saw polychaete worms, amphipods and a creature they dubbed “the eggroll,” a 4-inch-long, 1-inch-diameter, neutrally buoyant cylinder that seemed to swim using appendages at both ends of its body. It was observed bumping along the field of sea anemones under the ice and hanging on to them at times.

The anemones measured less than an inch long in their contracted state — though they get three to four times longer in their relaxed state, Daly said. Each features 20 to 24 tentacles, an inner ring of eight longer tentacles and an outer ring of 12 to 16 tentacles. After using hot water to stun the creatures, the team used an improvised suction device to retrieve them from their burrows. They were then transported to McMurdo Station for preservation and further study.

Because the team wasn’t hunting for biological specimens, they were not equipped with the proper supplies to preserve them for DNA/RNA analyses, Rack said. The anemones were placed in ethanol at the drilling site and some were later preserved in formalin at McMurdo Station.

Many mysteries remain. Though some sea anemones burrow into sand with tentacles or by expanding and deflating the base of their bodies, those strategies don’t seem feasible for ice. It is also unclear how they survive without freezing and how they reproduce. There is no evidence of what they eat, although they likely feed on plankton in the water flowing beneath the ice shelf, Daly said.

Rack said a proposal is being prepared for further study of this unusual environment using a robot to explore deeper in the ocean and further from the access hole through the ice. NASA is helping finance the development of the new underwater robot because the Antarctic discoveries have implications for the possibility of life that may exist on Europa, the ice-covered moon of Jupiter.

He said researchers hope to return to Antarctica as early as 2015 to continue studying the sea anemones and other organisms beneath the ice shelf.

 

Originally published here: http://newsroom.unl.edu/releases/2014/01/16/ANDRILL+team+discovers+ice-loving+sea+anemones+in+Antarctic

Posted January 23rd, 2014.

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Solving the Mysteries of the Sea: Biologists in Norway Strive to Discover Full Extent of Biodiversity

A crawfish that lives on the seabed along the Norwegian coast, Campylaspis costata is one of the 76 known species of crawfish found in Norwegian waters that we now know more about as a result of inventories conducted for the Norwegian Taxonomy Initiative. (Credit: Photo: Henrik Glenner, University of Bergen)

More than a thousand new species -nearly one-quarter of which are new to science — have been discovered in Norway since a unique effort to find and name all of the country’s species began in 2009.

The Norwegian Taxonomy Initiative is one of just two government efforts worldwide where scientists are being funded to find and catalogue the country’s true species diversity.

The Norwegian initiative is focused on describing poorly known species groups across the country’s varied habitats, from its alpine plateaus to the northernmost reaches of the island archipelago of Spitsbergen.

The finds range from new species of insects and lichens to new species of molluscs and cold-water sponges. The information gives scientists and policymakers a better platform for understanding of the complexity and function of Norway’s ecosystems.

“These are very good results that provide new knowledge of both individualspecies and ecosystems,” says Ivar Myklebust, director of the Norwegian Biodiversity Information Centre, which is coordinating the taxonomy initiative on commission from the Norwegian Ministry of the Environment.

Scientists believe that there are roughly 55,000 species in Norway, but until now only 41,000 have been discovered. The 1165 new species discovered by the taxonomy initiative over the last four years are thus an important addition to this number. However, it will take time before the species that are thought to be new to science can be added to this list. These newly discovered species must first be given a scientific name and a description of the species must be published in a scientific publication.

“Norway’s land, seas and coastal areas have a unique variety of landscapes and ecosystems with great variation over short distances, which is rare in a global context,” said Tine Sundtoft, Norway’s Minister of Climate and the Environment. “This gives us a rich and varied flora and fauna. The Government will take our management responsibilities seriously.”

Many new insect species The biggest discoveries have been made in the major species-rich groups where previous knowledge has been poor — including in the groups that include wasps, flies and mosquitoes.

Scientists believe that there are thousands of species in Norway yet to be discovered in these groups. The figures from the taxonomy initiative shows that nearly 60 per cent of the new species are insects or other small terrestrial invertebrates (729 species), including 667 new species of insects, 17 new spider species and 18 new springtail species.

A boost in knowledge about fungi Fungi represent another large and species-rich group in Norway. Since 2009, scientists have found 227 new fungi species as part of the taxonomy initiative.

Some of these fungal species have been discovered using DNA analysis to clarify the relationship between species. This has led scientists to split some species into two, or to increase the species numbers from 14 to 31, as was the case for coral fungi.

New marine species Norway’s rich marine environment supplied 157 new species, including sponges, snails, slime worms, bristle worms, fish parasites, molluscs and starfish. Another 16 new species were discovered in brackish and fresh water, primarily fish parasites and small crustaceans.

Marine species are not as accessible as terrestrial species for researchers. As a result, 48 per cent of the species found as part of the taxonomy initiative are completely new to the scientific world and have never before been described scientifically.

In comparison, 18 per cent of the new terrestrial species are what scientists call undescribed species. In some of the very poorly known marine species groups such as the worm-like (aplacophoran) molluscs that live on the ocean floor, Aplacophora/shell less molluscs, the proportion of undescribed species may be as high as 90 per cent.

New knowledge about better-known species groups Norway’s landscape varies greatly in its topography, climate and habitats, which are home to a rich lichen and moss flora, with more than 2000 species of lichens and about 11 000 species of mosses.

“Even though we believe that the flora of both lichens and mosses are relatively well known, we have learned a great deal about the incidence and prevalence of both groups as a result of the initiative” says Ingrid Salvesen, senior adviser at the Norwegian Biodiversity Information Centre and coordinator of the Norwegian Taxonomy Initiative.

This is partly because much of the current knowledge and species descriptions are based on very old data. DNA analyses, combined with surveys in little explored areas, have proven to be very useful.

Salvesen also says that the initiative has given scientists a better understanding of where better-known species are found and the relationships of these species to different habitats. This is an important cornerstone for knowledge-based management.

“Geo-referenced information records of species give us new knowledge of the habitat that these species live in, and the organisms that they live with,” Salvesen says. “That gives us the ability to better understand the complex interactions of nature.”

DNA reveals new species DNA barcoding is a method for identifying species using differences in genetic material. The method involves comparing a short DNA sequence of an unknown organism to known sequences in a reference library.

The DNA barcodes can identify species from just tiny tissue samples, such as from an insect leg or a drop of blood.

A selection of the material collected by the Taxonomy Initiative has been made available for DNA barcoding in collaboration with the Norwegian Barcode of Life network (NorBOL).

To date, NorBOL has registered barcodes from approximately 3800 species in Norway, over half of which have come via the Taxonomy Initiative. NorBOL is part of a global effort to build up the reference library of DNA barcodes for more and more of the Earth’s species.

The Research Council of Norway has provided funding for the country’s national infrastructure for DNA barcoding up to and including 2018, which will allow for a great number of Norwegian species to be registered in the library.

Facilitator and catalyst The major activity that has been generated by the Norwegian Taxonomy Initiative has revitalized the country’s biosystematics research. A large number of academics, experts, technicians and students from most natural science research institutions in Norway are involved in the survey work.

The project has also led to the establishment of solid, professional networks across national boundaries. Norwegian researchers have established working relationships with their colleagues in Sweden, Denmark, Finland, Estonia, the UK, Ireland, the Netherlands, Belgium, Poland, Germany, Austria, Hungary, Georgia Spain, Canada and Japan.

42 projects in five years The Norwegian Taxonomy Initiative has started 42 inventory projects for mapping and identifying species in Norway since its inception in 2009. About half of these projects are completed or will be completed during 2013. Another eight new projects will be initiated in 2014.

 

Originally published here: http://www.alphagalileo.org/ViewItem.aspx?ItemId=137581&CultureCode=en

Posted January 8th, 2014.

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Life in the Splash Zone

A male Pacific leaping blenny on the island of Guam. Photo: Courtney Morgans/UNSW.

One of the world’s strangest animals – a legless, leaping fish that lives on land – uses camouflage to avoid attacks by predators such as birds, lizards and crabs, new research shows.

UNSW researchers, Dr Terry Ord and Courtney Morgans, of the Evolution and Ecology Research Centre, studied the unique fish – Pacific leaping blennies – in their natural habitat on the tropical island of Guam.

Their study will be published in the journal Animal Behaviour.

“This terrestrial fish spends all of its adult life living on the rocks in the splash zone, hopping around defending its territory, feeding and courting mates. They offer a unique opportunity to discover in a living animal how the transition from water to the land has taken place,” says Dr Ord, of the UNSW School of Biological, Earth and Environmental Sciences.

The researchers first measured the colour of five different populations of the fish around the island and compared this with the colour of the rocks they lived on. “They were virtually identical in each case. The fish’s body colour is camouflaged to match the rocks, presumably so they aren’t obvious to predators,” says Dr Ord.

To see if background matching reduced predation, the researchers created realistic-looking models of blennies out of plasticine. “We put lots of these model blennies on the rocks where the fish live, as well as on an adjacent beach where their body colour against the sand made them much more conspicuous to predators,” says Dr Ord.

“After several days we collected the models and recorded how often birds, lizards and crabs had attacked them from the marks in the plasticine. We found the models on the sand were attacked far more frequently than those on the rocks.

“This means the fish are uniquely camouflaged to their rocky environments and this helps them avoid being eaten by land predators.”

The researchers then studied the body colour of closely related species of fish, some of which lived in the water and some of which were amphibious, sharing their time between land and sea.

“These species provide an evolutionary snapshot of each stage of the land invasion by fish,” says Dr Ord.

The similarities in colour between these species and the land-dwelling fish suggest the ancestors of the land-dwelling fish already had a colouration that matched the rocky shoreline before they moved out of the water, which would have made it easier for them to survive in their new habitat.

The Pacific leaping blenny, Alticus arnoldorum, is about four to eight centimetres long and leaps using a tail-twisting behaviour. It remains on land all its adult life but has to stay moist to be able to breathe through its gills and skin.

Originally published here: http://newsroom.unsw.edu.au/news/science/secrets-legless-leaping-land-fish

Posted December 3rd, 2013.

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