Friday, September 13, 2013

Study Explores Complex Physical Oceanography in East China Sea

From Science Daily: http://www.sciencedaily.com/releases/2013/09/130912112843.htm

Sep. 12, 2013 — Just days before a team of researchers from Woods Hole Oceanographic Institution (WHOI) and National Taiwan University set out to conduct fieldwork in the East China Sea, Typhoon Morakot -- one of the most destructive storms ever to hit Taiwan -- made landfall on the island, causing widespread damage and drastically altering the flow of water along the nearby continental shelf.

The typhoon, which struck in Aug. 2009, caused catastrophic damage in Taiwan, killing several hundred people and dropping up to 2 meters of rain in just 5 days in the mountains.

In their work to understand the strong currents over the continental shelf and slope in the East China Sea, the researchers used four ships for intensive sampling of the continental shelf and slope, and deployed several moorings and conducted high-resolution hydrographic surveys. But the timing of their research also enabled them to examine the impact of freshwater run-off from Typhoon Morakot on the continental shelf northeast of Taiwan, the upwelling and cooling that occurred over the continental shelf after the Typhoon, and the effect of Typhoon Morakot on the biogeochemistry and nutrient dynamics of the continental shelf.

The research has just appeared in a special issue of the Journal of Marine Research.

Although the East China Sea is home to some of the world's most active fisheries and shipping lanes, the basic oceanography of the area is not yet well understood, says WHOI coastal oceanographer Glen Gawarkiewicz, one of the primary investigators for the program. "It's a very difficult place to study -- the currents in the region are extremely powerful, and are constantly shifting and changing, which makes it tough to predict how the ocean will behave there at any given time," he notes. As a result, Gawarkiewicz says existing computer models of the area have a large degree of "uncertainty," or margin of error.

The joint program, called "Quantifying, Predicting, and Exploiting Uncertainty" (QPE), is using data collected in the field to understand how uncertainty in computer models of the ocean near Taiwan changes in time and space. In the process, Gawarkiewicz hopes the QPE team will not only be able to improve the current oceanographic understanding of the East China Sea, but improve methods used to model similar currents around the world. Funding for the program was provided by the U.S. Office of Naval Research.

The main goals of the QPE program are twofold, says Gawarkiewicz. First, it strives to understand how a feature caused by upwelling of cold water, dubbed the "Cold Dome," forms along the continental slope, and attempts to predict when and how it might appear. This phenomenon may play a role in both the formation of new currents and the transport of nutrient-rich water up from the deep ocean, a process essential for the health of marine fisheries. The QPE researchers also set out to examine when and where the Kuroshio Current (a large regional current similar to the Gulf Stream) pushes onto the continental shelf, causing complex currents to appear.

Gawarkiewicz says the shape of the ocean floor in the area may play a role in the complexity of those currents, and may contribute to the high uncertainty that appears in the computer models. As the Kuroshio moves along the continental slope, it passes over a series of three underwater canyons that alter its flow, creating new currents and eddies.

The QPE team conducted their fieldwork in the East China Sea during August and September 2009, using a satellite link to interact remotely with ocean modeler Pierre Lermusiaux at Massachusetts Institute of Technology. Each day, Lermusiaux ran computer models of the region, looking for areas of high uncertainty, then directed the team to those spots to collect samples and measure currents. The team immediately sent this new data back to Lermusiaux, who fed it back into the model. In this way, the researchers were able to improve the model's accuracy in real time.

"There's a feedback between the observations and the modeling," Gawarkiewicz notes. "Basically, if you can make good observations in areas of high uncertainty, you can reduce the uncertainty in the future for that area."

In addition to studying the currents of the East China Sea, the researchers also examined the formation of internal waves -- long pulses of energy created either by tidal currents or by water moving past underwater physical barriers, like a ridge or canyon on the ocean floor. "It's similar to wind flowing over a mountain range," says Tim Duda, a WHOI physicist who collaborated on the study. "As water flows over undersea ridges and valleys or is pushed over the continental slope, distinct waves begin to form."

Although these waves form deep underwater, he says, it's still possible to track their location by looking for surface disturbances. "You can actually see where an internal wave is going by looking at the surface of the ocean," says Duda. "The currents of the internal waves push surface waves and ripples together, forming alternating stripes of smooth and rough water that you can pick up either visually or using shipborne radar."

Duda also measured internal waves that passed beneath the ship by using sonar to track the movement of plankton, tiny plants and animals suspended in the water. Since these organisms can't move quickly through the ocean on their own, a passing internal wave would cause them to sink and rise in unison, revealing the wave's shape, size, and direction of travel.

Duda says that the internal waves he observed northeast of Taiwan are extremely powerful, including one wave that measured more than 50 meters (164 feet) tall. Some of these waves, he notes, can form a solitary pulse of energy that travels for miles in deep water before dissipating. Duda dubbed these "transbasin" waves, and thinks they may play a role in mixing layers of water in the ocean, pulling nutrients from the deep up into shallower regions. His paper describing internal wave formation in the East China Sea appears in the special journal issue.

While conducting fieldwork in the region, the QPE team was also given a rare opportunity to measure changes in ocean currents caused by Typhoon Morakot. After the powerful storm passed through the region, the researchers found a strong coastal current formed and began to pull freshwater runoff from Taiwan's coastal region into the ocean hundreds of miles north of the island. "This runoff carried pieces of wood, broken tree trunks, and even farmed freshwater fishes hundreds of miles northeast of Taiwan," says Sen Jan of National Taiwan University, a co-Principal Investigator for QPE. "Those observations are helping provide a new perspective on the disasters that take place after a typhoon." The storm also drove upwelling of deep, cold water onto the continental shelf, which increased the amount of nutrients and phytoplankton after the storm.

"Thanks to global climate change, we're seeing bigger and more powerful storms all over the world," adds Gawarkiewicz, "and understanding exactly how they affect our oceans in the future will be important for shipping, for food production, and for basic science."

Wednesday, August 14, 2013

Mystery Over Pristine Shipwrecks, Dead Whales Solved

From News.discovery.com: Mystery Over Pristine Shipwrecks, Dead Whales Solved
Both shipwrecks and dead whales tend to sink to the seafloor and gradually disappear due to erosion and scavengers. In the Antarctic, however, shipwrecks tend to stay pristine, whereas finding a dead whale carcass is an extraordinarily rare event, found for the first time off Antarctica only this year.
The difference is due to the type of scavengers that thrive in the Southern Ocean, and those that don’t.
PHOTOS: Underwater World Captured
Adrian Glover of The Natural History Museum and his team have discovered two new species of bone-eating Antarctic worms: Osedax antarcticus and Osedax deceptionensis. And unlike Osedax in warmer regions, O. antarcticus at least scavenges in droves.
Glover refers to shipwrecks, other wood waste, and dead whales as “organic falls,” since all tend to be large and very slow to break down. If you put a giant dead whale in your compost bin, you’d probably see and smell it for quite some time. In other parts of the ocean, Osedax worms and flesh-eating fish spend generations munching on a single whale fall. But little is known about what happens in the ocean depths of Antarctica.
Glover explained, “The deep sea that surrounds the Antarctic continent is one of the least explored ecosystems on Earth. The organisms that live there are dependent on a supply of food from the surface, in extreme examples this can be the remains of a whale or piece of wood. These large ‘organic-falls’ are unstudied in Antarctica.”
NEWS: Antarctic’s First-Ever Whale Skeleton Found
For this latest study, the researchers left planks of pine and oak as well as whalebone sitting for more than a year on the seafloor in three different locations along the West Antarctic Peninsula.
After the team recovered their samples, they found through microscopic analysis that the wood was nearly as good as new – albeit water laden. The whalebones from two of the sites, on the other hand, were infested with the newly identified O. antarcticus worms to the point where the bones looked like they still had skin attached, only it was the skin of the worms. The newly identified O. deceptionensis emerged from a hole in the bone from the third site after several days in an aquarium. The findings bring the number of known bone-munching Osedax worms to seven.
The findings are published in the latest Proceedings of the Royal Society B.
Usually wood is attacked by wood-boring bivalves that can penetrate solid materials. Scavengers such as teredinid shipworms and deep-sea xylophagainid clams consume the wood directly, but gain nutrients from their meal only after the fibers are broken down by their own personal bacterial endosymbionts. Other wood-boring bivalves don’t eat the wood directly, but dig into it with attachment bristles. As sometimes the only topographic feature for miles around, shipwrecks can provide an impressive amount of shelter. Until that is the bivalves dig, or with their bacteria eat, the wooden wrecks to the ground.
(Certain species of bacteria can even feast on rusting metal on their own, which is one reason why famous wrecks like the Titanic are in danger of eroding away. The hull of the Titanic, for example, is laden with bacteria-formed “rusticles.”)
NEWS: The Loneliest Whale in the World?
Shipwreck hunters that may have avoided the Southern Ocean in the past because of the danger and difficulty of exploring the region may find their efforts well worth the trouble. Glover and his colleagues suspect that wood-boring species are either absent or in low numbers in this region because the cold water and its current form a barrier that may act to keep the species away.
“It is possible that our experiments were not left long enough, or that the size of the lots of wood, or the presence of whalebone, has inhibited larval development” of wood-boring species, the researchers acknowledge. But similar experiments at other latitudes have shown that wood-boring species are capable of infesting wood at the end of three months, and in some cases, destroying a sample completely within a year, they reported.
But for more than 30 million years, the Antarctic continent was tree free.
“Since humans first started exploring the Antarctic, wood has been deposited on the seafloor in the form of shipwrecks and waste; our data suggest that this anthropogenic wood may be exceptionally well preserved,” the authors wrote.
Stay tuned for possible future discoveries!
An underwater field guide to McMurdo Sound is available at: http://scilib.ucsd.edu/sio/nsf/fguide/index.html. (Henry Kaiser, National Science Foundation)
 

Tuesday, May 21, 2013

Climate slowdown means extreme rates of warming 'not as likely'

From BBC NEws:  Climate slowdown means extreme rates of warming 'not as likely'

Scientists say the recent downturn in the rate of global warming will lead to lower temperature rises in the short-term.
Since 1998, there has been an unexplained "standstill" in the heating of the Earth's atmosphere.
Writing in Nature Geoscience, the researchers say this will reduce predicted warming in the coming decades.
But long-term, the expected temperature rises will not alter significantly.

Start Quote

The most extreme projections are looking less likely than before”
Dr Alexander Otto University of Oxford
The slowdown in the expected rate of global warming has been studied for several years now. Earlier this year, the UK Met Office lowered their five-year temperature forecast.
But this new paper gives the clearest picture yet of how any slowdown is likely to affect temperatures in both the short-term and long-term.
An international team of researchers looked at how the last decade would impact long-term, equilibrium climate sensitivity and the shorter term climate response.
Transient nature Climate sensitivity looks to see what would happen if we doubled concentrations of CO2 in the atmosphere and let the Earth's oceans and ice sheets respond to it over several thousand years.
Transient climate response is much shorter term calculation again based on a doubling of CO2.
The Intergovernmental Panel on Climate Change reported in 2007 that the short-term temperature rise would most likely be 1-3C (1.8-5.4F).
But in this new analysis, by only including the temperatures from the last decade, the projected range would be 0.9-2.0C.
Ice The report suggests that warming in the near term will be less than forecast
"The hottest of the models in the medium-term, they are actually looking less likely or inconsistent with the data from the last decade alone," said Dr Alexander Otto from the University of Oxford.
"The most extreme projections are looking less likely than before."
The authors calculate that over the coming decades global average temperatures will warm about 20% more slowly than expected.
But when it comes to the longer term picture, the authors say their work is consistent with previous estimates. The IPCC said that climate sensitivity was in the range of 2.0-4.5C.
Ocean storage This latest research, including the decade of stalled temperature rises, produces a range of 0.9-5.0C.
"It is a bigger range of uncertainty," said Dr Otto.
"But it still includes the old range. We would all like climate sensitivity to be lower but it isn't."
The researchers say the difference between the lower short-term estimate and the more consistent long-term picture can be explained by the fact that the heat from the last decade has been absorbed into and is being stored by the world's oceans.
Not everyone agrees with this perspective.
Prof Steven Sherwood, from the University of New South Wales, says the conclusion about the oceans needs to be taken with a grain of salt for now.
"There is other research out there pointing out that this storage may be part of a natural cycle that will eventually reverse, either due to El Nino or the so-called Atlantic Multidecadal Oscillation, and therefore may not imply what the authors are suggesting," he said.
The authors say there are ongoing uncertainties surrounding the role of aerosols in the atmosphere and around the issue of clouds.
"We would expect a single decade to jump around a bit but the overall trend is independent of it, and people should be exactly as concerned as before about what climate change is doing," said Dr Otto.
Is there any succour in these findings for climate sceptics who say the slowdown over the past 14 years means the global warming is not real?
"None. No comfort whatsoever," he said

 

Friday, March 29, 2013

Take your blood pressure medication!

Spent most of yesterday in the hospital, where my mother was admitted. Her doctor had changed her blood pressure medication a couple of weeks ago, it wasn't doing the job. Unfortunately her doctor was out of town and a home therapist said we should take her to the Emergency Room.

Bad idea, as far as I'm concerned. Put her back on her old medication which was working, just causing her to cough.

Instead we brought her to the emergency room, and since she's old and deaf, this got her more stressed out and scared than ever, because they were all gathered around her shouting questions and wanting to run tests and I'm sure she thought she was dying or something, which sent her blood pressure even higher.

She spent the night there, and is still in today for more tests, which I don't think she needs but I guess since they've got her in there they want to get their money's worth out of our insurance...  she's in a private room which must be costing a fortune....

The reason for my headline... she was about 40 when she was first diagnosed with high blood pressure...took pills for a couple of days but didn't like how they made her feel....so she stopped taking them and tried to do the "natural remedy" thing.

Result, 20 years later she had congestive heart failure, and now instead of taking 1 pill a day she has to take 4. And has to go into the hospital periodically on occasions like these.

Moral of the story - go get your blood pressure checked, and if you have high blood pressure make sure you take your meds, otherwise believe me you'll wish you had, when it is too late...

Wednesday, March 20, 2013

Tiny plants devour reefs in warming, acidic oceans

The University of Queensland:  Tiny plants devour reefs in warming, acidic oceans

A world-first scientific study has found that the world's coral reefs are being weakened by microscopic borers and will erode more rapidly as the oceans warm and acidify.

This phenomenon, combined with a slower growth of coral reefs due to ocean acidification, may make reefs more vulnerable to storms and cyclones, according to Ms Catalina Reyes of the ARC Centre of Excellence for Coral Reef Studies (CoECRS) and The University of Queensland (UQ).

“So fish, turtles, sharks, lobsters and other reef organisms may lose their homes, threatening reef biodiversity and the livelihoods of tens of millions of people,” Ms Reyes said.

Ms Reyes explained that corals use calcium carbonate, or limestone, to build the reef structure.

As the coral accumulates, carbonate and extend their skeleton, the old, dead parts are eroded by waves, currents, fishes, sponges and by tiny plants that live inside the reef.

“There is a fine balance between accumulating and losing carbonate, and healthy reefs are the ones that gain more than they lose,” Ms Reyes said.

“Anything that disrupts this balance puts coral reefs in danger.”

Coral reefs are already threatened by ocean acidification caused by human carbon emissions dissolving into the oceans.

Associate Professor Sophie Dove of CoECRS and UQ said coral reefs were already threatened by ocean acidification caused by human carbon emissions dissolving into the oceans.

This process reduced the amount of carbonate in the seawater, which meant the corals build the reef at a slower pace, she said.CoECRS researchers found that the lack of carbonate to build coral reefs wasn't the only challenge that these ecosystems faced.

In this latest study, CoECRS researchers found that the lack of carbonate to build coral reefs isn't the only challenge that these ecosystems face.

“Our research shows that when seawater is both acidic and warm – which is predicted to happen under future climate scenarios – coral reefs could be made more fragile by microborers such as algae, blue-green algae and fungi that inhabit reefs and bore tiny holes in it that undermine the strength of the coral skeleton,” Associate Professor Dove said.

To explore how the combination of a warm and acidic ocean affects the activity of microborers, the researchers exposed different types of coral skeletons in tanks containing seawater, which simulated two future climate scenarios.

Ms Reyes said the first scenario was ‘business as usual' where nothing was done by humanity to decrease CO2 emissions.

“In this case, the rate of erosion by the microborers of the coral skeletons almost doubled compared to the present day,” she said.

“In the second scenario, in which CO2 was above current levels but less than the ‘business as usual' scenario, the rate of erosion was 35 percent.

“We found that microborers were more abundant under both predicted scenarios, so it is possible that acidic and warm sea water will stimulate their growth, leading to coral skeletons dissolving faster."

Ms Reyes said the most abundant type of algae identified in the study was also the world's most common photosynthetic microborer, capturing sunlight to fuel its activities.

It currently inhabits 85 percent of the world's corals and has an extraordinary ability to cope with low light conditions, allowing it to penetrate deep into coral skeletons.

Dr Dove said in the future corals would have less material with which to build their reefs, and the old, dead parts that support them would erode much faster.

“If we think of the reef as a scaffold, it's now being taken apart faster than it can re-build, which means that it's at a higher risk of collapsing,” she said.

“Even if there are ‘super corals' that do well in an acidic ocean, this study shows that we mustn't underestimate how much climate change can affect other important reef processes.”

The study Ocean acidification and warming scenarios increase microbioerosion of coral skeletons by Catalina Reyes-Nivia, Guillermo Diaz-Pulido, David Kline, Ove-Hoegh-Guldbeg and Sophie Dove has been published in the latest issue of Global Change Biology. View the publication here

For more information visit http://www.coralcoe.org.au/ 

 

Tuesday, February 26, 2013

Never get involved in a land war in Asia

and never agree to transcribe 20 hours of meetings from an Australian business meeting.

That's what I've been doing for the last 4 days...utter nightmare. Could NOT understand their accents. Making it worse were the bad audio levels and the fact that a lot of the people preesnt insisted on talking over each other from all around the room except in front of the microphone... I will never transcribe ANYTHING every again.

Anyway, so sorry to be MIA from my blogs.

Monday, February 18, 2013

‘US to pay reef damages’

From Manila Standard Today: ‘US to pay reef damages’

US Secretary of State John Kerry said the United States government is ready to “fully and appropriately provide compensation for all damages” caused by the grounding on the Tubbataha reef, said Foreign Affairs Secretary Albert del Rosario.
Base from their phone conversation Wednesday night, Del Rosario said Kerry assured full cooperation in salvaging the USS Guardian which ran aground in January.
“One of the first things we discussed was the USS Guardian incident. We had a very frank discussion between friends. We both agreed on the importance of removing the USS Guardian from the reef without causing further damage,” Del Rosario said in a statement released Thursday.
“Secretary Kerry reiterated the deep regret of the US government over the incident and its readiness to provide full and appropriate compensation,” he added.
“Secretary Kerry said that he himself wants to know and get to the bottom of what truly happened. In this context he said that he wants to be a full partner of the Philippines in finding out what happened and that the U.S. government will cooperate fully with the investigation that the Philippines is conducting.”
Del Rosario said Kerry is also committed to share the US Navy’s findings and consult the Philippines and its expert before finalizing its report.
“We both agreed that it is important to understand what happened and to take the necessary navigational safety measures to protect the reef and that would prevent other ships from grounding there,” he said.
“I would like to assure the public that every effort will be made to obtain proper compensation. We also are of the view that a long term commitment of resources by the United States to the future well being of the reef is important, on top of the issue of compensation.”

Sunday, February 17, 2013

New Zealand dolphin faces extinction, group warns

From Global Post: New Zealand dolphin faces extinction, group warns

Scientists have urged New Zealand to take immediate action to protect the critically endangered Maui's dolphin, amid warnings the marine mammal could become extinct by 2030.
The animal, the world's smallest dolphin sub-species, is only found in waters off the North Island's west coast and experts estimate the adult population has dwindled to just 55, the US-based Society for Marine Mammalogy (SSM) said.
In a letter to New Zealand Prime Minister John Key, it said scientific data showed up to five dolphins a year died after becoming entangled in fishing nets, meaning urgent action was needed for it to survive.
While the findings are disputed by commercial fishers, the SSM said the evidence was "exceptionally strong" and called for a ban on trawling and a fishing method known as gillnetting in its marine habitat.
"In a situation such as this one, involving a critically endangered sub-species, delay to resolve uncertainty could have dire, irrevocable results," SSM president Helene Marsh said in the letter dated February 11, seen Thursday.
"I encourage you to act quickly and decisively to provide the leadership in marine conservation that the world expects of your country."
The SSM, which represents 2,000 scientists from 60 countries, said the population of Maui's dolphin was so small that allowing any of them to be die as "bycatch" to the fishing industry made it unsustainable.
Conservation group NABU International said the figures showed the Maui's dolphin was set to become extinct by 2030 if the government took no action.
"The scientific evidence for an immediate zero tolerance approach to Maui's dolphin mortality is overwhelming," NABU conservation expert Barbara Maas said.
"New Zealand is becoming embarrassingly isolated amidst growing international interest and concern."
In July last year, the International Whaling Commission also called for New Zealand to extend maritime protection zones for the dolphin.
The government began reviewing protection measures for the dolphin last year but is yet to make an announcement about whether they will be strengthened.

Sunday, February 3, 2013

Pacific bluefin tuna population is 'fraction of its 1950s size'

From SciDevNet:  Pacific bluefin tuna population is 'fraction of its 1950s size'

[PALAU] The population of the highly-prized Pacific bluefin tuna has dropped by more than 96 per cent from its estimated level in the 1950s before large scale commercial fishing began and it is unlikely to recover if fishing continues at its current intensity, according to a stock assessment.

The summary of the latest stock assessment report of the fish was released by the International Scientific Community (ISC) for Tuna and Tuna-like Species in the North Pacific Ocean on early this month (8 January).
The study analysed catch data from 1952 to 2011, using these to model the size of the current population and how it has changed over time.

Based on the estimates, the Pacific bluefin tuna population is in serious decline because of overfishing and its population is just a fraction of what it used to be. The assessment warns that the population could crash if commercial fishing is not drastically reduced and points out that fishers are now catching mostly juvenile fish.
Gabriel Vianna, a marine researcher at the Australian Institute of Marine Science, says that the practice of excessive fishing and catching juveniles is unsustainable and that there is in an urgent need for better management. 

But Sarah Shoffler, a fishery biologist from the National Oceanic and Atmospheric Administration (NOAA), United States, says that there is no solid evidence that there has been a sharp recent fall in the number of Pacific bluefin tuna that survive to maturity.

"While we are very concerned about the population, the NOAA fisheries scientists who worked on the assessment did not determine if the population is near extinction," Shoffler tells SciDev.Net.

But she says it is clear that the total weight of fish that are at a reproductive age is at or near its lowest level.
Pacific bluefin adults reproduce in only two spawning grounds, located off the coast of Japan.

Shoffler says that proper international management should allow the species to recover from its current low level.

US-based campaign organisation the Pew Environment Group says that measures to ensure this happens must include science-based catch limits and major cuts in juvenile bluefin catches by implementing minimum size limits across the Pacific Ocean and banning fishing in the spawning grounds. Robust monitoring and enforcement measures must also be implemented, it says.

At the last meeting of the Western and Central Pacific Fisheries Commission in December, member countries were unable to reach a consensus to limit overall catches of tuna species, particularly the big eye, and failed to ensure the long-term sustainability of the fishery.

Meanwhile, at its June meeting, sister organisation the Inter-American Tropical Tuna Commission adopted the first catch limits for Pacific bluefin tuna in the eastern Pacific. This conservation measure led to the fishery's early shutdown when the limit was exceeded in August. 

The full assessment report will be released in late February.

 

Saturday, February 2, 2013

Scientists watch a fish think as it swims freely about

From NBC News Science:  Scientists watch a fish think as it swims freely about

For the first time, scientists have imaged the brain activity of a fish watching its prey.
Observing neural signals in real time offers an important glimpse into how brains perceive the outside world. In the new study, researchers developed a way to follow these signals in the brain of a zebrafish larva, using a sensitive fluorescent marker.

"It's a breakthrough," molecular and cell biologist Florian Engert of Harvard University, who was not involved in the study, told LiveScience. "No one else can look at neuronal activity with fluorescence microscopy in a freely swimming zebrafish larva" with such good resolution.

See-through heads Zebrafish are widely used to study genetics and development in vertebrates. Their larvae are ideal for neuroimaging because they have translucent heads, and scientists can literally peer into their brains.
To see what was actually going on in those fish noggins, researchers developed a genetically engineered protein, called GCaMP7a, that lights up under a fluorescent microscope when neurons, or brain cells, fire. Transgenic zebrafish were bred to express this protein in a brain region called the optic tectum, which controls the movement of the eye when the animal sees something move in its environment.

In one experiment, the scientists imaged the brain of a transgenic fish larva as it watched a dot on a screen blinking on and off or moving back and forth. Under the microscope, signals flashed through the fish's brain, mirroring the movement of the dot.

Next, a live paramecium — zebrafish prey — was placed in sight of an immobilized fish. Again, neural signals could be seen zipping around the fish's brain, tracking the paramecium's movement. No signals were detected when the paramecium was motionless, however.
 
Lastly, a paramecium was placed in a dish with a zebrafish larva that was allowed to swim freely, hunting its prey. The researchers mapped the fish's brain activity as it zeroed in on the paramecium and swam toward it.

Understanding brain behavior The new approach will improve scientists' understanding of brain circuits involved in predatory behavior, the researchers report online Thursday in the journal Current Biology. The system could be used to image other brain areas, too, allowing scientists to observe neurons involved in behavior and locomotion.

Previously, scientists had been able to image single-cell brain activity in zebrafish, but this study was the first to do it in a freely swimming fish perceiving a natural object. "The technology for studying zebrafish is moving fast," said neuroscientist Joseph Fetcho in an email to LiveScience. Fetcho did some of the earlier imaging work but was not involved in the new study.

The closer you can get to revealing the patterns of neuronal activity in a freely behaving animal, the more likely the patterns will represent those that drive natural behavior, Fetcho said.

 

Tuesday, January 29, 2013

Biologists campaign to save fish

From the Taipei Times:   Biologists campaign to save fish

Marine biologists and conservation groups yesterday launched a signature drive for a petition urging the government to add two endangered bulbous-head fish species to the protected species list.
The petition will ask the Council of Agriculture to add the Napoleonfish and the Bumphead Parrotfish onto the Schedule of Protected Species List under the Wildlife Conservation Act (野生動物保育法).
The Napoleonfish is also known as the humphead wrasse, and its name in Chinese means “dragon king fish.” The bumphead parrotfish — Bolbometopon muricatum — is also known as the double-headed parrotfish. Both species are slow growing and long-lived, with delayed reproduction and low rates of replenishment.
“The number of these two fish species still left is lower than the number of Chinese white dolphins in the waters around Taiwan’s west coast,” Taiwanese Coral Reef Society (TCRS) chairperson Cheng Ming-shou (鄭明修) said.
TCRS secretary-general Chang Ming-lung (張銘隆) said that both the Napoleonfish and the bumphead parrotfish are considered giant species of the marine reef community, and they used to be quite common in the coral reefs near the shores of Taiwan.
However, they are now on the brink of extinction, after many years of unregulated harvesting by fishermen and spear fishing by recreational divers, he said.
“We estimate that there are only about 30 individuals of these two species left, which is less than the 66 recorded for the Chinese white dolphin in the Taiwan Strait,” he said.
“The Forestry Bureau held a meeting to discuss adding these two fish species to the Schedule of Protected Species List. However, Department of Fisheries officials thought there was insufficient data for assessment. So more data will need to be provided, and this issue will be put on the agenda of next month’s Wildlife Protection Advisory Committee meeting,” the head of the Forestry Bureau’s Protected Species Division, Guang Li-hao (管立豪), said.
It is quite alarming that it has been more than 10 years since a single Napoleonfish or bumphead parrotfish was sighted in the marine reef territories surrounding Taiwan and its offshore islands of Green Island, Lanyu (蘭嶼) and Penghu and recorded in the survey conducted by his organization, Chang said.
TCRS have sent letters to the Conservation Division of the Forestry Bureau, requesting to place Napoleonfish and bumphead parrotfish onto the Schedule of Protected Species List.
“My research programs focus on the waters around Kenting (墾丁) and the Pratas Islands (Dongsha Islands, 東沙群島). During my diving expeditions over the past decade, I have rarely spotted the Napoleonfish,” said Chen Cheng-ping (陳正平), a Taiwan Ocean Research Institute researcher.
Cheng, who is a researcher at the Biodiversity Research Center of Academia Sinica, said the Napoleonfish was the largest fish in the nation’s coral reef ecosystem, and can weigh up to 200kg.
However, due to overfishing, “most Napoleonfish have been eaten. We hardly see them anymore in the waters surrounding Taiwan,” he said.
“The bumphead parrotfish is easy prey for fishermen, because it has a fixed habitat and keeps regular sleeping hours,” Cheng said.
Both of these species are excellent attractions that pull in tourists and divers to renowned tourist spots in coastal recreational parks around the world and protected marine areas around tropical islands, he said.
“They are the star attractions and the real money-spinners for the marine tourist industry. Therefore, we urge the council to add these two ‘shining stars’ of the coral reef fishes to the protected species list. They should become attractions for marine recreation activities, and we should put them in the international spotlight,” Cheng said.

 

Monday, January 28, 2013

No haggling over reef fine–Abaya

From Global Nation Inquirer:  No haggling over reef fine–Abaya

The penalty for the damage caused to the Tubbataha Reefs by a US Navy minesweeper is non-negotiable, Transportation Secretary Joseph E.A. Abaya said Sunday.
But to be able to conduct a thorough investigation, the Philippine government should have access to the commanding officer and crew of the USS Guardian which has been stuck in the marine park since  Jan. 17, Abaya said.
“Well, there are laws in place. I don’t think this is subject to tawaran (haggling) or negotiation. I heard of the figure of $300 [fine] per square meter. If that is really engraved in the law then there’s no room for negotiation whether this is high or low,” he told reporters at the Ninoy Aquino International Airport.
Abaya said he had yet to look into whether there would be a need to impose an additional fine for the damage left by the minesweeper on the world-renowned reefs pending its extrication.
On the sidelines of the World Economic Forum in Switzerland, President Aquino told reporters the US Navy would be held liable and be made to pay for the damage.
The 63-meter, 1,300-ton ship, part of the US naval fleet stationed in Japan, docked at the former American naval base in Subic Bay on Jan. 12 for routine refueling, resupply and rest and recreation.
Palawan stop
 
It was scheduled to make a brief stop at Puerto Princesa City before heading off to its next port of call in India when it grazed the reef and got stuck 128 kilometers off Palawan 11 days ago.
The US Navy said a faulty navigational map or possible errors in the USS Guardian’s navigational system had caused it to stray into a protected marine area.
US officials have apologized for the accident and the damage it has caused to the Tubbataha Reefs Natural Park, a Unesco World Heritage Site in the Sulu Sea.
Two ships from Singapore are due to arrive this week or the next to extricate the grounded ship from the reef.
This early, Abaya stressed the need for Philippine investigators’ free access to the commanding officer and crew of the grounded ship to get a full picture of what happened.
“So we are conducting our investigation. It has been done since Day 1 and, necessarily, to have a thorough and complete investigation is we should have access to the duty personnel, the duty officer, and even the commanding officer to at least get a chance to hear them out on what actually happened so we could complete the picture of what transpired,” he said.
But this has to be coordinated through the Department of Foreign Affairs, Abaya said.
 
‘Essential ingredient’
 
“I have mentioned again to Secretary (Albert) del Rosario that that is an essential ingredient of the investigation,” he said.
Abaya reiterated that the government would insist on vetting the US Navy’s operation to salvage the ship.
“The least we would want is a scenario where they go about their way without us knowing about it. The President has strictly instructed us that any salvage plan should be vetted by the Philippine side and should be approved by the Philippine side,” he said.
So far, the general feedback from environmental groups in the area was that the US Navy has been “transparent,” he said.
“Of course, not all information, if they consider it confidential, is readily shared. But at least for public consumption and for planning purposes, our counterparts from the American side have been cooperating,” he said.

 

Thursday, January 24, 2013

OMG!

Never realized I hadn't posted in over 2 weeks!

Sorry, folks

Things have just gotten away from me the last week and a half...posting should be back on schedule starting this weekend.

Sunday, January 13, 2013

Killer whales' apparent escape from sea ice likely short-lived: expert

From Montreal Gazette :  Killer whales' apparent escape from sea ice likely short-lived: expertebec town cautiously celebrated Thursday after a dozen killer whales appeared to have freed themselves from the shifting floes of Hudson Bay.

Killer whales' apparent escape from sea ice likely short-lived: expert
 

A killer whale surfaces through a small hole in the ice near Inukjuak, in Northern Quebec, on Tuesday Jan. 8, 2013. A leader in a northern Quebec village says about a dozen killer whales that were trapped under sea ice appear to have reached safety as the floes shifted on Hudson Bay. THE CANADIAN PRESS/HO, Marina Lacasse

MONTREAL - A northern Quebec town cautiously celebrated Thursday after a dozen killer whales appeared to have freed themselves from the shifting floes of Hudson Bay.

But while some in the village of Inukjuak expressed relief, others feared the orcas might not have escaped danger.
Many locals believe the water currents and ever-moving ice in the massive, frigid bay may eventually box the mammals in somewhere else.
One expert in Arctic wildlife said they have good reason to be concerned, because the thicker winter ice has yet to form on the bay. The orcas, meanwhile, were still 1,000 kilometres from where they should be at this time of year, said Pete Ewins of World Wildlife Fund Canada.
"They got stuck (in Hudson Bay) and they're unlikely to get out," said Ewins, adding that killer whales are not accustomed to ice.
"These guys are on the edge and they might not make it through."
The animals' predicament made international headlines and the stunning images of the orcas circulated via media around the world.
For at least two days, the mammals were trapped around a single, pickup-truck-sized breathing hole in the sea ice, about 30 kilometres from Inukjuak.
Locals captured images of the orcas frantically bobbing for air from the opening, which allowed only a couple of the animals to surge for oxygen at a time.
The killer whales were first spotted Tuesday and were last seen at the hole late Wednesday. On Thursday, two Inukjuak hunters reported that the waters had opened up in the area and the orcas were gone.
Some villagers were skeptical the killer whales had escaped harm, so the community hired an airplane to scan the region Thursday for signs of the pod.
Mark O'Connor of the regional marine wildlife board said the aerial search did not locate the orcas, but he noted that large swaths of ice-free water were seen in the area.
"So as far as I could tell, the emergency, for sure, is averted," said O'Connor, the board's director of wildlife management.
"Whether the whales have found a passage all the way to the Hudson Strait, we probably will never know."
Inukjuak's town manager believes the orcas escaped the ice when the winds shifted overnight and blew back into the bay. Johnny Williams said the direction change seemed to have pushed the floating ice further away from the shore, loosening its coverage on the water.
He also credited the new moon for changing the conditions.
Tommy Palliser, a local government official, said in an email Thursday that the orcas' once-inadequate breathing hole was about 500 metres wide and up to five kilometres long.
He also expressed concern about the varying conditions.
"The problem is the wind is coming in again from the sea ice," wrote Palliser, a business adviser for northern Quebec's regional government.
Locals in Inukjuak, about 1,500 kilometres north of Montreal, believe the orcas were initially pinned under a vast expanse of ice after a sudden drop in temperature caught them off guard.
Ewins said that in recent years climate change has reduced sea-ice cover in Hudson Bay, opening the door to predators like orcas to spend more time there feeding in summer.
But sometimes they don't make it out, he said.
Ewins pointed to three ways to respond to the situation: rescue operations, such as helicopter lifts and icebreaker-dug channels; destroying the orcas if they start to suffer; and allowing nature to take its course.
"These clearly are the minority of the killer-whale population that didn't quite get it right and get out in time," Ewins said.
To survive the winter in the bay, he said the killer whales would have the challenge of moving from one ice-free area to another until the floes recede from the bay in May.
Experts say sea ice is known as a natural cause of death for marine mammals like orcas.
Palliser, who saw the animals up close several times, said they appeared to have less energy late Wednesday, the last time he saw them.
Many thought time was running out for the killer whales on Wednesday, as their breathing hole seemed to have shrunk in the freezing temperatures.
Inukjuak Mayor Peter Inukpuk asked the Department of Fisheries and Oceans on Wednesday to send an icebreaker to smash the ice to free the orcas, but he said he was told the site was too far away and that the ships were unavailable.
The federal department said Thursday that two DFO scientists were headed to the village to collect information.
Villagers, nonetheless, were ready to take action. They had made plans to launch a daring rescue operation Thursday in an effort to buy more time for the gasping killer whales.
Locals had agreed to attempt to enlarge the existing breathing hole — and cut a second opening using chainsaws and drills.
Williams hopes the villagers' prayers have been answered.
"These mammals are the same thing as humans, they deserve to live like everybody else," he said. "They don't need to suffer."

Overfishing causes Pacific bluefin tuna numbers to drop 96%

From the Guardian:  Overfishing causes Pacific bluefin tuna numbers to drop 96%

3 12.17 EST
Bluefin tuna, Spain
The latest data from the international scientific committee which monitors tuna in the Pacific showed bluefin tuna stocks were a small fraction of what they had been and were in danger of all but disappearing. Photograph: Brian J. Skerry/Getty Images/National Geographic
The bluefin tuna, which has been endangered for several years and has the misfortune to be prized by Japanese sushi lovers, has suffered a catastrophic decline in stocks in the Northern Pacific Ocean, of more than 96%, according to research published on Wednesday.
Equally concerning is the fact that about 90% of specimens currently fished are young fish that have not yet reproduced.
Last week, one fish sold in Japan for more than £1m, reflecting the rarity of the bluefin tuna and the continued demand for its fatty flesh, which is sold for high prices across Asia and in some high-end western restaurants.
Bluefin tuna is one of nature's most successful ocean inhabitants, the biggest of the tuna and a top-of-the-food-chain fish with few natural predators. But the advent of industrial fishing methods and a taste for the species among rich sushi devotees have led to its being hunted to the brink of extinction.
If current trends continue, the species will soon be functionally extinct in the Pacific, and the frozen bodies held in a few high-security Asian warehouses will be the last gasp the species.
More than nine out of 10 of the species recently caught were too young to have reproduced, meaning they may have been the last generation of the bluefin tuna.
Amanda Nickson, of the Pew Environment Group, which produced the latest report, said: "There is no logical way a fishery can have such a high level of fishing on juveniles and continue."
She said that urgent measures needed to be taken in order to preserve stocks and allow them to recover. "The population of Pacific bluefin is a small fraction of what it used to be and is in danger of all but disappearing," she said. "It's a highly valuable natural commodity and people naturally want to fish something that gives them such a high return."
She called for fishing of the species to be halted as a matter of urgency. Although there are measures to manage the exploitation of bluefin tuna in the Atlantic, and some measures in the eastern Pacific, the main spawning ground for Pacific bluefin tuna in the western part of that ocean is not managed. The main fishing fleets exploiting the stocks are from Japan, Mexico, South Korea and the US, and the high value of the few remaining fish is a further encouragement to fishermen to hunt down the last of the species. A single specimen could make the catchers rich for life, and without catch limits and rigorous enforcement, there is nothing to stop fishermen pursuing them.
Nickson said: "This assessment shows just how bad the situation really is for this top predator. This highly valuable fish is being exploited at almost every stage of its life cycle. Fishing continues on the spawning grounds of this heavily overfished tuna species."
About two-thirds of the world's tuna comes from the Pacific, but bluefin tuna accounts for only about 1% of this. For years, the species was neglected in fisheries management, being lumped in with other more prolific species. But in recent years it has become clear that it was in danger, from overfishing and its own biology - being bigger than other tuna, it takes longer to come to sexual maturity, which scientists estimate takes between four and eight years, which limits its reproductive ability and makes it more vulnerable to the predations of modern industrialised fishing techniques.

 

Friday, January 11, 2013

'Extinction threat' for UK orcas

From BBC News:  'Extinction threat' for UK orcas

The UK's only known resident population of killer whales is at risk of becoming extinct, marine life experts fear.
The group, which ranges from the north and west coast of Scotland to Ireland's west coast, is thought to contain just nine older animals.
The Hebridean Whale and Dolphin Trust (HWDT) said the group was at risk as a result of the "skewed" demographics.
The One Show is set to broadcast the last of a series of three features on the killer whales on Wednesday.
Presenter Mike Dilger and his crew were able to track down the group with help from Dr Andy Foote, a scientist who is studying genetics and genomics of killer whales at the Natural History Museum of Denmark.
Dr Foote has been carrying out collaborative research work with HWDT.
The trust's biodiversity officer Olivia Harries said the studies suggested the killer whales had become isolated from other groups in the north east Atlantic.
Killer whale The killer whale group is aged and dominated by males
She said: "The group demographics are highly skewed to older individuals and there is an unusually high ratio of adult males.
"Recruitment is therefore unlikely and the females are probably post-reproductive.
"This means that these killer whales are due to go extinct in our lifetime."
In Tuesday's programme, Mr Dilger said three different groups of killer whales visit UK waters.
However, the Scottish population is the only one which remained all year round.
He added: "With just nine individuals and a home range stretching from the Outer Hebrides to Galway on the west of Ireland, to find them at all is simply astounding."
Mr Dilger said the group comprised of five females and four males.
He said: "They haven't had a calf, or baby, for 20 years.
"It is thought killer whales are one of the few animals that goes through the female menopause and they might be too old and past breeding potential.
"So in our lifetime they could die out."

 

Thursday, January 10, 2013

A pod of killer whales is trapped by sea ice in northern Quebec and only Mother Nature can free them

From The Province:  A pod of killer whales is trapped by sea ice in northern Quebec and only Mother Nature can free them

MONTREAL — About a dozen orcas spent Wednesday circling a hole in the sea ice in northern Quebec, taking turns breathing.
They’re trapped, and human intervention is unlikely to save them.
Peter Inukpuk, mayor of the Quebec village of Inukjuak, urged the Department of Fisheries and Oceans on Wednesday to send an icebreaker as soon as possible to smash nearby floes to help the mammals reach open water.
But Inukpuk told The Canadian Press later in the day that DFO has informed him the icebreakers are too far from the area for such a mission.
Killer whales trapped by sea ice in norther Quebec
Video footage taken by residents showed the massive animals thrusting themselves skyward through an opening in the ice as they gasped for air from their blowholes.
Locals say about a dozen orcas gathered around the hole — which was slightly bigger than a pickup truck — amid their desperate bid to take in oxygen.
Now, Inukpuk is hoping a strong wind will come out of the east to push the floating ice far away enough from shore to free the killer whales.
“But that is (an) act of God and not in our control,” Inukpuk said.
“For me, anything that can help. I’m trying to look left and right and finally I went upstairs.”
Inukpuk plans to talk with DFO on Thursday by phone to see if any other course of action is possible.
In a brief statement Wednesday, the federal department said it was assessing the situation with partners and experts in the region. It’s unclear if any DFO action will be taken.
“Situations where marine mammals are trapped by the ice are not unusual in the North,” DFO spokeswoman Nathalie Letendre wrote in an email.
Killer whales trapped by sea ice in norther Quebec
Inukpuk said it was on Tuesday that a hunter from his village first spotted the pod of trapped orcas at the hole, which is some 30 kilometres from town. Inukjuak, on the eastern shore of Hudson Bay, is about 1,500 kilometres north of Montreal.
Word of the unusual spectacle spread quickly though the village, prompting dozens of locals to make the one-hour snowmobile ride Tuesday to the scene.
They snapped photos and shot video footage of the killer whales bobbing to the surface in the opening — and sometimes rocketing half their bodies straight up out of the hole as they took in oxygen.
Curious locals who didn’t make Tuesday’s trip gathered at a community centre that night to watch videos of the scene.
“Our people asked for a prayer for these killer whales,” said Inukpuk, whose village is home to 1,800 people. “Our local people are very much concerned.”
Killer whales trapped by sea ice in norther Quebec
One woman who made the journey to the gap in the ice said even a curious polar bear approached the hole amid the orcas’ commotion. Siasie Kasudluak said the bear was eventually shot by a hunter and the meat was shared among locals.
The trapped orcas, meanwhile, appeared to be in distress and the people were ill-equipped to help out. Time also appeared to be running out, as the hole seemed to be shrinking in the -30 C temperature, Kasudluak said.
“It was amazing, but they needed air and it’s very touching,” said Kasudluak, who stood on the ice with close to 50 other people from Inukjuak.
“I don’t know what’s going to happen, but we would love to see them free.”
Killer whales trapped by sea ice in norther Quebec
Another woman who saw the animals up close said the orcas appeared to cycle around the opening in an attempt to keep it from freezing over.
Marina Lacasse, who estimated the hole was slightly larger than a pickup truck, also said the creatures would pop up for breaths and then disappear under the ice for several minutes, probably in a frenzied search for open water.
“It was kind of hard to see whether the whales would find the open water because I think it’s frozen all the way now,” said Lacasse, who noted that one of the killer whales appeared to be bleeding.
Locals returned to the site Wednesday to see if they could remove some of the ice from the edge of the hole — or carve a new opening — with chainsaws, chisels and snowmobiles, the mayor said.
But Inukpuk fears such an undertaking so close to the stressed beasts could be dangerous.
“At times they are in a panicked state where the ice around them is moving,” said Inukpuk, who hadn’t yet visited the site himself.
“But one thing we know is that any species that we encounter here — especially large species like a polar bear — if we agitate them, then they get ferocious.”
Killer whales trapped by sea ice in norther Quebec
He said killer whales are rarely spotted near Inukjuak, but hunters have returned home with tales over the years of having their canoes followed by the animals.
Inukpuk believes the recent sudden drop in temperature caught the orcas off guard, leaving them boxed in under the ice.
The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) says the Northwest Atlantic/Eastern Arctic population of killer whales was designated as a species of “special concern,” according to its website. The special concern tag means the species may become threatened or endangered due to biological characteristics and other threats.
COSEWIC estimates the population has fewer than 1,000 mature adults and says it’s likely the actual number is smaller than 250.
The region’s limited orca population could be one reason why killer whale is not part of the diet in Inukjuak, where people hunt wildlife like beluga and polar bear for food.
Another reason could be the taste, the mayor said.
“We hear they’re not good to eat and their blubber and skin are not good to eat,” said Inukpuk, adding that it’s not in the community’s interest to kill the orcas.
“We just want to make sure that they’re safe and hopefully we can find means to get them safe.”

Tuesday, January 8, 2013

Posts resume Thursday

I know I've been saying this periodically but this will be the last time I say it...I'm visiting relatives and although they have Wi fi I don't have a private room to work.

I'll be home Thursaday and will get back into the swing of things then.

Thursday, January 3, 2013

Where'd my catch go? Spectacular photo captures moment great white is gobbled by an EVEN BIGGER shark as it's hauled into fisherman's boat

From DailyMailOnline: Where'd my catch go? Spectacular photo captures moment great white is gobbled by an EVEN BIGGER shark as it's hauled into fisherman's boat 

Being hooked by a fisherman is probably up there with the worst things that could happen to a shark. But what about becoming bait for an even bigger beast as you're being hauled into the boat?
This was the fate of a poor great white in New Zealand this week.

And a spectacular photograph of the encounter, which shows Charles Darwin's survival of the fittest - or perhaps biggest - theory in action, has taken the web by storm after it was posted on Reddit.
Chomp: The Kiwi fisherman took the spectacular photo, pictured, on December 28
Chomp: The Kiwi fisherman took the spectacular photo, pictured, on December 28, and posted it on Reddit

The decent-sized shark was hooked in the waters near Kaiteriteri during a post-Christmas expedition on December 28.

The fisherman, whose Reddit name is Mancubus, was probably pretty chuffed with his catch and daydreaming about a fish and chip dinner, with the shark firmly on the end of the line.

But that was before he had competition.
The Kiwi didn't even have time to haul his catch onto the deck before the smaller shark was in the jaws of the monster predator.
Shark waters: The epic photo was captured in the waters near Kaiteriteri, New Zealand, pictured
Shark waters: The epic photo was captured in the waters near Kaiteriteri, New Zealand, pictured
The larger shark, also a Great White, had obviously decided he'd be the one to gobble the fish up.

It is unclear exactly what happened next, though the fisherman presumably cut his losses and the line, losing his catch.

However, he did escape with the epic image, which immediately shot to Reddit's front page and has garnered also 1000 comments since.

It's not uncommon for sharks to prey upon each other, but it's rarely caught in such a daring fashion.

Now we know what it looks like to be bait for such a beast, it's probably best not to go swimming too far from the New Zealand coast any time soon.

 

Tuesday, January 1, 2013

Study: No Evidence Of Increasing Jellyfish Population Over Last Two Centuries

From Underwater Times: Study: No Evidence Of Increasing Jellyfish Population Over Last Two Centuries 


giant jellyfish bloom japan
This image shows giant jellyfish (Nemopilema nomurai) clogging fishing nets in Japan. Credit: Dr. Shin-ichi Uye

SOUTHAMPTON, England -- Scientists have cast doubt on the widely held perception that there has been a global increase in jellyfish.
Blooms, or proliferations, of jellyfish can show a substantial, visible impact on coastal populations – clogged nets for fishermen, stinging waters for tourists, even choked cooling intake pipes for power plants – and recent media reports have created a perception that the world's oceans are experiencing trending increases in jellyfish. Now, a new multinational collaborative study, involving the University of Southampton, suggests these trends may be overstated, finding that there is no robust evidence for a global increase in jellyfish over the past two centuries.
The results of the study, which includes lead co-author Dr Cathy Lucas, a marine biologist at the University of Southampton, appear in the latest issue of Proceedings of the National Academy of Science (PNAS manuscript # 2012-10920R).
The key finding of the study shows global jellyfish populations undergo concurrent fluctuations with successive decadal periods of rise and fall, including a rising phase in the 1990s and early 2000s that has contributed to the current perception of a global increase in jellyfish abundance. The previous period of high jellyfish numbers during the 1970s went unnoticed due to limited research on jellyfish at the time, less awareness of global-scale problems and a lower capacity for information sharing (e.g. no Internet).
While there has been no increase over the long-term, the authors detected a hint of a slight increase in jellyfish since 1970, although this trend was countered by the observation that there was no difference in the proportion of increasing vs. decreasing jellyfish populations over time.
Dr Cathy Lucas, who is based at the National Oceanography Centre, Southampton, says: "Sustained monitoring is now required over the next decade to shed light with statistical confidence whether the weak increasing linear trend in jellyfish populations after 1970 is an actual shift in the baseline or part of a larger oscillation."
To date, media and scientific opinion for the current perception of a global increase in jellyfish was evidenced by a few local and regional case studies. Although there are areas where jellyfish have increased; the situation with the Giant Jellyfish in Japan and parts of the Mediterranean are classic examples, there are also areas where jellyfish numbers have remained stable, fluctuated over decadal periods, or actually decreased over time.
Increased speculation and discrepancies about current and future jellyfish blooms by the media and in climate and science reports formed the motivation for the study. "There are major consequences for getting the answer correct for tourism, fisheries and management decisions as they relate to climate change and changing ocean environments," says Dr Lucas. "The important aspect about our work is that we have provided the long-term baseline backed with all data available to science, which will enable scientists to build on and eventually repeat these analyses in a decade or two from now to determine whether there has been a real increase in jellyfish."
"The realization that jellyfish synchronously rise and fall around the world should now lead researchers to search for the long-term natural and climate drivers of jellyfish populations, in addition to begin monitoring jellyfish in open ocean and Southern Hemisphere regions that are underrepresented in our analyses," says lead author Dr Rob Condon, marine scientist at the Dauphin Island Sea Lab (DISL) in Alabama.
Given the potential damage posed by jellyfish blooms to fisheries, tourism and other human industries, the findings of the group foretell recurrent phases of rise and fall in jellyfish populations that society should be prepared to face.