Biggest Great White Shark Caught, Released

ON TV:Shark Men—Biggest and Baddestpremieres at 10 p.m. ET/PT on Sunday, May 8, on the National Geographic Channel.

Talk about a bigfish—an expedition crew has hauled up—and released—what the team says is the biggestgreat white sharkyet caught.

The 17.9-foot-long (5.5-meter-long) male behemoth was found offMexico'sGuadalupe Island (map)in fall 2009.

The animal breaks the team's previous record of 16.8 feet (5.1 meters), set when they caught a female great white named Kimel. (Both records are unofficial and not maintained by a formal organization.)

The new titleholder was named Apache after the dog of Brett McBride, boat captain on the National Geographic Channel showShark Men.(The National Geographic Channel is part-owned by the National Geographic Society, which owns National Geographic News.)

Shark Menchronicles the work ofscientists and fisherswho catch and release great whites in an effort to figure out where the mysterious giants breed and give birth. The scientific team is led by Michael Domeier, president and executive director of theMarine Conservation Science Institute.

The two-ton Apache put up a fight—at one point breaking free from his barbless hook, said expedition leaderChris Fischer.

"The battle with Apache was like nothing we've ever dealt with,"Fischer said.

Once on board, the researchers fitted the fish with a satellite-tracking tag, took a blood sample, and released him, watching him vigorously swim away.

(See relatedpictures:"'Shark Elevator' Lifts Great Whites From Sea.")

"He was all scarred up and had big marks all over him—you could tell he was just a bad-ass shark,"Fischer said.

"It was so impressive and so humbling to be near him."

Size Doesn't Matter for Shark Research

In large ocean fish species, females are almost always bigger than males, because they need more girth to carry their young, Fischer noted. (Seegreat white shark pictures.)

However, even a male of Apache's size is not unheard of among great whites, other experts say.

"That is one big shark, {but} I have no doubt that this isn't the largest white shark in the wild,"John O'Sullivan, head of theMonterey Bay Aquarium's White Shark Program, said by email.

Shark expert Kenneth J. Goldman added,"I don't see anything overtly magnificent about it being so large. It's just another adult male they've tagged."

That's because size alone doesn't tell scientists much, said Goldman, a fishery research biologist at theAlaska Department of Fish& Gamein Homer.

Instead, Apache's real value would be in helping to resolve the lingering mysteries of great white behavior.

Biggest Shark May Help Crack Mysteries

Expedition leader Fischer agrees—and he and his team are now watching to see where Apache goes.

For instance, recent research suggests that Pacific great whites gather in specific spots near the coasts—including the Guadalupe Island site—and thentravel to a"cafe"in the middle of the ocean to feed. The animals often return to the same aggregation sites after feeding.

But this is still a tentative theory, so it"would be groundbreaking if, {say}, Apache left Guadalupe and went to the middle of the ocean and {returned} to a different aggregation site,"Fischer said.

(See"Great White Shark Filmed Breaching at Night—A First.")

Overall, tagging sharks to figure out where they migrate and congregate may help conservationists protect the species, Fischer added. Great whites are considered vulnerable by the International Union for Conservation of Nature.

Meanwhile, Apache lives on, he said, as a"giant male shark out there doing his great white thing."

National Geographic News

Source

Sea Urchin Body Is One Big Eye

Sea urchins may use the entire surfaces of their bodies—from the ends of their"feet"to the tips of their spines—as huge eyes.

Scientists had already known the marineinvertebratesreact to light without any obvious eye-like structures—raising the question of how the animals see.

(Also read:"Eyes Made of Rock Really Can See, Study Says.")

Previous genetic analysis of the California purple sea urchin had revealed that the animals possess a large number of genes linked with the development of the retina—the light-sensitive tissue lining the inner eyeball in people and other vertebrates.

This and other research suggested thatsea urchin vision might rely on light-receptor cells randomly scattered across their skin, which collectively function like retinas.

Scientists had theorized the animals' spines simulate the light-blocking pigmented cells found in most animals' eyes. Because light-receptor cells in the retina can soak up light from every direction, pigmented cells work to block light from the back and the sides so animals can"see"what's in front of them.

Now, however, the scientists have found two distinct groups of bristly, light-receptor cells concentrated at the bases and tips of the purple sea urchin's 1,400-plus tube feet. These long, suction-tipped tubes, located on the undersides of sea urchin bodies, help the organisms move.

The team suspects that sea urchins use their tube feet as retinas and the rest of their bodies to shield against the extra incoming light, said researcherMaria Ina Arnone, a developmental biologist at Anton Dohrn Zoological Station in Naples, Italy.

Prior studies did find the number and placement of spines on a sea urchin could affect how sharp its vision might be, and this new find"might well be part of the picture,"Arnone added.

The sea urchin-eye study appeared May 2 in the journalProceedings of the National Academy of Sciences.

forNational Geographic News

Source

Giant Squid Killed by Sound?

Whengiant squidwere found dead offSpainabout a decade ago, scientists suspected that powerful sound pulses from ships had harmed the animals. Now the evidence may be in.

A new study says low-frequency sounds from human activities can affect squid and other cephalopods, not just whales and other marine mammals, which have long been thought to be vulnerable to such pulses. (See"U.S. Navy Sonar May Harm Killer Whales, Expert Says.")

The finding suggests noise pollution in theoceanis having a much broader effect on marine life than previously thought, said study leader Michel André, a marine bioacoustician at Barcelona'sTechnical University of Catalonia.

"We know that noise pollution in the oceans has a significant impact on dolphins and whales {which use natural sonar to navigate and hunt}. ... but this is the first study indicating a severe impact on invertebrates, an extended group of marine species that are not known to rely on sound for living,"André said in a statement.

(Related:"Colossal Squid Has Glowing 'Cloaking Device,' Huge Eyes.")

Giant Squid Mystery Solved?

In the early 2000s the remains of giant squid were found off Spain'sAsturias province (map). In each case, the creatures' bodies appeared soon after ships had used air guns to conduct low-frequency sound-pulse exercises in the region, in some cases for oil-and-gas prospecting efforts.

Scientists investigating the giant squid remains at the time found evidence of extensive bodily damage, including mantles reduced to pulp, bruised muscles, and lesions in statocysts. These fluid-filled organs rest behind the creatures' eyes and help giant squid maintain balance and position. (Seepictures of a colossal squid dissection.)

At the time, marine biologist Angel Guerra speculated—but was unable to prove—that noise from prospecting ships was harming cephalopods and other marine life.

"With this study, we now have proof"that low-frequency sounds can harm cephalopods, said Guerra, a marine biologist at Spain'sMarine Research Institutewho was not involved in the current study, which will appear in a future issue of the journalFrontiers in Ecology and the Environment.

(See rarepictures of sperm whales eatiing a giant squid.)

Damage Worsened With Time

During the study, the research team examined the effects of low-frequency sound exposure in 87 individual cephalopods belonging to four species: two species of squid, one species of octopus, and one species of cuttlefish. (See"Cuttlefish Change Color, Shape-Shift to Elude Predators.")

For two hours the animals were exposed to sound with intensities of between 157 and 175 decibels and frequency ranges of 50 to 400 Hertz.

These frequencies and intensities"are commonly found in the noise produced by many activities at sea,"such as military sonar tests or efforts to detect oil and natural gas by gauging the nature of material beneath the seabed, the Technical University of Catalonia's André told National Geographic News.

After the sound exposure, the scientists killed the animals, either immediately or up to 96 hours afterward.

The animals that were killed immediately after exposure showed signs of damage to their statocyst tissue. Specifically, tiny hairlike structures in statocyst cells—which bend as the cephalopods move through water and help the animals balance—were lost, essentially crippling the creatures.

The animals allowed to live longer showed further damage, including large, visible holes in the statocyst tissue.

"This is a typical process found in land mammals and birds after acute noise exposure: a massive acoustic trauma followed by peripheral damage, making the lesions worse over time,"André said.

In their final seconds or hours, the test cephalopods"moved a little bit, but they were not swimming, eating, or mating,"André said.

A separate group of about a hundred cephalopods was not exposed to the pulses. They remained healthy and behaved normally.

Both groups had been kept in the same aquariums before being separated, and all the animals had behaved normally before the tests—ruling out the possibility that the damage observed in the test group was due to captivity or human handling, he said.

(Pictures:"Giant Squid Get Extreme Plastic Surgery.")

"Raise the Alarm"for Giant Squid?

Though the cephalopods in the experiments were much smaller than giant squid, the experiments represent"the same phenomena as with the giant squid,"the Marine Research Institute's Guerra said.

The test animals are appropriate stand-ins for their giant squid cousins, according to Guerra, who said he sees no reason why the findings wouldn't apply to giant squid.

There are some differences in the damage, though.

The injuries to the giant squid found last decade, he noted, were much more pronounced than in the experimental animals. Guerra attributes this to the higher acoustic intensities and multiple sound sources giant squid are exposed to in the real world.

And of course, the giant squid were found not just injured but dead, unlike the test animals. But scientists say the case of the giant squid off Spain suggests death is one possible outcome of exposure to low-frequency blasts.

At the time of the giant squid deaths,"we hypothesized that the giant squid died in one of two ways: either by direct impact from the sound waves or by having their statocysts practically destroyed and {the squid} becoming disoriented,"Guerra explained.

"The disoriented animals might wander up from the depths to the surface, where the temperature difference kills them."

Marine zoologist Michael Vecchione, of the U.S. National Oceanic and Atmospheric Administration (NOAA), isn't yet sure.

Though the new research presents enough evidence to"raise the alarm,"more studies are necessary before a solid case can be made that human-caused noise pollution is causing pervasive damage to marine life, said Vecchione, who also did not participate in the study.

But, he added,"the evidence is accumulating that what {Guerra} first proposed based on the giant squid might actually be correct."

More:Alien-like Squid With 'Elbows' Filmed at Drilling Site>>

forNational Geographic News

Source

Wild Pig Explosion May Spread Disease to Humans

An explosion of wild pigs in the U.S. could be exposing people to dangerous parasites, a new study says.

The wild pig, Sus scrofa, was first introduced to the U.S. from Europe as livestock in the 1500s, but over the years many animals have escaped captivity.

Today there's an estimated four million wild pigs spread across 39 states, with large populations in California, Texas, and the Southeast, according to the study.

Because they're so hardy and can eat almost anything, feral pigs have been living high on the hog, producing several litters of piglets a year, said study co-authorChris DePerno, an ecologist at North Carolina State University in Raleigh.

Mixed into this group are escaped domestic pigs,Sus scrofa domesticus. (Seepictures of unusual domesticated animals, including a Vietnamese potbellied pig.)

Within two generations out of captivity, domestic pigs usually lose their pink hue and turn striped and coarse-haired, DePerno said, allowing them to blend in with feral populations.

Though"Tasty,"Wild Pork May Be Dangerous

In the new research, DePerno and colleagues found evidence of exposure to the parasitesToxoplasma gondiiandTrichinellain the blood of 83 wild pigs killed inNorth Carolinabetween 2007 and 2009.

The results are very similar to those of studies conducted in other parts of the country—including Texas and South Carolina—that show feral pigs could be disease vectors, DePerno said.

(See"Wild Pigs in U.S. Spreading Disease, Ruining Property, Experts Say.")

However, this is the first time scientists have found these particular parasite species in wild pigs, he said.

AlthoughT. gondiiandTrichinellahave been eliminated in domestic swine, more people these days are hunting wild pigs for food, DePerno said.

"They're pretty tasty—more flavorful than domestic pigs."

People would most likely be infected by eating parasite-ridden meat. Once transmitted, both parasitic species can invade muscle tissue and organs and cause flulike symptoms, DePerno said.

More than 60 million men, women, and children in the U.S. already carry theToxoplasmaparasite, but very few show symptoms, because a healthy immune system usually keeps the disease in check.

(Related:"Parasite 'Brainwashes' Rats Into Craving Cat Urine, Study Finds.")

Still, toxoplasmosis—the disease caused byT. gondii—is a leading cause of death due to foodborne illness in the United States, according to theU.S. Centers for Disease Control and Prevention (CDC). The organism is especially toxic to pregnant women and those with weak immune systems.

Trichinellainfections can also range from mild to severe, with the worst cases causing potentially fatal heart and breathing problems, according to the CDC. Even in moderate cases, fatigue, weakness, and diarrhea can last for months.

Education, More Data to Combat Pig-Borne Illnesses

As the feral pig population expands, so will the incidence of wild-pig hunts, the study authors surmise.

The team therefore recommends education programs for hunters, to help them understand the risks of exposure to parasites both from cleaning pig carcasses and eating wild pork.

There's also the possibility that people could get the parasites from regular pork if domestic swine come into contact with infected feral pigs.

For instance, free-range pigs may bump into their wild brethren and pick up diseases—a possible downside to the popularity of free-range pork, he said. (Also see"Swine Flu Virus Hiding Out in Pigs, May Reemerge.")

"The take-home message," DePerno said,"is that more places need to do this kind of research to determine disease prevalence, especially related to domestic pigs, pets, and human health."

The parasite-carrying pigs study appeared in April in theJournal of Wildlife Diseases.

National Geographic News

Source

Is Your Brain Sleeping While You're Awake?

If you think you can function on minimal sleep, here's a wake-up call: Parts of yourbrainmay doze off even if you're totally awake, according to a new study in rats.

Scientists observed the electrical activity of brains in rats forced to stay up longer than usual. Problem-solving brain regions fell into a kind of"local sleep"—a condition likely in sleep-deprived humans too, the study authors say.

Surprisingly, when sections of the rats' brains entered these sleeplike states,"you couldn't tell that {the rats} are in any way in a different state of wakefulness,"said study co-authorGiulio Tononi, a neuroscientist at the University of Wisconsin, Madison.

Despite these periods of local sleep, overall brain activity—and the rats’ behaviors—suggested the animals were fully awake.

This phenomenon of local sleep is"not just an interesting observation of unknown significance,"Tononi said. It"actually affects behavior—you make a mistake."

For example, when the scientists had the rats perform a challenging task—using their paws to reach sugar pellets—the sleep-deprived animals had trouble completing it.

(See"Secrets of Sleeping Soundly Uncovered.")

Sleep Allows Neurons to Reset?

Tononi and colleagues recorded the electrical activity of lab rats via electroencephalogram (EEG) sensors connected to the rodents' heads.
As predicted, when the rats were awake, their neurons—nerve cells that collect and transmit signals in the brain—fired frequently and irregularly.

When the animals slept, their neurons fired less often, usually in a regular up-and-down pattern that manifests on the EEG as a"slow wave."Called non-rapid eye movement, this sleep stage accounts for about 80 percent of all sleep in both rats and people.

The researchers used toys to distract the rats into staying awake for a few hours—normally"rats take lots of siestas,"Tononi noted.

The team discovered that neurons in two sections of these overtired rats' cerebral cortexes entered a slow-wave stage that is essentially sleep.

Why Do We Sleep?

It's unknown why parts of an awake brain nod off, though it may have something to do with why mammals sleep—still an open question, said Tononi, whose study appears tomorrow in the journalNature.(Read aboutmysteries of why we sleep inNational Geographicmagazine.)

According to one leading theory, since neurons are constantly"recording"new information, at some point the neurons need to"turn off"in order to reset themselves and prepare to learn again.

"If this hypothesis is correct, that means that at some point {if you're putting off sleep} you're beginning to overwhelm your neurons—you are reaching the limit of how much input they can get."

(See"Sleep Cherry-picks Memories, Boosts Cleverness.")

So the neurons"take the rest, even if they shouldn't"—and there's a price to pay in terms of making"stupid"errors, he said.

(Seebrain pictures.)

Even"Alert"People Make Mistakes

Sleep deprivation may have dangerous consequences, Tononi said—and those mistakes may become more common.

For one, many people are getting fewer z's. In 2008 about 29 percent of U.S. adults reported sleeping fewer than seven hours per night, and 50 to 70 million had chronic sleep and wakefulness disorders, according to theU.S. Centers for Disease Control and Prevention. Adults generally need about seven to nine hours of sleep a day,according to the National Sleep Foundation.

(TakeNational Geographicmagazine's sleep quiz.)

What's more, you don't need to feel sleepy to screw up, Tononi emphasized.

"Even if you may feel that you're fit and fine and are holding up well,"he said,"some parts of your brain may not {be} ... and those are the ones that make judgments and decisions."

National Geographic News

Source

Pictures: Fire Ant Swarms Form Living Life Rafts

When a city floods, humans stack sandbags and raise levees. When a fire ant colony floods, the ants link up to form a literal life raft, such as the one pictured. Now, new research shows exactly how the ants manage this feat.

Engineering professor David Hu and graduate student Nathan J. Mlot atGeorgia Institute of Technologyhad heard reports of ant rafts in the wild that last for weeks. (Watch a fire ant video.)

"They'll gather up all the eggs in the colony and will make their way up through the underground network of tunnels, and when the flood waters rise above the ground, they'll link up together in these massive rafts,"Mlot said. Together with Georgia Tech systems-engineering professor Craig Tovey, the scientists collected fire ants and dunked clumps of them in water to see what would happen.

In less than two minutes the ants had linked"hands"to form a floating structure that kept all the insects safe. Even the ants down below can survive this way, thanks to tiny hairs on the ants' bodies that trap a thin layer of air.

"Even when they're on the bottom of the raft, they never technically become submerged,"Mlot said.

The fire ant life raft research is described in the April 25 issue of the Proceedings of the National Academy of Sciences.

—Rachel Kaufman

Source

Odd Animal Deaths, Deformities Linked to Gulf Oil Spill?

On the first anniversary of theGulf oil spill, scientists are observing strange deaths and deformities in animals that could be related to the disaster, experts say.

In the past six months, the numbers of dolphin and sea turtle deaths in theGulf of Mexico (map)have risen, and some fish that inhabit the Gulf'scoral reefshave developed abnormalities. (Read more about the Gulf oil spill anniversary.)

Yet projects to document and measure the oil's effects on Gulf marine life are still in the very early stages, scientists caution. Preliminary results may not be available for months, and it may be several years before any kind of scientific consensus is reached.

(See an interactive of the Gulf's layers of life inNational Geographicmagazine.)

Such uncertainty is not unusual for oil-spill studies, notedWilliam Patterson, a marine biologist at the University of West Florida (UWF) in Pensacola.

"If you look at the literature surrounding theExxon Valdezoil spill {in 1989}, there are still some unknowns associated with that,"Patterson said.

"What we know {in the case ofExxon Valdez} is that there was an insult to the system, that there were effects on the food web and ecosystem, and that some species have not recovered to the levels they were at before."(Related:"Exxon ValdezAnniversary: 20 Years Later, Oil Remains.")

Some of theExxon Valdezoil's effects are circumstantial evidence, he added,"but it's pretty compelling evidence."

Mysterious Spike in Dolphin, Turtle Deaths

This winter, an alarmingly high number ofbottlenose dolphins—113 at last count—washed up dead on U.S. shores, according to theNational Oceanic and Atmospheric Administration (NOAA). The agency confirmed in early April that six of the bodies hadDeepwater Horizonoil on them.

(Read more:"Dolphin-Baby Die-Off in Gulf Puzzles Scientists.")

"What's important to note, however, is that even though they have this oil on them, it may not be the cause of death,"Blair Mase, NOAA's marine-mammal investigations coordinator, told reporters at a news briefing April 7.

"That's something the investigative team and our working groups are looking into."

So far this year scientists have also seen a rise in deaths of various species of Gulf sea turtle hatchlings. But NOAA researchers say the culprits may be contact with boats and fishing gear and possibly poisoning by toxins in algal blooms, which naturally appear in the Gulf each spring.

"The carcasses that we have looked at . . . had no visible oil on them,"said Barbara Schroeder, national sea turtle coordinator for NOAA.

(Relatedpictures:"Baby Gulf Turtles Released Into Atlantic.")

Fish Found With Deformed Ovaries, Missing Fins

Meanwhile, other researchers are looking for effects of the oil on other marine species, such asfish, crustaceans, andcorals.

UWF's Patterson has recently observed an increase in physical abnormalities consistent with oil exposure in red snappers that live in Gulf coral reefs.

"There are parasites showing up on the fish. They're always present, but this fall and winter we're seeing them in what appears to be higher abundances,"Patterson said.

Some of the fish are suffering so severely from a disease called fin rot that entire fins are missing—something Patterson said he has never seen before. Some female red snappers also have been discovered with hardened or deformed ovaries.

(Also see"Sex-Changing Chemicals Can Wipe Out Fish, Study Shows.")

Other red snappers have strange pigmentation issues, Patterson said."We have some images of red snappers sent to us by commercial fishermen that have black bands across the sides of the fish that is discolored skin."

These symptoms are not unusual in themselves, Patterson said, but the fact that they're appearing at what looks to be increased rates at the same time concerns him.

"Some of these things that we're seeing are classic symptoms of hydrocarbon exposure that have been documented in lab studies."

For example, the odd pigmentation could be caused by the fish's kidney or bile duct being affected or clogged by oil components.

"So it does seem to be pointing in one direction, but we don't have anything definitive yet to tell the full story."

Chuck Jagoe, an environmental toxicologist at Florida A&M University in Tallahassee, is working with Patterson to test Gulf red snappers for telltale enzymes that are produced when the fish flush toxic oil components from their bodies.

"These enzymes are associated with the detoxification process,"Jagoe said.

"They can give us an indication that the animal has not only been exposed to {oil} compounds, but that the compound is having some kind of biological effect."

Jagoe has just begun testing the fish, and the first results won't be available until at least early summer.

One Species Not Enough Evidence

UWF's Patterson said he also plans to investigate whether other Gulf species are exhibiting symptoms similar to those of the snappers.

Even nearly a year after the disaster, oil could still be lurking in the Gulf's waters, he added.

"Oil is not one thing,"Patterson said."It's thousands of organic compounds. Some of them are fairly {unstable} and microbes break them down very quickly, while others could persist for a long time."

(See"Why the Gulf Oil Spill Isn't Going Away.")

Finding other affected species will be crucial to making a case that the oil spill is having a systemic effect on Gulf fish species, saidProsanta Chakrabarty, a fish biologist at Louisiana State University in Baton Rouge who was not involved in the snapper project.

"With one species, we can't really tell,"Chakrabarty said.

He also noted that red snappers are already a vulnerable species due tooverfishing, and that it's possible the symptoms that Patterson is seeing are due to inbreeding caused by a decreased population.

Whatever the cause of the deformities, though,"the oil spill didn't help any,"he said.

Fish Populations Measured via GPS

Chakrabarty is involved in another project calledDepthmap, which aims to use fish-population data collected using GPS technology before and after the spill to investigate the Gulf oil spill's impact on marine life. Museum records are also used to fill out pre-spill data.

"If, for example, 80 percent of Gulf pancake batfishes were found off the coast of Louisiana and they're not there anymore,"then that could be an indication the spill negatively affected the species, he said.

(See"Two New 'Walking' Batfish Species Found.")

And if this pattern is repeated for many fish species, it would indicate the spill has had a pervasive impact on Gulf marine life.

Chakrabarty's team hopes to gather pre- and post-spill population data for 600 fish species in the northern Gulf, but has only begun analysis for a fraction of that number due to limited funding.

His early results suggest that of the 53 species examined so far, 43 had major populations that lived in regions that were in the path of the spill.

Deep-Sea Effects Leave Scientists in the Dark

Even if Depthmap's goals were met, however, scientists would still know only about the impact the spill had on fish that live in relatively shallow water. But the spill's largest potential damage is to deep-sea creatures, Chakrabarty said. (See pictures of deep-sea animals.)

The broken wellhead blew at 5,000 feet (1,500 meters) underwater, and plumes of gushing oil floated nearly 1 mile (1.6 kilometers) up from the seafloor, polluting different layers of water as they rose.

"We knew that the oil wouldn't last at the surface for very long, but what happened at the deep sea?"Chakrabarty said.

Of particular concern, he added, are the effects of the oil dispersants piped into the waters near the wellhead in a desperate bid to break apart the oil before it reached the surface.

"The deep sea is such a stable environment. . . . It isn't used to perturbations like this influx of {dispersants},"Chakrabarty said.

"So what the impact {is} of having {dispersants} enter that area, even momentarily, is difficult to understand."

(See"Gulf Spill Dispersants Surprisingly Long-lasting.")

Despite his concerns about the deformed fish, UWF's Patterson added that it's important for scientists not to jump to conclusions.

"As scientists, we shouldn't be unwilling to say we're not quite sure,"he said.

"Instead of going out on a limb and making grand announcements, I think it's a safer approach to say, Well, these are issues that we're seeing that we're not able to attribute to any one thing, but we're concerned about them.

"And that's where we are."

*The photographer, a commercial fisher in the Gulf, requested to remain anonymous.

forNational Geographic News

Source