NatGeo News Watch

National Geographic scientist and Nat Geo News Watch blogger Stuart Pimm is one of two conservationists who have been awarded the 2010 Tyler Environmental Prize.

The award, consisting of a U.S.$200,000 cash prize and gold medals, goes to Laurie Marker, the co-founder and executive director of the Cheetah Conservation Fund in Otjiwarongo, Namibia, and Stuart Pimm, the Doris Duke Professor of Conservation Ecology at Duke University in Durham, North Carolina, the Tyler Prize administration announced today.

The Tyler Prize Executive Committee recognized Marker and Pimm "for their scientific contributions, their understanding of ecosystem functions, and for their applications of this knowledge to the management and restoration of ecosystems to the benefit of their inhabitants."

 Photo of Stuart Pimm courtesy of Stuart Pimm

Other National Geographic personalities in the pantheon of past Tyler laureates include Peter Raven, chairman of the National Geographic Committee for Research and Exploration, primatologist Jane Goodall, National Geographic Energy Fellow Thomas Lovejoy, and National Geographic Explorer Jared Diamond.

Today's announcement:

Laurie Marker has been involved in the study of wild cheetahs for more than 30 years and established an organization in Namibia to study them and protect them. The organization approaches wildlife conservation by clearly addressing the needs of human inhabitants and creating economic opportunities for them. The Tyler Prize award is made in recognition of her contributions to developing an ecosystem-based approach to sustainable management of a landscape that incorporates "the knowledge and economic interests of the local population" to support its long-term goal of protecting the endangered cheetah.

Marker has been involved in the study and captive breeding of cheetahs since the mid-1970s and established the Cheetah Conservation Fund in 1990. The group addresses problems, real and perceived, of cheetah predation on livestock as well as the very real degradation of grazing land and wildlife habitat by an invasive plant. Marker has initiated projects that raise guard dogs for livestock herds to reduce cheetah predation and that create an economic enterprise to clear invasive thorny bushes and process them into fuel. The projects are building a constituency among rural Namibians for cheetah conservation and, at the same time, are restoring and protecting farmland, livestock pastures and wildlife habitat.

Marker's nomination for the Tyler Prize was initiated by a former U.S. Ambassador to Namibia, Jeffrey Bader. In his letter of nomination, Bader described Marker as "literally and figuratively a force of nature," and he described the work of the Cheetah Conservation Fund as "the most successful project I have ever seen to protect the world's biodiversity."

Stuart Pimm has a long career in conservation research, teaching and public policy, and when Pimm's colleagues refer to his work, they frequently cite its influence as well as its substance. His Tyler Prize award is made in recognition of his work to delineate the structures of ecological food webs, to understand the expected lifetimes of plant and animal populations, and to determine the populations that are most vulnerable to risks of extinction and those that have the capacity to recover most rapidly from disturbances. In his letter of nomination for the Tyler Prize, Edward O. Wilson, an emeritus Harvard University professor and himself a Tyler Laureate, said Pimm's achievements "serve as an environmental conservation template."

Pimm has studied the structure of ecological communities and the consequences of diminished species diversity across the trophic levels of ecological communities. In addition, Pimm has developed theory and empirical analysis to address the conservation of endangered species in terms of their communities and populations. Pimm has contributed to more than 200 journal articles, many of them as the lead author or sole author, has managed research projects around the world and has worked as a university-level professor for 36 years.

Pimm is well known for working beyond the scientific community as a policy advisor and source for media interviews. One of his colleagues, in a letter of support for his nomination for the Tyler Prize, said Pimm's contributions to conservation science are notable because he cares enough to "find a way to make a difference."

On Thursday, April 22, Marker and Pimm will deliver public lectures at the Davidson Conference Center of the University of Southern California, which administers the prize.

The Tyler Prize for Environmental Achievement is one of the premier awards for environmental science, environmental health and energy.

It was established by the late John and Alice Tyler in 1973 and has been awarded annually to sixty-one individuals and four organizations associated with world-class environmental accomplishments.

An estimated million bats have died in the northeastern United States from white-nose syndrome, a disease characterized by a white cold-loving fungus that invades the skin of the bat.

Named for a distinctive ring of fungal growth around the muzzle, the disease also infests ears and wings. The bats lose their fat reserves and ultimately starve.

The relentless spread of the white-nose syndrome has alarmed biologists and conservationists, especially as colonies of rare indigenous species come into its path.

Photo courtesy of West Virginia Division of Natural Resources

Last November, the Smithsonian's National Zoo accepted 40 endangered Virginia big-eared bats (Corynorhinus townsendii virginianus) to establish a security population and scientifically develop husbandry practices--a feat no one else has undertaken with this subspecies, the zoo said in a recent news statement.

"In the months since, efforts to keep the bats alive have proved challenging, but the lessons Zoo scientists have learned will help save these, and other, insectivorous bats in the future," the zoo said.

The U.S. Fish and Wildlife Service funded this and other research projects focused on white-nose syndrome and bat survival. The West Virginia Division of Natural Resources assisted with the project.

The bat colony has been living at the Smithsonian Conservation Biology Institute in Front Royal, Virginia. "The possible extinction of an endangered subspecies, and the loss of its essential role in local ecosystems, were the reasons the National Zoo accepted the high-risk project," the zoo said.

"Over the past four months, the majority of the bats have died; 11 bats remain in the National Zoo's colony," the zoo added.

"The initial challenge the team faced was how to feed the animals.

"Virginia big-eared bats, which are a subspecies of the Townsend's big-eared bat (Corynorhinuss townsendii), eat on the wing (in flight).

"While some in the security colony successfully learned to eat mealworms out of pans, others did not, sometimes resulting in their death.

"Some of the bats that ate mealworms did not adequately groom themselves, which resulted in dermatitis (inflammation of the skin). Others developed foot, toe and digit problems that, in part, may have caused deadly bacterial infections that spread rapidly through the blood stream despite aggressive treatments with antibiotics and fluids."

"Virginia big-eared bats face an imminent threat from white-nose syndrome," said the U.S. Fish and Wildlife Service's National White-Nose Syndrome Coordinator Jeremy Coleman. "Developing a successful captive breeding program is a reasonable precautionary step to ensuring the long-term viability of the subspecies. The Smithsonian's National Zoo was the only organization to accept the challenge of this risky, groundbreaking, but essential endeavor."

Photo courtesy of West Virginia Division of Natural Resources

Because it is extraordinarily difficult to maintain insect-eating bats in captivity, extensive planning and preparations went into designing the project, the zoo said.

The zoo formed a bat care team made up of biologists, husbandry and animal care specialists, veterinarians, and a nutritionist who relied on protocols developed by the Virginia Big-Eared Bat Group convened by FWS. "The SCBI team worked around the clock to care for, and learn from, the colony," the zoo said.

"We expected some of the feeding challenges," said David Wildt, head of the National Zoo's Species Survival Center. "But we were surprised to learn how sensitive this particular subspecies of bat is. Even the smallest change in environment or husbandry practices seemed to affect the ability of the bats to adapt to their new environment."

National Zoo researchers found that bats learned to eat from the bowl faster when confined in a small enclosure for a few hours. In the future, the zoo said, scientists could use this information to better provide for the needs of the subspecies in captivity. "The bat team learned a great deal about enclosures and medical care required for insectivorous bats in captivity."

"Faced with the possibility of white-nose syndrome eliminating the entire subspecies, we took decisive action to attempt to protect the bats," Coleman said. "Together with the Zoo, we will examine this project, take what we have learned and be ready to apply it to captive propagation projects in the future."

White-nose syndrome continues to devastate wild bat colonies. The fungus is now present in caves in West Virginia that support the largest hibernating populations of Virginia big-eared bats in the world. It has spread to 10 states, from New Hampshire to Tennessee, and more endangered bat species are now within its range.

For additional information, visit the National Zoo's website. Learn more about white-nose syndrome on the Fish and Wildlife Service's white-nose syndrome page.

In an effort to encourage breeding in a critically endangered frog, scientists at the San Diego Zoo's Institute for Conservation Research have placed 24 mountain yellow-legged frogs into refrigerators.

"The cold temperatures mimic high-elevation winter conditions that cause the frogs to hibernate. Typically, mountain yellow-legged frogs display mating behaviors after emerging from hibernation," the zoo explained in a news statement yesterday.

U.S. Geological Survey scientists found this adult mountain yellow-legged frog last year in a rediscovered population of the endangered frog in the San Jacinto Wilderness, San Bernardino National Forest, California. This re-discovery--along with the San Diego Zoo's first successful breeding of the frog in captivity, and successful efforts by California Department of Fish and Game to restore frog habitat--renews hope of survival for this Southern California amphibian, USGS said.

Photo by Adam Backlin, U.S. Geological Survey

This is the first time the mountain yellow-legged frog has been put into a refrigerated unit to induce breeding. In 2009 the San Diego Zoo was the first to successfully breed the mountain yellow-legged frog in captivity after a slight chilling of their water, the zoo said.

"We hope that by simulating the cold of the mountains where this critically endangered frog has been found, the San Diego Zoo will be able to increase the mountain yellow-legged frog population," said Jeff Lemm, a research coordinator for the San Diego Zoo. "The tadpoles we raise will be reintroduced into remote mountainous areas of Southern California where these frogs were found historically."

In their native habitat, the female mountain yellow-legged frog lays eggs as soon as the snow begins to melt. A female mountain yellow-legged frog can lay up to 200 eggs that hatch into tadpoles three weeks later, the zoo said.

Jeff Lemm, a research coordinator with the San Diego Zoo's Institute for Conservation Research, takes a sample of the mountain yellow-legged frog's chilled water. The critically endangered frogs were put into a special refrigeration unit so they would hibernate. When the frogs emerge from the cold in April, scientists hope they will produce thousands of fertilized eggs. This is the first time scientists have chilled the mountain yellow-legged frog in an effort to induce breeding.

Photo by Ken Bohn, San Diego Zoo

"The frogs at the San Diego Zoo's Institute for Conservation Research were put into the refrigerated units, which are beverage coolers being used as hibernacula, on January 1, 2010. After the frogs have hibernated for a few months in 40-degree temperature, San Diego Zoo scientists will begin to raise the temperature a degree a day to slowly warm them back up. Scientists expect to move the frogs to an area of the lab for breeding at the beginning of April," the zoo said.

There are about 200 of the federally endangered mountain yellow-legged adult frogs remaining in the San Gabriel, San Bernardino and the San Jacinto mountains of Southern California, said Adam Backlin, an ecologist for the U.S. Geological Survey (USGS). Sixty-one more live at the San Diego Zoos Institute for Conservation Research. The goal of the breeding program at the Institute for Conservation Research is to return frogs to their native habitat.

While assessing suitable sites in southern California for reintroducing endangered southern mountain yellow-legged frogs, USGS scientists rediscovered a population in the San Jacinto Wilderness, 50 years since this frog was last seen there.

Photo by Liz Gallegos, U.S. Geological Survey

"Globally, amphibians are on the decline because of habitat loss, nonnative predators, effects of climate change and the spread of a deadly pathogen called the chytrid fungus. The mountain yellow-legged frog is one of three frogs or toads on the federal Endangered Species List in Southern California," San Diego Zoo said.

The breeding at the San Diego Zoo's Institute for Conservation Research is a part of a collaborative effort to save the species by organizations including USGS, California Department of Transportation, U.S. Fish and Wildlife Service, U.S. Forest Service, University of California, California Department of Fish and Game, and the Fresno Chaffee Zoo.

The Zoo's breeding program, in conjunction with its partners, began in 2006 after a forest service biologist with the San Jacinto Ranger District discovered pools where the frogs had been living that were drying up. A USGS team rescued 82 tadpoles, which were taken to the San Diego Zoo's Institute for Conservation Research, the zoo said.

Bluefin tuna are voracious predators, feasting constantly on fish and squid. But they have the misfortune to not be on the top of the food chain. Humans prey on tuna, and we seem to not be able to eat enough of this magnificent animal, especially when it is offered as sashimi in the finest restaurants.

So prized is the flesh of bluefin tuna that it can sell for hundreds of dollars a pound. A 512-pound (232.6-kilogram) bluefin fetched a near-record 16.28 million yen (U.S.$175,000) at an auction at Tokyo's Tsukiji fish market in January, according to media reports.

A painting of Atlantic bluefin tuna as they spawn in warm water.

NGS illustration by Stanley Meltzoff

Japan eats more bluefin tuna than any other nation. But the fish is also popular in many other parts of the world, and that's what's leading to its demise. Tuna is being harvested faster than the species can replace itself, especially on the eastern side of the Atlantic Ocean.

The scarcer bluefin tuna becomes, the more its price rises, the more it is in demand as a delicacy. National Geographic Explorer in Residence and marine biologist Sylvia Earle once told me, "When the world is down to the last tuna, someone will be willing to pay a million dollars to eat it."

There is money to be made all along the supply chain for such a valuable commodity--from ocean to dinner plate--and this might explain why there is a fight brewing between fishing nations over whether it's time to shut down the international trade in the Atlantic bluefin tuna, before we eat it out of existence.

Extensive research has made it clear that the Atlantic bluefin tuna is so overfished that its populations have fallen to levels that threaten its survival. This has prompted conservationists to support a ban on international commercial trade in Atlantic bluefin tuna, giving the endangered fish a chance to recover.

The instrument that would secure such a ban, at least in theory, is Appendix I of the Convention on International Trade in Endangered Species (CITES).

So Atlantic bluefin tuna wil be on the agenda, if not on the menu, when some 175 governments attend a CITES conference in Doha, Qatar, later this month to discuss listing the species in Appendix I. (175 governments weigh stricter controls over wildlife trade)

Monaco has proposed that the meeting include the Atlantic bluefin tuna in Appendix I, which would make trade in wild-caught specimens of the fish illegal. Two thirds of the 175 CITES member countries present at the Doha conference would have to vote in favor for Monaco's proposal to be adopted.

The United States supports the proposal. European Union nations appear to be divided over the issue. According to a Reuters news report, a bloc of African countries will vote for the listing, provided that the countries who want to protect the tuna support an African proposal to uphold a CITES ban on the international trade of elephant ivory. (The ivory issue is a separate story, to be visited in a future blog post.)

Some tuna-fishing countries, notably Japan, are reported by various news organizations to be opposed to the proposed trade ban on bluefin tuna. Japan, it is said, will lodge reservations about the listing and will defy it if it is passed.

Atlantic bluefin tuna are managed as two separate stocks: an eastern Atlantic and Mediterranean stock, and a western stock.

Overlapping ranges of eastern and western bluefin tuna. Some tagged specimens have been tracked swimming from North American to European waters several times a year.

NGS map by Jerome Cookson 

Announcing the support for the proposal to ban all international commercial trade of Atlantic bluefin tuna, Tom Strickland, Assistant Secretary of the Interior, this week said the U.S. continued to have strong concerns about the long-term viability of either the fish or the fishery.

The Eastern Atlantic and Mediterranean tuna stock was threatened by overharvesting, which included illegal, unregulated, and unreported fishing, Strickland said in a statement. The western spawning stock had stabilized at a very low population level, he added.

If the bluefin tuna is listed under Appendix I, commercial fishermen in the U.S. could continue to sell to U.S. consumers western Atlantic bluefin tuna caught in U.S. waters. The same rule would apply to other nations selling tuna caught in their waters to their domestic markets.

A painting of bluefin tuna devouring mackerel.

NGS illustration by Stanley Meltzoff

In welcoming the U.S. Government's support for a listing of bluefin tuna on CITES Appendix I, the conservation charity WWF said: "The U.S. has a vested interest in this issue, as a fishing nation of Atlantic bluefin tuna--so if the U.S. can see the bigger picture and back the international trade ban proposal for the long-term survival of a species and a fishery, all countries can and should do so."

The Pew Environment Group, a policy think tank based in Washington, D.C., strongly supports the proposal to include the Atlantic bluefin tuna in CITES Appendix I.

The Pew Environment Group praised the Obama administration for supporting the proposed CITES Appendix I listing for Atlantic bluefin tuna. Pew also called for all governments to join the United States in advocating for the proposal which would prohibit international commercial trade of the species.

"The Obama administration's decision to support a CITES Appendix I listing of Atlantic bluefin tuna could be a real game changer for the species."

"The Obama administration's decision to support a CITES Appendix I listing of Atlantic bluefin tuna could be a real game changer for the species," said Susan Lieberman, director of international policy at the Pew Environment Group. "Other governments can either join Monaco and the United States in boldly supporting the conservation of bluefin tuna, sharks and other marine species or they can yield to commercial fishing interests that focus more on short-term profits than a sustainable future for both fish and local fishing communities," Lieberman said in a statement.

"The bluefin is a giant, warm-blooded fish that's capable of sudden acceleration to highway speeds," said former tuna fisherman Carl Safina, founder of Blue Ocean Institute. "They were thrilling to catch, but right now a sea-going buffalo hunt is forcing them toward commercial extinction. The United States and other governments--must vigorously support the effort to hit the brakes."

The city-size asteroid that slammed into Earth with the force of a million nuclear bombs is what snuffed out the dinosaurs and half of all other species on Earth 65 million years ago, an international group of scientists who reviewed all available evidence said today.

The asteroid that ended the 160 million-year reign of the dinosaurs was about 10,000 times more massive than the total mass of the human world population, according to the University of Texas at Austin. "At impact, the asteroid is estimated to have been traveling at 20 kilometers per second (44,640 miles per hour), roughly 20 times the speed of a rifle bullet," the university said in a news statement. Impacts of this size on Earth are thought to happen on average about once every hundred million years.

Illustration courtesy of NASA

The cataclysmic extinction of that time was not caused by massive volcanic activity, as another theory has suggested, according to the new analysis, published today in the journal Science.

A panel of 41 experts from Europe, the U.S., Mexico, Canada and Japan analyzed new data from ocean drilling and continental sites and reviewed the research of palaeontologists, geochemists, climate modelers, geophysicists and sedimentologists who have been collecting evidence over the last 20 years to determine the cause of the Cretaceous-Tertiary (KT) extinction, which happened around 65 million years ago.

"The impact hypothesis has grown stronger than ever."

"They find that alternative hypotheses are inadequate to explain the abrupt mass extinction and that the impact hypothesis has grown stronger than ever," the University of Texas at Austin said in a news statement.

"Today's review of the evidence shows that the extinction was caused by a massive asteroid slamming into Earth at Chicxulub (pronounced chick- shoo-loob) in Mexico," said Imperial College London, in a separate statement.

Scientists from both institutions participated in the study.

The KT extinction wiped out more than half of all species on the planet, including the dinosaurs, birdlike pterosaurs and large marine reptiles, clearing the way for mammals to become the dominant species on Earth, Imperial College added in its release.

The impact released about a billion times more energy than the atomic bombs dropped on Hiroshima and a million times larger than the largest nuclear bomb ever tested, said the University of Texas. "The initial impact crater was about 100 kilometers (60 miles) wide and 30 kilometers (18 miles) deep."

Illustration courtesy of NASA

"The asteroid, which was around 15 kilometers [9 miles] wide, is believed to have hit Earth with a force one billion times more powerful than the atomic bomb at Hiroshima. It would have blasted material at high velocity into the atmosphere, triggering a chain of events that caused a global winter, wiping out much of life on Earth in a matter of days," Imperial College said.

The asteroid smacked Earth on what is today's Mexico's Yucatan peninsula.

Google Maps

Illustration courtesy of NASA

Some scientists have suggested that the Chicxulub impact happened 300,000 years before the KT boundary, and therefore came too early to have been the major cause of extinctions, the University of Texas said.

The KT boundary, also known as the Cretaceous-Paleogene (K-Pg) boundary, is how geologists refer to the time of the great extinction. Life on Earth after the event that caused the extinction was dramatically different to what was on the planet before.

The Cretaceous Creekbed diorama in the Prehistoric Journey exhibit at the Denver Museum of Nature & Science shows two Stygimoloch spinifer dinosaurs fighting in the woodlands of North Dakota. The scene, based on an actual fossil site, represented the final ecosystem of the Cretaceous. Paleontology from this site documents the extinction of the dinosaurs as well as more than 50 percent of plant and insect species.

Image courtesy of the Denver Museum of Nature and Science

Scientists who suggest that the Chicxulub impact came earlier point to deposits at sites around the Gulf of Mexico with a layer of tiny glass-like blobs of melted impact material that, according to their interpretation, was deposited at about 300,000 years before the mass extinction, the University of Texas said.

"As an alternative, they suggest the Deccan Traps--unusually active volcanoes in what is now India--led to global cooling and acid rain, and were the major cause of mass extinction, not the Chicxulub impact in Mexico."

However, the University of Texas added, the reviewers of the study published today find that what appears to be a series of layers neatly laid down over 300,000 years near the impact site were actually violently churned and then dumped in a thick pile in a very short time.

The Earth Impact Effects Program website created by Gareth Collins, from the Department of Earth Science and Engineering at Imperial College London, allows the user to select different effects such as air blasts, seismic shaking and thermal radiation to determine their effect on Earth after the Chicxulub asteroid impact. The illustration at the top shows intensity of seismic shaking around the point of impact. At bottom is the area covered by ejecta, or material blasted into the air.

Illustrations courtesy of Imperial College London 

"Models suggest the impact at Chicxulub was a million times more energetic than the largest nuclear bomb ever tested. An impact of this size would eject material at high velocity around the world, cause earthquakes of magnitude >10, continental shelf collapse, landslides, gravity flows, mass wasting and tsunamis and produce a relatively thick and complex sequence of deposits close to Chicxulub."

"If we are to unravel the sequence of events across the K-Pg boundary, perhaps the last place in the world we should look is close to the Chicxulub impact site, where the sedimentary deposits will be most disturbed," write the reviewers.

In addition, the reviewers note, as you go farther from the impact site, these layers become thinner and the amount of ejected material decreases until it becomes one layer that can be found globally exactly at the KT boundary coincident with the mass extinction. Moreover, the ejecta (blasted material) within the global KT layer is compositionally linked to the specific sediments and crystalline rocks at Chicxulub.

The K-Pg boundary as exposed along the side of Interstate 25 near Raton Pass in southern Colorado. The obvious white layer is the K-Pg ejecta layer, says the University of Texas at Austin. It contains elevated levels of iridium and shocked mineral grains. Pollen and spores from Cretaceous plants are found immediately below this layer but not above it, a pattern that is seen from the southern United States all the way north to the Arctic Ocean. "This direct link between impact ejecta and plant extinction suggests a very strong cause and effect relationship between impact and extinction."

Image courtesy of Kirk Johnson, Denver Museum of Nature and Science

The reviewers find that despite evidence for relatively active volcanism in India, marine and terrestrial ecosystems showed only minor changes within the 500,000 years before the KT boundary. "Then, precisely at the boundary, there was an abrupt and major decrease in productivity (a measure of the sheer mass of living things) and species diversity," the University of Texas explained.

"The Deccan hypothesis is further weakened by a review of models of atmospheric chemistry, according to the latest study. "Although significant volumes of sulfur may be emitted during each volcanic eruption and form aerosols in the stratosphere, these sulfur aerosols fall out rapidly and any adverse environmental effects are apparently only short-lasting. In comparison, during the Chicxulub impact, much larger volumes of sulfur, dust and soot were released in a much shorter time, leading to extreme environmental perturbations (such as darkening or cooling)."

"Combining all available data from different science disciplines led us to conclude that a large asteroid impact 65 million years ago in modern-day Mexico was the major cause of the mass extinctions," says Peter Schulte, assistant professor at the University of Erlangen in Germany and lead author of the review paper.

The Earth Impact Effects Program website created by Gareth Collins shows the extent of the fireball that engulfed the impact zone (top) and the area covered by an air blast.

Illustrations courtesy of Imperial College London 

"Far from Chicxulub, the geologic record clearly shows a single large meteorite hit the Earth exactly at the K-Pg  boundary. Thickening of the K-Pg boundary layer towards Chicxulub shows Chicxulub was the impact site. The significant changes in Earth's ecosystems all occur precisely at this boundary and thus, say the reviewers, a large asteroid impact into the sulfate-rich sediments at Chicxulub remains the most plausible cause for the K-Pg boundary mass extinction," the University of Texas said.

"We now have great confidence that an asteroid was the cause of the KT extinction," said Joanna Morgan, co-author of the review from the Department of Earth Science and Engineering at Imperial College London. "This triggered large-scale fires, earthquakes measuring more than 10 on the Richter scale, and continental landslides, which created tsunamis.

"However, the final nail in the coffin for the dinosaurs happened when blasted material was ejected at high velocity into the atmosphere. This shrouded the planet in darkness and caused a global winter, killing off many species that couldn't adapt to this hellish environment."

Illustration courtesy of NASA

"The asteroid was about the size of the Isle of Wight and hit Earth 20 times faster than a speeding bullet," said Gareth Collins, Natural Environment Research Council Fellow and another co-author from the Department of Earth Science and Engineering at Imperial College London. "The explosion of hot rock and gas would have looked like a huge ball of fire on the horizon, grilling any living creature in the immediate vicinity that couldn't find shelter.

"While this hellish day signalled the end of the 160 million-year reign of the dinosaurs, it turned out to be a great day for mammals."

"Ironically, while this hellish day signalled the end of the 160 million-year reign of the dinosaurs, it turned out to be a great day for mammals, who had lived in the shadow of the dinosaurs prior to this event.

Paved the way for humans to become dominant

"The KT extinction was a pivotal moment in Earth's history, which ultimately paved the way for humans to become the dominant species on Earth."

The Earth Impact Effects Program website shows the estimated tsunami zone created by the Chicxulub impact.

Illustration courtesy of Imperial College London

In the review, the panel sifted past studies to analyze the evidence that linked the asteroid impact and volcanic activity with the KT extinction, Imperial said.

"One key piece of evidence was the abundance of iridium in geological samples around the world from the time of the extinction. Iridium is very rare in Earth's crust and very common in asteroids. Immediately after the iridium layer, there is a dramatic decline in fossil abundance and species, indicating that the KT extinction followed very soon after the asteroid hit.

"Another direct link between the asteroid impact and the extinction is evidence of 'shocked' quartz in geological records. Quartz is shocked when hit very quickly by a massive force and these minerals are only found at nuclear explosion sites and at meteorite impacts sites. The team say that an abundance of shocked quartz in rock layers all around the world at the KT boundary lends further weight to their conclusions that a massive meteorite impact happened at the time of the mass extinction," Imperial College said.

Female brown anole lizards have figured out how to pass on the genes of large males they mate to their sons, and the genes of small males to their daughters, Dartmouth College biologists have discovered.

Female brown anoles (center) produce more sons via large sires (left) and more daughters via small sires (right).

Image © Science/AAAS

"The females of this species mate with several males, then produce more sons with sperm from large fathers, and more daughters with sperm from smaller fathers," Dartmouth said in a statement about the research.

The researchers believe that the lizards do this to ensure that the genes from large fathers are passed on to sons, who stand to benefit from inheriting the genes for large size.

The study is published in the March 4 issue of Science Express, the advance online publication of the journal Science.

"This species has figured out a clever way to pass on genes with gender-specific effects on fitness," said Bob Cox, the lead author on the paper and a post-doctoral researcher at Dartmouth. "Usually, when natural selection pulls genes in different directions for each gender, the species faces an evolutionary dilemma. But these lizards have solved this puzzle, they've figured out how to get the right genes into the right gender."

Photo of anole lizards courtesy of Dartmouth

By manipulating opportunities for females to mate with males of different sizes, the researchers determined that females prefer larger males, Dartmouth said. "But, when the choice of partners was limited to small males, females minimized the production of sons," the university said.

The researchers explain that the genes that make males more fit are often different from the genes that benefit females, "which presents a conundrum because males and females share most of their DNA. The valuable traits for one gender are not always the same for the other."

"In an evolutionary sense, what's good for the goose is not always good for the gander," Cox said.

In these lizards, however, mothers can enhance the fitness of their offspring by manipulating their gender depending on the size of the father, Dartmouth said. To demonstrate this, Cox and Calsbeek measured the survival rates of sons and daughters over eight months when released to their natural habitat in The Bahamas.

"As we predicted, the survival of the male offspring increased if they had large fathers," said Calsbeek. "But, we found that the survival of the daughters was not influenced by the size of the father. This suggests that the genetic benefits of large size are specific to sons."

A female brown anole, Anolis sagrei, in the Bahamas.

Image © Science/AAAS

How do females control the gender of their progeny? "That's the big question at this point," Cox said. The researchers will continue their studies to learn more about the mechanisms involved in this most fundamental of all evolutionary processes, the struggle to pass on advantageous genetic material, Dartmouth said.

Cox's co-author is Ryan Calsbeek, an assistant professor of biological sciences at Dartmouth.

Here's why you really don't want to encounter a polar bear in the wild.

This bear statue is part of the "How You Measure Up" area of an exhibit at San Diego Zoo that will give guests the chance to see how they compare to a polar bear--in height, weight and food consumption. This lifesize statue of a male polar bear measures 10 feet 1 inches tall, the same height as the Zoo's male polar bear, Kalluk.

Construction workers at the zoo placed the polar bear statue outside the polar bear exhibit yesterday.

Photo by Ken Bohn, San Diego Zoo.

The Conrad Prebys Polar Bear Plunge exhibit is being redesigned for visitors to address the challenges facing polar bears due to climate change.

Read about a National Geographic photographer who approaches wild polar bears for the best shots. 

American bison have the best chance of full recovery as wildlife by being allowed to roam freely across hundreds of thousands or even millions of acres, conservationists said in a study released today.

"Making this possible poses one of the biggest challenges for restoring bison herds as both public and private landowners will need to give their support," the Switzerland-based International Union for the Conservation of Nature (IUCN) said in a news statement.

NGS stock photo by Sam Abell

A new publication by IUCN, American Bison: Status Survey and Conservation Guidelines 2010, reports on the current status of American bison, in the wild and in conservation herds, and makes recommendations on how to ensure that the species is conserved for the future.

The next 10 to 20 years could be extremely significant for restoring wild populations of American bison to their original roaming grounds. But for this to happen, more land must be made available for herds to roam free, government policies must be updated and the public must change its attitude towards bison, IUCN said.

"Although the effort to restore bison to the plains of North America is considered to be one of the most ambitious and complex undertakings in species conservation efforts in North America, it will only succeed if legislation is introduced at a local and national level, with significant funding and a shift in attitude towards the animal," said Simon Stuart, chairman of the IUCN Species Survival Commission.

Five hundred years ago, tens of millions of American bison roamed free on the plains of North America, from Alaska to northern Mexico. Now the American bison--which includes both plains and wood bison--is listed as Near Threatened on IUCN's Red List of Threatened Species.

As of 2008, there were approximately 400,000 bison in commercial herds in North America, some 93 percent of the continental population, IUCN estimates.

"But little progress has been made in recent decades to increase the number of animals in conservation herds, which are managed carefully for their genetic diversity and ecological roles," IUCN elaborated.

NGS stock photo by William Albert Allard

"In 2008, there were 61 plains bison conservation herds in North America containing about 20,500 animals, and 11 conservation herds of wood bison, containing nearly 11,000 animals."

"While substantial progress in saving bison from extinction was made in the 20th Century, much work remains to restore conservation herds throughout their vast geographical range," says University of Calgary Environmental Design Professor and co-editor of the study, Cormack Gates, who is also co-chairman of the IUCN/SSC Bison Specialist Group. "The key is recognition that the bison is a wildlife species and to be conserved as wildlife, it needs land and supportive government policies."

NGS stock photo by James P. Blair

The survival of bison populations is affected by many factors, including limited habitat and severe winters. Yet the greatest challenge is to overcome the common perception that the bison, which has had a profound influence on the human history of North America, socially, culturally and ecologically, no longer belongs on the landscape, IUCN said.

"The decimation of the American Bison in the late 1800s inspired the first recovery of bison and an entire conservation movement that protected wildlife and wild places across North America," says Keith Aune, Senior Conservation Scientist, Wildlife Conservation Society. "The IUCN Status Survey and Conservation Guidelines provide a new framework for inspiring a second recovery of bison and restoring functional grassland ecosystems."

"The bison is the largest land mammal in North America, and yet it is perhaps the most neglected icon," said Steve Forrest, WWF Northern Great Plains Manager for Conservation Science.

"These guidelines provide a roadmap for bringing the bison back to its rightful place as a keystone of the great plains."

As the rampant invasive plant purple loosestrife spreads across North America, it might be facing a natural barrier, according to researchers at the University of Toronto.

Lythrum salicaria, a  beautiful but highly destructive plant, has been heading north since it was first introduced from Europe to the eastern seaboard 150 years ago, the university says in a news statement. 'This exotic invader chokes out native species and has dramatically altered wetland habitats in North America."

NPS photo

Purple loosestrife's native range is throughout the UK, and across central and southern Europe to central Russia, Japan, China, southeast Asia and northern India, according to the U.S. National Park Service.

"Purple loosestrife adapts readily to natural and disturbed wetlands. As it establishes and expands, it outcompetes and replaces native grasses, sedges, and other flowering plants that provide a higher quality source of nutrition for wildlife. The highly invasive nature of purple loosestrife allows it to form dense, homogeneous stands that restrict native wetland plant species, including some federally endangered orchids, and reduce habitat for waterfowl," NPS says on its Web site.

According to the U.S. Fish and Wildlife Service, purple loosestrife now occurs in every state except Florida.

Wanted: Dead, Not Alive! Purple Loosestrife poster distributed for public information

California Department of Food and Agriculture image

Purple loosestrife destroys wildlife habitats by displacing native vegetation that provides food, shelter, and breeding areas for wildlife, Toronto University said.

"In urban areas, it invades ditches where it can block or disrupt water flow. It has few pests and diseases, resists various control methods, and plants can produce as many as 3 million seeds a year."  

But it turns out it may have a vulnerability after all: the northern climate.

As this invasive plant has spread north it has run into challenges posed by a shorter growing season, according to a study conducted by Robert Colautti, who recently obtained his Ph.D. from the University of Toronto's Department of Ecology and Evolutionary Biology.

The results are published online last week in the Proceedings of the Royal Society of London, series B and published in the journal Nature.

The scientists have found that adapting to the Great White North carries a severe reproductive penalty that may limit its spread, the University of Toronto explained.

"The authors used modeling and experimental studies of 20 purple loosestrife populations along a 1,200 kilometer [750-mile] latitudinal gradient from Maryland to Timmins, Ontario, representing a one-month difference in growing season.

"They found that northern populations have become locally adapted and flower earlier in response to a shorter growing season," the university said.

"However, early flowering plants suffer a cost in terms of smaller size and reduced seed production. The reason: a genetic constraint," the university said.

"Genes that cause early flowering also reduce plant size, so early flowering and small size evolve together,"  Colautti said. "Smaller size results in lower seed production, which is likely to limit the spread of purple loosestrife in northern regions."

But isn't that only while the northern climate remains cool?

Co-authors of the study are Colautti's supervisor Professor Spencer Barrett of the Department of Ecology and Evolutionary Biology and Christopher Eckert of Queen's University. The research was funded by the Natural Sciences and Engineering Research Council of Canada, an Ontario Graduate Scholarship and a Premier's Discovery Award from the Ontario Government.

As the rampant invasive plant purple loosestrife spreads across North America, it might be facing a natural barrier, according to researchers at the University of Toronto.

Lythrum salicaria, a  beautiful but highly destructive plant, has been heading north since it was first introduced from Europe to the eastern seaboard 150 years ago, the university says in a news statement. 'This exotic invader chokes out native species and has dramatically altered wetland habitats in North America."

NPS photo

Purple loosestrife's native range is throughout the UK, and across central and southern Europe to central Russia, Japan, China, southeast Asia and northern India, according to the U.S. National Park Service.

"Purple loosestrife adapts readily to natural and disturbed wetlands. As it establishes and expands, it outcompetes and replaces native grasses, sedges, and other flowering plants that provide a higher quality source of nutrition for wildlife. The highly invasive nature of purple loosestrife allows it to form dense, homogeneous stands that restrict native wetland plant species, including some federally endangered orchids, and reduce habitat for waterfowl," NPS says on its Web site.

According to the U.S. Fish and Wildlife Service, purple loosestrife now occurs in every state except Florida.

Wanted: Dead, Not Alive! Purple Loosestrife poster distributed for public information

California Department of Food and Agriculture image

Purple loosestrife destroys wildlife habitats by displacing native vegetation that provides food, shelter, and breeding areas for wildlife, Toronto University said.

"In urban areas, it invades ditches where it can block or disrupt water flow. It has few pests and diseases, resists various control methods, and plants can produce as many as 3 million seeds a year."  

But it turns out it may have a vulnerability after all: the northern climate.

As this invasive plant has spread north it has run into challenges posed by a shorter growing season, according to a study conducted by Robert Colautti, who recently obtained his Ph.D. from the University of Toronto's Department of Ecology and Evolutionary Biology.

The results are published online last week in the Proceedings of the Royal Society of London, series B and published in the journal Nature.

The scientists have found that adapting to the Great White North carries a severe reproductive penalty that may limit its spread, the University of Toronto explained.

"The authors used modeling and experimental studies of 20 purple loosestrife populations along a 1,200 kilometer [750-mile] latitudinal gradient from Maryland to Timmins, Ontario, representing a one-month difference in growing season.

"They found that northern populations have become locally adapted and flower earlier in response to a shorter growing season," the university said.

"However, early flowering plants suffer a cost in terms of smaller size and reduced seed production. The reason: a genetic constraint," the university said.

"Genes that cause early flowering also reduce plant size, so early flowering and small size evolve together,"  Colautti said. "Smaller size results in lower seed production, which is likely to limit the spread of purple loosestrife in northern regions."

But isn't that only while the northern climate remains cool?

Co-authors of the study are Colautti's supervisor Professor Spencer Barrett of the Department of Ecology and Evolutionary Biology and Christopher Eckert of Queen's University. The research was funded by the Natural Sciences and Engineering Research Council of Canada, an Ontario Graduate Scholarship and a Premier's Discovery Award from the Ontario Government.

More than seven hundred people were killed and two million have been displaced by the magnitude 8.8 earthquake that struck Chile yesterday, according to news reports. (See Chile earthquake pictures.)

"We face a catastrophe of such unthinkable magnitude that it will require a giant effort" for Chile to recover, President Michelle Bachelet told a news conference at the presidential palace, the Associated Press said.

Bachelet ordered the military to take control of Concepcion, which was badly damaged by the temblor, one of the strongest on record. Widespread looting has broken out in Chile's second-largest city a day after a the devastating earthquake, the Wall Street Journal reported.

"The mayor of Concepcion city has said food is running out and police used tear gas and water cannon against looters at a supermarket on Sunday," the BBC said.

About 1.5 million homes and many roads and bridges across the affected region were damaged or destroyed, the BBC added.

Despite a massive evacuation of Hawaii, tsunamis in Hawaii measured only about three feet (one meter), too small to do any damage, Richard Lovett reported today for National Geographic News..

"But this doesn't mean the tsunamis in Hawaii fizzled," Costas Synolakis, director of the Tsunami Research Center at the University of Southern California, told Lovett. Read the full story: Hawaii Tsunamis Fell Short but Didn't "Fizzle," Expert Says.

The U.S. Geological Survey released two maps that model the differences between the tsunamis generated by the 1960 Chile earthquake (magnitude 9.5) and this weekend's magnitude 8.8 quake.

Filled colors show maximum computed tsunami amplitude in centimeters during 24 hours of wave propagation. Black contours show computed tsunami arrival time.

1960 Chile tsunami (earthquake magnitude 9.5) maximum amplitude plot--for comparison with February 27, 2010 Chile tsunami event.

Image courtesy of NOAA

2010 Chile tsunami (earthquake magnitude 8.8) maximum amplitude plot.

Image courtesy of NOAA 

It looks like a pig with a trunk, but it is related to horses. Not yet a month old, San Diego Zoo's newest Malaya tapir is starting to nibble on solid food already, the zoo said in a caption released with this photograph.

The tapir has been named Tembikai, which means "watermelon" in Malay, the zoo said.

Photo by Ken Bohn

The Malaya tapir is an Endangered species, so this birth is significant to the species' population, the zoo said. "It also was significant because his mother, Chantek, is 25 years old, which is older than most tapirs when they give birth. But, Tembikai is doing well. He weighed 13 pounds when born Jan. 29, 2010, and is now 30 pounds," the zoo added.

More photos of zoo animals can be found in our regular feature Zoo News.

A tsunami generated by an 8.8-magnitude earthquake in Chile struck Hawaii Saturday, but an official with the Pacific Tsunami Warning Center (PTWC) said the island chain "dodged a bullet" after smaller-than-expected waves were reported, CNN  said.

The PTWC lifted all tsunami warnings, watches, or advisories.

"The first waves of the tsunami were recorded on The Big Island around noon (5 p.m. ET), 16 hours after the Chilean temblor.

"Gauges showed water levels rising 3 feet in Hilo, and remaining at that level," CNN said.

The map above shows an estimate of how long it might take for a tsunami to roll across the Pacific Ocean following the earthquake off the coast of Chile earlier today.

Map courtesy of NOAA

The Pacific Tsunami Warning Center confirmed the tsunami reached Hawaii just after 11:30 a.m. local time, 4:30 p.m. ET, ABC World News reported.

"Initial reports indicate the waves have been smaller than expected, but officials are warning residents to remain on high alert. The tsunami is a series of waves that will continue to march toward Hawaii's shores," ABC said.

"This could be bigger but we don't know yet," said Nathan Becker of the PTWC, noting the first wave measured 1 meter, or roughly 3 feet. Later waves could be larger, he said.

Chile Earthquake Pictures: Quake Spurs Tsunami Threat

In the White House video below, President Obama talks about how he was briefed by his national security team on the steps that the U.S. is taking "to protect our own people, and to stand with our Chilean friends."

"Early indications are that hundreds of lives have been lost in Chile, and the damage is severe.  On behalf of the American people, Michelle and I send our deepest condolences to the Chilean people," Obama said. 

"The United States stands ready to assist in the rescue and recovery efforts, and we have resources that are positioned to deploy should the Chilean government ask for our help.  Chile is a close friend and partner of the United States, and I've reached out to President Bachelet to let her know that we will be there for her should the Chilean people need assistance, and our hearts go out to the families who may have lost loved ones.

"We're also preparing for a tsunami that could reach American shores later today, particularly in Hawaii, American Samoa, and Guam.  A tsunami warning is in place, and people have been alerted to evacuate coastal areas.  I urge citizens to listen closely to the instructions of local officials, who will have the full support of the federal government as they prepare for a potential tsunami, and recover from any damage that may be caused.

"I also urge our citizens along the West Coast to be prepared as well, as there may be dangerous waves and currents throughout the day.  Again, the most important thing that you can do is to carefully heed the instructions of your state and local officials.

The map above shows a projection of energy intensity through the Pacific Ocean following the eaerthquake near Chile.

Map courtesy of NOAAA

The State of Hawaii posted a warning on its Web site, urging residents in evacuation zones to move to high ground.

Above: A severe tsunami warning for Hawaii was posted by the Pacific Tsunami Warning Center hours after the earthquake off Chile.

Below: PTWC canceled all warnings and advisories after smaller-than-expected waves were reported in Hawaii.

A tsunami generated by an 8.8-magnitude earthquake in Chile struck Hawaii Saturday, but an official with the Pacific Tsunami Warning Center (PTWC) said the island chain "dodged a bullet" after smaller-than-expected waves were reported, CNN  said.

The PTWC lifted all tsunami warnings, watches, or advisories.

"The first waves of the tsunami were recorded on The Big Island around noon (5 p.m. ET), 16 hours after the Chilean temblor.

"Gauges showed water levels rising 3 feet in Hilo, and remaining at that level," CNN said.

The map above shows an estimate of how long it might take for a tsunami to roll across the Pacific Ocean following the earthquake off the coast of Chile earlier today.

Map courtesy of NOAA

The Pacific Tsunami Warning Center confirmed the tsunami reached Hawaii just after 11:30 a.m. local time, 4:30 p.m. ET, ABC World News reported.

"Initial reports indicate the waves have been smaller than expected, but officials are warning residents to remain on high alert. The tsunami is a series of waves that will continue to march toward Hawaii's shores," ABC said.

"This could be bigger but we don't know yet," said Nathan Becker of the PTWC, noting the first wave measured 1 meter, or roughly 3 feet. Later waves could be larger, he said.

Chile Earthquake Pictures: Quake Spurs Tsunami Threat

In the White House video below, President Obama talks about how he was briefed by his national security team on the steps that the U.S. is taking "to protect our own people, and to stand with our Chilean friends."

"Early indications are that hundreds of lives have been lost in Chile, and the damage is severe.  On behalf of the American people, Michelle and I send our deepest condolences to the Chilean people," Obama said. 

"The United States stands ready to assist in the rescue and recovery efforts, and we have resources that are positioned to deploy should the Chilean government ask for our help.  Chile is a close friend and partner of the United States, and I've reached out to President Bachelet to let her know that we will be there for her should the Chilean people need assistance, and our hearts go out to the families who may have lost loved ones.

"We're also preparing for a tsunami that could reach American shores later today, particularly in Hawaii, American Samoa, and Guam.  A tsunami warning is in place, and people have been alerted to evacuate coastal areas.  I urge citizens to listen closely to the instructions of local officials, who will have the full support of the federal government as they prepare for a potential tsunami, and recover from any damage that may be caused.

"I also urge our citizens along the West Coast to be prepared as well, as there may be dangerous waves and currents throughout the day.  Again, the most important thing that you can do is to carefully heed the instructions of your state and local officials.

The map above shows a projection of energy intensity through the Pacific Ocean following the eaerthquake near Chile.

Map courtesy of NOAAA

The State of Hawaii posted a warning on its Web site, urging residents in evacuation zones to move to high ground.

Above: A severe tsunami warning for Hawaii was posted by the Pacific Tsunami Warning Center hours after the earthquake off Chile.

Below: PTWC canceled all warnings and advisories after smaller-than-expected waves were reported in Hawaii.

An 8.8 magnitude earthquake was registered 22 miles underground off the coast of Chile early this morning, the U.S. Geological Survey reports.

One of the strongest earthquakes on record, the temblor has triggered tsunami advisories across the Pacific Ocean, including Japan and California.

This map put out by NOAA's Pacific Tsunami Warning Center shows the location (the red star, lower right) of the 8.8 magnitude earthquake. A dotted line has been added to the map to indicate potential tsunamis in the direction of Hawaii.

Map courtesy of NOAA

The Pacific Tsunami Warning Center issued a severe warning to the state of Hawaii, as follows:

A TSUNAMI HAS BEEN GENERATED THAT COULD CAUSE DAMAGE ALONG
COASTLINES OF ALL ISLANDS IN THE STATE OF HAWAII. URGENT ACTION
SHOULD BE TAKEN TO PROTECT LIVES AND PROPERTY.

A TSUNAMI IS A SERIES OF LONG OCEAN WAVES. EACH INDIVIDUAL WAVE
CREST CAN LAST 5 TO 15 MINUTES OR MORE AND EXTENSIVELY FLOOD
COASTAL AREAS. THE DANGER CAN CONTINUE FOR MANY HOURS AFTER THE
INITIAL WAVE AS SUBSEQUENT WAVES ARRIVE. TSUNAMI WAVE HEIGHTS
CANNOT BE PREDICTED AND THE FIRST WAVE MAY NOT BE THE LARGEST.
TSUNAMI WAVES EFFICIENTLY WRAP AROUND ISLANDS. ALL SHORES ARE AT
RISK NO MATTER WHICH DIRECTION THEY FACE. THE TROUGH OF A TSUNAMI
WAVE MAY TEMPORARILY EXPOSE THE SEAFLOOR BUT THE AREA WILL
QUICKLY FLOOD AGAIN. EXTREMELY STRONG AND UNUSUAL NEARSHORE
CURRENTS CAN ACCOMPANY A TSUNAMI. DEBRIS PICKED UP AND CARRIED
BY A TSUNAMI AMPLIFIES ITS DESTRUCTIVE POWER. SIMULTANEOUS HIGH
TIDES OR HIGH SURF CAN SIGNIFICANTLY INCREASE THE TSUNAMI HAZARD.

THE ESTIMATED ARRIVAL TIME IN HAWAII OF THE FIRST TSUNAMI WAVE IS

                     1119 AM HST SAT 27 FEB 2010

MESSAGES WILL BE ISSUED HOURLY OR SOONER AS CONDITIONS WARRANT.

News reports said the State of Hawaii was planning to sound a siren alarm throughout the state at 6 a.m. local time--the first since 1964.

If the tsunami warning alarms sound at 6 a.m., "we are urging people not to panic," a local official told the Honolulu Advertiser. "It's important that those in low-lying areas can get to higher ground. We want to remind people that they have five hours to evacuate after the alarms sound."

The Honolulu Advertiser also reported that the state Department of Transportation was urging all shipping agents and shipping companies to get their ships out of the port of Honolulu before the time the tsunami was expected.

Read our news story: Tsunami Warning for Hawaii After Huge Chile Earthquake

Watch our video: Tsunamis 101 

Learn more at: Tsunamis--Killer Waves

Map of earthquake zone courtesy of NOAA 

By Stuart L. Pimm

"This land is your land, this land is my land ... "

According to Mary Turnipseed of Duke University's Marine Laboratory, Woodie Guthrie got it wrong in 1940. What's ours---as citizens and coastal residents--stretches well beyond "California and New York Island." Two hundred miles out to sea, in fact.

And her point has everything to do with how to protect the ocean's biodiversity.

I caught up with Mary at the annual meeting of the American Association for the Advancement of Science (AAAS) in San Diego, over the weekend. Several of the workshops dealt with how we manage our oceans. "Not well!" is the resounding cry.

Mary and her colleagues have argued that states--as well as the federal government--have a public trust to look after the oceans and the species that live there. Since 1983 that jurisdiction stretches 200 miles from shore.

That's not only a lot of ocean. In total, it's more surface area than our nation's land area.

The Public Trust Doctrine is an American law that exists in all 50 states. Each state has its own version. [See this California version of the Public Trust Doctrine, for example.]

The state governments have to manage natural resources for the benefits of their citizens.

Commercial fishers (top) and recreational fishers (bottom) exploit marine biodiversity with catch restrictions that often do not maintain healthy populations of marine life.  The Public Trust Doctrine argues that citizen interest requires state and federal governments to act in the broad interests of the public to manage marine resources.

Photos by Stuart L. Pimm

When the U.S. extended its authority out to the edge of its Exclusive Economic Zone---or EEZ--that added a band of jursidiction 200 miles around the coastline. And 200 miles around every island--however small, so long as that didn't conflict with any other nation's claim. There are lot of small islands scattered around the Pacific!

What bothers Mary is the government has not exercised its full public trust responsibilities to that space. "This fundamental law was never applied out that far," she said.

"And what does that mean," I asked.

"I think it's hampered the ability of U.S. citizens to engage in the management of these resources--living and non-living," she said.

Watch my interview with Mary in this video:

The ocean's biodiversity is in bad shape. The reason that Mary and I were at the AAAS meeting was to brainstorm with many others about what one could do about it.

For whatever reasons, ocean life has been depleted of one species after another.

This gives me a chance to recommend a compelling book by Callum Roberts, of the University of York, in the UK. In The Unnatural History of the Sea, Callum tells of relentless destruction of marine resources over centuries. Callum has a deep fascination for history and is a great story teller.

Watch this video interview with Callum about his book:

Scientists debate a wide range of countermeasures. Better fisheries management, of course, but it's rare that fishers voluntarily reduce catches.

Bluefin tuna is the poster child for a fishery where the agreed-upon limits always far exceed what scientists recommend--and everyone accepts that a lot of extra fish are landed illegally.

One solution that is growing in importance both in the U.S. and internationally are marine protected areas. "National Parks," but in the oceans, not just on land.

An example is the Papahānaumokuākea Marine National Monument signed into existence by President Bush on June 15, 2006. It covers an area of 360,000 square kilometers (140,000 square miles) in the northwestern Hawaiian islands. It's one of the largest marine protected areas in the world.

President Bush signs the proclamation to establish the Northwestern Hawaiian Islands Marine National Monument--later renamed the Papahānaumokuākea Marine National Monument. Marine Conservation Biology Institute Board Member Sylvia Earle (on the right) was present at the ceremony. Sylvia Earle is also a National Geographic Explorer-in-Residence.

Photo courtesy of Marine Conservation Biology Institute

The idea behind the Public Trust Doctrine, Mary told me, is that the fish--and all the other components of the ocean's biodiversity--belong to all of us.

"For so long, we thought the seas were boundless--and we've managed them with that perspective, under that conceptual map. We just couldn't have had that great an impact on our oceans. In fact, when we formed the EEZ it was to expand our fisheries--and to kick out the foreign fleets.

"Now we realized we're having dire impacts. There are extreme depletions in large predatory fish. We're looking for practical, tractable ways to improve ocean governance."

With her colleagues, Mary published a paper in the journal Science last year. "The doctrine is a simple but powerful legal concept that obliges state governments to maintain natural resources in the best interests of their citizens," she said.

That's your ocean, my ocean--and everyone else's. That it's not just those for fish for sport or profit is bound to be very controversial.

Professor Stuart L. Pimm is a conservation biologist at Duke University, North Carolina. A former member of the National Geographic Committee for Research and Exploration, Pimm is the author of dozens of books and research papers, including the book "The World According to Pimm: A Scientist Audits the Earth."

Read earlier blog posts by Stuart Pimm>>

By Ford Cochran

Today adventurer, environmental advocate, and National Geographic Emerging Explorer David de Rothschild unveiled Plastiki--a sailboat constructed of more than 12,000 recycled plastic bottles--at a press conference near San Francisco.

Photograph by Luca Babini courtesy Adventure Ecology

David plans to sail the remarkable craft from California to Sydney, Australia, to show what can be done with ingenuity, determination, and reclaimed materials.

Joining him will be a crew that includes skipper Jo Royle, co-skipper David Thomson, and Josian and Olav Heyerdahl--grandchildren of Thor Heyerdahl, whose famous 1947 journey in the raft Kon-Tiki demonstrated that South American voyagers could have populated the Polynesian islands.

I spoke with David about Plastiki and the expedition.

We've spent nearly four years preparing for this expedition. We started building with an ambition to go as many places as possible. But over the months and years, the plan has evolved. We know we're going to be judged a success when we sail through the gates into Sydney Harbor. The journey is a testament to innovation, a symbol of solutions. So we've decided to take a more direct route with fewer stops.

Kon-Tiki was our inspiration here: It was very pure, very direct journey that proved something important. So we're striving to keep our route more direct.

We can jibe--for those unfamiliar with sailing, that's putting the back of the boat to the wind--but we can't tack upwind. We can only move downwind in Plastiki. Our average speed will be five to six knots, the speed of a typical jogger. So our voyage will be the equivalent of a jog across the Pacific.

Photograph by Luca Babini courtesy Adventure Ecology

We're leaving San Francisco for Sydney, will sail down the coast to San Diego and Baja, then catch the currents and trade winds that take us across toward the Equator, toward the Line Islands.

Marine explorer Enric Sala's been advising us on the regions he's worked in there with his Ocean Now project. Then we'll be headed toward Easter Island, toward Tuvalu. We'll be looking at sea level rise, since these places have been at the forefront of concern about sea level rise and the possibility of nations disappearing.

From there we'll be sailing on toward Sydney. First, perhaps, Lord Howe Island in the Pacific east of Australia, then we'll work our way down toward Sydney in June or July.

What will your days be like on the boat?

Besides the work of sailing, everyone on our crew's got a number of daily assignments on the boat--tending the vertical garden in the back, rotating the watch, with three hours on and six hours off on a 24-hour rolling clock.

There are a number of other tasks--from being in charge of the evening group meal to making GPS observations, scouting for marine debris, noting the marine mammals that may cross our path, trawling in parts of the ocean where we've got convergence zones, places where debris from the rest of the world accumulates. The doldrums push floating refuse there, and we'll collect data on what we find to share with groups doing research on the problem.

What other parallels would you draw between the Plastiki and Thor Heyerdahl's 1947 voyage in Kon-Tiki?

One source of resonance is the idea of both of us testing materials.

Thor was proving a point, using materials that were only available to the indigenous communities in their time to prove it was possible to traverse the Pacific back then the trade winds.

His ability to tell a compelling story, to engage people about out-of-sight/out-of-mind places, was astonishing. People were looking for an inspirational story after a long and terrible war, and here were these crazy Norwegians headed out to the Pacific.

They say "We'll build a balsa wood raft and tackle this amazing adventure in a compelling manner against all the odds." People questioned their sanity!

As they were headed out to sea, the port master commented that they were crazy, and if they made it alive, he'd buy them (I think it was) whiskey for life.

With all the new technology and materials we've put into Plastiki, we hope we've captured some of the same excitement. In a world where people constantly strive to make things more predictable and safer, we can find solutions. But to do it, we need to take risks sometimes, push our ability to rise to big challenges and break the mold.

Photograph by Luca Babini courtesy Adventure Ecology

One other thing about Thor Heyerdahl and Kon-Tiki: He and his crew spoke over and over again about the abundance of our oceans. You could see it in their footage, all these fish that jumped onto the deck of the boat. They'd scoop them up, eat some, toss some overboard.

Now, 63 years later, we realize that the ocean isn't endless, and so much of that abundance is gone. It has really, really changed. That was less than one lifetime ago--not a lot of time for humans to transform entire oceans. But that's what we've done.

What's unique about Plastiki, and where did your team find inspiration for the designs?

The first stage was looking at nature, "biomimicry."

We tried to come at the challenges from an angle that was unique, to look at the things in the world that plastic was threatening to destroy. One natural model that bubbled to the surface was the pomegranate. It's compact and tough, but when you cut it open and get to the seeds, they're soft and fragile.

On Plastiki, the seeds are the bottles. Individually, they're fairly soft and fragile, but packed together they become buoyant, strong, and stable. That's where the inspiration for the makeup of the hull came from.

We were also inspired by the traditional way some Japanese people carry their eggs, wrapping bamboo around eggs and strapping them to their backs. We looked at bamboo itself.

At one point we were introducing wire and plywood, but then we decided we had to stay true to our path: The plastic bottle needed to be visible in its original form, and it needed to be functional. The vessel needed to float and sail on the recycled bottles.

That principal is at the essence, the core of this project. The bottles are there in their original form, pressured to about 36 psi, equivalent to a truck tire, with carbon dioxide.

Photograph by Luca Babini courtesy Adventure Ecology

A normal, everyday boat has no more than three floatation tanks, and usually just one, the main hull, to keep the water out. If you damage the hull--fiberglass, carbon fiber, glass-epoxy mix, whatever it may be--if it's punctured, that basically sinks your vessel.

We let our vessel rest on the buoyancy of all those bottles, nearly 70 percent of the buoyancy in 12-plus thousand chambers. We'd have to be crazy-unlucky to lose all of those bottles, and even if we lost them all, we couldn't sail but we could bob in the water and float!

We also innovated new materials just for the boat, and invited in people who would treat the expedition as a petri dish, a laboratory.

One's a self-importing textile, brand new, developed to create the superstructure frame. That in itself has real-world applications. I'm curious to see how far that can go in wind turbines, in housing, in multiple applications which will hopefully showcase the material in smart, cradle-to-cradle uses.

To get that bonded in places on the vessel, we didn't want to follow the easy path with nasty carcinogenic glues. We went with a bio-based glue made from sugar and cashew nuts. And it's made from the waste part of the cashew nut, the shell, not the seed.

Does Plastiki handle like any other boat you've sailed?

For me, she sails amazingly. If you were used to being in an America's Cup-winning vessel, using super-lightweight materials, you'd probably say she's a dog! But the charm of her, all the innovations would match the experience and give you that exhilaration.

We're also completely networked from sea: We've got state-of-the-art transmission devices from technology partner Hewlett Packard and communication partner Inmarsat. We will blog and tweet and update and broadcast and stream from out there in the middle of the Pacific. This will be one well-tracked voyage!

Beyond completing the journey to Sydney, what's your goal?

I've got the utmost respect for the ocean. It's probably the most important environment in our natural world, and yet it's the most disrespected in so many ways. Less than one percent of it is under marine protection. Hence the need for voices like Enric's and Ocean Now, the call for more marine parks and better marine protection--an ocean that's protected, looked after, properly managed. We know more about Mars than we do about our oceans, and that's the crazy state of play that we're faced with.

I want to pull people out of their landlocked imaginations and showcase to them this amazing, not-endless, not-endlessly-resource-filled environment that is driving our planet and essential to it. Without the oceans humanity can't live on this planet. How do we create a network that allows accountability for the exploitation of our oceans?

Does Plastiki have a lifeboat?

Plastiki is our lifeboat.

Ford Cochran is the editor of National Geographic BlogWild. 

Read Cochran's earlier posts on Nat Geo News Watch.  

Read more about Plastiki and monitor its progress with National Geographic News, National Geographic Adventure, and the official Plastiki Website.

By Mary Anne Potts

Last November the editors of National Geographic Adventure introduced the 2009 Adventurers of the Year, recognized for their extraordinary achievements in exploration, conservation, actions sports, and humanitarian work.

Their accomplishments ranged from the longest BASE jump ever to educating 10,000 women and girls in war-torn Afghanistan to rocketing 350 miles above the Earth to save a telescope.

Then, for the first ever Readers' Choice Award, readers were invited to vote for the person they felt best embodied the spirit of adventure. (See the entire Best of Adventure feature here.)

This week, with nearly 20,000 votes cast, we are thrilled to announce a tie.

Photographs from top left: Michael Hennig; Matt Hage--courtesy of NG Adventure

Both winners are equally impressive, but in entirely different ways.

• Explorer-engineer Albert Yu-Min Lin organized a high-risk expedition into Mongolia's "Forbidden Zone" to search for the lost tomb of Genghis Khan using state-of-the-art mapping technology. (He also happens to be a National Geographic Waitt grantee.)
• Wounded Iraq war veteran Marc Hoffmeister led a team of soldiers, many missing limbs, up the dangerous West Buttress route on Denali. When we delivered the news to each winner, both assured us of one thing: They could not have done it alone--and their adventures continue.

"For me, it's about being part of a team that is the Adventurers of the Year. A whole group of people made a huge effort towards this project, people from University of California, San Diego, local Mongolians, the Mongolian Academy of Science," said Lin, whose team will return to northern Mongolia this summer to continue their ground-breaking exploration.

"The long-term goal is to create a protection mechanism to preserve the cultural heritage of Mongolia. The Mongols created a lot of what we know of as our modern history, and that story hasn't been told completely.

"And while we were blown away by the technology used in the first phase of this project--the unmanned aerial vehicle flyovers, the 3-D virtual environment StarCAVE--Lin's work reminds us that the future of exploration is now.

"We're trying to strengthen our tool kit to bring the best noninvasive tools to the field."

Watch a video of Lin accepting the award >>

A similar gratitude was expressed by Hoffmeister, whose transformation on Denali was just the beginning.

"This goes beyond personal recognition. It's what the team did to get up the mountain. I'm pretty humbled, let's just put it that way," said Hoffmeister, who just returned from a belated honeymoon where he and his wife Gayle chased their Kilimanjaro summit with a safari in the Serengeti.

Since the article, public interest in future climbs has been huge. "I am working with a few different organizations to select and train another team of Wounded Warriors and hopefully complete another climb upon my return from Iraq, so I have a little time," he joked.

Hoffmeister will be in command of a U.S. Engineer Battalion working with the Iraqi Army to conduct route clearance operations and counter improvised explosive devices (IEDs) over the next year. "We've talked about Aconcagua or maybe Denali again or possibly even Everest, should funding and support develop."

Watch a video of Hoffmeister accepting the award >>

Thanks to everyone who voted--we hope you are as inspired as we are. These two adventurers remind us that the time is now to dream it, plan it, do it. So the question really is: What's the adventure of your life, and why aren't you doing it now?

National Geographic Adventure

By Ed Yong

(via @Not Exactly Rocket Science @ScienceBlogs)

In The Descent of Man, Darwin talked about the benefits of life among the treetops, citing the "power of quickly climbing trees, so as to escape from enemies". Around 140 years later, these benefits have been confirmed by Milena Shattuck and Scott Williams from the University of Illinois.

By looking at 776 species of mammals, they have found that on average, tree-dwellers live longer than their similarly sized land-lubbing counterparts. Animals that spend only part of their time in trees have lifespans that either lie somewhere between the two extremes or cluster at one end. The pattern holds even when you focus on one group of mammals - the squirrels. At a given body size, squirrels that scamper across branches, like the familiar greys, tend to live longer than those that burrow underground, like prairie dogs.

These results are a good fit for what we already know about the lives of fliers and gliders. If living in the trees delays the arrival of death, taking to the air should really allow lifespans to really take flight. And so it does. Flight gives bats and birds an effective way of escaping danger, and they have notably longer lives than other warm-blooded animals of the same size. Even gliding mammals too tend to live longer than their grounded peers.

These trends make sense when you think about ageing in the light of evolution. Imagine a creature that never ages, say, a Tolkienesque elf. Even this potential immortal could succumb to a predator or a disease or an accident. The more time passes, the greater the odds that one of these external calamities will claim its otherwise never-ending life. This creature will therefore have a "statistical lifespan", an age by which it will probably have been killed.

Now think about the genes of this hypothetical immortal. A mutated gene that harms the creature early on in life, when it's still having sex and bearing young, has little chance of being passed onto the next generation. Such mutations will be weeded out by natural selection. However, mutations that harm individuals after their statistical lifespan are a different story because their carriers will probably have been killed before they experience any ill effects. Accumulating under the radar of natural selection, these late-acting genes are the ones that contribute to ageing.

There are many evolutionary explanations of ageing but almost all share this basic concept. And note that a central part of this concept is the threat of dying from predators, diseases and so on. If such threats are minimised, then an animal's statistical lifespan increases, more late-acting genes are exposed to natural selection and more will be weeded out. Based on this theory, you'd expect that species that can escape external threats, whether by flying off or by hiding in the branches of trees, can evolve to age more slowly and live longer. And that, of course, is exactly what Shattuck and Williams have found.

In fact, they showed that the link between long life and a treetop existence holds true for all but two groups of mammals. The first are the marsupials, including kangaroos, koalas and wombats, and the second are the euarchontans, a group that includes treeshrews, flying lemurs and primates, like monkeys, apes and ourselves. At first, this seems odd, for some scientists had thought that a life in the trees could actually explain why primates have such relatively long lives. But to Shattuck and Williams, these are the exceptions that prove the rule.

Both marsupials and euarchontans have experienced a long and persistent evolutionary history in the treetops. For other mammal groups, the occasional member may have evolved to negotiate trunks and branches, but Shattuck and Williams say that the marsupials and euarchontans started off in the trees. Their members have repeatedly descended back to the ground. For the euarchontans in particular, this long tree-based history may have meant that all primates are long-lived for their size.

Of course, if the species that returned to terra firma faced a greater threat from predators, evolutionary theory would predict that their lifespans would eventually contract. But ground-living primates have other defences. They're typically large and they live in big social groups (larger ones that tree-dwelling primates). These qualities may have provided them with the protection they needed to retain the relatively long lives that first evolved in the branches. For the moment, this is just a hypothesis, and it will need to be tested further.

Reference: Shattuck, M., & Williams, S. (2010). Arboreality has allowed for the evolution of increased longevity in mammals Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.0911439107

Ed Yong is an award-winning British science writer.

This entry was posted originally on Not Exactly Rocket Science on ScienceBlogs. National Geographic and ScienceBlogs have formed a partnership.

By GrrlScientist

(via @ Living the Scientific Life @ScienceBlogs)

Yesterday afternoon, experienced whale trainer, 40-year-old Dawn Brancheau, was attacked and killed by 30-year-old male orca [killer whale], Tillikum, during the afternoon show at SeaWorld, in Orlando, Florida. The 12,000 pound male orca, Orcinus orca, apparently grabbed his trainer and thrashed her to death in front of the horrified audience. This animal has killed two other humans during his lifetime.

Two newsreports with the Orange County (Florida) Sheriff's Department reveals the homicide department is conducting a "death investigation". It appeared to be an accident, not foul play. Dan Brown, spokesperson for SeaWorld Orlando explained that they also are conducting an investigation. "We have never in the history of our parks experienced an incident like this and all of our standard operating procedures will come under review."

A witness to the event, Eldon Skaggs, tells a different story from that stated by SeaWorld officials, saying that the "trainer was massaging the whale on his belly, then the whale took off really fast, came around, right up to the glass, popped up and started thrashing, grabbed the trainer by the waist, started thrashing, and her shoe came off. The sirens went off."

The orcas were apparently agitated and misbehaved during the noon show, which eventually was ended early. Yet the afternoon show went on, despite this unusual behavior. Orca expert, Janet Mann of Georgetown, says it's impossible to tell if an orca is in an aggressive mood:

Here is a 2007 video by "Rose" (who also goes by the YouTube handle, "TillikmTrainer") that tells her version of Tillikum's life story:

"GrrlScientist" is the blog pseudonym for a female evolutionary biologist/ornithologist and freelance science and nature writer who lives in Frankurt am Main, Germany.

This entry was posted originally on Living the Scientific Life on ScienceBlogs. National Geographic and ScienceBlogs have formed a partnership.