Arctic sea ice melting, which scientists have linked to global warming, may be a boon for the shipping industry. As the sea ice continues to melt a shipping passage to Russia’s north is becoming more navigable, and now two German ships are close to completing the first trip from Asia to Europe via the Arctic shortcut. However, walruses that live in the Arctic could care less, since their sea ice habitat is rapidly disappearing.
Thousands of walruses are congregating on Alaska’s northwest coast, a sign that their Arctic sea ice environment has been altered by climate change. Chad Jay, a U.S. Geological Survey walrus researcher, said Wednesday that about 3,500 walruses were near Icy Cape on the Chukchi Sea, some 140 miles southwest of Barrow [AP]. Walruses wear themselves out diving for clams, and need to rest on the sea ice between meals. Since the sea ice is disappearing, they are turning to the shore for a break. Federal managers and researchers worry that so many walruses in one location could lead to a deadly stampede or could drive off prey. Highlighting the animals’ peril, the Obama administration is considering adding walruses to the endangered species list.
Here’s the good news: Plastic may break down in the ocean in as little as a year, not 500 to 1,000 years as scientists previously thought. Now, the bad news: This degradation could be releasing harmful compounds such as bisphenol A (BPA) into the ocean, according to research presented at the American Chemical Society meeting on Wednesday.
Ocean-borne plastic, such as that in the vast Great Pacific Garbage Patch, has traditionally been viewed as an environmental hazard due to the danger it can pose to sea life and birds. But to find out more about how plastic behaves when in the ocean, researchers acquired water samples from Japan, India, Europe, the United States, and other locations. The results? All the water samples were found to contain derivatives of polystyrene, a common plastic used in disposable cutlery, Styrofoam, and DVD cases, among other things [National Geographic News].
Scientists will venture this summer to the Eastern Pacific Garbage Patch–a blob of discarded plastic twice the size of Texas that’s floating in the Pacific Ocean–in an extensive effort to assess just how detrimental the patch is to the marine ecosystem.
Two boats push off this month to examine and analyze the patch of plastic; one left from San Diego yesterday, the other is set to leave from San Francisco tomorrow. The expeditions will last four weeks and will cost $1.1 million. Researchers from the Scripps Institution of Oceanography in San Diego will conduct a wide range of experiments on the debris’ impact on phytoplankton, zooplankton, fish, whales, birds, salts and fouling communities – groups of organisms that live on the debris. They will spend 10 days traveling to and from the remote region [San Diego Union-Tribune]. Once the researchers are back on dry land, it will take months to fully analyze the samples collected during the voyage.
The Chesapeake Bay was once carpeted with oysters, but that was before centuries of overfishing, pollution, and disease took their toll: Today the oyster population has been reduced to less than 1 percent of its historical population. But a new restoration effort has shown unprecedented progress in bringing the bivalves back. In the Great Wicomico River, a tributary of the Bay, researchers have created a 87-acre oyster colony that contains about 185 million oysters.
The Chesapeake’s oyster reefs were destroyed by centuries of watermen towing rakelike metal “dredges” and silted over by dirt flowing from the mid-Atlantic’s farms and growing cities. The final blow came in the mid-20th century: A pair of new diseases killed oysters by the millions. Now, in many places, the bay bottom is a flat expanse of green mud. “Just picture, you know, a clear-cut forest,” said Kennedy Paynter, a biology professor [Washington Post].
The region today known as Iraq was once known as Mesopotamia, which means “Land Between the Rivers,” and since that ancient time the land between the Euphrates and Tigris rivers has been renowned for its fecund soil and thriving farms. But now the Mesopotamian cradle of civilisation seems to be returning to desert [New Scientist].
Decades of war and mismanagement, compounded by two years of drought, are wreaking havoc on Iraq’s ecosystem, drying up riverbeds and marshes, turning arable land into desert, killing trees and plants, and generally transforming what was once the region’s most fertile area into a wasteland…. “We’re talking about something that’s making the breadbasket of Iraq look like the Dust Bowl of Oklahoma in the early part of the 20th century” [Los Angeles Times], said Adam L. Silverman, a social scientist with the U.S. military.
The motion of jellyfish and other sea creatures might mix the oceans just as much as the winds and tides do, according to a study published in Nature. The study’s findings provide support for a theory called Darwin drift, which was developed by Charles Galton Darwin (the grandson of the Darwin). The theory holds that a body moving through water brings along some of the wet stuff.
To test the theory of Darwin drift, researchers first modeled the motion of swimming organisms in a lab, using liquids of various viscosities, or levels of internal resistance. They found that bodies drag more liquid along with them when the liquid is thicker. This effect can be significant; in fact, when marine plankton-sized objects moved a couple of body lengths forward in the most viscous liquids, they carried with them up to four times their volume in liquid. Next the researchers monitored jellyfish as they swam through clouds of dye in a lake on the Pacific island of Palau. A trail of dye followed each animal, as Darwin’s mechanism would predict. Using a laser-equipped camera, the team then measured the dye’s movement and the stirring of suspended particles in the animal’s wake [Nature News]. The scientists found that the mechanism proposed by Galton Darwin provided for 90 percent of the mixing between the water and the dye.
To stop the spread of the Sahara Desert, one innovative thinker has proposed a bold plan: a wall along the southern border of the desert that would hold back the advancing dunes. Swedish architect Magnus Larsson says the wall would effectively be made by “freezing” the shifting sand dunes, turning them into sandstone. “The idea is to stop the desert using the desert itself,” he said. The sand grains would be bound together using a bacterium called Bacillus pasteurii commonly found in wetlands.” It is a microorganism which chemically produces calcite – a kind of natural cement” [BBC News].
Larsson is already well-known in the field thanks to his proposed Great Green Wall, a 4,349 mile line of trees stretching across Africa to stop desertification [Fast Company]. The sandstone wall could compliment the green wall, Larsson says, because if people chopped down the trees for firewood the sandstone wall would still remain.
Human beings are increasingly making their homes on the coasts of continents, but this demographic shift is taking a toll on a sensitive coastal ecosystem that is often overlooked: seagrass meadows. A new analysis of seagrass abundance around the world found that 27 percent of these meadows have disappeared since 1879, and the rate of loss is accelerating. The study’s authors write: “Seagrass loss rates are comparable to those reported for mangroves, coral reefs and tropical rainforests, and place seagrass meadows among the most threatened ecosystems on earth….. Our report of mounting seagrass losses reveals a major global environmental crisis in coastal ecosystems, for which seagrasses are sentinels of change” [Nature News].
Endangered species expert Susanne Livingstone notes that despite these losses seagrass rarely makes it into the public consciousness. “It’s probably because they’re not as sexy [as corals], they’re not as attractive,” she says. “They’re just as ecologically important if not more so” [Nature News]. Seagrass meadows provide grazing for a variety of marine animals, including the green turtle and the manatee-like dugong. The coastal areas also serve as nurseries for fish; both coral reefs and commercial fisheries would feel the impact if seagrass meadows vanish.
The state of Louisiana is losing its coastal wetlands to the Gulf of Mexico, and a new study suggests that conservationists won’t be able to turn the tide. If engineers don’t divert sediment-rich waters from the Mississippi River to help replenish a sinking river delta, about 10 percent of [the] state will slip beneath the waves by the end of this century. However, even if the engineers do try to abate the subsidence, the Mississippi doesn’t carry enough sediment to offset more than a small fraction of that loss, a new analysis suggests [Science News].
Before American settlers subdued the Mississippi and its tributaries, the river periodically overflowed its banks and spilled muddy water, thick with sediment, into surrounding wetlands. But the new study found that the Mississippi and Atchafalaya rivers today carry only half the sediment they did a century ago — between 400 million and 500 million tons a year then, compared with just 205 million tons today. The rest is now captured by more than 40,000 dams and reservoirs that have been built on rivers and streams that flow into the main channels [The Times-Picayune].
So even if Louisiana officials embark on an all-out campaign to restore the marshes through controlled levee breaks and diversion projects that bring back river water, it wouldn’t be enough to save the land–especially since sea levels are rising due to global warming. “We conclude that significant drowning is inevitable” [The Guardian], the study’s authors wrote.
In the heat and humidity of the tropics you might expect that mammals take it slow and easy–but on the genetic level, they’re accelerating past their mammalian relations that live in more temperate zones. A new study has discovered that tropical mammals are accumulating mutations more quickly and are therefore evolving faster, in a finding that could help account for the phenomenal biodiversity of the rainforests. But the study’s unexpected results have posed a puzzle for biologists. “[It's] an empirical pattern that is begging for an explanation” [The Scientist], says evolutionary ecologist James Brown, who was not involved in the current study.
Previous research had shown that plants and marine microorganisms evolve more quickly in the tropical zone near the equator, but scientists believed that pattern would hold true only for cold-blooded creatures, whose body temperatures and metabolisms are determined by the temperature of the surrounding environment. Scientists believe that this link between temperature and metabolic rate means that, in warmer climates, the germ cells that eventually develop into sperm and eggs divide more frequently. “An increase in cell division provides more opportunities for mutations in the population over a given time,” explained [lead researcher Len] Gillman. “This increases the probability of advantageous mutations that are selected for within the species” [BBC News]. But this mechanism wouldn’t work in warm-blooded mammals, whose body temperatures remain roughly constant regardless of environmental factors.
Cleveland’s Cuyahoga River caught on fire 40 years ago June 22 when oily garbage floating in it was ignited, probably by sparks from a passing train. In turn, the fire sparked the creation of environmental agencies such as the Environmental Protection Agency, along with passage of 1972′s Clean Water Act. And the river, once a dumping ground for industrial waste and an icon for environmental disrepair, today supports more than 60 species of fish along with beavers and various bird species, and serves as an example of environmental restoration.
The river’s recovery is an inspirational account of how even the most putrid bodies of water could be cleaned up. Indeed, the first time [Cleveland resident] Gene Roberts fell into the Cuyahoga River, he worried he might die. The year was 1963, and the river was still an open sewer for industrial waste. Walking home, Mr. Roberts smelled so bad that his friends ran to stay upwind of him. Recently, Mr. Roberts returned to the river carrying his fly-fishing rod. In 20 minutes, he caught six smallmouth bass. “It’s a miracle,” said Mr. Roberts, 58. “The river has come back to life” [The New York Times].
After 120,000 years of slumbering in a Greenland glacier beneath almost two miles of ice, an ultra-small bacteria has been resurrected by the patient efforts of scientists. After incubating the bacteria for almost a year in water that was just above freezing temperature, colonies of the tiny purple-brown bacteria began to grow in a petri dish. Researchers say the bacteria’s resilience provides clues to how life can survive in hostile environments like the Arctic–and maybe even other planets.
The Herminiimonas glaciei bug is not the oldest to ever be resurrected, but it’s the first “ultramicrobacteria” to be revived. Ultramicrobacteria, tiny even by bacterial standards, are about 10 to 50 times smaller than the common human intestinal microbe E. coli. Their diminutive size could give the bacteria a survival advantage over other microorganisms. H. glaciei, for example, is thought to have survived in thin capillaries of nutrient-rich water in the Greenland glacier that would have been too tight a fit for larger bacteria [National Geographic News].
In a rare conservation success, a beautiful butterfly species that was headed for extinction has been brought back from the brink, thanks to careful biological observations of the insect‘s life cycle. The mysterious disappearance of the Large Blue Butterfly across most of northern Europe was originally put down to its popularity among insect collectors [Telegraph]. Then biologist Jeremy Thomas spent six summers in the 1970s studying the very last colony of large blue butterflies in the United Kingdom, and determined that the butterflies were dependent on one species of red ant for their survival–and those ants were losing their habitat.
The butterflies lay their eggs on flowering thyme plants, and the hatched caterpillars fall to the ground and begin to impersonate immature red ants. They secrete chemicals and even make noises that make the red ants believe they are wayward grubs. The ants then mistakenly carry the caterpillars to their underground homes and keep looking after them even though the adopted intruders gobble ant grubs for 10 months before forming a chrysalis and flying away as adult butterflies [Reuters].
More than 220 years since a ship wrecked on the rocks surrounding a remote Aleutian island, biologists believe they may have finally cleaned up the resulting mess. Rats have ruled the island since 1780, when they jumped off a sinking Japanese ship and terrorized all but the largest birds on the island [Reuters]. The voracious rodents feed on bird eggs and even chicks and small adult birds, and they so dominated the tiny island that it was given the name Rat Island. Biologists embarked on an ambitious effort to wipe out the rats last year, and now say they may have accomplished their task–but the campaign may have resulted in some avian casualties.
Nine months after scattering poisoned pellets across the island, biologists say they haven’t spotted any remaining rats, but they have found the carcasses of 186 glaucous-winged gulls and 41 bald eagles. U.S. Fish and Wildlife spokesman Bruce Woods said it’s unlikely carnivorous eagles ate the Rodenticide grain pellets, but they may have devoured some dead rats that had consumed them. “Eagles are scavengers of opportunity,” he said. “Rats don’t make up a big part of their diet naturally, but if meat is available, they’re going to take it” [Anchorage Daily News].
Scientists have long known that coral reefs are being threatened by disease, global warming and other factors. Now a new study shows that that majority of Caribbean reefs have, in fact, been “flattened” in the past four decades, as ornate branched corals have died out and been replaced by flatter, fast-growing “weedy” species. Most of the reefs have lost all the intricate, tree-like corals that until the 1970s provided sanctuary for unique reef fish and other creatures, as well as protecting coastlines by sapping the energy of waves [New Scientist], according to the report, published in the journal Proceedings of the Royal Society B.
The coral reefs that were initially the most complex have almost been completely eliminated, says the researchers, who analysed changes in the structure of reefs using 500 surveys across 200 reefs conducted between 1969 and 2008. They found that 75 per cent of the reefs are now largely flat, compared with 20 per cent in the 1970s [ScienceDaily]. That’s bad news for sea life and storm defenses, says study coauthor Lorenzo Alvarez-Filip: “For many organisms, the complex structure of reefs provides refuge from predators…. This drastic loss of architectural complexity is clearly driving substantial declines in biodiversity, which will in turn affect coastal fishing communities” [ScienceDaily].
80beats is DISCOVER's news aggregator, weaving together the choicest tidbits from the best articles on the day's most compelling topics.
80beats is written by Veronique Greenwood and Valerie Ross. This team darts through each day's science news faster than the ruby-throated hummingbird that beats its wings 80 times per second. Send ideas, tips, suggestions, and complaints to [azeeberg at discovermagazine dot com].
Arctic sea ice melting, which scientists have linked to global warming, may be a boon for the shipping industry. As the sea ice continues to melt a shipping passage to Russia’s north is becoming more navigable, and now two German ships are close to completing the first trip from Asia to Europe via the Arctic shortcut. However, walruses that live in the Arctic could care less, since their sea ice habitat is rapidly disappearing.
Here’s the good news: 
Scientists will venture this summer to the 
The Chesapeake Bay was once carpeted with 
The region today known as Iraq was once known as Mesopotamia, which means “Land Between the Rivers,” and since that ancient time the land between the Euphrates and Tigris 
To stop the spread of the Sahara Desert, one innovative thinker has proposed a bold plan: a wall along the southern border of the 
Human beings are increasingly making their homes on the coasts of continents, but this demographic shift is taking a toll on a sensitive coastal 
The state of Louisiana is losing its coastal wetlands to the Gulf of Mexico, and a new study suggests that conservationists won’t be able to turn the tide. If engineers don’t divert sediment-rich waters from the Mississippi River to help replenish a sinking river delta, about 10 percent of [the] state will slip beneath the waves by the end of this century. However, even if the engineers do try to abate the subsidence, the Mississippi doesn’t carry enough sediment to offset more than a small fraction of that loss, a new analysis suggests [
In the heat and humidity of the 
Cleveland’s Cuyahoga River caught on fire 40 years ago June 22 when oily garbage floating in it was ignited, probably by sparks from a passing train. In turn, the fire sparked the creation of 
After 120,000 years of slumbering in a Greenland 
In a rare conservation success, a beautiful butterfly species that was headed for 
More than 220 years since a ship wrecked on the rocks surrounding a remote Aleutian island, biologists believe they may have finally cleaned up the resulting mess. Rats have ruled the island since 1780, when they jumped off a sinking Japanese ship and terrorized all but the largest birds on the island [
Scientists have long known that coral reefs are being threatened by disease, 
