From pandas to polar bears, animals have served as icons for wildlife conservation. Now a new documentary called The End of the Line has helped the bluefin tuna, an endangered species, swim into the limelight by highlighting the overfishing common in fisheries today. Based on a book by journalist Charles Clover, the film has spurred some retailers to remove bluefin from their menus and stores and even moved some celebrities to pose naked with the fish to advocate conserving them.

A growing demand for bluefin tuna, commonly found in sushi and now as endangered as the giant panda, has not only decreased the fish‘s population, but also increased the number of undersized fish that are harvested, preventing the fish from reaching maturity. “Bluefin tuna has become the poster boy for the overfishing campaign. It’s on the buffers – it’s really on the slide down now,” Clover says.  “There are no large tuna anymore. There were bluefins of 250lb in Japanese fish markets when I went there four years ago – there are none now. A third of the catch is undersize” [BBC News].

The solution, experts say, doesn’t necessarily have to entail eschewing tuna altogether. Instead, consumers should stick to skipjack tuna, a more common variety, that has been caught using a method called pole-and-line, which avoids accidentally netting bluefish tuna and other sea life. Most commercial fishing operations that target skipjack use nets, Clover says, but “the skipjack run with all these other tuna species, like bigeye and bluefin. The skipjack are close to the surface and the bluefins swim further down, so there is often bluefin bycatch” [BBC News].

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Fierce dust storms this spring have stained Colorado’s snow-covered peaks with brown, red, and pink dust, and state officials point out that this isn’t just a change in scenery. The darker snow is absorbing more radiation from the sun and is therefore melting faster and sooner than it normally would, which is upsetting the careful water rationing that defines life in the American West. Twelve dust storms barreled into the southern Rockies from the deserts of Arizona, Utah and New Mexico so far this year…. That, coupled with unseasonably warm temperatures, has sped up the runoff here, swelling rivers to near flood stage, threatening to make reservoirs overflow and fueling fears that there will not be enough water left for late-summer crops [Los Angeles Times]. 

In Colorado, melting snow accounts for about 80 percent of the water that flows through rivers and ends up in the state’s lakes and reservoirs. Colorado water engineer Scott Brinton explains that the early snowmelt could spell disaster for thousands of farmers and ranchers in the region who depend on slowly melting snow to provide water flows over the dry summer months…. “Those people who were relying on the mountain snowpack are going to have difficulty later in the year…. There’s not a whole lot we can do about it,” Brinton said. “We’re telling people, ‘You’ll be getting your water early this year, so use it while it lasts’” [Greenwire]. But scientists note that this may not be just a year of freak storms, it may be a harbinger of things to come.

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Before the end of the year, the backhoes are expected to dig into the dirt on a patch of coastal land in southern California, as construction begins on a massive plant that will draw fresh water from the salty sea. California regulators have given the green light for the construction of the largest desalination plant in the Western Hemisphere in Carlsbad, California, overriding environmental protests.

Some green groups are appealing the plant’s approval to a state water board, but officials with Poseidon Resources, the development company, seem confident that construction will begin on schedule. When the plant cranks up to high gear, engineers expect it to produce enough fresh water for 110,000 households in the San Diego area.

Advocates of desalination tout its potential for limiting strain on scarce water supplies, and easing the environmental consequences of diverting freshwater from rivers and streams and pumping it long distances to urban centers. But critics cite major environmental drawbacks — namely the harm to marine life from intake pipes that suck water into desalination plants and from the highly concentrated brine byproduct that gets discharged back into the ocean [Reuters]. In the environmental agreement hammered out between Poseidon and the San Diego Regional Water Quality Control Board, the company will create 55 acres of wetlands as breeding grounds for fish to offset those killed by the plant’s operations. The company has also pledged to keep brine concentrations below toxic levels.

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Life sure turns up in the darnedest places. The latest discovery comes from Blood Falls, a rusty red discolouration on the face of the Taylor Glacier in Antarctica [that] occasionally gushes forth a transparent, briny, iron-rich liquid that quickly oxidizes and turns red, staining the ice below [Nature News].

The source of that water is an intensely salty lake trapped beneath 1,300 feet of ice, and a new study has now found that microbes have carved out a niche for themselves in that inhospitable environment, living on sulfur and iron compounds. The bacteria colony has been isolated there for about 1.5 million years, researchers say, ever since the glacier rolled over the lake and created a cold, dark, oxygen-poor ecosystem.

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In the latest development in the ongoing debate about why some leaves turn bright red in the fall, a new study suggests that the color is a signal to insect pests to stay away. Harvard biologist Marco Archetti sought to prove the theory, first put forth in 2001 by the late evolutionary biologist William Hamilton, that the red pigments, or anthocyanins, serve as a plant’s chemical defense. Archetti studied aphids’ survival rates in wild apple trees, which turn more red, compared with farmed trees, which produce more green and yellow leaves. He found that aphids don’t show up as frequently on apple trees that turn red in the fall [ScienceNews]. He also reports in the study, published in Proceedings of the Royal Society B, that once spring came, young aphids who had fed on red trees in the fall were less likely to grow to maturity than aphids placed in the green or yellow trees.

Archetti chose aphids for the study because fall is their mating season: They leave their summer plants to find a good tree for mating and egg laying. Aphids can damage trees in two ways, especially when the new generation hatches in the spring. The insects steal the sap and also spread diseases with their piercing mouthparts that end up as entomological dirty needles. So trees would do well to dodge aphids [ScienceNews]. To test whether the red signals a threat to the insects, Archetti placed nesting aphids in both red- and green-leaved apple trees in the fall of 2007, and found that the next spring, 60 percent of those in green trees had survived, compared with 29 percent in red trees. The reason behind this disparity is unclear, but Archetti’s and other studies suggest that the red leaves either have toxic chemical defenses or hold fewer nutrients for young aphids [ScienceNow Daily News].

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Powerful sonar causes temporary hearing loss in dolphins, a new study has confirmed, and could explain some incidents of mass stranding of the marine mammals. The impact of sonar on dolphins has been debated for years, but for the first time, researchers have played recordings of actual naval sonar to a marine mammal and tested its hearing after progressive step-ups in intensity over a couple of months [ScienceNews].

Tests were conducted at the Hawaii Institute of Marine Biology on a captive dolphin, whose head was fitted with a suction cup attached to a sensor that monitored brainwaves. The dolphin was then exposed to progressively louder pings of mid-frequency sonar…. When the pings reached 203 decibels and were repeated, the neurological data showed the mammal had become deaf, for its brain no longer responded to sound [AFP].

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Researchers in Australia think they have found a solution to the country’s toxic cane toad problem: make Australian meat ants eat them. Cane toads—which can grow up to 8 inches (20 centimeters) in length—were imported from South America to Queensland [in northeast Australia] in 1935 in a failed attempt to control beetles on sugarcane plantations. Trouble was, the toads couldn’t jump high enough to eat the beetles, which live on top of cane stalks [AP]. Since their introduction… cane toads have spread through most of tropical Australia, eating and poisoning native animals [New Scientist]. No one has been able to get their population growth under control, and past suggestions to do so by introducing exotic diseases have only raised concerns about causing as much harm as the toads have themselves.

But a research team led by ecologist Rick Shine found that cane toads are more vulnerable to being eaten by Australia’s predatory meat ants than are native frogs, which may allow the ants to be used as a “safe” biocontrol agent that would not interfere with native frog species. Shine said the team plans to try ways of encouraging meat ants to build colonies near toad breeding ponds. One way would be to plant trees the ants favour [The Australian]. He is hopeful the strategy will work because unlike native frogs, cane toads are active during the day, when meat ants roam about scavenging for food. Toads also tend to breed in ponds that are out in the open sun, which results in their young emerging onto bare, baked mud areas, a habitat where meat ants like to forage [Sydney Morning Herald]. The toad is also more vulnerable because it lays its eggs in the dry season when water is low and there’s little protective vegetation at the pond’s edge [The Australian].

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While concerns over ocean acidification are not new, a recent study provides more concrete evidence than ever before that the process has already begun. Australian scientists found that shells of the microscopic, amoeba-like organisms called foraminifera, which exist by the billions in oceans around the world, have become significantly thinner since the Industrial Revolution.

The study, published in Nature Geoscience, is the first to look specifically at acidification and pin it to greenhouse-gas pollution, which is driven especially by the invisible product of burning oil, gas and coal. “It is the invasion of anthropogenic (man-made) CO2 that is causing this particular source of acidification,” said co-author William Howard [AFP].

The research team compared newer shells of Globigerina bulloides, a species of foraminifera, with shells of the same species that had sunk hundreds of years earlier; the modern shells were found to be 30 to 35 percent lighter than older specimens of about the same size. The older shells predate the industrial age, when CO2 levels started rising and the acidity of the ocean, caused by the absorption of the gas, began to increase…. As ocean acidity increases, the saturation levels of carbonate minerals in the water decreases, making it more difficult for organisms to precipitate out the carbonate for their shells [The New York Times].

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Workers taking a biological census have just completed their first 10-year count of marine organisms living near the North and South poles, and they found more inhabitants than anyone expected. They found some 13,000 kinds of animals living at one pole or the other, or, in a surprising number of cases, at both” [Science News]. The Census of Marine Life began the project in 2000 and involves thousands of researchers worldwide, hundreds of whom participated in more than a dozen expeditions to both poles.

The complete report will be issued next year, but a summary of findings has just been released and reports about 7,500 species in the Antarctic region and 5,500 in the Arctic. The poles were found to share 235 species, although further DNA testing is being conducted to confirm that they are identical, and that they do not just look alike. Among the “bi-polar” organisms are worms, crustaceans, and birds, as well as great whales, which after centuries of whaling … had been thought to remain only in the North Pacific and along the west coast of North America [Environment News Service]. Some of the bi-polar species identified, such as two snail-like species that have become almost as filmy as jellyfish and flutter through seawater instead of crawling, are not known from anywhere in between the poles [Science News].

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Contrary to conventional wisdom, fish in the Nile delta are thriving in waters polluted with fertilizers and sewage, according to a new study. While nitrogen-rich runoff usually causes excessive growths of algae and plankton that suffocate other marine life, the Nile delta is different because it has suffered from a lack of autotrophs (that fish feed on) ever since the Aswan Dam was built in the 1960s. Researchers found that more than 60 percent of the current fishery production in the region can be attributed to human-generated runoff. “This is really a story about how people unintentionally impact ecosystems,” explained co-author Autumn Oczkowski [BBC News].

The building of the Aswan Dam on the Nile blocked off much of the fertile floodwater that drains into the Mediterranean Sea, which in turn produced a sharp fall in the number of fish being landed by Egypt’s fishermen. “But in the late 1980s, the coastal fishery began to exhibit a surprising recovery,” the researchers observed. “Today, landings are more than three times the pre-dam level” [BBC News]. The increase in fish production coincided with the rise in fertilizer use along the Mediterranean coast. To quantify the effect, researchers collected more than 600 fish from four regions contaminated by runoff and two regions that were not. In regions affected by runoff, the fish contained nitrogen isotopes that could be traced to anthropogenic sources of nitrogen, according to the study published in the Proceedings of the National Academy of Sciences.

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A flock of unfortunate Canada geese are thought to have crossed paths with a U.S. Airways Airbus A320 yesterday afternoon, causing the plane to make an emergency splash landing in the Hudson River. All 155 passengers survived with no serious injuries, but the incident is highlighting the problem of birds striking aircraft, which experts say is common but rarely dangerous. Since 2000, at least 486 commercial aircraft have collided with birds, according to the Federal Aviation Administration. Of those incidents, 166 led to emergency landings and 66 resulted in aborted takeoffs [The New York Times].

Just seconds after take-off from LaGuardia airport, the pilot of the U.S. Airways plane reported a “double bird strike” that damaged both engines. Such collisions are most common at low altitudes and the birds most likely to be sucked into aircraft engines are waterfowl, gulls, and raptors. Canada geese, a frequent visitor to golf courses and open spaces in the metropolitan New York area during the winter, pose a particular danger to planes because of their size. The impact of a 12 pound bird hitting a plane traveling at 150 miles per hour is equal to that of a 1,000 pound weight dropped from a height of 10 feet, according to experts on bird strikes [The New York Times]. But smaller birds can pose dangers too. Bird Strike Committee USA even refers to starlings as “feathered bullets,” since they say these birds possess “a body density 27 percent higher than herring gulls” [Discovery News]. Sometimes the impact can cause the engine blades to break off, becoming dangerous pieces of shrapnel that further destroy the engine. 

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The cats ate the birds until the humans killed the cats, but now the rabbits are out of control.

That’s the sad state of affairs on Macquarie Island, an island near Antarctica that was declared a world heritage site in 1997 due to its status as the sole breeding ground for the royal penguin. For decades researchers have attempted to get rid of the invasive species that have altered the island’s ecological balance, but a new study notes that the latest effort, an all-out push to eradicate feral cats, has had the unintended consequence of allowing a boom in the rabbit population. Those rabbits have quickly denuded the landscape of its vegetation, researchers say.

Things began to go wrong on Macquarie Island … soon after it was discovered in 1810. The island’s fur seals, elephant seals and penguins were killed for fur and blubber, but it was the rats and mice that jumped from the sealing ships that started the problem. Cats were quickly introduced to keep the rodents from precious food stores. Rabbits followed some 60 years later, as part of a tradition to leave the animals on islands to give shipwrecked sailors something to eat [The Guardian]. The invasive species all thrived to the detriment of local species, and by the 1970s biologists were concerned enough to introduce a rabbit-killing disease called myxomatosis, which thinned the rabbit herds considerably. However, that left the cats with less available prey and caused them to begin hunting the island’s native burrowing birds.

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A German research ship carrying 20 tons of iron sulfate is currently motoring towards the South Atlantic, and the crew plans to dump its mineral cargo into the ocean in a controversial science experiment. The researchers will be testing a technique called ocean fertilization, in which iron is dumped into nutrient-poor waters to induce a huge blooms of phytoplankton. After the photosynthesizing plankton grows and absorbs carbon dioxide, researchers hope it will die and sink down to the seafloor still bearing that greenhouse gas in a natural form of carbon sequestration. Ocean iron fertilization is considered one of the more promising options for global-scale geoengineering, which aims to slow or reverse the effects of climate change caused by man’s burning of fossil fuels [Wired News].

But the so-called LOHAFEX experiment has raised the ire of some environmentalists, who worry about unknown consequences of interfering with the marine ecosystem. Ocean fertilisation experiments have been carried out on a few occasions in the past, but became controversial in 2007 when a company called Planktos announced it would dump iron fillings [sic] off the coast of the Galapagos islands. Some environmental organisations … expressed concerns that this was tantamount to pollution and, by affecting plankton at the bottom of the food chain could have unforeseen consequences [New Scientist]. The company Planktos went out of business and never conducted its experiment (largely due to the bad publicity), but the incident caused the UN Convention on Biological Diversity to ask countries not to permit ocean fertilization experiments.

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President Bush will establish three national monuments in the Pacific Ocean today in a move that will protect a vast marine ecosystem from mining, oil exploration, and commercial fishing. With the stroke of a pen this afternoon, Bush will have set aside more square miles of ocean for protection than any other political leader in history. The three new monuments, surrounding far-flung islands, reefs and atolls scattered across the Pacific, will add 195,000 square miles of protected waters to the nearly 140,000 square miles around the Northwest Hawaiian Islands that Bush protected in 2006 [Los Angeles Times]. The United States has authority over these waters because the tiny atolls and islands are U.S. territories.

The three areas are thronged with fish, sharks, coral reefs, and other forms of sea life, all of which will benefit from the new protections. Blue-water fish such as yellowfin, bigeye tuna, and marlin–all in decline–will be big winners because they breed in these waters. So will sharks, birds, turtles, and dolphins accidentally caught by the tuna long-line fleets [ScienceNOW Daily News]. One of the new national monuments also encompasses the deepest location of the earth’s crust. The Marianas Trench, which reaches depths of more than 36,000 feet in some locations, contains undersea volcanoes and hydrothermal vents around which cluster tough organisms that can withstand high temperatures and harsh chemicals. These “extremophiles” are of interest to scientists who think they signal forms that extraterrestrial life could take.

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The growth of the world’s largest coral reef system has slumped to its slowest rate in at least four centuries, according to a new report in Science [subscription required]. Researchers studying coral colonies in the Great Barrier Reef found that calcification, the process that builds the reefs, has dropped 13.3 percent since 1990. They fear the decline is indicative of a worldwide threat to coral reefs caused by rising seawater temperatures and ocean acidification. The loss of coral growth threatens food webs and may lead to “precipitous” changes in biodiversity, the authors said [Bloomberg].

The Great Barrier Reef along the northeast coast of Australia stretches more than 1,200 miles and is visible even in space. Coral reefs, delicate undersea structures resembling rocky gardens made by tiny animals called coral polyps, are important nurseries and shelters for fish and other sea life. They also protect coastlines, provide a critical source of food for millions of people, attract tourists and are potential storehouses of medicines for cancer and other diseases [Reuters]. Massive coral reefs materialize from the gradual accumulation of calcium carbonate by billions of coral polyps over thousands of years.

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