Tuesday, April 28, 2009
A Look Into Future Oceans for Shellfish Reasons
Carbon Dioxide, Absorbed by the Seas, Changes the Chemistry of Water and the Growth of Marine Life
The Wall Street JournalIn the living laboratory of a submerged volcano, marine biologist Verena Tunnicliffe glimpsed sea creatures trying to survive in acidic oceans.
Carbon dioxide that bubbles up in the sulfur chimneys of the undersea Eifuku volcano near the Pacific's Mariana Islands has turned the water into an acidic broth, with striking effects on sea life. Scientists say the corrosive conditions there offer clues to how rising levels of man-made CO2 in the air could unbalance oceans world-wide.
To her surprise, Dr. Tunnicliffe found that mussel shells she collected at Eifuku were so thin that she and her colleagues could see right through them. The water chemistry made it impossible for the mussels to extract enough calcium carbonate to form a proper covering. Compared with shells of the same species collected in more normal waters, "they were half the thickness and half the weight," she said.
To live in these inhospitable conditions, the mollusks cannibalized their own shells, leaching from them the carbonate needed to maintain their internal muscle chemistry. "They are dissolving whatever shell they do have," says Dr. Tunnicliffe at the University of Victoria in British Columbia. They manage to survive despite their weakened shells, the scientists speculated, because the water's harsh chemistry is too much for the hard-shell crabs that prey on these mussels elsewhere.
Islands, Marine Sanctuaries, and the Struggle Against Extinction
Bali, Mauritius, Iceland, Galapagos, Madagascar: these are fine and exotic places, far away from the busy center of things. Yet, no matter how remote they may seem, islands are at the epicenter of the ongoing mass extinction of animal and plant species—one that has every chance, one day, of involving humans not as agents but as victims.
Now, islands are, by definition, geographically isolated: bits of land, large or small, separated from other bits of land by water. That isolation, as David Quammen, quoting biologist Ernst Mayr, remarks, is “the flywheel of evolution”: on islands, species separate and transform markedly. The smaller the island, for complex reasons, the greater the danger of extinction. This formula is one of many elaborated in Robert MacArthur and E. O. Wilson’s theory of island biogeography, which has been highly influential in ecological circles in the five decades since its publication.
Getting from one island to another is fraught with peril as well, as the plight of the leatherback turtle suggests. These sea creatures emerged more than 100 million years ago to occupy a niche in the ecology of what is now the eastern Pacific Ocean. In the last 20 years, biologists estimate, their numbers have fallen by 90 percent. The reasons are many, but, reports a team of researchers from Stanford University, the National Oceanic and Atmospheric Administration, and other institutions, one is the turtle’s migration route from the waters of Costa Rica beyond the Galapagos Islands to small islands in the middle of what is called the South Pacific Gyre. Given worldwide demand for seafood, the area and points all along the turtle’s migration route are being heavily fished by trawler fleets from many nations—and many of the creatures pulled up in their nets are leatherbacks.
Wednesday, April 22, 2009
Nature stars in Disney's impressive "Earth"
The Seattle Times
by Moira Macdonald
Narrated with sonorous majesty by James Earl Jones, Disney's rather generically titled nature documentary "Earth" flies us around the planet, finding wonders at every turn.
In New Guinea, a glossy black bird of paradise spreads his feathers like a cheerleader's skirt, the better to look perky as he performs a mating dance. A penguin glides across the Arctic snow on his stomach — he is, we're told, the only species equipped with a built-in toboggan. Baboons gingerly parade in a line through the flooded Okavango Delta, their cranky expressions indicating they just heard bad news about their 401Ks, or maybe that they just don't like water.
Alastair Fothergill, creator of the TV series "Planet Earth," and Mark Linfield codirected this film, the first from the studio's new DisneyNature division. And while you wonder if this sort of photography might be best suited to a vast IMAX screen, "Earth" is impressive and often beautiful in its swooping views of a variety of creatures around the globe.
Fishing down the food chain
For most of his life, Daniel Pauly has been ahead of the curve, and it’s not a pretty one: it’s the curve showing the myriad ways in which our oceans are dying.
Until 2001, the statistics compiled by the United Nations Food and Agriculture Organization (FAO) suggested that the total amount of fish taken out of the oceans had stabilized at about 100 million tons a year. While certain species like cod and bluefin tuna were undeniably in serious trouble, the agency indicated that the world’s highly-trained fisheries scientists wielding complex mathematical models were well equipped to regulate fishing in coastal waters, from which most fishes are taken, and on the high seas.
But in a series of scientific studies pioneering a global approach carried out since 1995, Pauly has shown the just how broad the devastating effects of fishing on marine ecosystems have become. He also demonstrated that in fact, the world catch has been declining since the late eighties, despite a huge catch—on the order of 50 million tons—never making it into the FAO statistics. Pauly believes that by the time a child born today reaches old age, wild fresh fish will be as rare and expensive as caviar is now.
Wednesday, April 15, 2009
Tuesday, April 14, 2009
Deep-sea corals may be oldest living marine organism
ENN
From: DOE/Lawrence Livermore National Laboratory
LIVERMORE, Calif. - Deep-sea corals from about 400 meters off the coast of the Hawaiian Islands are much older than once believed and some may be the oldest living marine organisms known to man.
Researchers from Lawrence Livermore, Stanford University and the University of California at Santa Cruz have determined that two groups of Hawaiian deep-sea corals are far older than previously recorded.
Using the Lab's Center for Accelerator Mass Spectrometry, LLNL researchers Tom Guilderson and Stewart Fallon used radiocarbon dating to determine the ages of Geradia sp., or gold coral, and specimens of the deep-water black coral, Leiopathes sp. The longest lived in both species was 2,740 years and 4,270 years, respectively. At more than 4,000 years old, the deep-water black coral is the oldest living skeletal-accreting marine organism known.
Pacific island nations step in to save tuna
San Francisco GateChristopher Pala, Chronicle Foreign Service
Saturday, April 11, 2009
Until a group of small Pacific island nations imposed unheard-of restrictions on foreign fishing fleets in December, most tuna species were on the road to extinction, experts say.
The measures are expected to reduce the catch of yellowfin, bigeye and albacore species by between 10 and 30 percent over three years, enough to guarantee that the world's top tuna fishing areas, which earn an estimated $3 billion annually, will remain productive for the foreseeable future.
"This is exactly what's needed to reverse the decline of Pacific tuna stocks," said Eric Gilman of International Union for the Conservation of Nature.
The conservation measures, which take effect Jan. 1, 2010, were imposed after international fishing fleets, mostly from Europe, Asia and the United States, overfished the waters of the eastern Pacific Ocean and the Atlantic Ocean and sought new fishing areas.
Fish farms to fight back with EU help
BBC NewsBy Russell Padmore
Europe business reporter, BBC News, Brussels
At a time when stocks of some species of fish in the world's oceans are dangerously low, the authorities in Brussels are concerned that Europe's aquaculture sector has stagnated.
Most of the seafood consumed within the EU is imported, but the Commissioner for Maritime Affairs and Fisheries, Joe Borg, believes that can be reduced with the right strategy to encourage the industry to grow.
Among the key measures likely to be announced are plans to encourage more investment in the sector, by making it easier to open a fish farm. That, in turn, will create more jobs.
Sonar Can Cause Temporary Deafness in Dolphins
The New York TimesBy HENRY FOUNTAIN
Sonar has been implicated in some strandings of whales and dolphins, but the mechanism by which acoustic pings might cause disorientation is uncertain.
Researchers at the University of Hawaii tested one possibility: that sonar can deafen marine mammals. T. Aran Mooney, now at the Woods Hole Oceanographic Institution, and colleagues exposed a bottlenose dolphin to naval sonar signals and then determined whether its hearing was affected. The pings, about a half-second long and about one second apart, were recorded in Puget Sound, Washington, just before a stranding in 2005.
As reported in Biology Letters, the dolphin suffered hearing loss for up to 40 minutes. But the effect was seen only with repeated exposure to the sonar pings at very high sound levels. The researchers calculated that a dolphin or other marine mammal would have to be within about 45 yards of a sonar source, and stay within that range for several minutes, for temporary deafness to occur.
It seems unlikely that an animal would stay so close to the source of a sound that was causing it discomfort, so sonar-induced deafness may not be much of a factor in strandings. But the researchers suggested that under certain conditions — multiple sonar sources, for example, or undersea features that reflect signals — an animal may not be able to avoid intense exposure.(No) Drill, Baby, Drill
By THOMAS L. FRIEDMAN
Sailing down Costa Rica’s Tempisque River on an eco-tour, I watched a crocodile devour a brown bass with one gulp. It took only a few seconds. The croc’s head emerged from the muddy waters near the bank with the footlong fish writhing in its jaws. He crunched it a couple of times with razor-sharp teeth and then, with just the slightest flip of his snout, swallowed the fish whole. Never saw that before.
These days, visitors can still see amazing biodiversity all over Costa Rica — more than 25 percent of the country is protected area — thanks to a unique system it set up to preserve its cornucopia of plants and animals. Many countries could learn a lot from this system.Read more...
Tuesday, April 07, 2009
Sea Cucumbers Threatened by Asian Trade
Dot Earth
By Neil MacFarquhar
Most Western palates do not deem sea cucumbers — with their big, lumpy, worm-on-steroids appearance — anything close to edible, let alone a delicacy.
But across much of Asia, the creatures are a staple in stir-fry, soups and stews and are so sought after that they are in imminent danger of being over-harvested, according to a report on the sea cucumber trade released Wednesday by the Food and Agriculture Organization of the United Nations.
(It should be noted that sea cucumbers, although they can be pickled, are not cucumbers at all. Rather they are a form of echinoderm along with starfish, sea urchins and sand dollars.)