There’s more bad news for the Baltic Sea. Reports had already indicated that it was one of the most polluted bodies of water in the world, and now a report from a Swedish TV station alleges that Russia dumped nuclear and other toxic waste into Swedish waters in the Baltic in the early 1990s.
According to a report by the SVT network, Russian boats sailed out at night to dump barrels of radioactive material, from a military base in Latvia, into Swedish waters. And even though the Swedish government at the time reportedly knew this, no action was taken to find the waste [BBC News]. These accusations—particularly that the Swedish government knew about the dumping and did nothing—aren’t sitting well with current Prime Minister Fredrik Reinfeldt. But Carl Bildt, who was the country’s prime minister during the alleged dumping, says he never heard about it.
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At the bottom of the Baltic Sea, history sits largely intact. Because shipworms don’t care for these cold, low-salt waters, shipwrecks can endure for centuries without great decay. The Vasa, a famous Swedish warship that sank in Stockholm harbor in 1628, was in terrific condition when engineers raised it from the depths more than 300 years later. But, scientists now warn, those conditions could be coming to an end due to global warming.
Shipworms, which can obliterate a wreck in ten years, have already attacked about a hundred sunken vessels dating back to the 13th century in Baltic waters off Germany, Denmark, and Sweden, reported study co-author Christin Appelqvist [National Geographic News]. Now, Appelqvist says, their range is beginning to extend beyond those areas into the northern part of the Baltic. That could threaten close to 100,000 shipwrecks scattered across the bottom of the sea.
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The next generation of bulletproof vests and military armor could well be inspired by a deep-sea snail, say scientists.
A team led by materials scientist Christine Ortiz of the Massachusetts Institute of Technology investigated the iron-rich shell of the “scaly foot” mollusk, whose triple-layered shell gives it one of the strongest exoskeletons seen in nature. The researchers believe that copying its microstructure could help in the development of armor for soldiers, tanks, and helicopters. Their work was published (pdf) this week in the Proceedings of the National Academy of Sciences.
Scientists were first drawn to this snail in 2003 when they discovered it living in a relatively harsh environment on the floor of the Indian Ocean. It lives near hydrothermal vents that spew hot water–thereby exposing it to fluctuations in temperature as well as high acidity. It also faces attacks from predators like crabs and other snail species. But unlike other snail species, this snail survives because of its thick shell and the different properties of each of its three layers.
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More than two decades have passed since the Exxon Valdez spilled 38,000 tons of crude oil into Alaska’s Prince William Sound, but despite cleanup efforts and time, thousands of gallons of oil remain stuck in the region’s beaches. A new Nature Geoscience study offers an explanation for why the oil has been so slow to disperse: it’s the composition of the beaches themselves.
According to study leader Michel C. Boufadel, natural forces have created beaches in Prince William Sound with two distinct layers, and water moves 1,000 times slower through the bottom layer than the top. Once the oil entered the lower level, conditions were right to keep it there, he said. Tidal forces worked to compact the finer-grained gravel even more, creating a nearly oxygen-free environment with low nutrient levels that slowed the ability of the oil to biodegrade [AP].
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Part animal, part plant, bright green, and totally bizarre: Meet the sea slug Elysia chlorotica.
Biologists already knew that this organism, native to the marshes of New England and Canada, was a thief that somehow pickpocketed genes from the algae it eats. At last week’s meeting of the Society for Integrative and Comparative Biology in Seattle, researcher Sidney Pierce said he has found that the slugs aren’t just kleptomaniacs—they use the pilfered genes not only to make chlorophyll, but also to execute photosynthesis and live like a plant. Said Pierce: “They can make their energy-containing molecules without having to eat anything,” Pierce said. “This is the first time that multicellular animals have been able to produce chlorophyll” [LiveScience].
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Cleaner fish have a pretty good little business going. These select species of small underwater inhabitants set up “cleaning stations” where they eat parasites and dead tissue off larger fish. Sure, it might not be a gourmet meal, but in exchange for the service the large fish don’t eat the cleaners.
In some cases a pair of fish work in tandem, and a new study has found that males will punish their female partners if the females go overboard and eat more of the client than they should. While the research shows that fish, like people, can be aggrieved on behalf of a third party, don’t be too impressed with the males’ altruism—they get plenty out of the deal.
For a study in Science, researchers looked at the fish Labroides dimidiatus, whose females usually play by the rules of the cleaning business. But the females can sometimes be too greedy and “bite the flesh of the fish they are cleaning in a bid to get to the mucus, which is more tasty than the parasites on the surface,” researcher Redouan Bshary found. The male fishes, which are bigger in size, would then step in to chase the females away [AFP].
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You could’ve seen this one coming a mile away—the high seas tensions between Japanese whalers and the environmental groups that harass them degenerated into downright naval warfare this week. A Japanese whaling ship collided with a environmental group’s boat in waters near Antarctica yesterday, sparking finger-pointing, international bickering, and even more bad blood.
The collision late yesterday damaged the Ady Gil, a powerboat that is part of the Sea Shepherd Conservation Society protest against the Japan’s annual whaling expedition to the Southern Ocean. Six crew members were rescued by another protest vessel and the boat may sink, Sea Shepherd said in a statement [Business Week]. The governments of Australia and New Zealand say they plan to investigate the crash; the Ady Gil is registered in New Zealand, which opposes the Japanese whaling.
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After 20 years in one spot, anyone can get restless. That goes for the famous sea lions of San Francisco’s Pier 39. They swelled to their largest population ever just a couple months ago and then almost totally disappeared this month, baffling local marine experts.
The animals have been a fixture on Pier 39 since 1990, when a big herring run lured the sea lions into San Francisco Bay. The Marine Mammal Center gets so many questions about the 1,000-pound creatures that the nonprofit staffs a small kiosk on Pier 39; the pier’s insignia includes the silhouette of a sea lion [San Francisco Chronicle]. In October more than 1,700 sea lions laid about on Fisherman’s Wharf. But the exodus began the day after Thanksgiving, and by yesterday only 10 remained hanging out near the docks.
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Chalk up another unexpected consequence of pumping too much carbon dioxide into the air: According to a new study, the excess CO2 that ends up in seawater is gradually making the oceans noisier.
The changing chemistry of the ocean is one of the major impacts of CO2 emissions. The dissolved gas is changing the pH of the water by making it more acidic, which makes life harder for corals and marine critters with calcium carbonate shells that are corroded by the acidic water. But the new study, published in Nature Geoscience, found that changing the pH of the oceans also reduces the levels of chemicals that absorb sound, like magnesium sulphate and boric acid.
Low-frequency sound in the ocean is produced by natural phenomena such as rain, waves and marine life, and by human activities such as sonar systems, shipping and construction. The sound is absorbed mainly through the viscosity of the water and the presence of certain dissolved chemicals…. But the concentration of chemicals that absorb sound in the oceans has declined as a result of ocean acidification [AFP]. The study found that sound absorption could fall by some 60 percent in high latitudes and deep waters by 2100.
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The world’s largest network of fully wired undersea science stations has gone live off Canada’s western coast. The NEPTUNE network has begun streaming data from undersea instruments and sensors located on the Pacific Ocean floor directly to the Internet. The network is expected to produce 50 terabytes of data annually, all of which will inform scientists about everything from earthquake dynamics to the effects of climate change on the water column, and from deep-sea ecosystems to salmon migration [Scientific American].
NEPTUNE will also feature a deep sea rover nicknamed Wally that will measure the temperature, salinity, methane content, and sediment characteristics on the ocean floor. The $100 million project will produce more than pretty pictures and a fire hose of data—it can also provide advanced tsunami warnings that could save both lives and money.
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For a geologist, “fast” still means thousands and thousands of years. But in a new study in Nature scientists argue that the modern Mediterranean Sea filled with water in a geologic blink of an eye. A torrential flood of water that moved 1,000 times faster than the Amazon River replenished the once-dry sea in perhaps just a few months, the researchers say.
History shows that the Strait of Gibraltar has often determined access to (and thus control of) the Mediterranean, and that goes for the water itself, too. Around 5.6 million years ago the Mediterranean Sea almost completely evaporated when it became disconnected from the Atlantic Ocean. This was due to uplift of the Strait of Gibraltar by tectonic activity, combined with a drop in sea level [New Scientist]. When the strait sank just enough to reach the water level 5.3 million years ago, ocean waters began to cascade through and fill the sea.
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In a bit of unexpected climate related good news—not for us, of course—some shell-building ocean dwellers like blue crabs, shrimp, and lobsters may actually benefit from increased ocean acidification. This surprising finding seems to be good news for lobster lovers, but researchers note that the ongoing acidification still appears to spell trouble for many marine creatures.
Scientists now think that acidifying oceans may allow these select crustaceans to build stronger shells and exoskeletons, instead of making them more brittle. Carbon dioxide (CO2)—the notorious byproduct of fossil fuel burning—dissolves in the ocean. That makes the ocean more acidic. It also reduces the number of so-called carbonate ions in seawater, and these ions are among the primary materials that sea creatures use to build their calcium carbonate shells and skeletons [LiveScience]. Justin Ries, a coauthor on the new study, speculates that these bottom dwellers are somehow better able to manipulate CO2 ions to build their shells, even though fewer CO2 ions are available to them in an acidic environment. However, exactly how they accomplish this is unknown.
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Like humans, sea stars enjoy lounging on the shore during the hot summer months. But when they get too hot, they can’t run for shade, so they have a back-up plan—fattening themselves with cold ocean water before the tide recedes, according to new research published in the journal The American Naturalist. This finding shows that sea stars, or ochre starfish, aren’t as helpless as previously thought. The sea stars are likely cued during low tide that it’s a hot day, the researchers say, and that signals them to soak up more water during the next high tide. “It would be as if humans were able to look at a weather forecast, decide it was going to be hot tomorrow, and then in preparation suck up 15 or more pounds of water into our bodies,” said study researcher Brian Helmuth [LiveScience]. Talk about staying hydrated.
The researchers first studied starfish in an aquarium using heat lamps to simulate a scorching summer day, an infrared camera to measure their internal temperatures, and a scale to weigh the sea stars and determine how much water they had absorbed. The researchers say the amount of water a starfish absorbs can decrease its body temperature by almost 4 degrees Celsius. But researcher Sylvain Pincebourde is concerned that this novel strategy may have limitations in a rapidly changing world…. As oceans warm together with air temperature the thermoregulatory mechanism used by the starfish will cease to work, he warns. “The colder the sea water, the more it is able to lower its body temperature. The efficiency of this thermoregulation strategy therefore might be annihilated by ocean warming” [BBC News]. Yet another reason to get a handle on global carbon emissions.
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For elephant seals, at least, there is some rest for the weary.
These marine mammals undertake epics migrations of thousands of miles, in which they might not return to land for as long at eight months. But elephant seals don’t have the same talent as whales and dolphins, which can have one hemisphere of their brains sleep while the other stays awake, so marine biologists weren’t sure how the seals managed to doze off while at sea. A new study in Biology Letters, however, suggests the seals might sleep as they drift slowly downward.
Past research had identified certain types of dives that include a period of slow descent that might be a siesta of sorts, for resting or digesting [The New York Times]. So scientists tagged a half-dozen young northern elephant seals off the California coast with instruments that tracked the seals’ positions and modeled their dives in three dimensions.
The monitors revealed that the seals periodically flip onto their backs and slip into slow, spiraling dives. The seals wobble as they drift down, and most of the time their bodies follow circular paths toward the bottom of the sea, said study co-author Russel Andrews…. “[They] resemble a leaf that has dropped from a tree branch and is falling toward the ground, fluttering from side to side,” he said [National Geographic]. It seems likely, the scientists say, that the seals catch a quick nap during these long drifts; in fact, once in a while they strike bottom without even noticing.
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Great white sharks, much like humans, tend to stick to familiar turf, according to new research. Also like a lot of people, they like to hang out along the coastal waters of California. Sharks tagged with acoustic devices often spent up to 107 days at four key sites along the central and northern California coast where seals and sea lions are abundant: Southeast Farallon Island, Tomales Point, Año Nuevo Island and Point Reyes [LiveScience]. A few of the fearsome predators were tracked as far inland as the Golden Gate Bridge, apparently in search of snacks, say the researchers. The study, the largest and most detailed study of North American great white sharks, provides evidence contrary to the popular notion of great white sharks swimming aimlessly in the ocean.
The sharks under study divided most of their time between three locations: Northern California, Hawaii, and an area that the researchers called the white shark café, a spot in the open ocean about halfway between the Baja Peninsula and the Hawaiian Islands. Exactly what goes on at the café is still unknown–although researchers suspect it may be a hot spot for mating. Lead researcher Salvador Jorgensen explains that male white sharks “converge in a very specific area of the cafe,” Jorgensen said, while female sharks move in and out of the area. “It adds a little more evidence to the argument that this could be an important reproductive area” [Washington Post].
The scientists tracked the snaggly toothed predators between 2000 and 2008 from the Bay Area to San Diego, Hawaii and back as the sharks followed a route that was carried out with surprising precision and under a strict time frame [San Francisco Chronicle]. These great whites have been isolated from other great white sharks near Australia and South Africa for so long that they are now genetically distinct. The study was published in the journal Proceedings of the Royal Society B.
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