Coming soon: Salmon that grow to full size in half the time?

With all sorts of genetically modified crops on the market and in the grocery store in the United States, genetically modified animals have been the next step waiting to happen. The New York Times reports that salmon could be the first up: This year the Food and Drug Administration will weigh approval of a GM salmon created by the company AquaBounty, which could be the first GM animal eaten by Americans.

It is an Atlantic salmon that contains a growth hormone gene from a Chinook salmon as well as a genetic on-switch from the ocean pout, a distant relative of the salmon. Normally, salmon do not make growth hormone in cold weather. But the pout’s on-switch keeps production of the hormone going year round. The result is salmon that can grow to market size in 16 to 18 months instead of three years, though the company says the modified salmon will not end up any bigger than a conventional fish [The New York Times].

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Your brain is hungry. That big gray calculating machine in your head is an energy hog that needs lots of calories—more than the diet of fruits and plants that our distant hominin ancestors probably ate could provide. It’s a mystery, then, just how human ancestors like Homo erectus—who were around when our craniums started to expand in a hurry—ate enough to start growing big brains. But buried in Kenya, a two-million-year-old hint has emerged: Those hominins started eating seafood way back then, archaeologists say.

Near a place called Lake Turkana, archaeologists David Braun found two intriguing groups of items: The bones of fish, turtles, and even crocodiles with the scars of stone tools still showing, and stone fragments that Braun says come from the simple tools these hominins used to carve up the marine animals. He and his colleagues report the find of our ancestors’ ancient feast in the Proceedings of the National Academy of Sciences.

Today, their leftovers—in the form of hundreds of bones and several thousand stone tools—are the earliest “definitive evidence” of hominins butchering and eating aquatic animals, which are rich in fatty acids essential for growing bigger brains [ScienceNOW].

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The media-savvy eco-pirates of the Sea Shepherd Conservation Society have a new target in their sights: commercial fishing boats that illegally scoop endangered bluefin tuna out of the sea.

The Sea Shepherd activists have become famous for harassing Japanese whaling ships; a reality TV show about their exploits documented the many tricks the activists used to slow down the whalers, including shooting stink bombs onto their ships and attempting to disable their propellers. With their new project, dubbed Operation Blue Rage, the activists hope to bring the same level of attention to the fight to save endangered tuna.

Stocks of bluefin tuna have fallen by roughly 85% since the industrial fishing era began…. Yet despite quotas that are arguably too high to begin with, quotas are still being ignored in many places [Ecopolitology].

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There are few more dramatic examples of humanity’s careless treatment of the earth than the Aral Sea.

The Aral’s precipitous decline began in the 1960s, when the Soviet Union began using river water to irrigate the mega-farms it established on the arid steppe. As the river water flowing into the sea slowed to a trickle, the Aral began drying up.

Once a colossal geographic feature—at 26,000 square miles (67,300 square kilometers), it was the fourth largest inland water body on earth in terms of surface area—the Aral shrank to hold just one-tenth of its original volume, becoming a tragic shadow of itself [National Geographic]. Fisheries collapsed, people moved away, towns were abandoned, and the Aral became famous primarily for its ghostly landscapes, with rusting ships lying on sand dunes.

But now scientists report that the northern sector of the Aral is making a recovery, due to a concerted effort from the Kazakh government, the World Bank, and scientists. A dam completed in 2005 raised water levels and decreased salinity, and increased the North Aral’s span by 20 percent. Soon native plants, stifled for years by the saltwater, began to sprout, and migrating birds like pelicans, flamingos, and ducks again began to visit the Aral.  Nowadays, “It’s a paradise for birds,” says Russian Academy of Sciences zoologist Nick Aladin, who has been studying the Aral since the 1970s. “It’s a place for pleasure, and it’s an enormous victory” [National Geographic]. Freshwater fish have also returned, leading to hopes of a resuscitated fishing industry. And while the South Aral remains in dire straits, researchers say the tentative revival of the North Aral gives them hope.

Another sea, another headache. Over in the Middle East, several countries are weighing a proposal that could give new life to the dwindling Dead Sea–but that may cause environmental problems of its own.

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When a person has a heart attack, the heart repairs its damaged muscle by forming scar tissue. As a result, the heart never truly goes back to the way it was. But when a zebrafish has a heart injury, like having a large chunk of it chopped off, it grows a brand new piece to replace it.

Two independent reports published in the journal Nature show that within days of an injury to its heart, the zebrafish has the remarkable ability to regenerate most of the missing cardiac tissue using mature heart cells–not stem cells, as some researchers had suspected.

The findings help explain why human beings can’t regenerate a heart or missing limbs. The reports contradict a previous study (pdf) done by one of the research teams in 2006 that suggested that stem cells, the general all-purpose cells that develop into all the mature and functional cells of the body, were responsible for self-repair.

The finding suggest that doctors have been on the wrong track with recent stem cell-based therapies for heart attack patients. Many heart patients have received injections of stem cells, often ones taken from their own bone marrow. But the beneficial effects have generally been unremarkable [The New York Times].

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Sushi chefs in Japan are keeping a close eye on Doha, Qatar this week as delegates at the Convention on International Trade in Endangered Species (CITES) debate the future of their beloved bluefin tuna. The fish, a delicacy in Japan that can sell for more than $100,000 apiece, is being overfished, and convention delegates aim to prevent the tuna from becoming extinct altogether. The proposal on the table: A complete ban on international trade of the fish to allow stocks to regenerate.

The bluefin tuna ban was proposed by Monaco, and the vote will probably come up next week. Japan has already dispatched a delegation to Doha with the message that Japan won’t comply with a total ban, and would instead prefer a fishing quota. But quotas have failed to help the depleted bluefin tuna stocks thus far. Japan last year pledged to help meet an accord to slash the total catch in the eastern Atlantic and Mediterranean by 40 percent, although environmental groups charge that such quotas are routinely exceeded [AFP].

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We know that there’s a whole spectrum of different wavelengths of light beyond the puny band of visible light we humans can see. And we knew that some animals, like certain species of fish and birds, have vision that extended beyond ours into wavelengths like ultraviolet. But a new study in Current Biology demonstrates that not only can damselfish see in UV, but that they can discern specific patterns in UV light, which is much more than we ever gave them credit for.

The findings are the first to show an animal “that is able to discriminate between fine-scale UV patterns using only their short-wavelength receptors (UV cones),” the researchers wrote in their study. These fish seem to use the UV cues to distinguish their own from other similar-looking species [Scientific American]. Prior to this, many researchers thought the fish’s UV vision just allowed them to detect the presence of UV light, and wasn’t refined enough to detect any kind of patterns.

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Asian carp—the giant invasive fish that have been moving up the Mississippi River for the better part of a decade–are getting close to the Great Lakes, and in fact some may have already crossed the barrier. For the lakes’ protectors, this is a near-doomsday scenario: Many fear that the ravenous carp could destroy the ecosystem by gobbling up the food that native fish depend on. This week the White House proposed a plan that would devote nearly $80 million to stopping the fish’s advance, but it’s not pleasing many people around the issue.

On one side, many environmentalists, as well as people who rely on Great Lakes fishing for their livelihood, have called on the federal government to shut down locks that connect the river to Lake Michigan. Michigan Governor Jennifer Granholm says, “The economic damage from these carp coming into the Great Lakes system would be irreparable…. They should shut the locks down until they get these other measures in place, and permanently have a solution to separating these two water systems” [Detroit News]. Granholm and other governors from the region met recently to try to craft another solution after the Supreme Court ruled that Illinois didn’t have to close the locks to stop the carp if it didn’t choose to.

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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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Sushi lovers, we’ve got some bad news. For a study that came out in PLoS One, researchers ordered sushi at restaurants across New York City and Denver, Colorado, and found that an alarming percentage wasn’t made from the fish it was advertised to be. More than half of the eateries weren’t completely clear and honest about the fish they offered, the study says. Some even mistakenly served up escolar, which can give people diarrhea and stomach problems.

Although their results were shocking, exposing sloppy sushi joints wasn’t their main goal. The scientists were trying to improve on a new species-identification technique, called DNA barcoding…. Their goal is to build a catalog of every fish species on earth so that anyone with a handheld DNA reader could definitively identify fish within minutes [Wired.com].

One reason researchers investigated sushi is that so much of it has been made from endangered species like the bluefin tuna. In the restaurants that lead scientist George Amato checked out, the device showed 25 percent of what was labeled as tuna on sushi menus was bluefin, Amato said. The device also has been used to identify the presence of endangered whales in Asian markets and fraud in the labeling of caviar and red snapper [UPI].

This study comes in the wake of an international ruling that reduces the quota for bluefin catch from 22,000 metric tons annually to 13,500 for 2010. But that isn’t enough for many environmentalists, nor for The New York Times editorial board, which this weekend called for the United States to list bluefin under the Convention on International Trade in Endangered Species. The law effectively bars commercial trade in any listed species, and has been helpful in protecting other animals like elephants and whales [The New York Times].

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Image: flickr / avixyz

The Great Lakes are under threat from an Asian carp invasion that could wipe out fishing stocks, and with it, the lakes’ billion dollar fishery. On Friday, officials from the Army Corps of Engineers reported that genetic material from the carp had been found for the first time in a nearby river beyond an elaborate barrier system, which has cost millions of dollars and was meant to block their passage [The New York Times]. There is concern that if carp make it into Lake Michigan, they will gobble up the plankton that native fish feed on.

Officials also say that recreational boating may be affected–the carp can grow up to 4 feet long and weigh up to 100 pounds, and the massive fish will occasionally leap up and strike boaters. Since they were found to be moving up the Mississippi River in 2002, agencies have been trying everything they can think of to slow them down, including erecting the expensive electric barriers that cost around $9 million. The barriers work by sending low-voltage electric current through steel cables that are strung across the canal; this creates an electric field that’s uncomfortable for the fish and that’s supposed to prevent them from swimming across it.

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Toys, refrigerators, washing machines, socks—more and more products contain silver nanoparticles. It’s no wonder: These particles, which measure less 100 nanometers (smaller than a single HIV virus), can kill microbes on contact. But, researcher Darin Furgeson says, nanosilver can also escape into ecosystems and cause serious damage to fish embryos. Furgeson’s team published its results in the journal Small.

In one new experiment, Furgeson, a professor of pharmaceutical sciences, exposed zebrafish embryos to silver nanoparticles in a laboratory, and found that some died and others were left with dramatic mutations. “Some of the fish became extremely distorted, almost making a number nine or a comma instead of a linear fish,” he said [Scientific American]. Eyes, tails, and other body parts turned out malformed in the fish that survived.

Just how much nanosilver gets into the environment? A separate study from Environmental Science & Technology washed nine kinds of nanosilver-containing textiles, including some “anti-bacterial and anti-odor socks” that are already on the market. The researchers found that anywhere from less than 1 percent to as high as 45 percent of the silver came out in the first wash. Most of the silver was in the form of coarse particles of greater than 450 nanometers, suggesting that mechanical stress in the washing machine was responsible for most of the release [The New York Times], and that the nanoparticles might have aggregated to reach that size.

Those nanoparticles flushed out by a washing machine can end up in both fish habitats and drinking water supplies. Furgeson says his fish experiments could help show whether nanosilver is a health concern for humans, too. “Zebrafish have similar tissues and organs to us,” Furgeson said. “They don’t have lungs, but they do have a liver, kidneys and heart – though it is only two chambered – and they have a blood-brain barrier” [Scientific American].

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Image: Wiki Commons / Kristof vt

Atlantic bluefin tuna populations have declined so drastically that trade in the fish should be completely outlawed, says a new report. The population of the Atlantic tuna, a sushi staple, is now about 15 percent of the original stock size, says International Commission for the Conservation of Atlantic Tunas’ (ICCAT). The report has delighted conservation groups, who have criticized ICCAT’s regulation policies. The report was triggered by Monaco’s recent proposal to ban international trade in the Atlantic bluefin under the Convention on International Trade in Endangered Species (CITES) – a proposal that has gathered support from several other European countries [BBC News].

ICCAT has a history of setting quotas higher for the fish than scientists say is safe, while CITES seems to take a more proactive approach.Atlantic bluefin tuna are mainly caught from countries around the Mediterranean Sea, but most of the meat is consumed in Asia, particularly Japan. Japan has previously argued that commercial fish species should be controlled by bodies like ICCAT rather than CITES [BBC News]. In Japan, the fish are so highly prized that a single giant tuna can sell for more than $100,000 at the wholesale fish market. ICCAT will meet in 10 days to discuss the report.

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Image: Wikimedia Commons

Snooty wine pairing rules, such as the edict that one must only drink white wine with fish, now have a little data behind them, according to a new study. Researchers found a correlation between the high iron content of red wine and a nasty, fishy aftertaste when the reds are sipped with seafood. In the experiment, tasters ate a bit of scallop, tasted some wine and evaluated the aftertaste on a scale of 1 to 4. The diners found the unpleasant aftertaste was more intense with wines that had a higher iron content, the researchers say [Los Angeles Times]. The researchers were able to block the aftertaste by adding a compound that masks the iron.

The iron content of a wine depends on the composition of the soil in which the grapes were grown, the dust on the berry, contamination during harvesting, transportation, and crushing, and the conditions during fermentation [Telegraph]. The new research, published in Journal of Agricultural and Food Chemistry, suggests that some low-iron red wines are OK to drink with fish. While red wines tend to have more iron than whites, it varies according to the type of grape, country of origin, and vintage.

But the iron is only half the story. The researchers report that they haven’t yet isolated the compound in the scallops that reacts with the wine, but they suspect it’s an unsaturated fatty acid, which could be breaking down rapidly and releasing the decaying fish smell when exposed to iron [ScienceNOW Daily News].

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Image: flickr / yashima

Nissan is looking to schools of fish to learn about how to help people reduce car crashes and traffic jams. The car company developed tiny robots that move in fish-like groups of up to 7 without bumping into each other. Each uses a laser range-finder to measure the distance between obstacles. The data is constantly shared between peers via radio, allowing the group to travel as a “shoal” without bumping into each other. The technique allows the cars to travel side-by-side or quickly switch direction as a group [BBC News]. The robot is dubbed Eporo, which stands for Episode O (Zero) Robot, meaning zero episodes, or accidents, and zero emissions.

This is Nissan’s second attempt at designing a crash avoidance system based on animal behavior. Their last attempt was the BR23C robot, modeled after the anti-collision behavior of bumblebees (check out a video of the bee based bot here). The Eporo, however, imitates three rules of fish movement: avoiding crashes, traveling side by side, and keeping close to other members of the school [CNET]. Nissan plans to unveil the Eporo at the Ceatec conference in Tokyo on October 6. 

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Image: Nissan