As a native Michigander, I’m a sucker for news about the Great Lakes. (That’s HOMES, remember? Huron, Ontario, Michigan, Erie, and Superior.) Engineers at the U of M Marine Hydronamics Laboratory have now designed a boat without a ballast tank in order to prevent the introduction of non-native species.
A ballast tank is a compartment that sits at the bottom of any large boat. When the boat doesn’t have any cargo, its crew can fill the ballast tank with water to help it stay afloat. The mechanical details on how this works can be found here; but basically, the extra water lowers the boat’s center of gravity and makes it more stable on the water.
Trouble is, these ballast water pools typically harbor lots of aquatic species. Researchers have identified 185 non-native species in the Great Lakes, and guess that most of them got there via cargo ship. The most famous are Zebra mussels, which are native to the Caspian Sea and were first introduced to the Great Lakes in 1988. Since then, they’ve disrupted ecosystems all over the U.S., out-competing local species for food and wreaking havoc in harbors, boats, and power plants.
Those U of M engineers are clever, though. They’ve figured out how to keep a ballast-free boat from sinking. As a press release explains:
Instead of hauling potentially contaminated water across the ocean, then dumping it in a Great Lakes port, a ballast-free ship would create a constant flow of local seawater through a network of large pipes, called trunks, that runs from the bow to the stern, below the waterline.
This design concept has been around since 2001, but only now have its creators built a prototype. When testing their 16-foot, $25,000 wooden scale model (shown above), the engineers found that not only does it work, but propelling it requires 7.3 percent less power than regular ships. That efficiency translates to a savings of $540,000 per ship (which is only slightly less impressive when you consider that a typical vessel costs a whopping $70 million to construct).
If you’ve ever gone swimming in places like the Sea of Cortez during summer, or even in a sluggish Florida bayou, you’ve probably noticed how it’s possible for ocean water to be too warm. Where you begin to suspect that you may still be sweating, even though you are under water.
Tropical corals suffer from the same problems–but new research suggests they may have begun to deal with them.
Despite corals’ longtime affinity for waters languid and warm, the recent, gradual creep of temperatures has led to widely publicized episodes of bleaching and die-off (reeffutures.org has a nice explanation). The problem, it seems, stems from a parting of ways between a coral’s two component organisms: a small, reef-building animal related to a jellyfish, and single-celled algae that it shelters in its cells in return for nutrients.
Tragically, cracks appear in this happy arrangement as the temperature rises. The algae (or “zooxanthellae”) start to produce toxic waste products. The host has no choice but to eject its guest, and both parties are the sorrier for it. Whole swaths of reef turn a ghostly white.
But recently, scientists working near the Great Barrier Reef found that a coral called Acropora millepora could distinguish between two strains of algae. One strain, originally quite rare on the reef, handled high temperatures ably, allowing corals to stay alive. Three months after a severe bout of bleaching in 2006, the researchers discovered that the heat-tolerant strain had proliferated, spreading to many of the surviving corals, and presumably lending them some protection from future heat waves.
New Scientist tells the story well–though be sure to read all the way to the end, where one expert dourly suggests continued warming may have all corals living on borrowed time. And no one even mentioned the problem of ocean acidification rendering corals unable to build reefs.
A decade ago, thanks to the Federal Endangered Species Act, gray wolves were reintroduced into Yellowstone National Park. Conservationists have since used radio collars and overhead surveillance technologies to keep track of the animals’ whereabouts. But at the end of this month, federal support will dissolve—meaning scientists will no longer be able to use the expensive equipment.
But a new, cheaper technology might save the day. “Howlbox,” developed by scientists at the University of Montana in Missoula, is a $1,300 speaker-recorder system that broadcasts digitized wolf howls and then records any real howls that respond to the fakes. The system is pretty sophisticated: a precise frequency analysis of the recordings shows not only how many wolves responded, but which specific ones did.
The Howlbox was tested in one spot in Montana in January. The University of Montana’s pilot project, involving four remote sites in Idaho, is slated for June.
The biggest problem with the box might not be the response from wolves, but from humans. As this NYT article points out:
To the uninitiated, a Howlbox-enhanced forest could sound as if wolves were everywhere—a scary proposition. Montana wildlife officials are braced for a public relations campaign if the project moves forward.
Here at The Gist we were going to try to make it through the week without saying anything about any former New York governers – because, you know, ew. But as you may have noticed, that hasn’t stopped everyone else in the world. And then ace Gist-er Virginia Hughes pointed out on her own blog an interesting evolutionary-psychology angle printed in the L.A. Times. Unfortunately, author David Barash boiled down his evolutionary primer to a single, creepy shoulder shrug:
You want monogamy? Elect a swan. Or better yet, a [worm called] Diplozoon paradoxum.
Surely there had to be a way to write that article without implying that unfaithful men make better politicians. Thankfully, science writer Jennie Dusheck promptly set Barash straight in the same newspaper, just six days later. She gets in some good ones, including:
Barash makes the threadbare argument that men just can’t help themselves, titillating his readers with the tattered news that male animals copulate with more than one mate…
Even Natalie Angier, in the New York Times, couldn’t resist wading into the fray on Tuesday. But both these writers seemed mostly content to point out that female animals are just as capable of faking monogamy as males. Cheating is entirely unoriginal, Angier says, no matter how much time a pair spends
reaffirming their partnership by snuggling together like prairie voles or singing hooty, doo-wop love songs like gibbons, or dancing goofily like blue-footed boobies.
The ubiquity of what academics delicately call extra-pair copulation is worth pointing out. But as an argument against male randiness, it’s a little like saying Clyde wasn’t so bad because Bonnie was also a mean person.
The really interesting lessons come from a bit deeper in the evolutionary textbooks. The great variety of romantic norms in the animal world stem from a few basic principles, such as how much care the kids require in order to survive. Does it take two parents working for months on end just to raise one fat, happy kid? Choose monogamy – just ask an emperor penguin. Or can a mother raise a kid or two on her own? Then she’s likely to look for no more than a hasty donation of genes from a strong male of her choosing. Think elk, bighorn sheep, elephant seal. Many fish don’t even bother to get acquainted, simply spewing gametes into the water and trusting to the wisdom of the currents. Kids never know either parent.
Take a still closer look, and the soap opera of the sexes gets positively bizarre. Some people may take heart in the stories of phalaropes – shorebirds whose females wear bright colors and dominate males, leaving incubation to them. Then there’s the across-species relationship between relative testes size and degree of monogamy (you don’t want to know where humans fall on that graph). And that’s just the beginning of the field of sperm competition. It’s a world nicely described (with appropriate nudges and winks) in Dr. Tatiana’s Sex Advice to All Creation (now a TV show!).
If it’s any consolation, all this does suggest that philandering politicians are just about as advanced as your typical weevil or prairie dog. Now about the rest of us…. (Wikipedia: Bonnie and Clyde)
Last July, as we began to prepare an article about the mountain gorillas of Congo and Rwanda (Guerrillas in Their Midst) for the magazine, we received the horrible news that one of the gorilla families our author visited had been the victims of a brutal crime. Four gorillas—including the silverback Rugendo—had been killed. By the end of 2007, the body count at Virunga National Park reached ten. And to make the situation even worse, rebel forces had taken over the park and barred the rangers. Thus, the gorillas have gone unwatched and unprotected for months.
Today comes the news, though, that an arrest has been made in the case of last year’s gorilla killings. Honore Mashagiro, the head of the park’s southern sector, has been accused of organizing the killings, and six other foresters may be questioned about their role, BBC News reports. The gorillas may have been killed to divert attention from the illicit trade in a coal-like mineral called makala (according to the AFP) or the destruction of the forest to make charcoal (see the Gorilla Protection blog).
Digg
Reddit
Stumbleupon
Here at The Gist we were going to try to make it through the week without saying anything about any former New York governers – because, you know, ew. But as you may have noticed, that hasn’t stopped everyone else in the world. And then ace Gist-er Virginia Hughes pointed out 
