Discovery News: Environmental

Green Life at the Fair

2008-09-03T00:40:22-04:00

So... summer's over. I know because the Minnesota State Fair ended yesterday.

State law says school can't start before the fair is over. People here say things like, "I can't believe the fair starts tomorrow!" (i.e. "I can't believe a few days of livestock showings, Whac-a-Mole games, and fried food on a stick is all that stands between us and six months of -40-degree weather!") One of the public radio hosts even said, on the night before it started, "It's State Fair Eve!!!"

So it's a big deal. And it's a heckuva lot of fun. I went over this weekend, partaking of delicacies like a grilled chocolate sandwich, and all-you-can-drink milk for $1. I went to see the prize-winning pumpkin (834 pounds), and a whole bunch of newborn piglets. I missed checking out the butter booth in the dairy building where the dairy queens of the fair--the finalists for the title of Princess Kay of the Milky Way--each have their busts carved in 90-pound blocks of butter on display.

I also went over to check out the "Progress Center", the headquarters for all things green. Outside the center was a single, full-sized wind turbine blade, planted in the ground like a statue. It was absolutely immense--123 feet long--and elegantly shaped, twisting slightly as it thinned to the tip.

According to the stats printed at its base, the single blade weighed six tons, as much as an African elephant. When in place, at the top of a wind turbine, the tip would rise more than 389 feet into the air, taller than the Statue of Liberty. A turbine made of such blades would produce 1.5 megawatts, which would offset 90,000 tons of CO2 over its 20-year lifetime.

Other highlights from the center included an exhibit showing off how much trash the average Minnesota family of four generates in a year: four tons. The model heap must have been 15-20 feet across and equally tall. It would certainly take up most of my backyard. Thirty-two percent of that is packaging.

One way to reduce all of that trash is by composting... which a Progress Center exhibit described in terms a Minnesotan could really understand: "microbe hotdish".

Hmm... I'll hold out for the more appetizing kind now that winter is just around the corner.

(Image: J. Marshall. For more images of the Minnesota State Fair, check out this NYT slideshow.)

Nemo's Nose

2008-08-29T14:58:38-04:00

Today Discovery News published an article about research showing how orange clownfish follow the smell of leaves and anemones, presumably to find their way back to the reef anemones they live within.

The researchers recorded how much time each fish spent on either side of a chamber where each side contained water from different sources. This allowed them to measure the fishes' preference for different-smelling water. (Read the details here.)

Above is a video from Jelle Atema of Boston University, who developed the chamber, showing how the experiment works.

He tested a juvenile blue damsel fish with water from its home reef and from a reef 15 miles away. Watch how the fish switches sides when Atema swaps which side carries the familiar water. The fish quickly swims back into its homey water.

The researchers in the study described today observed similar behavior with the clownfish they studied.

I particularly enjoyed reporting on this research because it was such a great example of the scientific method.

The experiments were as simple as a school science fair project in their straightforward comparisons: No particle accelerators or DNA extractions required. But the tests were clever and the results were clean.

What was incredibly striking is just how strong the fishes' preferences were. When presented with beach water, anemone-scented water, or rainforest-leaf-scented water, the fish spent anywhere from 89 to 98 percent of their time in those waters compared with what you might call "unscented" water. When offered water laced with the scent of an unfamiliar tree leaf, all of the fish scooted out of it immediately, spending 100 percent of the time in the neutral water.

This struck me because when I was in college, I took a class in behavioral ecology where we had to try to measure some aspect of guppy behavior for a class project. We were each given a dozen guppies and a wading pool and sent back to our dorm rooms to run an experiment.

Our groups' experiment was to see whether the size of a guppy school affected how fast the guppies found food. We put six little feeding stations (fish flakes floating inside loops made of drinking straws) around the perimeter of the pool and released schools of 1, 2, 4, 6 and 12 fish, and timed how long it took them to find food in the station that was stocked with food (randomly selected by rolling a die).

The problem was, first of all, that we didn't get the experiment done before winter break. So, we decided that I would carry the guppies home on the airplane and do the experiment in my parents' basement. We figured I could just buy a kiddie pool when I got home.

Somehow, it didn't occur to us that NOBODY sold wading pools in December in Colorado.

Then, one of the guppies gave birth and died, so I went to the pet store to replace the guppy with another grownup. Pregnancy might have been a confounding factor anyway.

After borrowing a wading pool from some neighbors, I retreated to the basement for the guppy time trials ... which failed miserably. The fish just swam around. There was no real trend, and I didn't really have time to make sure the guppies got hungry again in between searches, so who knows what they were looking for.

The whole experience (which, I should add, followed a project earlier in the semester for which I chased squirrels around a campus lawn trying to monitor their nut-caching behavior) convinced me that trying to make quantitative measurements of animal behavior was impossible, or at the very least would lead to several decades in graduate school waiting for animals to get hungry again.

So that's why I took note that the Jones' groups fish time trials come out so cleanly... I guess I should have realized that all those animal research journals weren't just reporting on aimless guppy wandering, so there must be better observations to be made. Still, it's great that this group for found such opinionated fishes.

(Video: Jelle Atema, Boston University)

Bat Cam

2008-08-25T16:45:12-04:00

Check out these cool, eerie infrared videos of bats circling wind turbines in the dark.

(A bat repeatedly investigates and briefly lands on the turbine tower while the rotor spins slowly.)

Here's the story:

We reported today on a study showing that the cause of many mysterious bat deaths near wind turbines is not slamming into the blades, as you might expect (except that bats have that whole echolocation thing, so they are pretty good at locating moving objects in the dark)... but rather that their lungs more-or-less pop if they fly through zones of rapid pressure drop near the blades, which causes the air in the lungs to expand rapidly like a scuba diver surfacing too fast. Sad.

Researchers have been trying to figure out what is behind these deaths for a while, and Ed Arnett of Bat Conservation International and the Bat and Wind Energy Cooperative thinks the problem is exacerbated because the bats are attracted to the wind turbines, maybe because of sounds the turbines make, or because they look a bit like the trees bats might roost in.

To try to better understand the bats' behavior around turbines, Arnett and colleagues at Boston University set up thermal infrared cameras at the base of the windmills (can I call them windmills or is that déclassé?)

According to Arnett, the results of the videos show the bats checking out the turbines. "They go up and investigate the turbines. We've got pictures of them chasing the blade tips."

The videos can't tell the researchers why, but check them out for yourself (more below). You can also read the study that goes with them at the same link.

( A bat investigates moving blades.)

(A bat investigates the turbine tower (monopole), showing typical 'touch-and-go' behavior.)

(One or more bats repeatedly investigate the turbine blades and tower (monopole).)

(Videos: Jason Horn and Bat Conservation International)

Organic Motivations

2008-08-20T23:54:52-04:00

CNN carried a story about a study concluding that organic produce does not contain more nutrients than the same five fruits and veggies (carrots, kale, mature peas, apples and potatoes) conventionally grown.

That is certainly a bummer for the organic food industry, which would no doubt like to make nutrition claims about the food. But, Michaeal Pollan, in The Omnivore's Dilemma, cites a similar 2003 UC Davis study that found corn, strawberries and blackberries grown organically had more vitamin C and polyphenols than conventionally grown ones in neighboring plots. So, does it vary from plant to plant, place to place, or is something else going on?

More to the point, I don't think most people buy organic food because they believe it has more vitamins. I think they do it because they don't want to risk eating food with any pesticide residues. They may also do it because they want to reduce the amount of pesticides and petrochemical fertilizer entering the environment, or because they want to support agricultural practices in which the workers aren't exposed to such chemicals.

As with so many things, though, organic farming is not an across-the-board win. Sigh. The CNN story mentions a 2006 report by the University of Manchester Business School investigating the environmental impacts of food. While organic food used less pesticide, the land requirements were often greater--presumably because the crop yield was reduced.

The energy requirements for organic milk were less than conventional, but the land use was greater, and the greenhouse gas emissions per gallon were higher for organic. And, according to the study summary, "organic wheat production has higher impact than non-organic," mainly because its eutrophying emissions are higher.

This is just one example of why shopping these days is such a paralyzing experience: when choosing which apple to buy becomes a trade off between deforming the local frogs or drowning the polar bears, it feels easier to go hungry.

Fortunately, Consumer Reports offers some advice on which fruits and veggies are worth buying organic--at least from a pesticide perspective.

(Image: Flickr user Scoobymoo. Some rights reserved.)

Sex in Acid Has Low Returns

2008-08-05T19:42:22-04:00

You've probably heard that ocean acidification is predicted to cause problems for calcifying sea critters, like certain plankton, which are anticipated to have trouble building their calcium carbonate skeletons in lower pH seas.

Research published today in Current Biology uncovers another possible problem with a more acidic future ocean: sperm-meets-egg may not work as well. At pH levels predicted for the end of this century, Jon Havenhand of Sweden's University of Gothenburg and colleagues found sea urchin sperm swam more sluggishly (that is, both speed and motility were significantly reduced.) They also found a 26 percent reduction in the number of eggs that developed into swimming larvae under such conditions.

Havanhand expects his results will apply to fertilization in other ocean species. "Of course, this is a fairly sweeping extrapolation, and many more data are required before we can say anything definitive on the topic," Havenhand told Discovery News. "However as a first look at the effects of acidification on fertilization in marine invertebrates, this doesn't paint an encouraging picture!"

Energy From Water

2008-08-01T16:32:13-04:00

Two papers published in today's issue of Science announce breakthroughs in making cheap solar energy a reality.

A big problem with getting energy from the sun has been that the sun doesn't shine all the time, at least down where we are.

Plants get around this by harnessing the sun's energy to split water into hydrogen and oxygen and using the energy in these molecules to make storable sugars. The plants can break these down later, come rain or shine, releasing the stored energy.

Researchers have tried to make this process work without plants, by using catalysts to split water into hydrogen and oxygen and then using a fuel cell to recombine the stored hydrogen and oxygen later to make water and energy. But making this work has required harsh conditions and expensive materials. The new papers get around these problems by finding new catalysts, opening the door to 'round the clock solar energy.

The first paper uses a cheap cobalt-phosphate catalyst to create oxygen from water, and the second gets around the expensive platinum catalyst needed for the hydrogen side of the process, replacing it with one made from organic materials.

There's plenty of development to do to take the process from lab to the real world, but the researchers are clearly fired up about it, and others in the field are, too. Read some more about it:here, here, and here.

(Image: New oxygen catalyst in action, credit: MIT/NSF)

Migrations Got Me Down

2008-07-31T22:58:46-04:00

Usually, my job is really fun. I get to learn about how bumps on whale fins may make wind turbines more efficient or explore a surprising new take on how to reduce one's carbon footprint. But sometimes, this job is depressing.

While it captures the imagination to ponder the seemingly infinite migrations of passenger pigeons that once darkened the sky, or the huge masses of bison wandering the plains, reading up on these migrations, as I did for today's story, also makes me feel pretty sick at our history. We managed to wipe out three to five billion passenger pigeons from this continent within a couple of hundred years, using methods that were not pleasant to read about.

People saw the extinction coming, but nobody acted effectively to protect the species. By the time captive breeding efforts started, there were too few passenger pigeons; they needed large numbers to court and breed. The last known passenger pigeon died in 1914.

The buffalo story is equally depressing. Maybe you've heard it before, but I was reminded of it as I researched today's article. You can look at heaps of bison skulls, the animals killed for their pelts and the meat wasted. This story seems to have a happier ending, because we still have bison, but not that many.

These stories wouldn't get me so down if it didn't sound just exactly like what we're doing in a zillion ways today--with many aspects of climate change and conservation. Reading the stories in retrospect, the actors come across as ludicrously greedy and shortsighted. I can't help thinking that's how we'll look down the line, too.

(Image: Passenger pigeon)

Getting There Sans Car

2008-07-31T18:44:09-04:00

While we're on the subject of walking, this week Google launched a version of Google maps for pedestrians. If you ask for directions to a spot less than 6.2 miles away, Google will now give you the option to select directions for going either by car or walking.

When I tried it, Google gave me a shorter route for walking to the University of Minnesota from my house than for driving, but certainly not a more pleasant one, sending me down a very busy street instead of along the river (which is about a half-mile longer). It looks like even when less-trafficked routes are equally direct, it picks a major street. But at least it won't send you on the freeway.

Meanwhile, here's a Google-maps-based cycling map created for the Vancouver, B.C. area. You can choose whether or not you want to include major streets in your route, and you can select whether you want to take the path with the least elevation gain, the most vegetation, the shortest distance, the least traffic pollution, or if you want to require that your route have no spots along the way that are steeper than a slope of your choice. Once it marks your way, the path is color coded to indicate the hilly parts.

In addition to telling you how far the route is and how long it's likely to take you, the site tells you the amount of greenhouse gases you avoided by biking instead of driving, the mean nitrogen oxide concentration along the route, and how many calories you burned. I want one for the Twin Cities.

There's a push for more tools like this. Here's an AP story with some more info on efforts in other places.

(Image: From Cycle Vancouver)

How Walkable Is Your 'Hood?

2008-07-31T00:41:12-04:00

Today Discovery News highlighted research showing that the more your neighborhood allows or encourages you to walk, the less you are likely to weigh.

So if you're looking to slim down and you've decided moving is cheaper than joining a gym (it is more likely to stick), Walk Score can help you pick the most walkable parts of any of the country's largest 40 cities. I'm a bit disappointed that Minneapolis-St. Paul is not on the list, because the two cities are counted separately and neither makes the top 40 on its own.

But if you live in Milwaukee, Cleveland, or 38 other cities, you can see a map and list of the most walkable neighborhoods in town.

According to Lawrence Frank of the University of British Columbia, Walk Score uses distance to many destinations to determine walkability, which has limitations. "You could be right near a mall, and you could be on the end of the culdesac and not be able to get to the mall," he said.

So, that's just to say that you shouldn't buy a house without visiting it first and making sure you really can walk where you want to. Indeed, Walk Score suggests this and notes its own limitations. But the site has some pretty nice maps and it's certainly better than nothing.

Check out America's most walkable neighborhoods.

Do you live in one? Does a walkable lifestyle make your life or health better?

(Image: Flickr user Atilla1000, some rights reserved.)

Saving the Planet, One Sandwich at a Time

2008-07-28T01:51:06-04:00

I've been meaning to highlight the PB&J Campaign since one of its members brought it to my attention a couple of weeks ago in a comment on a blog post I wrote about meat consumption.

But late last week, our gassy, mooing ruminant friends showed up again at Discovery News, which gives me a good excuse.

I concluded my original blog post by saying, "To the climate conscious: learn to love lentils." But PB&J's Bernard Brown rightly pointed out that lentils need not be your only protein if you leave meat behind: don't forget the good ol' peanut butter and jelly sandwich.

It's a mighty good suggestion. If you haven't eaten a PB&J since fourth grade, I suggest you try one. The combination of nostalgia and tastiness makes returning to the most-classic of sandwiches a powerful experience.

Of course, the point of the campaign is not just to bring back one's playground days, but to highlight the reduced carbon footprint of a plant-based diet.

As for the PB&J, the campaign notes: "Each time you have a plant-based lunch like a PB&J you'll reduce your carbon footprint by the equivalent of 2.5 pounds of carbon dioxide emissions over an average animal-based lunch like a hamburger, a tuna sandwich, grilled cheese, or chicken nuggets."

The site also highlights some fun food carbon calculators here and here.