Friday, April 9, 2010

A radical transformation

Al Gore -- "I used to be the next President of the United States" -- came to Duke Thursday to deliver the Duke Environment and Society Lecture, and lots of people, both receptive to his message on global climate change, and hostile to it, turned out to watch.

"If you are running a corporation, as long as you can drag your pollution into the air like an open sewer, then you have always have an incentive to work against anything beneficial to the environment," said Gore, who has been awarded both the Nobel Peace Prize and an Academy Award for this work.

Caption: Former Vice President Al Gore met with Nicholas School of the Environment students Eric Ward, Kim Novick, and Angie Lee in the green room of Page Auditorium just prior to Gore's presentation. Photo by Chris Hildreth/Duke Photography

Although many apparently expected a recap of his "Inconvenient Truth" talk, the Duke appearance was more similar to his latest book, "Our Choice: How We Can Solve the Climate Crisis," and included many verbatim quotes from it.

"One hundred and fifty one years ago, two things happened: the first oil well was drilled in Pennsylvania, and at the same time another scientist discovered that carbon dioxide (reflects) infrared radiation. The birth of climate science and the oil age coincided."

Justin Ko, a Trinity sophomore and a Premed student said afterward that Gore's philosophies would make him a great President. "He is extremely passionate about protecting the environment and I like his radical ideas about global warming," Ko said. "Adding a cost to pollution is justified morally, socially and politically. However, his efforts are not very effective right now. That's why he needs to re-enter politics and enforce policies at a broader level."

Gore highlighted four major instruments to combat the environmental disasters, especially global warming. "We need to focus on educating children, empowering women, raising the child survival rate, and improve fertility management."

Further, he added that "we need to make a decision to move wholly into renewable energy, and include forestry and agriculture in our solutions."

Vysak Venkateswaran, a Pratt sophomore and a Biomedical Engineering major, feels that this argument needs to revised a bit. "You simply cannot achieve longstanding change in the market of climate change without significant government intervention. Bringing up the topic of investing in newer and more expensive technology in the current recession is not the best idea. Even if the government does decide to go full out in developing green technology, there is going to be a lag time."

The audience, heavy on Nicholas School faculty and students, gave him a standing ovation both entering and leaving Page Auditorium.

Sunday, April 4, 2010

Hide and Seek in the Open Sea

Duke biologist Sonke Johnson has made many trips underwater to study aquatic organisms. The direct observations enable his research, but he laments that any observation - whether via submersible, diving, or otherwise - causes some disturbance that impedes observation of normal behavior. At worst, with a schoolbus-sized submersible, “you film responses of stark terror,” Johnsen said.

Johnsen’s lecture, April 2, was given in memoriam of Dr. Knut Schmidt-Nielsen, the pioneering physiologist who discovered, among other things, the function of a camel’s hump for storing water and energy. (You may have seen the statue of him with a camel near Bio Sci.)

Johnsen equated trawling, another research method, to “flying over London with a grappling hook and trying to determine the behavior of a London gentleman from what you catch. You can get some information from this, but it’s very limited.”

Blue water diving, sans submersible, is less disruptive, but “you’re left studying the slow and the dumb.”

Johnsen has also spent time researching the ecological pressures (namely predators) that cause ocean organisms to look one way or another. These organisms live in an environment where there is nowhere to hide, and where successful camouflage ensures survival.

“Predation in the open ocean is, even by predation standards, pretty brutal,” Johnsen said.

Johnsen described four modes of camouflage used by ocean organisms:
  1. transparency

  2. cryptic coloration

  3. mirroring

  4. counterillumination (“hiding yourself with lights”)

Transparency is a very common adaptation in the ocean, Johnsen said, but there are strings attached. “The fundamental trick these animals have to solve is how not to scatter light.” Transparent organisms must be extremely flat, because if their bodies give light a chance to scatter (even at a cellular level), they will appear opaque-- and thus vulnerable to predators.

Unfortunately, a flat body is not the only problem transparent animals have to solve. In order for eyes to work, they must have pigment to absorb light. Thus, they must be visible-- unless the organism can find another solution. Some organisms spread out the eye to present less of a target to predators and others compact their retinas (at a great cost to function).

Transparent stomachs also can be troublesome, Johnsen said. Even transparent animals will become opaque when chewed, and perhaps colorful. “You’ll need an opaque gut, otherwise you’ll light up like a Christmas tree when you’re digesting your food.” Some organisms address this problem by making their gut as small as possible, or by resorting to a liquid diet.

Cryptic Coloration
According to Johnsen, “something that is ridiculously colorful on land could actually be ridiculously cryptic underwater.” Organisms’ coloring also depends greatly on where they live in the water column. “As you go deeper, some of the blue light is actually converted into red light,” due to Raman scattering. For that reason, many abyssal creatures are either transparent, red, or both.

“The oceanic light field is fairly symmetrical. Turn around, and you’ll see the same amount of light.” Mirroring takes advantage of this, and works by effectively showing a representation of what should be at a particular spot (if the organism were not). “It’s not lost on nature that this works really well.”

Johnsen tried to evaluate whether mirroring or coloration was a better protection from predators, depending on the effectiveness of each in different environments (coastal vs. oceanic water, noon vs. sunset, different depths). He found that in general, mirroring was more successful because it was more robust, but that coloring was fine if the organism tended to stay in the same spot.

Some deep-sea organisms hide themselves from predators below with bioluminescence (creating their own light). These organisms can replicate light that is the same intensity of daylight, and thus trick predators into thinking they aren’t there.