Grizzlies vs. wolves! Killer whales vs. great white sharks!

I ignored the Golden Globes last night to flip between the Discovery Channel, which was airing a new 2-hour episode of its Planet Earth series (which is really the best, most beautifully filmed nature series I've ever seen), and channel 9 (public broadcasting) which had a new episode of Nature called Clash: Grizzly Bear and Wolf Encounters. The interactions of these two top predators of Yellowstone certainly make for fascinating viewing. Sometimes the wolves keep the carcass, sometimes the bear (when it's big enough, or hungry enough) takes it away from them, and the wolves simply wait patiently until the bear is finished. As for the Planet Earth footage, have you seen the images of the so-called "chandelier ballroom" of Lechuguilla Cave? (A secret cave whose exact location is not available to the public, and which the Planet Earth crew had to negotiate for two years to get to film.) Fucking incredible. There are lifeforms there that live by eating the rock itself. Scientists say that cave, which was completely sealed off from the rest of the planet for millions of years, and contains some of the purest water on earth (completely free of pollutants), is similar to what might be found in subterranean caverns on the moon.

Then this morning I caught a National Geographic episode called The Whale That Ate Jaws, documenting the first-ever eyewitness account of a killer whale attacking and killing a great white shark not far outside of San Francisco Bay in 1997. It was a really fascinating program! Orcas are so smart (as one might expect, being basically giant dolphins) they know how to turn the shark upside down to place it into what's known as "tonic immobility," meaning that it goes into a trance, its brain floods with serotonin and it's basically helpless at that point. Even more amazing, once one great white is killed, it releases a chemical into the water that alerts all the other great whites in the area and they all flee en masse hundreds of miles away to escape further predation. Absolutely astounding.

This raised a fascinating question for me, though, which wasn't addressed in the segment. If scientists can re-create the shark's death chemical and use it to make sharks flee with lightning speed even in the middle of a feeding frenzy, as was demonstrated in the show, couldn't that chemical be sold to human swimmers and used as a fail-proof shark repellant in waters inhabited by great whites? Surely someone else must have thought of that by now...