Monday, August 2, 2004

Reverse chumming?

Researchers tout shark repellent (MSNBC - AP - 30 July 2004)

If proven effective, the repellent one day might protect divers, surfers and swimmers. But researchers say that would require much more study. First they hope it can protect sharks — in decline worldwide due to overfishing — by reducing the numbers caught needlessly by long-line commercial fishermen.

The repellent, called A-2 because it was the second recipe tried, is derived from extracts of dead sharks that Stroud gathered at New Jersey fish markets and piers. Fishermen and scientists have long noted sharks stay away if they smell a dead shark. ...

Sad to say, but humans are quite the opposite. We are drawn to fellow human's blood, at least in the moral sense. We prey on the failures of others.

A dose of 4 fluid ounces is enough to scare away feeding sharks, Stroud said, keeping them away from a fish head for two hours with just a few drops per minute. ...

The repellent, though nontoxic, is apparently so disagreeable to sharks it can revive them from semiconsciousness. Some species slip into a hypnotic state if turned belly-up, and tests found the repellent brought captive sharks out of that trance.

Repellent research began in World War II, when the U.S. Navy created “Shark Chaser” for sailors and downed pilots. Mixed with black dye, it was made of copper acetate, which scientists thought would smell like a rotting shark. Studies later showed it wasn’t that effective.

A promising find came in 1972, when University of Maryland shark expert Eugenie Clark discovered that a Red Sea fish, the Moses sole, secreted a milky substance that repelled sharks. ...

In most cases, the danger of attack is extremely slight. The International Shark Attack File, at the Florida Museum of Natural History, recorded 55 unprovoked attacks worldwide last year, including four deaths.

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