January 2005

Vol. 20, No. 1     What's this?

Shark Be Gone

from the January, 2005 issue of Undercurrent  

Scientists may have come up with the perfect solution to an age-old problem that’s good for both humans and marine life. Researcher Eric Stroud, of the New Jersey based Oak Ridge Shark Lab, reports that he has developed a chemical that magically shifts sharks from hunting mode to flight mode. The pheromone-like substance is from a group of chemicals called “semiochemicals,” chemical messengers that aid in communication with other animals in the same species. For example, a minnow that has been attacked will emit a semiochemical that prompts the rest of the minnows in the school to dissipate rapidly. Stroud and fellow researcher Mike Herrmann believed that sharks must act upon similar semiochemicals and began investigating the molecular chemistry of shark tissue till they discovered a substance that sends sharks into “alarm mode.”

So far, the chemical has been tested on six different species of sharks feeding in chum-filled waters. After the shark repellent was dropped from a boat, sharks immediately stopped feeding and left the area, but other species of fish feeding nearby were unaffected. The chemical appears to be effective in doses as low as 0.1 part per million, yet does not seem to cause pain to sharks or be toxic in any way. The substance has obvious appeal and may soon be incorporated into wetsuits, sunblock, and swimwear. At the same time, it holds promise for alleviating commercial fishermen’s “shark bycatch” as well as helping sharks avoid hazardous human encounters, ultimately aiding their survival.

National Geographic News