Shark Repellents Come in Small PackagesWednesday, September 17th, 2008 by Wojcik |
photo of a moses sole.
When I was a tyke, sharks were my thing (they’re still my thing for that matter.) I had the best collection of books on sharks that I have ever seen, even to this day. So you can imagine in 1982, when I was fourteen, the ground breaking National Geographic special on sharks came out, I was pretty stoked. Coincidentally, VCR’s became popular about that same year. I recorded that show and watched it over and over and over again. I was so much of a dork that I use to take notes so that didn’t miss anything. My fathers shark fishing buddies would even call me on the telephone to ask me things like “Do M80’s really work to attract sharks?” and “Do sharks like clear water or do they like it more murky?”. Shark-boy.
One of the things that came out of that program… was that there was this little flatfish that lived in the Red Sea called the Moses sole and for some reason sharks would avoid these little suckers like the plague. Dr Eugenie Clark, of the University of Maryland, was the first to discover this and started to do some research into what was going on. By hanging a bunch of live fish of different species on a line around hungry sharks, she notice that all of the other fish were eaten except the moses soles. In fact, when the sharks attempted to eat the little flatfish their jaws would lock up and they couldn’t complete their bite. Pretty cool!
Further research revealed that the fish excreted a toxin called pardaxin from the base of their dorsal and anal fins and that it really did repel sharks. As you can imagine there was a lot of excitement about the potential human uses for this chemical compound for swimmers, surfers, and the survivors of sinking ships. Coppertone even tried to incorporate it into sunscreen so that bathers would be protected. Unfortunately, the chemical becomes extremely unstable outside of the fishes body and the synthetic version breaks down in less then 24 hours after forming in the laboratory. Recent studies have shown that a flounder that lives in the Caribbean, called a peacock flounder, has similar effects on sharks but they don’t know if it is the same chemical is doing it.
Video of a peacock flounder
Other shark repellents have been tested. Sodium lauryl sulphate, a chemical commonly found in detergents, has shown some promise. At this point nothing has really worked well enough to have any practical applications.
Maybe I’ll look into shark shields next…
