JERUSALEM (Jul. 8)
Research conducted by the Hebrew University here has resulted in the surprising discovery that common household detergents can be effectively used as shark repellent.
The discovery is the result of studies of the poisonous secretion of the Red Sea flatfish. The studies were conducted by Prof. Eliahu Zlotkin of the zoology department at the Alexander Silberman Institute of Life Sciences and Prof. Yechezkel Barenholtz of the biochemistry department at the Hebrew University-Hadassah Medical School.
The professors succeeded in extracting the active agent in this secretion, a toxin called pardaxin, and discovered in their research that the toxicity of pardaxin and its shark repelling qualities seemed to be related to its surfactant, detergent-like properties, expressed in reduction of water surface tension causing foaming and reduction of drop volume.
Zlotkin, in concert with Prof. Samuel Gruber of the University of Miami, then compared the effect of pardaxin and a number of common detergents on the aggressive lemon shark. They found that two of the 15 compounds they tried were even more effective in repelling the lemon shark than even the natural toxin of the flatfish. Most recently, these detergents were found to be effective also in repelling large dangerous blue sharks in the open sea water off California.