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Magnetic shark repellents utilize permanent magnets, which exploit the sensitivity of the Ampullae of Lorenzini in sharks and rays (electrosense). This organ is not found on bony fishes (teleosts), therefore, this type of shark repellent is selective to sharks and rays. Permanent magnets do not require power input, making them ideal for use in fisheries and as bycatch reduction devices. == History == During November 2004, Sharkdefense researcher Eric Stroud accidentally dropped a magnet onto a rubber mat near a captive tank at the Oak Ridge Shark Laboratory. He noticed that juvenile nurse sharks (''G. cirratum'') near the tank wall swam away. While the initial event may have been due to vibrations, it led him to test the effects of the magnet on the captive sharks. Placing the magnet within the tank, Eric observed that nurse sharks avoided the region around the magnet. Follow-on tests in 2005 with Michael Herrmann at the laboratory used an acrylic Y-Maze and showed preference towards non-magnetic exits and strong conditioning. During February 2005, Patrick Rice and Eric Stroud conducted tonic immobility trials at the Bimini Biological Field Station, Bahamas, which confirmed that juvenile lemon sharks (''N. brevirostris'') and juvenile nurse sharks (''G. cirratum'') roused when permanent magnets were presented within 50 cm of the sharks nares. Interestingly, mobility was not terminated when strong electromagnets were placed near the sharks. In May 2006, SharkDefense won the WWF (SmartGear ) award for its proposal to selectively reduce sharks bycatch in commercial fisheries using permanent magnets. Michael Herrmann accepted the award in Brussels on behalf of SharkDefense. SharkDefense is the inventor and is currently the patent application holder for this technology and actively collaborates with other researchers to investigate species-specific effects and gear design. On January 1, 2009, a peer-reviewed publication described experiments in Australia showing the efficacy of using magnets to deter sharks.〔Rigg, D.P., Peverell, S.C., Hearndon, M., Seymour, J.E. 2009. Do elasmobranch reactions to magnetic fields in water show promise for bycatch mitigation? ''Marine & Freshwater Research'', 60, 942-948.〕 On January 12, 2010, Craig O'Connell from SharkDefense also published a peer-reviewed paper on the efficacy of magnetic shark repellents.〔O’Connell, C.P., Rice, P.H., Stroud, E.M., Abel, D.C., Simuro, N.C. 2010. The Effects of Permanent Magnets on the Southern Stingray (Dasyatis americana) and the Nurse Shark (Ginglymostoma cirratum). ''Marine and Freshwater Behavior and Physiology''. A second, confirming paper is currently in peer review.〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「magnetic shark repellent」の詳細全文を読む スポンサード リンク
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