Permanent magnets do not require power input, making them practical for use in fisheries and as bycatch reduction devices.
Its manufacturers cite numerous scientific papers which support the effectiveness of permanent magnets in a range of contexts.
[2] 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.
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.
On January 1, 2009, a peer-reviewed publication described experiments in Australia showing the efficacy of using magnets to deter sharks.
[3] On January 12, 2010, Craig O'Connell from SharkDefense also published a peer-reviewed paper on the efficacy of magnetic shark repellents.
[5] Several species of sharks have demonstrated the ability to sense magnetic fields (Kalmijn, 1978; Ryan, 1980; Klimley, 1993; 2002).
The Ampullae of Lorenzini organ within sharks is used to detect weak electrical fields at short ranges.
The detection range of this organ is effective only within inches, as sharks sense bioelectrical fields in the final stages of prey capture.
Animals which lack that Ampullae of Lorenzini organ do not display aversive behavior in close proximity to the magnetic field, making this technology selective.
In 1995 researchers found that sharks have a heightened sensitivity to low frequency electrical fields, at a close range.
This helped with the development of technologies like SharkShield, which is a product that is used for various water-sport activities (such as surfing) that emits a 3-D electronic field that surrounds person who is using it.
[citation needed] In 2011, the first test of a permanent magnet repellent on a Great White shark was successfully conducted in South Africa with Chris Fallows and Craig O'Connell (SharkDefense).
Responses of the Southern Stingray (Dasyatis americana) and the Nurse Shark (Ginglymostoma cirratum) to Permanent Magnets.
Investigation of Grade C8 Barium Ferrite (BaFe2O4) Permanent Magnets as a Possible Elasmobranch Bycatch Reduction System.
Highly directional swimming by scalloped hammerhead sharks, Sphyrna lewini, and subsurface irradiance, temperature, bathymetry, and geomagnetic field.