[2] The best-understood factor is pardaxin, acting as an irritant to the sharks' gills, but other chemicals have been identified as contributing to the repellent effect.
[3][4] In 2017, the US Navy announced that it was developing a synthetic analog of hagfish slime with potential application as a shark repellent.
[5] Some of the earliest research on shark repellents took place during the Second World War, when military services sought to minimize the risk to stranded aviators and sailors in the water.
The future celebrity chef Julia Child developed shark repellent while working for the Office of Strategic Services.
Building on this work, Stewart Springer and others patented a "shark repellent" consisting of a combination of copper acetate and a dark-colored dye to obscure the user.
Since the 1980s,[12] there is evidence that surfactants such as sodium lauryl sulfate can act as a shark repellent at concentrations of the order of 100 parts per million.
From 2005-2010, an extensive study on the effectiveness of semiochemicals as a shark repellent was conducted by scientists from SharkDefense Technologies and Seton Hall University.
[15] As of 2014, SharkDefense partnered with SharkTec LLC to manufacture the semiochemical in a canister as a shark repellent for consumers called Anti-Shark 100.
[18] The 1947 Robb White book Secret Sea mentions a copper acetate shark repellent developed by the U.S.