Chemist Eric. M. Stroud demonstrates his shark repellent.Credit: Joseph Caputo/Science Metropolis
Eric. M. Stroud
Sharks didn’t become the terrors of the sea by looking cute. With a sixth sense to detect electrical signals, these creatures are natural hunting machines.
This evolutionary trademark may also be the key to keeping sharks safe from the fishing industry. According to Oceana.org, a marine advocacy group, 50-million sharks are unintentionally caught by commercial fishermen each year. While some survive, many die or are de-finned as a result.
The trouble is, both fishermen and sharks know where to find fish, so keeping sharks away from catch sites isn’t going to happen. The solution is to make a repellent, a chemical or bait that will keep sharks out of harm’s way.
SharkDefense, a six-year old organization of researchers that specializes in keeping sharks safe, now has evidence that certain kinds of metals and magnets may repel sharks by overloading their electricity-detecting sense.
“A magnet is all about electrons,” said Eric. M. Stroud, lead chemist and SharkDefense co-founder. The magnets he experiments with have thousands of times the strength of the Earth’s magnetic field. Put one near a human or fish - no effect. But place one near a shark and it can awaken from even the deepest rest. (See video below).
Stroud, also a Ph.D. student at Seton Hall University, discussed SharkDefense’s progress Tuesday night as part of the New England Aqiarium’s Free Lecture Series. In addition to magnets, sharks tend to avoid chemicals secreted by dead sharks as well as rare Earth metals.
The company’s goal is to apply this knowledge to baits that fishermen can purchase to avoid catching sharks, although the product has to be practical. One idea was to hang dozens of magnets from the side of a boat. The problem: Boats are made of metal. More promising is a hook that includes a small piece of magnet nudged between a sleeve and steel leader.
Although the technology is available, SharkDefense still needs to hook manufacturers. “As a small company, we can’t make the stuff,” said Stroud. He hopes to get the support of government agencies like the National Oceanic and Atmospheric Administration.
As far as keeping sharks away from humans. There is always a company like SharkShield, which sell electronic wave devices for “peace of mind.” Although, don’t spend too much - for every 50 million sharks captured by humans, only a dozen humans are caught by sharks.