Putting a mild electric field on fishing weights may save endangered hammerhead sharks from becoming part of the bycatch.
Hammerhead shark numbers have declined precipitously in the last twenty years, mostly due to poaching and bycatch. The decreased population is determined by a 90% reduction in bycatch numbers. Scientists are looking for ways to reduce bycatch in order to give the sharks a chance to build the population back up.
Hammerhead sharks hunt for their prey by sensing the mild electric currents generated by living creatures. This way, they can find fish even in murky waters. Scientists found that adding mildly electric fishing weights to longlines decreased the amount of hammerheads caught by 50% without decreasing the number of commercially important fish caught.
The electrically charged fishing weights are made of neodymium and praseodymium. The big problem, so far, is that these two rare earth metals are expensive and they dissolve fairly quickly in water. They need to be replaced often.
Still, it’s an interesting thought. Perhaps some entrepreneur will come up with an inexpensive way to electrify fishing line cheaply without scaring away other fish (or endangering the humans who work in fisheries.)
Hammerhead shark photo via Shutterstock