A series of tests with a new Selective Magnetic and Repellent-Treated hook (SMART hook) capable of deterring sharks in commercial fishing operations has been discovered and provides several advantages over conventional fish hooks.
Researchers in the grant-funded study discovered the new technology by combining shark-repellent metal alloys and magnetism which helps reduce unintended shark catch (shark bycatch).
reports sharks contain a highly sensitive electrical sense in their nose allowing them to react differently to magnets and metals
. “Combining a magnetic repellent with a galvanic repellent is very important, because many studies have show that sharks behave differently to magnets or metals alone,” said Craig O’Connell, a researcher with Shark Defense.
“There are many species of shark, and they seek out their prey differently. Having two repellents available increases the chances that the sharks will be deterred,” O’Connell added.
Market value species, such as tuna, do not have the electrical sense and are not repelled by the new hook.
A total of 50 tests were conducted on two different shark groups and scientists found a 66 percent reduction in baits taken using small recreational-size hooks and on commercial hooks’ ability to contain more magnetism and shark-repellent materials
because of their size, a 94 percent reduction in baits taken was recorded.
Overall numbers, depending on species and location, have shown an 18 percent to 64 percent decline in shark catch.
notes accidental catches of sharks result in damage and loss of gear, a reduction in the catch of marketable species, an increased risk of injury, and a major loss of time in retrieving or replacing gear.
The new SMART technology is being promoted as non-polluting and the slight increase in cost-per-hook is offset by increased target catches. New research continues being conducted which will make the technology available for use in all fisheries.
Among species tested
in ongoing repellent studies are the Carribean Reef shark, blacknose shark, lemon shark, nurse shark, bull shark and the southern stingray.