SYDNEY, July 26 (Xinhua) -- Using simple magnets as a barrier at the entry of fish traps can reduce the number of sharks and rays netted as bycatch in commercial fishing, as well as significantly increase the amount of fish caught, according to latest Australian research.
Sharks and rays are particularly sensitive to magnetic fields due to special sensing pores typically used to locate prey, so attaching magnets at the trap entries can create a cost-effective magnetic field barrier, the University of Newcastle said in a statement about its research on Thursday.
The findings, published in journal Fisheries Research, deployed 1,000 fish traps over eight months across three sites near New South Wales state capital Sydney.
The magnet pieces were found to help fish traps reduce the bycatch by more than 30 percent and increase the catch of targeted fish species by the same amount.
The results could have wide implications for the conservation of sharks and rays, said lead researcher Dr Vincent Raoult.
Much of the bycatch is released back into the ocean, but "the stress from being out of the water and handled are likely to have repercussions that will last for a period of time after they are released. The trauma may impact their energy levels and desire to feed, which can be lethal in the short term," he said.
The magnets help reduce the bycatch and increase profitability for fishermen "as they spend less time accidentally catching sharks and rays, and more time catching the fish they want."
The devices could potentially be adopted across the industry with further research, said Raoult.
