A study from the University of Newcastle shows catch-and-release fishing may be having a seriously damaging effect on sharks.
During the study, one group of sharks were exposed to the air for up to fifteen minutes in controlled conditions to represent being left on deck, and a second group were released immediately after being pulled from the water.
Underwater drones were used to capture footage of how the animals behaved in their regular habitat following the exposure, and the results show the ability to swim away does not reflect a shark's health.
Sharks captured and exposed to a boat deck for fifteen minutes swam for a maximum of thirty seconds after release before becoming largely immobile for five minutes, a worrying trend linked to high stress, oxygen starvation and thermal shock.
Marine Ecologist Dr Vincent Raoult said the key message he wants fishermen to understand is that if they intend to keep a shark alive, they must release it as soon as physically possible.
"This often means actually cutting the line as close as you possibly can to the hook and releasing the shark immediately," said Dr Raoult.
"It's better to leave the hook in, in many cases, than to take a long time fighting the shark trying to get the hook out and getting to that level where the animals are very stressed and are potentially going to have long-term impacts on their health."
Dr Raoult stressed that fishermen need to stop taking a shark's ability to swim off as an indicator they've treated it appropriately.
"They need to listen to the research, not just my research, but a growing body of research that suggests sharks are very threatened by a lot of these fishing practices."
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| Image: ABC |
