By collaborating with scientists and commercial, we have increased our understanding of the physiological and survival impacts of accidental capture on non-target fishes.
We worked with participating fishermen to develop a less damaging hook removal method in order to improve the survival of the sub-legal sized bycatch. Participating fishermen installed a foot pedal mechanism to retrieve their longline gear that left their hands free to handle the fish. A maneuver that flipped the fish around the circle hook left a small hole in the jaw similar to when hooks were carefully removed.
Preliminary results using this less traumatic method of hook removal did improve the survival of juvenile cod bycatch over mechanical release however sample size was too small to allow robust statistical treatment.
Catching Less Undersized Cod
The best way to improve bycatch survival rates would be to avoid catching the unwanted fishes in the first place. We worked with commercial longline cod fishermen to develop and test a larger-sized experimental hook in order to reduce the bycatch rate of undersized Atlantic cod. Longline cod fishermen typically use 11/0 circle hooks. We discovered that a larger 15/0 circle hook—constructed from the same wire gauge as the 11/0 hooks—captured the same number of legal cod as the 11/0 hooks, but caught one-third fewer sub-legal sized cod.