Entanglement from Fishing Nets Entanglement in fishing gear is the biggest global threat to whales, dolphins, porpoises and turtles. Around 300 000 sea mammals die every year from being caught in huge fishing nets. When a dolphin, whale or porpoise is trapped in fishing they cannot return to the surface to breathe therefore they drown.
Entanglement in fishing nets has been identified as the greatest threat to the harbour porpoise. Universal attention has been given to the most lethal drift nets which the EU has banned. Gill nets or mid-water trawling nets can be just as lethal to dolphins and porpoises. No net is allowed to exceed 2.5 kms anywhere in the world.
The WWF is working with fisheries to develop fishing gear that reduces the chance of any by catches or lets the unwanted species escape. Why most of these products are still being developed WWF thinks they can reduce the by-catch of turtles of 90% without restricting the fisherman's chance of catching any fish in some areas with the use of Circle hooks instead of J hooks.