Fishermen who use longlines to catch various fish off Hawaii have been advised to use a different kind of hook so they don't accidentally severely injure or kill false killer whales.

Conservationists want the longline fleet captains to undergo training on how to release any mistakenly caught false killer whales in a way that minimises the chance they'll be seriously harmed. Data shows the fleet is accidentally killing or seriously injuring an average of 8 whales each year, exceeding the 3 per year that the population can lose without effecting its ability to sustain itself. It is estimated that 120 of the animals live in waters up to 60 miles off Hawaii's coasts with more than 300 living more in shore. They get caught by the longlines because they eat the fish that the fishermen are also aiming to catch - yellowfin tuna, mahimahi, and ono.

The problem has been an issue for over 10 years and the National Marine Fisheries Service is expected to compile a list of proposed regulations after reviewing recommendations which include the longline fleet using circle hooks instead of straighter Japanese-style tuna hooks. Other recommendations are for boat captains to attend training sessions on the least harmful ways to cut hooked false killer whales free and to close a fishing area north of the main Hawaiian islands year-round instead of just for eight months a year. Many false killer whales are found in this area known as the Northern Exclusion Zone, which is also a rich tuna fishing ground.

Sean Martin, president of the Hawaii Longline Association has said the longline industry wouldn't wait for the fisheries service to complete new regulations before it started changing some of its practices and will now begin training boat captains and urging fishermen to use circle hooks right away. Half the fleet currently uses circle hooks. False killer whales don't reproduce frequently and start calving at around 15 or 16 years old so any moves forward to help the species is vital.