The Government's approach to saving the endangered New Zealand sea lion will probably fail, a new study says.
Efforts to save the species have focused on improving the survival of pups, whose numbers have halved since 1998.
However research led by Otago University used population modelling and concluded the focus should instead be on protecting adult female sea lions.
The study's lead author, Stefan Meyer, said keeping adult survival high provided protection in years when pup birth rates or survival was low.
"That's pretty much the insurance for the population not to decline - and the opposite," he said.
"Adult survivors are important, so even a small decrease in that adult survival, for example caused [by] fishing, can wipe out a population, particularly in bad years when reproduction is low."
Banning trawl-fishing from parts of the Auckland Islands to prevent sea lions being caught as by-catch would be a simple option to improve adult survival, he said.