A marine researcher says commercial fishing could be killing New Zealand's largest group of native sea lions.
Bruce Robertson, the author of a new report, says breeding at the Auckland Islands, home to about 70% of the population, has declined by 40% since 1988, with only 1500 pups born in 2009.
He says the study identifies competition for food and sea lions being caught in nets as the most likely cause of the population decline.
Dr Robertson says New Zealand sea lions are listed as nationally critical.
