New Zealand fishing trawlers kill more than 800 fur seals a year, according to a new report.
The Fisheries Ministry study covers the five years to 2008 and shows the number caught in nets peaked at over 1300 in the 2004-05 year.
Boats trawling for Hoki were responsible for a large number of fur seals caught because of the high volume of trawls, but Hake and Southern Blue Whiting fisheries had significant problems.
Conservation group Forest and Bird's marine advocate Kirstie Knowles says it would be shocking to many people that the Hoki fishery has been internationally certified as sustainable when it kills hundreds of fur seals every year.
Ms Knowles says the Hoki fishing fleet should be stripped of its Marine Stewardship Council label until it finds ways to keep fur seals out of its nets.