Bottom-trawling fisheries have been banned from a 10,000 hectare area off the West Coast of the South Island.
Government confirmed three new "marine protected areas" for the West Coast today.
The three MPAs will prevent "mobile, bottom-impacting" fishing methods in the region, while allowing some other fisheries to operate.
Conservation Minister Maggie Barry said the new protections were a "win-win situation" because they protected marine life without significantly impacting on fisheries.
The MPAs were designed to complement five existing marine reserves on the West Coast, where fishing was banned altogether.