The Ministry of Fisheries is keeping a close eye on two foreign vessels believed to have been plundering swordfish stocks.
The two Spanish fishing boats, Vieirasa Cinco and Robaleira, have been detected fishing without authorisation in international waters between French Polynesia and New Zealand.
Despite being in internationalwaters, the protected swordfish stocks come under the control of the Western and Central Pacific Fisheries Commission.
The two Spanish vessels, flying Senegalese flags, have been reported to the commission and may face being banned from the Pacific.
The Ministry of Fisheries' manager of international fishing, Jane Willing, said: "We are very concerned at any vessel in the area that does not have the authorisation to fish from the commission."
Monitoring for unauthorised fishing, with assistance from the Air Force, would continue in the area.
Meanwhile, holidaymakers in Tasman Bay and Queen Charlotte Sound are being warned not to fish in marine reserves.
"Too often over the summer holidays we catch people fishing inside marine reserves," said Department of Conservation spokesman Gavin Udy.
They faced going to prison or being fined up to $10,000.
