They must use special hook shielding devices.
Alternatively, they can employ a combination of three measures — use bird scaring devices called tori lines (streamers), line weighting to sink hooks faster, and set their gear at night.
The new rules, which will come into effect on October 1, aim to protect critically threatened albatrosses and other seabirds from being caught accidentally.
"Surface longline vessels have been operating onboard cameras since January this year," Fisheries New Zealand fisheries management director Emma Taylor said.
Scientific modelling, a review of the camera programme, and public feedback led to the rule change, she said.
"We have systems to monitor the position of all commercial fishing vessels in real time, and fishers are legally required to report their catch and position to us electronically.
"Alongside this, onboard cameras provide independent verification of fishing activity, including accidental bycatch of protected species."
About 145 seabird species called New Zealand’s waters home, she said.
"Fishers don’t go out to catch seabirds and these measures will help ensure that the surface longline fleet have the best chance of avoiding seabirds that are trying to sneak a feed off their hooks."
The Department of Conservation and Fisheries will help fishers transition to the new rules.
The new measures, referred to as "three out of three", will replace the existing rules that only mandate two seabird mitigation measures.
