Recreational fishers in New Zealand waters could eventually be limited to two snapper per person unless changes are made to fisheries management, a new research paper says.
The "What's the Catch" report, released today by think tank the New Zealand Initiative, said this country had some of the most relaxed recreational fishing rights in the world.
Fishers had generous bag limits by international standards, did not need a permit, and faced no reporting requirements.
This approach was not sustainable when New Zealand's population was set to increase from 4.7 million to 6 million by 2060, the report said.
"Most New Zealanders regard the ability to drop a line into the water and catch a few fish as a right," the report's author Randall Bess said.
"But the depletion of some fish stocks and increases in New Zealand's population and tourism numbers means that this important pastime will increasingly come under threat."
The Snapper 1 fishery in the northeast North Island has had daily bag limits slashed from 30 fish in 1985 to seven in 2014.
The scallop fishery is now closed in the Marlborough Sounds for seven months of the year, and blue cod bag limits in the same area have been cut from 12 in 1985 to two in 2011.
Without changes to fisheries management, further inshore fisheries are likely to face stricter bag limits and seasonal closures, Bess said.
While these policies appeared to be a responsible response, they were not without their problems.
"It means we catch and throw back more undersized fish, which increases mortality rates."
The report said it was conceivable that New Zealand's snapper fishery could eventually end up like the red snapper fishery in the United States' Gulf of Mexico, where the daily bag limit is two per person and the season is limited to nine days a year.
The initiative will look at potential solutions in future reports, but highlighted several areas for improvement.
In particular, it was critical of how total allowable catch (TAC) was allocated between the recreational and commercial fishing sectors.
This process had become too politicised and influenced by lobbying, Bess said.
"New Zealand needs a robust system where the catch allocation decisions are not politicised to the extent they are currently."
The findings in the report prompted New Zealand First to call for a Commission of Inquiry into fisheries management.
Fisheries spokesman Richard Prosser said the inquiry could investigate quota allocation and how TACs were set.
"The inquiry should look at everything, from the effectiveness of surveillance technology, to the resourcing available to Fisheries Officers and the Navy for enforcement, and who should be allowed to fish in the inshore," he said.
Responding to the report this afternoon, Primary Industries Minister Nathan Guy said the report "raised some interesting points".
But with careful management, major cuts to bag limits should not be needed, he said.
"For example, we're setting up recreational fishing parks in the Hauraki Gulf and Marlborough Sounds to give priority to recreational fishers.
"For the first time ever, we have commercial, recreational and customary fishers sitting around the table together to come up with long term plans for the Snapper1 region around Auckland."
The Quota Management System was also being reviewed, he said.