Proposed changes to fishing rules could see a limit put on the number of salmon anglers in the South Island are allowed to catch each season.
In a bid to help rebuild Canterbury's wild sea-run salmon population, Central South Island Fish and Game Council (CSIFGC) and North Canterbury Fish and Game Council (NCFGC) have proposed a 'season bag limit' regime should be implemented across both regions.
If put in place, it would be the "most significant change ever to the way sea-run salmon are managed in New Zealand", Fish & Game New Zealand said.
The fisheries of Canterbury and North Otago account for 90 percent of all sea-run salmon caught in the South Island but they now have less than 10 percent of the number seen in the 1990s.
Dr Andrew Simpson, chair of CSIFGC, said it was crucial the species is protected.
"We must have enough sea-run salmon spawning to sustain future generations and right now that's our priority," he said on Tuesday.
According to the proposal, the size of the season bag limit will be reviewed annually, based on where the size of the spawning population sits within the range of spawning thresholds.
"Any angler who reaches their season bag limit must stop fishing for salmon for the remainder of the season," said Dr Simpson.
"A season bag limit will be new to New Zealand anglers but is a common fisheries management tool around the world. It is the single most effective regulation to ensure enough sea-run salmon reach the spawning grounds to sustain our iconic east coast salmon fisheries."
According to catch surveys cited by Fish & Game, after spending three years at sea, between 40 percent and 60 percent of salmon returning to spawn in rivers are caught by anglers. By implementing a season limit catch of four, the number of salmon caught by anglers would reduce by around 16 percent.
"About 95 percent of anglers catch four or less salmon each season, so most anglers won't be affected by the season limit bag of four fish and more fish will be able to spawn," said Dr Simpson.
Fish & Game is currently seeking Government regulations to implement the proposal.