Fishing boats will now have to bring their entire catch back to port - as part of moves to ensure skippers report other wildlife that is accidentally caught.
Minister for Oceans and Fisheries David Parker said cameras would be installed on 300 vessels to ensure the unwanted bycatch was not thrown overboard instead.
Parker told Nine to Noon skippers would have no excuse not to follow the new rules once the cameras were in place.
"It's primarily about getting better outcomes with less discarding, but it also will have a benefit to encourage all fishers if they do accidentally catch a sea bird or a dolphin to report that, because it will be captured on the video footage and there will be no doubt about it," he said.
The rollout follows the installation of cameras on 20 vessels fishing in Māui dolphin habitats in 2019.
Greenpeace Aotearoa welcomed the move but wanted to see cameras on all commercial fishing vessels to ensure rules were followed.
"Over the years we've seen repeated scandals with widespread illegal fish dumping by the industry. Every year hundreds of tonnes of fish are dumped dead or dying back into the ocean. This new measure is a step in the right direction to tackling that," Greenpeace Aotearoa executive director Russel Norman said.
"But without a more comprehensive cameras-on-boats programme the industry can continue to operate out of sight, out of mind. Quite simply, we need cameras across the board to ensure compliance."
There were about 1500 registered fishing vessels in New Zealand and Norman said given the industry's past illegal dumping, there was no reason to think crews would follow the rules if cameras were not in place.
But the changes could spark a new market for fish bycatch products emerge.
Fisheries researcher Dr Glenn Simmons told Nine to Noon similar regulations in Norway and Iceland have led to new markets cropping up to sell fish byproducts.
"In Iceland now, the fillet is actually the byproduct, and it's the bycatch that's far more valuable, in some cases up to 10 times more valuable than the fillet," he said.
Simmons said fish byproducts were often seen as worthless, but the new regulations would force people to better utilise fish waste.