The Government needs to act urgently to protect critically endangered Maui dolphins and right now it's not doing enough, says the International Whaling Commission.
In a just-released report, the IWC has reiterated previous calls for the Government to take more steps to protect the world's smallest dolphins.
Last year researchers found the dolphin's numbers had dropped to less than 50 and could become extinct within 15 years if more protections weren't added.
Two North Island hapu, Ngati Te Wehi and Ngati Tahinga, recently argued their treaty rights had been breached by lack of protection for the dolphin, but the Waitangi Tribunal rejected their claim.
The hapu argued the Crown's management plan - revised in 2013 - did not go far enough, and ignored evidence from several international fishing research groups which had called for a total ban on nets and trawlers within the dolphin's habitat.
The subspecies of Hector's dolphin can only be found off the west coast of the North Island and its habitat ranges from Maunganui Bluff to Whanganui.
Now, the IWC's scientific committee says the Government has been too slow to act, by focusing on commissioning research, "often leading to merely confirming a severe decline rather than preventing it".
Its first priority should be to introduce management actions to eliminate bycatch, accompanied by research and monitoring, the IWC says.
It again expressed "grave concern" over the status of the dolphin.
"The human-caused death of even one individual will increase the extinction risk."
The committee recommended closing fisheries within the dolphin's habitat that were known to pose a risk of bycatch, and stopping the use of set nets or trawling in that area.
It urged the Government to commit to specific population increase targets and timelines for Maui dolphin conservation, and to provide annual progress reports.
World Wildlife Fund New Zealand spokesman Peter Hardstaff said the Government needed to "do the maximum possible, rather than the minimum it can get away with".
"The Government must act without further delay by helping affected fishers transition to dolphin-friendly methods and extending the ban on set netting and traditional trawling to cover all of Maui dolphins' known range," he said.