The Green Party is urging the Government to do more to protect critically endangered Maui dolphins.
The Government has called for public submissions on its plans to further protect the dolphins.
It is considering extending set net bans and sanctuary areas following the release of a new study that shows there are just 55 adult Maui dolphins left, less than half the amount recorded in 2005.
The main areas where the dolphins were found are protected by marine mammal sanctuaries, but new measures could see a set-net ban and marine sanctuary extend off the coast of Taranaki.
Conversation Minister Kate Wilkinson said action was needed and extending the set net ban should be effective.
However, the Green Party claims a bigger area is needed.
"The Government needs to act now to protect the critically endangered Maui dolphins," said Green Party Oceans spokesperson Gareth Hughes.
"At this stage, talking is not enough."
Hughes said the net ban extension may impact the fishing industry, but the alternative is the extinction of the Maui dolphin species.
"The species will become extinct if more than one dolphin dies every five to seven years," he said.
"Two Maui dolphins have died in the last five months."
And global conservation group WWF is criticising the Government for not acting quickly enough.
"The female Maui dolphin drowned in fishing nets off the coast of Taranaki in January, outside of the protection zone, should have resulted in an immediate extension of set net and trawling restrictions throughout the dolphin's full range," WWF's Marine Programme Manager Rebecca Bird said.
"It has long been known that Maui live off the Taranaki coast and it shouldn't have taken the death of this animal to prompt an official recognition of this fact."
Dr Rochelle Constantine from The University of Auckland, who has been working on the joint study on the dolphins, said one concern with "such a dangerously low number of breeding females" has been that the fertility of the population may be compromised.
"But our work shows that the number of pregnant females is within the expected range, which is encouraging."