Global conservation organisation WWF presented a paper to the IWC Scientific Committee 65th meeting in Jeju, Korea in June that highlighted the lack of progress from New Zealand to save the last estimated 55 Maui's dolphins.
The IWC made a similar call last year.
The Government announced interim protection measures in June 2012, but Mr Howe said dangerous fishing activity is still allowed to continue in parts of Maui's habitat, including off the Taranaki coast and inside harbours.
"Eight months ago a public consultation on the Threat Management Plan for Maui's dolphin closed, yet the government has yet to make a decision on protecting them," he said.
"We call on Conservation Minister Nick Smith and Primary Industries Minister Nathan Guy to announce permanent measures that remove fishing gear which kills dolphins from their waters, and help affected fishermen adopt dolphin-friendly methods. Anything less will not give the species a fighting chance at survival."
Maui's is the world's rarest and smallest known subspecies of dolphin, with an estimated adult population of just 55.
Population numbers have dropped by an estimated 90 per cent since set netting was introduced in the early 1970s.
Scientists estimate that more than 95 per cent of unnatural Maui's deaths are caused by entanglement and drowning in gillnet or trawl fishing.
An expert panel convened by the government last year estimated that around five Maui's dolphins are killed each year in fishing nets, a rate 75.5 times what the population can withstand.
Their range has also diminished over the last 40 years, given Maui's used to be found from Northland to Wellington in the west and up to Hawke's Bay.
"The world is watching and waiting for New Zealand to take action to save these small and critically endangered dolphins," said Mr Howe.
"Both the survival of Maui's and our international reputation is on the line."
Forest & Bird also welcomed the IWC report
New Zealand does not want to join China in letting a dolphin species disappear since Yangtze River dolphins, or baiji, have not been seen since 2007, it said.
"The idea that New Zealand's environmental priorities are on a par with China's will go down very badly with most Kiwis,'' said Forest & Bird Advocacy Manager Kevin Hackwell.
"We are not talking about reducing the quota that west coast North Island fishermen can catch. The situation demands that they change their methods, which are killing these dolphins.
"We must not let Maui's dolphins become extinct."
