Wellington, Sep 6 (IANS): The New Zealand government Friday proposed a further fishing net ban off the west of the country's North Island in a bid to save the world's most endangered dolphin but critics say the move is too little too late.

Conservation Minister Nick Smith proposed extending a set net fishing ban by 350 sq km, but left it open to submissions until Oct 10. This prompted renewed accusations that government inaction would result in the extinction of the Maui's dolphin, which is endemic to New Zealand waters.

"Maui's are the world's smallest and rarest dolphin. They are critically endangered with their numbers down to just 55 adults. New Zealand needs to do everything practically possible to ensure their survival," Smith said in a statement.

"I am advised by marine scientists that the accidental deaths of Maui's dolphin need to be limited to no more than one every 16 years to ensure their survival. However, there have been three confirmed and two likely deaths from set netting since 2000," he said.

"Set netting involves laying a fine nylon net up to three kilometres long and 10 metres deep along the seabed, typically overnight. The danger for Maui's, who rely on echolocation for navigation, is they cannot detect these fine filaments and can become entangled in the nets and drown."

Opposition parties and conservation groups called on the government to act immediately, saying the scientific evidence in favour of fishing restrictions were mounting.

"The government is recklessly risking the extinction of the Maui's dolphin by continuing to allow lethal fishing methods to be used in Maui's dolphin habitat and delaying action," opposition Green Party conservation spokesperson Eugenie Sage said in a statement.

"The International Whaling Commission's 2012 Scientific Committee, the International Union for the Conservation of Nature, and the Society for Marine Mammology, which has 2,000 scientists, have called for all areas where these dolphins are found to be closed to gillnets and trawl nets out to the 100 meter depth contour, but our government refuses to listen," he added.