Blue whale feeding grounds off the South Taranaki coast would be protected from seabed mining under a Green Party plan to create the country's largest marine mammal sanctuary.
Party leader James Shaw likened seabed mining to emptying a vacuum cleaner on a whale's dinner plate in announcing the policy near Patea on Tuesday.
"Thousands of New Zealanders have spoken out about seabed mining and today we are standing with them to say that in government, the Greens will always protect our marine environment," he said.
The party would declare a 30,000 square kilometre marine mammal sanctuary, with boundaries decided with iwi, communities and the Department of Conservation, to protect the blue whales and other species that call the area home.
"One hundred years ago there were more than 10 times the blue whales there than there are now. It's time to stop taking them for granted," Mr Shaw said.
"The Green party's marine mammal sanctuary for blue whales provides a win-win opportunity: protect the environment and potentially create sustainable local jobs through new eco-tourism ventures, such as whale watching."