The Green Party says mineral mining permits have been granted across a third of a marine sanctuary inhabited by Maui's Dolphins.
Today the party released maps comparing sightings of the endangered mammals with areas where mining companies have been granted exploration permits on the west coast of the North Island.
The maps show there have been 254 sightings of the dolphins.
"This is another yet example of National sacrificing the last remaining 55 Maui's dolphins in order to give the mining industry a leg-up," Green Party oceans spokesman Gareth Hughes said.
"Mining and Maui's don't mix. The dolphins' habitat would be degraded as a result of noise and pollution and there's a risk they'd be displaced into areas where they have no protection."
Energy and Resources Minister Simon Bridges said the Government had taken steps to tighten regulation around mineral exploration, and the permits were for prospecting, with more onerous requirements if the companies elected to progress to drilling.
"Using an evidence-based approach there has been no harm to Maui's Dolphins [from mineral exploration]", Bridges told Radio New Zealand.
Where there had been issues from set net fishing, the Government had ordered changes to regulations.
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