Rather than demonise key primary sectors such as dairy and fishing - the business model adopted by Greenpeace and, increasingly, Forest & Bird - TNC seeks to collaborate with all parties to find solutions to pressing environmental issues.

With a 65-year-history, activity in 72 countries, 600 scientists employed and a healthy bankroll, it has had plenty of practice.

TNC this week sponsored a symposium in Auckland on freshwater and marine issues, challenges, initiatives and opportunities, opened by Conservation Minister Eugenie Sage.

That followed its initial foray into New Zealand in 2016, a study of the world-leading Quota Management System that it found "offers lessons relevant to many other countries that are contemplating fishery reform efforts".

Eugenie Sage listed the many pressing environmental issues contributing to a decline in biodiversity.

They included habitat loss and predation, sediment from poor land management, kelp and coastal fisheries being impacted, irrigation changing river flows, algal growth from sewage runoff and agricultural nitrates, invasive weeds limiting nesting sites.

She said only one freshwater fish had legal protection. That is the grayling - and it is extinct.

In the marine sphere priorities included promoting abundant fisheries, extending marine reserves, restoring the Hauraki Gulf and working with iwi to advance the Kermadec Ocean Sanctuary.

Jamie Tuuta, a Maori trustee and chair of Te Ohu Kaimoana, outlined a clear Maori perspective on the stalled Kermadec sanctuary to the northeast of mainland New Zealand covering 600,000 square kilometres.

The proposed sanctuary was announced by the Key Government without consultation and is seen by Maori as hostile to the customary principle of sustainable use.

"The Kermadecs discourse shows that beneath the rhetoric of sustainability is the desire for New Zealand to be lauded as a pioneer in marine conservation," Tuuta said.

"Our pursuit for leadership in the marine conservation space needs to be one that is culturally, scientifically and intellectually robust."

He said that everything that had ever gone wrong between Maori and the Crown since 1840 was a clash of ideology.

"We must adopt a Maori world view, one where conservation solutions meet multiple social and ecological goals.

"This will not be achieved as long as conservation is framed as a human versus nature contest."

He said the concept of kaitiakitanga - guardianship - speaks to wise and enduring use that was summed up by his grandfather: We protect future generations from the claims of the present.

"We simply cannot be kaitiaki of our land and sea if we have lost ownership or control and influence over it.

"In a fisheries context it was always understood by Maori that fisheries might rise and fall on the science of sustainability.

"Where stocks are under pressure, fishing effort would reduce. We saw that with the hoki and the orange roughy resources over the last 10-15 years and they are now in great shape. We accepted the cuts in quota to help rebuild."

He added he was hopeful that our new Prime Minister's statements of her desire to achieve a true partnership with Maori come to fruition.

Department of Conservation director-general Lou Sanson said the two major environmental challenges facing his department with its $380million budget were reversing the biodiversity decline and responding to a significant increase in tourism.

They were encouraging partnerships to deal with those issues.

As for TNC's role, the stage is set for it to take leadership in meeting some of the many challenges confronting us.