A settlement to the vexed issue of a Kermadecs ocean sanctuary must be based on objective science, not subjective ideology.

That is according to former Attorney-General and Treaty of Waitangi Negotiations Minister Christopher Finlayson in a forthright address to the annual Seafood NZ conference held in Queenstown today.

He said the scourge of plastics in the oceans was a more presssing issue. That could only be done if an international clean up fund was established with contributions from all nations bordering the Pacific Ocean. 

"In the Kermadec zone there is no evidence of fish stock depletion of abundance in any species.

"The case for the sanctuary cannot on any evidence be made on any observable danger to biodiversity or ecology."

In the rush to declare a sanctuary covering 620,000 square kilometres midway between New Zealand and Tonga, there had been inadequate consultation with Maori and an undermining of rights in the 1992 fisheries settlement.

"The legislation giving effect to the sanctuary is now in limbo because the issues have not been resolved," Finlayson told the 280 conference delegates.

"I don't think it will be resolved by further consultation.

"In any event, a strong argument can be made that with the Quota Management System, there is in fact no need for such a large marine reserve.

"Conservation of fisheries species is an essential ingredient of the QMS. It is the intelligent and proper recourse to that system on which we should rely for the conservation and management of our fisheries resources."

The best way to address stock depletion in this part of the world was to tackle the flotilla of tuna fishing boats around the northern end of the Kermadec zone on the edge of New Zealand's 200-mile Exclusive Economic Zone.

"The tuna fleet is mainly based out of American Samoa," he said.

"The USA needs to address this issue."

He suggested a fresh start  with the Kermadecs discussion, one without anger or recrimination.

"Let's maintain the basic principles of the Treaty relationship and the Treaty-based agreements we have made. And this time let's get it right.

"Any solution has to be based on ecology, not ideology.

"If the sanctuary proposal goes ahead some fishing must be permitted.

"That is not an absurd proposition. It has been agreed to in Rapa Nui (Easter Island).

"The integrity of the 1992 Settlement must be safeguarded at all costs." 

The conference was opened by Regional Economic Development Minister Shane Jones in the absence of Fisheries Minister Stuart Nash.

Speakers today include US Ambassador to NZ Scott Brown on trade; Seafood NZ chair Craig Ellison with a critical assessment of the industry's performance under its code of conduct; Department of Conservation director-general Lou Sanson on predator free Auckland Islands and co-operation with the seafood sector; fisheries science manager Dr Rich Ford on the healthy state of our sustainable fish stocks; an international perspective on seafood markets from Rabobank analyst Gorjan Nikolik; a panel discussion on Treaty and property rights; a preview from Graeme Sinclair of the third series of the Ocean Bounty television series; and the presentation of Seafood Stars awards.

The conference was preceded by a packed technical day that included innovation in bioactives from marine resources; ocean warming; marine mammals and seabird protections; electronic reporting update and a Seafood Innovations Ltd project with Scott Technologies and Mt Cook Alpine Salmon to add value to king salmon by automatic removal of pinbones from fillets.

A transtasman rock lobster conference is also in Queenstown - on Monday and Tuesday (Aug 12-13) next week.