An exhausting battle spanning nearly 20 years for a new marine reserve in Akaroa Harbour is nearly at an end. 

The Akaroa Marine Protection Society, a group of about 20 determined locals headed by husband and wife team Brian and Kathleen Reid, has been fighting for a 530-hectare marine reserve in Akaroa Harbour since 1996.

The reserve, near Dan Rogers Bluff, would protect about 12 per cent of the harbour from fishing.

This afternoon, Conservation Minister Nick Smith announced his approval of the reserve. 

Akaroa Marine Protection Society secretary Kathleen Reid told The Press they were ''thrilled'' to hear their battle had paid off.

It has been a long road to victory for the society, who Reid said started as a ''small group of slightly whacky conservationist''.

The group made a formal application for the reserve in 1996, which received 2334 submissions in support and 709 objections. 

The principal opponents were Ngāi Tahu and recreational fishers.

Former conservation minister Kate Wilkinson declined the society's application in August 2010 on the grounds that it would '''adversely affect recreational fishing''. 

The society sought judicial review of the decision in the High Court, and in May last year Justice Whata overturned the minister's decision.

''It has been an enormously long and exhausting battle and we are glad that it is coming to a close,'' Reid said.

''It shows what a community can do if they work together tirelessly for a common goal.

''However, she said the society had been forced to make some compromises with Smith. 

Smith had adjusted the northern boundary of the proposed reserve by 55ha, reducing the reserve to 475ha, to ''take account of concerns from customary and recreational fishers''.

''We are getting a smaller reserve, but at least it is still a reserve,'' Reid said. 

''Compromises are the nature of politics and we have to accept that.'' Smith had also directed the Department of Conservation to review the reserve in a decade's time in ''the hope that over time and with scientific monitoring, differing views may come together on how to manage this spectacular harbour.

''Society president Brian Reid said he hoped the success of the reserve would be such that '' the success of the reserve will be such that the naysayers will embrace and support the reserve in the long term.''  

Smith's decision was not the final stage in establishing the new marine reserve; he needed to secure the ''formal concurrence'' of the Minister for Primary Industries and Minister of Transport, before the reserve would be gazetted by the Governor-General.
Brian Reid said he looked forward to ''turning a page on past differences and starting a new process of working together on the management of the marine environment on Banks Peninsula''.

''The winner here is the protection of biodiversity in the most scenic part of the Harbour.''