Port Otago says it expects to go to court to defend its harbour dredging plans after only partially successful mediation with opposing groups.
At least six parties have appealed against the consents given last year to deepen the shipping channel by two metres, and dump the spoils offshore.
The port's chief executive, Geoff Plunket, says mediation has settled the appeals by the Southern Clam company and local runanga, but the other four or five appeals must be decided by the Environment Court.
The chairperson of the fisheries group East Otago Taiapure, Brendan Flack, says he is disappointed to have to go to court.
But Mr Flack says the group is insisting on the monitoring of fine sediments likely to damage kelp forests and fish breeding grounds.
The Otago Chamber of Commerce says mediation is not over because not all the parties have walked away from the talks.
Chief executive John Christie says the dredging project is fundamentally important to the future of the port and the region's businesses.