Greenpeace says fish canning company, John West, needs to change its practices or face plummeting Pacific fish stocks.
The environmental watchdog says John West's vessels use fish aggregating devices, or FADs, that act like magnets for fish.
Greenpeace's oceans campaigner, Nathaniel Pelle says FADs attract juvenile tuna, as well as other species and nearly ten per cent of every haul is by-catch.
Mr Pelle says the company's practices are threatening Pacific fish stocks, and people in the region are being prevented from expressing their opinions.
"All that tuna is from the Pacific, and Pacific Islanders absolutely have the right to comment on how a company like John West gets its Tuna. We're talking nearly one hundred million tins of tuna a year they sell profiting from a Pacific resource."
In a statement John West says less than 2 per cent of its haul is by-catch, and the company is working towards being fully sustainable by 2015.