An ecological lobby group is calling for New Zealand to withdraw from deep sea Antarctic toothfish operations in the Ross Sea.
The annual toothfish catch is valued at about $30 million, and most goes to the United States.
According to ecological group The Last Ocean Trust, the Ross Sea is the only remaining pristine ocean, and needs to be protected.
New Zealand has four vessels operating there.
The Ministry of Foreign Affairs and Trade says all fishing boats carry scientific observers to ensure sustainable fishing is carried out, and there are already bans in many areas of the Ross Sea.