An environmental group says large numbers of toothfish discovered in Ross Sea should not influence decisions about the ocean's future.
New research indicates that Antarctic toothfish are not declining in numbers.
New Zealand's Ministry of Fisheries commissioned a survey of juvenile toothfish and found relatively high numbers of the prized species in the southern part of Ross Sea.
The survey was carried out by the National Institute of Water and Atmospheric Research (NIWA), which dropped long-lines at 59 random locations and found high densities of the fish.
Principal scientist Stuart Hanchet told Radio New Zealand's Morning Report programme on Monday the numbers of toothfish discovered is comparable to the abundance 10 years ago when the fishery first started, and adult spawning stock is at about 80% of the original level.
"From the data, there's no evidence of any decline in abundance."
But The Last Ocean Trust says the survey's findings are irrelevant, because the Ross Sea has far more value as an intact marine ecosystem than a fishing ground.
Co-founder Peter Young told Radio New Zealand there should not be any fishing in the waters - regardless of a species' abundance.
"The Ross Sea is the most pristine marine ecosystem that we have on Earth and there shouldn't be any fishing there.
"It's value as a living laboratory, as an example of how the world's oceans looked before humans impacted them - it's far more valuable as that than as a fishing ground."
The Last Ocean Trust is one of several environmental groups campaigning to protect the waters by creating the world's largest marine reserve.
The Commission for the Conservation of Antarctic Marine Living Resources will decide if and how the ocean should be protected at the end of this year.