Fisheries Minister Phil Heatley shouldn't be using a new scientific report to tout New Zealand's fisheries as "clean and green", environmental lobbyists say.
The Ministry of Fisheries said today it was "very satisfied" with New Zealand's rating in an international study of key fisheries in New Zealand, Australia, Europe and North America.
Ministry chief scientist Pamela Mace was one of the authors of the research paper, Rebuilding Global Fisheries, in the journal Science.
New Zealand marine areas were rated second equal with Alaska as the healthiest in the world, with general efforts to halt over-fishing helping stocks to recover.
Along with New Zealand and California, the Bering Sea, which yields mainly Alaskan pollock, were the only areas surveyed where fewer than one in 10 of the fish species was in trouble.
The key to their success was in having reduced catches below a critical threshold, through measures such as restricting the type of nets used, closing off areas to fishing vessels, and limiting catches.
Fisheries Minister Phil Heatley said the local hoki fishery was an example of good management delivering sustainable stocks.
But independent conservation organisation Forest and Bird said fisheries management wasn't as green as Mr Heatley says.
Forest and Bird marine conservation advocate Kirstie Knowles said the report looked only at 19 of the 629 fish stocks in New Zealand waters.
And though a key finding of the report was that stocks should be managed well above a benchmark at which point fish stocks begin the decline towards collapse - the maximum sustainable yield - most New Zealand stocks were at or below this benchmark or their status was unknown.
Orange roughy had become one of the best assessed fisheries, after some of its stocks had been fished to the point of commercial collapse, yet it was not considered in the research paper.
Ms Knowles said some orange roughy stocks had collapsed to less than 5 percent the original unfished population.
Snapper was also in trouble in some areas, with stocks estimated at about 10 percent of original population levels.
The research did not consider the impacts of destructive fishing methods, such as bottom trawling, the bycatch of seabirds, marine mammals and other non-target marine life.
"Forest and Bird does not agree with Minister of Fisheries Phil Heatley that this report gives a green tick ... just because we have a good fisheries assessment process, it does not mean that we are good at implementing it," Ms Knowles said.
A key problem was underfunding of fisheries research: this year the ministry cut its science budget 30 percent, all of which covered environmental research.
Green Party co-leader Metiria Turei said overall the report stressed that globally, the fish stocks were in a terrible state.
"It then compares New Zealand to another country in the way they manage fisheries, declaring that the fish stocks are in a terrible state and New Zealand is not quite as terrible as other countries," said Ms Turei.
A report in Conservation Biology journal suggests the Oceania region is losing species at least as fast as the rest of the planet - and possibly faster.
"Earth is experiencing its sixth great extinction event and the new report reveals that this threat is advancing on six major fronts," said that report's lead author, Professor Richard Kingsford of the University of New South Wales.
Nearly a quarter of the 24,000 publications included in the review came from New Zealand.
Prof Kingsford and his colleagues are particularly concerned about destructive fishery practices, including bottom trawling, in which large areas of ocean floor are "clear felled", and the use of explosives to blow up coral reefs.
The Kingsford report called for governments to increase protected terrestrial, freshwater and marine areas, with up to 50 percent of marine areas protected, though even this may not be enough.
