New research has found the amount of fish being caught in New Zealand could be 2.7 times greater than official statistics suggest.
The study is part of an international collaboration between 400 researchers, including a team from Auckland University. Unreported and discarded fish are behind the massive difference in the figures.
The report also criticises New Zealand's much-celebrated qouta management system, saying while well-intentioned, it encourages misreporting and dumping of fish.
Catch statistics that New Zealand and other countries report to the United Nations Food and Agriculture Organization do not include illegal or otherwise unreported commercial catches and discards. Discarding is when certain species are returned to the sea if the operator does not have quota for that species, or if the fish is too small.
Lead researcher Dr Glenn Simmons says to maintain sustainable fisheries, New Zealand needs to know with precision how much is being caught.
"There was already strong evidence that we didn't know that, because the official statistics are incomplete. Unreported catches and dumping not only undermine the sustainability of fisheries, but result in suboptimal use of fishery resources and economic waste of valuable protein."
The study looked at official data between 1950 and 2013, and found that 24.7 million tonnes of fish went unreported, compared to 15.3 million that was reported.
"The majority of what's not reported is small, uneconomic-sized fish," says Dr Simmons. "If you take out all the juveniles and those that are too old, you're up to some pretty big proportions."
And he says the Government knows it.
"The ministry's known for decades about misreporting. They've also known about the scale of it."
Greenpeace New Zealand says the research is "explosive" and it suggests the Ministry of Primary Industries (MPI) has been deliberately suppressing information about illegal dumping.
Executive director Russell Norman says we've been relying on misleading and incorrect data to sustain our fisheries and wants an independent investigation.
But MPI has raised concerns with the study's methodology.
"Many of the conclusions it draws rely on the recollections of interview subjects. A key scientific principle, when gathering this type of data, is to try to eliminate bias in your sample of interviews," says MPI director fisheries management Dave Turner.
"In addition, it's unclear how this qualitative information has been turned into quantitative findings. The report appears to extrapolate negative points of view and assume they apply in all circumstances."
He says it also can't be used to draw conclusions about fisheries sustainability.
"The measure of sustainability is abundance… not extraction as the report attempts to analyse.
"We have decades of peer-reviewed science that shows steadily increasing levels of abundance. The situation now is that New Zealand fisheries are healthy overall, and that’s because of careful, science-based management."
MPI's view was somewhat backed up by NIWA, which says between 1991 and 2013 it found discard rates of about 6.6 percent.
"An important difference between the studies is that the NIWA analyses are based on empirical data and, unlike the Simmons study, do not attempt to estimate the prevalence of discarding activity that may have been intentionally hidden from observers, or make any assumptions about the influence of observer presence on discarding behaviour," says Owen Anderson, fisheries scientist. "We also note that the Simmons report relies heavily on anecdotal evidence to apply multipliers to reported catches and discards. It is difficult to independently assess the appropriateness of these multipliers."
Prime Minister John Key says the Government is "quite sceptical" of the report, saying it only deals with historic data, though it goes up to 2013.
"We've had observers on boats, cameras on boats, we have GPS tracking.
"To us, looking at it, we think the probability of the numbers being as high as what they have in the report, seem a bit odd to us and a bit out of whack from the advice that we're getting from our scientists," he said at his post-Cabinet news conference.
Where there is evidence of illegal activity, MPI says it will investigate.
Newshub.
