New Zealand is braving an international backlash by going after fish species environmentalists say are unsustainably caught. But the industry says science is behind the decision to increase catches in two vulnerable fisheries. Geoff Cumming reports.
Orange roughy stocks have been severely depleted in our waters. Photo / Supplied
Call it the curious case of the orange roughy. On any scale it is a curious fish, taking 30 years to reach maturity and reproduce (about the time it appears on the menu of trawl fishers), and living to 130 years if it eludes the nets.
It enjoys life in the slow lane, congregating around seamounts (undersea volcanoes) and hills in the deep ocean. New Zealand boasts - or boasted - the biggest concentration in the world, at fishing grounds around the Chatham Rise with smaller stocks off the West Coast and East Cape.
Valued for its delicate, shellfish-like taste and white flesh high in Omega 3 oil, it can fetch prices higher than snapper, triggering an export boom in the 80s and 90s which came back to bite us. It's scarcer than West Coast whitebait in supermarkets, due as much to demand from US consumers as the plunder of previous decades by destructive bottom trawling.
By 2000, estimated stocks on the Challenger Plateau, west of Taranaki, had sunk to as low as 3 per cent of the pre-fishing population, well below the "maximum sustainable yield" which guides the allowable catch set each year under New Zealand's pioneering quota management system. The Challenger and South Island West Coast fishing grounds were closed and catch limits on the Chatham Rise have since been progressively reduced.
On a different scale is hoki: the McDonald's of the seas (it is the stuff of Filet-O-Fish) to orange roughy's restaurant trophy status. Though worth far less per kilogram, its faster reproductivity and availability at mid-ocean depths mean it can be harvested in far greater numbers.
Hoki became the pin-up fish for the quota management system in the 1990s - the promise that commercial fishing could be managed sustainably by setting targets to ensure that, on average, catches were limited to the "maximum sustainable yield" - a level which varies from 25 to 45 per cent of the pre-fishing stock, depending on the species. The allowable catch rises or falls from year to year, depending on Niwa and Ministry of Fisheries scientists' assessment of the health of the fishery.
Scientists know more about hoki than most species but, despite this, the western hoki stock was heading in the same direction as orange roughy a decade ago and, by 2007, the allowable catch was down to 90,000 tonnes - about a third of the amount taken in 2000.
Amid heightened consumer interest in sustainable food supply, New Zealand's management of these species has damaged our clean, green reputation. Both species feature in environmental groups' "fish to avoid" guides - orange roughy is at No. 1 and hoki at No. 5 on Greenpeace's NZ Red Fish list. Influential newspapers The Guardian and The New York Times have cited New Zealand in critical stories and columns about "unsustainable" trawling and the impacts of bottom trawling.
British supermarket chain Waitrose was reported last year to be boycotting New Zealand hoki. (The fact the report was misleading doesn't matter - perception is what counts). This year, the Trader Joe's supermarket chain in the US and Loblaw, Canada's largest retail chain, refused to sell orange roughy. Shipping giant Maersk announced in May it would no longer carry roughy (though it rescinded after ministry lobbying).
What, in the face of this international backlash, does New Zealand do? Last month, Fisheries Minister Phil Heatley re-opened the Challenger fishing ground for orange roughy and increased (for the second straight year) the allowable hoki catch.
Brave, obstinate or quiet faith that the quota management system is working?
The ministry (and fishing industry) says the QMS is grounded in science; environmentalists say the science remains as uncertain as picking Lotto numbers.
While reopening one orange roughy ground, the Minister slashed the catch for the biggest roughy fishery in the world, around the Chatham Rise, amid growing evidence that stocks are in deep decline. It was the third successive quota cut and the fishery is lurching towards closure. The 2010/11 take will be 4840 tonnes - well below the 1980s' Chatham Rise peak of 33,000 tonnes.
Estimating the health of stocks and assessing trends is a science of variables - scientists combine survey information on the age, size and quantity of fish in the area with historical trends in survey and catch data and knowledge of the species' growth rates, spawning rates, age of reproduction and natural mortality. More is known about some species than others and it takes years to build up the databases needed for accurate computer modelling.
Deepwater fisheries such as orange roughy have a short history and the track record in managing them worldwide is far from good.
Orange roughy don't exactly help their cause. Acoustic monitoring is unreliable and a typical trawl survey costs $2 million.
The ministry has only a $22 million research budget for the 100 or so species (over 600 separate stocks) in the QMS. Adult fish are difficult to age and not enough is known about frequency of spawning and recruitment of adults into the fishery.
The reopening of the Challenger fishery follows trawl and acoustic surveying last year indicating the population has bounced back significantly in just a few years. The stock (or biomass) is estimated to have recovered from about 20,000 tonnes in 2006 to 52,000 tonnes last year. Curious indeed for such a slow-maturing fish.
Scientists recommended that 1000 tonnes could be caught, but Fisheries Minister Heatley opted for a more cautious 500 tonnes - not much more than can be taken for scientific research.
Environmentalists query how reliable the evidence of recovery is, given the roughy's slow growth and suspicion that recruitment of juveniles into fisheries is sporadic.
"We really need to look at the data over a couple of years rather than rely on just one estimate," says Environmental and Conservation Organisations (ECO) spokesman Barry Weeber. He notes the ministry has reopened the fishery before the population has recovered to the maximum sustainable yield (or take), about 35 per cent of the pre-fishing population.
Adding to the unease is the continuing decline of the much bigger stocks on fishing grounds around Chatham Rise. The population is not just below the maximum sustainable yield, it is thought to be below the "soft limit" - 20 per cent of the unfished population - which signals the stock is depleted and triggers a rebuilding plan. Some estimates suggest the stock is approaching the "hard limit" of 10 per cent, which could force the closure of the world's biggest orange roughy fishery.
Weeber puts it like this: "We've done as much to orange roughy in the last 20 years as happened to the [Atlantic] cod fishery in over 300 years. You can do major things in very short periods of time with the technology you have today."
MFish chief executive Wayne McNee says it's accepted practice to let stocks fall to the soft limit before making major interventions. He says the ministry has learnt its lesson with orange roughy. "So when we see what's happening on Chatham Rise at the moment we cut those catches rapidly and if we need to we will cut them further next year."
On the Challenger Plateau, McNee says there's "good, peer-re |
