Fish expert sounds warning on stocks

By PETER JESSUP

The future for global fisheries is not rosy, aquaculture offers false hope and governments should be setting aside up to half of fishing grounds as marine reserves to ensure the future of sea life.

That is the line from fisheries expert Professor Daniel Pauly, of the University of British Colombia, whose visit to New Zealand this week is sponsored by the Department of Conservation.

Professor Pauly also advocates the end of all bottom-trawling, which he says is incredibly damaging to the ecosystem.

The university's Fisheries Centre in Vancouver, of which he is director, maps catches globally, by species and area of distribution, collated with catch landings.

As demand increases, so does price, making it economical to go farther afield and deeper, especially in the Southern Hemisphere, given that the north is now so badly depleted.

A computerised vision of fisheries activity would show it spreading like a skin disease, Professor Pauly says.

"What we're doing is taking fish from one area then moving on. It is not sustainable. There are fewer areas to move on to."

Commercial fishers target the biggest fish first. As those decline, they go for the next-biggest but in doing so also catch the juveniles of the species they were previously targeting, which precludes any recovery by the species at the top of the food chain.

Though New Zealand's fisheries may be in a better state than those in other countries, and the quota management system allows some control, Professor Pauly disputes the premise of Maximum Sustainable Yield on which it is based.

The New Zealand Fisheries Act requires the minister to set total catch quotas at the level which will ensure individual species stocks are maintained at existing biomass. What that means is that the industry catches juveniles that are schooling because that takes the least effort and expense.

Professor Pauly says scientists may be able to show that fishing to MSY is most productive under existing circumstances, but the theory does not consider what the oceans and fish stocks would be like under pristine conditions.

He cites the international agreement on southern bluefin tuna, the most prized fish at the Tokyo markets. Catch levels were set based on catch records from the 1980s forward.

"The Japanese were not interested in looking at old data on southern bluefin because the figures would have suggested the fishery be closed."

Professor Pauly says we forgo the benefits attainable from an improved fishery by never allowing the stocks to recover.

"While you are fishing, all species are in decline. You cannot fish 'clean', you never get only the fish you are targeting."

Much of the fish taken as bycatch is thrown overboard or ground up for meal because it is not high value.

Technology is allowing man to go farther and fish deeper so that areas once protected by weather or depth are not any longer - think Antarctic toothfish.

"The size of stocks produces pressure for feeding so fish move to shallow water to eat. We catch them. But now we've caught all the shallow-water fish so we go deeper. The fish don't come into the shallows any more.

"We know exactly where the fish are, we can go to the last deep canyon and catch the last mature female laden with eggs - that means we have to have marine protected areas."

Professor Pauly says a badly reduced fish stock would require 50 per cent of a country's fishing grounds to be declared no-take in order to precipitate full recovery, especially if there was still to be some catch. If stocks were not badly reduced then 20 to 30 per cent might be enough.

His view on New Zealand's system: "ITQ [transferable quota] reduces expansion of the fishery but the fishery cannot be said to be sustainable because all species are being fished down. You have to consider the ecosystem as a whole."

We will become more aware of the global problem, he predicts.

In Northern Hemisphere markets, people have plenty of choice but often it is not the fish they know, the ones they grew up with. It comes from overseas, from the Southern Hemisphere, from deeper waters or from fish farms.

"Aquaculture uses huge quantities of anchovies and pilchards - this doesn't help the recovery of other species."

China is a major fish meal importer and the increase in Northern Hemisphere farms is dragging resources from the south, Professor Pauly says, in a way that cannot go on endlessly.

Fisheries being commercially exploited decrease at around 10 per cent a year, he generalises. Since the late 1980s the world catch has been in decline. And now there is increasing pressure because of population and health advice recommending fish.

Professor Pauly suggests action now. "It's when you get in trouble you need drastic action."

There will be some pain as commercial fishermen lose jobs and companies lose income. But it will be short-term pain for long-term gain, he maintains.

Professor Pauly sees little progress in terms of repairing the damage of the past century, despite international fisheries agreements.

"There is some awareness that change is needed, but no agreement on how that should be done. Actions are not following words.

"It's like global warming - everyone agrees it is a problem but China is using more and more coal and the United States is making noise but not moving. Non-destructive fishing gear would be a big improvement, he says. "In the long term, bottom trawling will have to be phased out."

Despite fighting a battle that appears to be endless, Professor Pauly does have hope.

"The seas can recover. Life invades everything if you give it space. Stop weeding your garden and see what happens."

Saving Nemo

Professor Daniel Pauly's views on conserving fish species:

Commercial fishing, which has already ruined fish stocks in the Northern Hemisphere, is set to do the same here.

New Zealand's quota system is better than nothing but still does not allow fish stocks to recover.

The only way to do this is to stop fishing - by setting aside between 20 and 50 per cent of our fishing grounds as marine reserve.

* Professor Pauly speaks tonight at 7pm at Auckland Girls Grammar School.