Heartening news from the deep

For the sake of their hearts, consumers are being told to eat more fish. However the advice comes as global fish stocks collapse, as seafood demand from China and India booms and the price of fish in some countries soars towards $100 a kilo.

The days of the affordable seafood feed are gone for good. Or are they? For the first time, marine science is finding substantive answers to the problem of the vanishing fish stocks, and Australia is a global leader. But that’s not a fact well known to Australians.

A survey by the Fisheries R&D Corporation (FRDC) found only 13 per cent of Australians regard fishing as sustainable. In comments by governments, conservationists and the media the fishing industry is constantly portrayed as in trouble and depleting its resources.

The view - if dated - is understandable. With celebrated “disasters” like gemfish, orange roughy, scallops and school sharks in the late 20th century, the public image of fishing and fisheries science took a hammering. Not without reason: the original scientific estimate of the orange roughy stock was 2 million tonnes and there were said to be “haystacks” of them! A fisheries scientist of the day famously remarked that “the science of stock estimation is imprecise. It’s really a case of where one puts the decimal point”.

For roughies, the point was woefully out of place. From 50,000 tonnes in the boom year with 56 specialist deepsea trawlers racing to cash in, the fishery has this year been restricted to a few hundred tonnes and two or three boats. It was a classic boom-bust, brought on by the fact that no-one knew anything about orange roughy or their biology.

Roughy are still mysterious, but at least we know they live up to 120 years, gather in huge numbers to spawn and something of their genetics, habits and distribution. This has enabled science to set rational catch limits and restrict fishing to allow the once-prolific stock to rebuild and the fishery itself to recover.

Experts agree Australia has probably the only sustainable orange roughy fishery in the world today - though New Zealanders might contest the call. Through science a spectacular disaster promises eventually to become a modest triumph for environmentally sustainable development, a hard lesson well-learned.

An equally notable turnaround is in the southern Australian scallop fishery, scarred by 50 years of crazy booms and savage busts:

The last few years in the chart tell the story of how fisheries science has changed all that, says Associate Professor Malcolm Haddon of the University of Tasmania. From a tradition of “pillage and plunder” until the scallops were totally fished out, the industry has adopted a new professionalism and an ethic of husbanding its resource.

Nowadays, Haddon says, fishers only open the beds when the shellfish are the right size and density. They rotate fishing effort from year to year and place to place, ensuring no stock is ever “fished out”.

“We optimise catch rates, target only the best beds and minimise the impact of dredging on the seabed and other marine life. As a result scallop fishing now provides a steady income to the fishers who manage it, the harvest is stable and of high quality - which suits customers - and the environment recovers. It’s a win all round.”