Scientists demand 'fish parks'

By John Duce in San Francisco

A hundred and fifty of the world's leading marine scientists are calling for a ban on fishing in vast areas of the world's oceans.

The experts say large numbers of fish and other aquatic species are on the verge of extinction and the only realistic way of saving them is to create specially protected marine reserves, or "national fish parks", covering as much as 20% of the Earth's seas.

The marine scientists released their consensus statement at the annual meeting of the American Association of Advancement of Science (AAAS).

The scientists' main concern is overfishing which has dangerously depleted fish stocks all over the globe. In the Atlantic, for example, it is estimated that industrial fleets have reduced the numbers of cod by 90% in recent years.

More and bigger fish

At the moment, only 1/100 of 1% of the world's seas are fully protected with fishing of any sort totally banned. Scientists have spent over two years studying whether these marine reserves have allowed fish stocks to recover.

The results have been "startling", the researchers say. Population densities in the reserves were on average 91% higher than in unprotected areas; the average size of species was 31% higher; and species diversity was 23% higher.

In the Leigh marine reserve to the north of New Zealand, numbers of snapper fish and spring lobster have increased significantly. And in a reserve covering 17,000 square kilometres in the Gulf of Maine, scallop populations have rebounded to nine to 14 times their density in fished areas.

Dr Callum Roberts, from York University, UK, said networks of marine reserves should now be set up around the globe. He said the prospects for the world's fish stocks were bleak if action was not taken.

Scientific facts

"The consequences are going to be continued declines in fishery stocks and collapses of important species," he told the BBC. "We're going to get less and less production from the sea. But we're also going to see global extinctions of marine species, just as we've been seeing on the land.

"Things lag behind in the sea in that respect but, without protecting significant areas, that extinction wave is coming."

The scientists stress fishermen will benefit both in the long and medium term. Practice has shown that trawling the edge of marine reserves can result in high catches as adult species move out of the safe areas on ocean currents.

A major obstacle to the implementation of marine reserves has been the lack of scientific information about whether such strategies actually work. Professor Jane Lubchenco, from Oregon State University, US, said the uncertainty was gone.

"Marine reserves work and they work fast," she said. "It's no longer a question of whether to set aside fully protected areas in the oceans, but where to establish them. We urge the immediate application of fully protected marine reserves as a central oceans management tool."