Scientists call for 'national parks' of the oceans

By STEVE CONNOR

Scientists have identified "rainforests" under the oceans - including in Australian waters - where biological diversity is at its greatest.

These wildlife hotspots should be preserved to give the marine environment a chance of recovering from decades of over-exploitation, the researchers said.

Dr Boris Worm of the University of Kiel, Germany, and Dr Ransom Myers of Dalhousie University in Halifax, Canada, want the major nations of the world to demarcate thousands of square kilometres of the open water for unprecedented environmental protection.

In effect, they want the oceans to have their own national parks, where any form of industrial or large-scale fishing would be banned.

They describe the regions as the "Serengetis of the sea", after the famous wildlife park in East Africa.

"We have discovered for the first time in the open ocean there are hotspots of species diversity which we have metaphorically called ocean Serengetis," Worm said.

Using data gathered by the highly destructive long-line fishing industry, Worm and Myers located the areas of the North Atlantic, and the North and South Pacific where the long-line fishers caught the most abundant and most diverse range of animals - ranging from the targets of their trade, such as tuna and marlin, to the "bycatch", such as turtles, dolphins and albatross.

The researchers found that large species such as shark and tuna, which roamed entire ocean basins, tended to aggregate relatively close to the major land masses.



The biodiversity hotspots tended to be in subtropical waters between 20 degrees and 30 degrees north and south of the equator, and depended on features such as intersecting currents of warm and cold water.



The study was published in the Proceedings of the National Academy of Sciences.

It found the richest hotspots tended to be off prominent topographical features, such as islands, coral reefs and the point at which the relatively shallow waters of a continental shelf break down into the much deeper regions.

That explained why the scientists found their marine Serengetis off the islands of Hawaii, the Great Barrier Reef, the shelf breaks off the north-west Atlantic and north-east Australia, and the seamounts off the coast of south-east Australia.

Computer modelling showed the benefits of closing hotspots to the fishing industry.

Most of the data came from long-line fishing in American and Australian waters because those two countries pay for scientific observers to record the bycatch.

There may be some unrecognised hotspots in the Indian Ocean or off Antarctica.

The US and Australia are well placed to take unilateral action to protect the richest part of the oceans so that fishing can become more sustainable.

Measures could include eliminating fishing techniques that are simply too destructive, such as trawling and drift nets.

- INDEPENDENT