Freshwater Fish Supplies Under Threat

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MELISSA BLOCK, host:

From NPR News, this is ALL THINGS CONSIDERED. I'm Melissa Block.

ROBERT SIEGEL, host:

And I'm Robert Siegel.

Overfishing is a big problem in the world's oceans. Scientists and conservationists have been talking about that for quite a while. But freshwater rivers and lakes are also losing fish at an alarming rate. The authors of a new survey say many inland fisheries will collapse if present trends continue. That could forces tens of millions of people in developing countries to find new jobs and new sources of food. NPR's John Nielsen reports.

JOHN NIELSEN reporting:

When European settlers arrived in Australia in the late 1700s, the Murray River Basin was full of giant fish known as Murray cod. David Allan, a fisheries expert at the University of Michigan, says these fish were so big and so common that the locals thought them supernatural.

Mr. DAVID ALLAN (University of Michigan): In the aboriginal legends, in fact, it carved the river channels. It dug them with its snout.

NIELSEN: The Murray cod is a tasty fish, but for a long time it managed to stay abundant. Then after World War II, the annual catch increased dramatically and the Murray cod population crashed. Pollution problems made a comeback hard, as did the diversion of river waters into nearby farmlands.

Mr. ALLAN: And the introduction of a non-native perch that fed on the eggs and the young of the Murray cod. So it was like factor after factor began to kick in in the middle and latter part of the 20th century.

NIELSEN: In the new study, Allan and other scientists say the problems that brought down the Murray cod are now a threat to other important freshwater fish; the Black Sea sturgeon, the Indian carp and the giant Mekong River catfish just for starters. In a few cases, these fish are being caught and sold in fish markets, but in many more, they are being caught and eaten by the fishermen themselves. All of which leads Allan to what he says is an inescapable conclusion.

Mr. ALLAN: That overfishing of inland waters is a neglected crisis.

NIELSEN: Allan and his colleagues say approximately 8.5 million tons of fish are taken out of inland waters every year, four times more than the annual harvest in 1950. Most of this fishing takes place in parts of Africa and Asia, where fish are the main source of local protein. When fish populations crash, many fishermen start hunting on land, compounding what Gene Helfman of the University of Georgia says may be an even bigger crisis.

Mr. GENE HELFMAN (University of Georgia): People, in order to meet their protein needs, are going into the bush and killing off the monkeys and the other mammals and birds.

NIELSEN: The authors of the inland fishing paper say there are several reasons why these problems haven't got much attention so far. One is that they're not taking place in the United States or Western Europe; another is the fact that governments don't always keep good records on inland fisheries. David Allan of the University of Michigan says it won't be easy to revive the inland fisheries. It will take not only new fishing regulations, but tough pollution rules and new restrictions on dam building and irrigation. But he thinks it can be done. In fact, he says it has been done in Australia's Murray River Basin, where a broad package of land use changes appears to have saved the giant Murray cod.

Mr. ALLAN: And the fish are recovering. Whether they'll get back to the abundance and the sizes that were historically the case is something we can all hope for, but that's a long ways to go.

NIELSEN: The inland fishing study was published in the journal Bioscience. John Nielsen, NPR News, Washington.

SIEGEL: For a close-up look at one country's freshwater fishing crisis, you can tune in to "Morning Edition" tomorrow and hear a Radio Expedition to Cambodia, home to catfish that grow to more than 600 pounds.

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