Fish farming would seem to be a great way to meet the world’s increased need for protein as the population grows. In fact, fish production from aquaculture, as it is also known, will soon outpace conventional fishing But if this industry is to live up to its promise, it will have to grow in a way that is environmentally sustainable, and that works in favour of the poor and hungry.

Cultivating fish for food has been around for some time now as a small-scale practice, but large-scale farms don’t work in quite the same way. In Vietnam where aquaculture is being scaled up to meet increased global demand for fish, new concerns about the effects of industrial fish farming on the environment and on the poor are emerging.

Listen to the audio of this report done by Sam Eaton for Marketplace as part of the Food for 9 Billion project.

In the 1960s, poor rural farmers in Vietnam created ponds within their farms to raise fish for their own consumption. They fed the fish their agricultural waste and then ate the fish themselves. The farmers drained the pools and used the fish pond waste to fertilize their fields. Then they started the self-contained cycle over again. They never had to buy fish feed or fertilizer and it actually worked quite well. The problems seem to occur when the operations are scaled up.

Large fish farms use imported soy-based feed instead of locally produced agricultural waste to raise the fish. And rather than using the pond waste as fertilizer, the large farms are dumping it in rivers creating ecological problems. Though environmental groups in Vietnam are trying to create standards to help clean up the process, it raises the question of whether industrial-scale fish farming can be done without creating new hazards.

Since there is money to be made in raising fish for the global market, there is also the danger of forests and wetlands being destroyed as new ponds are created. Smaller farms that use the traditional system of feeding and fertilizing are kept out of the global market because their practices don’t fit international standards for food products.

Perhaps the point that is most often overlooked is that industrially produced fish is not destined to feed the people of Vietnam, or poor people in other parts of the world. It is shipped  to supermarkets in Europe and the United States and sold as frozen fillets.