Visit Your Local PBS Station PBS Home PBS Home Programs A-Z TV Schedules Watch Video Donate Shop PBS Search PBS

Herbivorous Fish & Mollusks

Herbivorous Fish Farming & Mollusk Aquaculture

Viewpoints

Dr. Daniel Pauly

Dr. Daniel Pauly

Professor at the Fisheries Centre, University of British Columbia

There are two forms of aquaculture, one that is sustainable, herbivore-oriented, small industry, small enterprise, and the other that is industrial oriented, carnivorous, and is usually large enterprise.

I personally like the idea of shellfish aquaculture. These are animals that stay quiet, they stay where you put them, and they clean up the water. They eat what they have extracted from the water that they clean. You can produce absolutely enormous amounts of food, of wholesome, human food, food for people, in a very small area. Shellfish, in fact, have the potential of feeding humanity, if we go that way.

Tilapia have often been represented as the aquatic chicken, and it's perfectly justified. It's a filter feeder; it can eat a little bit at the bottom, and it eats essentially phytoplankton and detritus that is to be found in ponds. It doesn't have to be fed with flesh. It is a very tasty fish, robust. It can handle a wide range of environmental conditions. You can grow it in a backyard operation but you can also grow it in an industrial context. That could become the chicken, the aquatic chicken of the future.


Lester Brown

Lester Brown

Founder and President of the Earth Policy Institute and World Watch Institute

In many ways China is the model for aquaculture in the future, not that everything it's doing is right, but it's doing a lot of things pretty well. They have concentrated heavily on fish farming. The big one is carp production with a poly-culture system, which is ecologically much more sophisticated than any other system in the world. In China, which totally dominates world aquacultural output, there must be 12 million acres or 5 million hectares in carp ponds and other ponds.

Another form of fish farming that's quite common in China and also Japan is the production of shellfish: oysters and clams. These are in environmental terms, the least intrusive of any of the farmed fish seafood. They're grown in coastal regions in saltwater, and they filter the water and obtain their nutrients from that. So that's one of the big “pluses”.

In some countries, almost all the oysters and clams today come from farming rather than from natural beds. The Chesapeake Bay, at one time, produced 100 million pounds of oysters per year. It's now down to less than 3 million pounds per year. There was a time, a few generations ago, when farmers on the eastern shore of Maryland used to feed oysters to their pigs to fatten them. The oysters were so abundant, and so they used them to convert some of them into pork.


Dr. Randy Macmillan

Dr. Randy Macmillan

President of the National Aquaculture Association

The question is whether or not the use of-the growing of-carnivorous species is unsustainable. I think you also have to look at in the first world, in the developed countries, what consumers will buy. And one thing we know in the seafood industry, consumers like choice. So there is always going to be demand for carnivorous species of fish.

I think we can expect to increase demand for a variety of seafood, and certainly herbivorous animals would play a part in that. But how you change the consumer's preference is a real, real challenge. We see other cultures, their way of cooking foods coming into play in the United States. They like Asian cooking, they like the whole broad range of different kinds of styles of cooking. And that's really good, that encourages people to try different kinds of aquatic animals and so there will be opportunity for those herbivorous animals.

Whether you can see a ground swell of change from Tuna to Carp for example, that's a long difficult road. And the danger there is that a farmer might grow Carp or another kind of herbivorous animal but there's no market. There's no place to sell his product. He's out of business. And in our society, that doesn't work. So it is a major challenge to get United States consumers to change the types of animals and plants that they eat.