TCS Daily


Move Over Culture War. Here's the Aquaculture War

By John Baden - August 29, 2003 12:00 AM

Three years ago I was returning from Santiago, Chile, on a new Delta flight. It was less than a quarter full. I asked a flight attendant if we would go faster since the plane seemed empty. He responded that we were maxed out on weight. "Why?" I asked. "We're nearly empty." No, he responded, we're carrying many tons -- of salmon.

This was my introduction to modern aquaculture.

I've spent a great deal of time, moved much dirt, and called upon professional expertise, to create a trout habitat on our ranch. We have a healthy population of wild trout in our spring creek and a string of ponds open only to a few friends. This, however, is not real aquaculture. It's just fun.

Serious aquaculture is different indeed. With emerging biotechnology, aquaculture will yield a brighter, greener future. Here's why.

Fish are healthy alternatives to red meat. But wild fish stocks are in serious trouble. We've grossly overfished wild fisheries in the oceans. This is a classic "tragedy of the commons." With no ownership of fish on the high seas, the resource is overexploited.

The answer seemed to be aquaculture, raising ocean fish in captivity. This practice, however, has been problematic at best. Four ecological problems plague commercial fish farming.

First, massive fish farms create pollution. Second, high concentrations of fish require medications, just like cattle in feedlots. Third, there is the real potential of escape and genetic contamination of wild stocks. Fourth, and perhaps most seriously, many "domestic" fish require feed taken from the wild in the form of fish meal.

These are real problems. And solutions are emerging.

While we have been farming the land for over 3,000 years, and we are still wrestling with ecological problems, modern aquaculture is only about 40 years old. Our progress here is remarkable. Regulation is essential to progress. And so is biotechnology.

Waste from fish farms, as from feedlots, must be controlled or serious consequences follow. New feeding technologies have reduced nitrogen loading to one-sixth that from early farms. Feed for growing salmon has declined 56 percent from 39 years ago. In Norway, antibiotic use has decreased 99 percent over the last 10 years.

The biggest remaining problem is the use of fish meal. Carnivorous fish such as salmon have relied on the protein and omega-3 oil from ground-up and processed wild fish. And here, biotechnology offers an answer.

Wild fish sources are not necessary and ag research at Montana State University may soon offer an alternative. Researcher Duane Johnson of the MSU Northwest Agricultural Research Center in Kalispell and professor Dave Sands of MSU are exploring substitutes for fish meal. This holds great promise in terms of health, ecological systems, and economics.

We've learned that eating fish high in omega-3 fatty acids promotes healthy hearts and other benefits while providing protein. The American Heart Association recommends that people eat tuna or salmon at least twice a week.

Scientists studied the Inuit (Eskimo) of Greenland in the 1970s. The Inuit suffered far less from coronary heart disease, rheumatoid arthritis, and diabetes mellitus than their European counterparts. Yet their diet was very high in fat from eating whale, seal, and salmon. Eventually researchers realized that these foods were all rich in omega-3 fatty acids, which provided real disease-countering benefits.

The problem is that we're overharvesting these wild fish. This explains the demand for aquaculture. One important constraint in fish farming is the need for fish meal made from herring and anchovies.

The object of the MSU research is to develop a farmed alternative to fish meal. According to Johnson, "the best means of capturing omega-3 from a plant would be to transform a cultivated oilseed crop into producing omega-3." A plant called carpetweed produces the omega-3 fatty acids required by the farmed fish. The fish, however, require a low-fiber food such as hulled sunflower seeds.

The MSU researchers are working to genetically alter sunflowers with the carpetweed gene to produce a fish food high in omega-3 oil and digestible by the farmed fish. The health, ecological, and economic benefits of success may be enormous. Modern science may drastically reduce the time required for progress in aquaculture while dramatically reducing the negative ecological consequences.

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