Fish Food

Fish Food Photo Credit: Clipart.com

Small fish are being fed to almost anything except people. And, that's a waste.


Where have all the small fish gone? I'm Bob Hirshon and this is Science Update.

Small fish like sardines and anchovies are being fished to the max. Thirty million tons are taken out of the ocean each year. But a new study from the University of British Columbia finds that very few of them end up on people’s plates—most go to feed pigs, chickens, and farmed fish. Jackie Alder, now at the UN Environment Programme, says that’s a waste. For example, twenty pounds of fish go into producing just one pound of farmed tuna.


And so if we can change taste preferences over to these small pelagic fish, we wouldn’t have the fish crisis that we have at the moment.

And, she adds, there’s a bonus: the small fish are more nutritious and heart-healthy than many of the big ones. I’m Bob Hirshon, for AAAS, the science society.

Making Sense of the Research

Many popular seafood fish, including cod, tuna, and flounder, suffer from overfishing. Simply put, overfishing describes any situation in which fish are caught faster than they can reproduce. Overfishing has shrunk countless fish populations all over the world. In fact, the United Nations' Food and Agriculture Organization estimates that over 70 percent of the planet's fish species have been overfished, and over 50 percent have been pushed to the limit. Although protective measures have helped some fish populations recover, the bad news still far outweighs the good. A 2006 study in the journal Science estimated that if fishing keeps on its current course, we'll run out of edible fish by the middle of this century.

So why does Alder recommend eating more small fish like sardines and anchovies, when they're already overfished? Because, she argues, if those small fish went directly to your dinner plate instead of to other food animals and fish, we wouldn't need as many. To elaborate on her example, one pound of farmed tuna provides enough fish for just three or four human-sized entrees, but the twenty pounds of small fish that it took to grow that pound of tuna could feed eighty people. If humans were to eat more of the small fish and less of the big fish, we'd actually consume fewer big and small fish than we do now.

In fact, this principle applies to more than fish. Eating “low on the food chain,” in other words, plants and some small fish and animals, generally has a much smaller environmental impact than eating larger animals. That's because raising large animals, especially cattle, uses up a lot of water, grain, land, and other resources, but only a small fraction of what you put into the cow over its lifetime ends up in the meat it produces. It's more efficient, nutritionally and environmentally, to just eat what you would have fed to the cattle. In fact, some scientists suggest that Westerners should consider eating insects (see below), which have long been popular in parts of Asia and Africa, in order to reduce our environmental impact. But even if caterpillars and crickets don't make it onto many American menus anytime soon, it's clear that we'll have to change our eating, fishing, and farming habits in order to make it through the next century.

Now try and answer these questions:

  1. Why are small fish being overfished?
  2. How might eating more small fish (instead of big fish) protect their populations?
  3. What does it mean to eat "low on the food chain"?
  4. Do you think it's more important for people to develop sustainable eating habits, or sustainable farming and fishing practices? Should new laws lead the way, or should people be encouraged to change their personal choices and behavior? Give reasons for your answer.

For Educators

Overfishing: A Threat to Marine Diversity is one of the United Nations' “10 Stories the World Should Hear More About.”

The Monterey Bay Aquarium's Seafood Watch: A Consumer's Guide to Sustainable Seafood offers information about sustainable seafood practices and threats to fish populations, including overfishing.

The Discover Magazine article Want to Help the Environment? Eat Insects reports on a group of scientists promoting eating bugs for efficient and environmentally friendly nutrition.

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