Food Chain "You are what you eat." That's what my Mom says! Fish are important to us. They provide food for millions of people and fishermen enjoy catching them for sport. Fish are also important in the balance of nature. They eat plants and animals and, in turn, become food for plants and animals. This is called the food chain. Here's how it works: Food chains begin with tiny floating plants called phytoplankton and small animals called zooplankton. The next step in the chain is a small fish, like a bay anchovy or a menhaden, which eats the small organisms. The next step is a larger fish like a spotted sea trout eats the smaller fish. The next link in the chain is the fisherman who catches the sea trout and eats him for dinner. If you take out a link in the chain you affect everything in that chain. For example, if you pollute the water so the phytoplankton and zooplankton die, then the bay anchovy or the menhaden can't survive. Without the smaller fish to feed on, the larger fish disappear.