Compared to lots of other animals, they're not too cute. They're not furry or cuddly. In fact, they can be kind of slimy. But trout are probably the most important wildlife species in the ecosystem around Lake Isabella, California, where many people depend on trout fishing for income, food and sport. At Woodrow Wallace Elementary School, students in Martine Metzenheim's 4th-grade class complete a whole science unit all about trout. They learn about the trout's life cycle, diet and habitat. Then they take a field trip to the local Kern River and splash around among the fish.

The class also studies the environmental needs of trout, including the need for clean water. But not everyone who comes to Lake Isabella understands the importance of keeping the Kern River clean. Sometimes campers throw trash into the river. Some even use the river as a place to go to the bathroom! Polluting the river is a serious threat to trout and their babies, called fry.

A Stream Dream

Metzenheim's class wanted to protect their favorite fish. They decided the best way to do that was to teach people about trout and how to care for the rivers where trout live.

The Kernville Hatchery, a local fish farm where trout are raised for sale, made Metzenheim's class an offer. The students were invited to build a miniature trout stream at the hatchery. Informational signs near the stream could educate the hatchery's 20,000 visitors each year.

What a great idea! The class decided to start the project right away. They set up a three-month work schedule beginning in November.

Planning, Digging and Planting

First the students had to measure, map and design the pond. Leith Hasanin, age 11, even skipped recess to finish work on the map!

Next came the digging--the toughest part. "Moving rocks and plants out of the way was really hard," recalls Matthew Abbott, 10. Fortunately, the students had some help from a nearby school, which loaned a giant backhoe to speed up the digging process.

But the students still had lots left to do before the streambed and pond could be filled with water. They arranged rocks to strengthen the pond's sides. They also built a hill alongside the stream. Now they will watch for signs of the hill wearing away, called erosion. Erosion is dangerous to fish because the loose dirt that washes into the river can choke the trout fry.

One way to avoid erosion is to plant grasses and shrubs, which hold the soil together. Plants also shade and cool the stream. Allie Jones, 9, and her mom helped with that task. Says Allie: "It was fun because we were helping the fish."

A Trout Triumph

At last, the stream was filled with water! Today it serves as an ideal trout habitat. There is a deep, clear pool for the adult trout, shallow water for the fry and a gravel-bottomed creek for the rock nests, where adult trout lay their eggs.

But the stream is much more than a trout habitat. It is a learning center as well. The students made signs to line a walkway along the stream. The signs explain the trout's life cycle and how people can help preserve the river. One sign really sums up the class's message: clean rivers make healthy fish.

--By Michelle R. Derrow. Reported by Roberta Grant/Lake Isabella