The Ojibwe need to keep track of the abundance of walleye fish to make sure that they keep showing up year after year. But counting the entire population of fish in a lake is an impossible task. How can they get the information they need?
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Lake Science
In this video, members of the Ojibwe tribe take a survey, or poll, to find out if the number of walleye fish in the lake is growing or shrinking. They will catch a small group of fish, called a sample, and use this information to understand the entire population in the lake. This method is called population sampling.
First, they set out two fishing nets in different parts of the lake. Later on, they will pull up the nets and count the types of fish that they caught. They hope that the fish they catch are representative of all the fish in the lake.
Click on the left to watch the video. After you watch, answer the question below.
In the video, the Ojibwe placed two nets in different parts of the lake. Why do you think they didn’t just use one big net and put it close to shore? Write two to three sentences to explain your answer.