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Fish Population by Ronnie and Denise

Hey, something's fishy up here in Northern Minnesota! We're members of the Ojibwe Nation, and we want to keep the lakes and rivers on White Earth Reservation stocked and healthy. Our question: Is the fish population in our local lake increasing, decreasing or staying the same?

What did we do?
We used gill nets and trap nets to catch six kinds of fish: walleyes, black crappies, white suckers, bluegills, pumpkinseeds and bullheads. Working with tribal biologist, Doug McArthur, we counted these fish and used the totals to figure out how many of each kind of fish were living in this huge lake. We then compared our fish count to data that had been collected on the lake for the past three years to determine the fish population's stability.

What did we find out?
Our tribe's walleye restocking program is working. The number of walleye is stable. Compared with data from the past three years, all other kinds of fish are also thriving in this lake. This is great news, because not only does it suggest that the restocking program is working, it also shows that the lake itself is a healthy environment for wildlife.

What can you do?
  • A healthy lake doesn't just have a lot of fish, it has a lot of different fish. That's called biodiversity. Biodiversity is one of the best signs that a lake, field or forest is healthy. Check out the bugs in a field near school. Mark off a three-meter square and look for as many different bugs as you can. Compare that to what you find in your yard. Which place is "healthier" for insects?
  • How do you count all the fish in a lake? Well, you don't but you can get an estimate. Check out the the New England Aquarium Web site at www.neaq.org and try this activity which teaches you techniques for counting fish. Then, come up with a similar strategy to count all the squirrels in a park or all the bees in a flower garden.
  • Plant your own garden of biodiversity. Work with your parents or teachers to plant a butterfly garden at home or school. What's a butterfly garden? It's a garden of diverse plants and flowers that attracts butterflies. Visit The Butterfly House Web site to find out how to plant one.
  • Use this animals investigation as a science fair project idea for your elementary or middle school science fair! Then tell us about it!
more resources
More on the Characteristics of Populations

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