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Kelp Forest by Megan and Ian

We love to scuba dive in the deep waters off the coast of California. On one of our dives, we observed an underwater forest made of kelp plants. We were curious about the variety of animals that live in different parts of the kelp forest. Our question: Do larger animals live at the top of the kelp forest or at the bottom?

What did we do?
We worked with our scuba instructor to plan a dive to the base of a kelp forest. The part of the kelp plant that secures it to the ocean floor is called a holdfast. We found a loose, damaged holdfast and brought it to the surface so we could see what animals were hiding in it. We counted the number of creatures and identified them using a picture book. We then returned these creatures to the sea and gathered part of a kelp frond (leaf) from the top of the kelp forest. We brought it to shore to investigate the creatures living inside of it.

What did we find out?
Our original hypothesis was that larger animals lived in the holdfasts and that smaller creatures lived up in the kelp fronds. What we found was something entirely different! Several small creatures lived in the holdfast, including an octopus, some sea stars and sea worms. We found fewer animals living in the kelp frond. We concluded that we would have to examine more samples, at different times of day, before we formed our final conclusions.

What can you do?
  • What's living in the pond or stream near your house? Take an adult with you and use a small fish net to look for small fish, tadpoles and even freshwater shrimp! See what lurks in that stand of cattails!
  • Look for animal nests in different trees in your neighborhood. Why do some animals choose pine trees, while others choose oak trees for their nests? What kind of protection do different trees offer?
  • Use this scuba investigation as a science fair project idea for your elementary or middle school science fair! Then tell us about it!
more resources
More on Marine Ecosystems

Go to the DFTV Boards, and tell us about your science investigation.
whiz quiz
What is the world's largest living organism?

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