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Science_Lab_Yellow / Lesson 13: Food Webs Affect Us

Food Webs Affect Us
What will we be learning today?


  • In this lesson, we are going to learn all about how food webs affect us.


How Do Food Webs Affect You?


  • "Red Tide Observed Off the Coast of Maine" might not seem like a scary headline. You might even ignore this important warning. However, it could mean trouble for the average person.


  • You have learned that single-celled organisms called algae are at the base of the marine food web. When the algae population increases very rapidly, or blooms, it can turn hundreds of square miles of ocean red. Scientists call this a red tide. Most red tides are not harmful. However, some algae produce poisons. Fire algae are an example. A bloom of these algae is very dangerous to all the species in a food web.





  • Deadly red tides, like this one, occur when the population of fire algae greatly increases.


  • Small fish and mussels feed on the algae. The algae's poison may kill or infect the fish. The decline in the fish population reduces the energy available to the consumers that feed on fish.


  • How does this affect you? People who eat contaminated fish may become very sick. You are part of a food web, too. Humans are at the top of most food webs. Changes in any population may also affect you.


  • Let's Review What We Learned Today!


    • Now complete your worksheet!