Meet the underwater characters that make a living cycling nutrients through the watershed. Learn how the physical, chemical, and biological systems within watersheds work together to create a continuum of resilient, interconnected ecosystems. Watch the food chains spiral nutrients in and out of the river basin in vast web of interactions. Click for a PDF of the video transcript.  This website is part of the Surface Water series.

Pre-viewing Question

  • What do you think happens to all the nutrients that enter the watershed through the excrement of aquatic organisms?

Discussion Questions

  • Use your imagination to list ten types of substances for microbes to colonize in the headwaters, mid-sized streams, and rivers.
  • What would happen to this food web if collector organisms like Hydropsychae and Maccaffertium were absent?
  • How do nutrients travel upstream from rivers to headwaters?
  • How do nutrients spiral up and out of the watershed permanently?

Post-viewing Question

  • Which stream would you prefer your city’s water treatment plant pull your drinking water from: one with or without a food web of macroinvertebrates?  Why?

Extension Activity

  • Watch How Wolves Change Rivers and discuss what might happen to the food web if the aquatic predators like Eccoptera, Rhyacophila and Aeshna were absent from the watershed.

Links to Learn More

Next Generation Science Standards

  • Performance Expectation: Develop a model to describe the cycling of matter and flow of energy among living and nonliving parts of an ecosystem. HS-LS2-3
  • Disciplinary Core Idea: Ecosystems are dynamic in nature; their characteristics can vary over time. Disruptions to any physical or biological component of an ecosystem can lead to shifts in all its populations. LS2.C
  • Crosscutting Concept: Energy and matter
  • Engineering Practice: Developing and using models


Follow That Nutrient 18 December,2015Lucy Laffitte


Lucy Laffitte

Lucy B. Laffitte, PhD has been a science communicator and environmental educator for over thirty years. She has produced in-class and on-line instructional design, curriculum development, and certificate programs to a variety of conservation organizations, including the Oregon Museum of Natural History, Tall Timbers Research Station, North Carolina Museum of Natural Science, Salt River Project, New England Wildflower Society, Rachel Carson Institute, and Nicholas School of the Environment. She has published in print and on air—writing a nature column for The Cape Codder and was the founding radio producer for the environmental program the Allegheny Front. She has a bachelor’s degree in natural science, from the University of Oregon, a Master’s in adult education and graphic design and a PhD in environmental resources from North Carolina State University. She has been science education consultant for UNCTV working on QUEST and NC Science Now since April 2013.

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