Coastal Habitats & Species—Tides of the Estuary

Summary: This lesson is designed to give an introduction to how tides and tidal cycles work by having students visualize, act out, reading and graph how tidal cycles work. Context is given to tides by way of discussing and understanding how they influence life around the estuary and open coast.

Concepts to teach: Tidal cycles, interconnectedness and balance

Goals: Students will develop an understanding of the fundamental role and ways that tidal forces play on the waters and habitats of the estuary.

3.2P.1, 4.2E.1, 5.1E.1, 5.2P.1

Specific Objectives:

  1. Students will be able to describe the tides and the forces that influence their height and frequency.
  2. Students will be able to accurately read a tabular and graph form tide table and identify at least two high tides and two low tides by time and elevation.
  3. Students will be able to describe at least three ways the tides influence life and activities in the estuary.

Activity Links and Resources:

  • The TIDES “Tides of Change” lessons were developed by the South Slough National Estuarine Research Reserve.
  • Tide Predictions for Hatfield Marine Science Center in Newport, OR
  • NOAA Ocean Explorer: Tides—This narrated video provides a great visual for both how tides work and how they impact the earth
    • Predicting the Tides activity provides information, assessment questions, and an opportunity to apply knowledge
  • Understanding Tides—This inexpensive 20-page publication available from Oregon Sea Grant describes the creation of tides, the roles of the moon and the sun in producing tides, the effects of elliptical orbits, the interactions among astronomical movements, and types of tides. The author, a high school teacher, also looks at phenomena such as seiches and tidal currents that are associated with tides.


  • Tide Table Discussion Guide included in “Tides of the Estuary” OCEP Summary