Coastal Ecosystems

Teacher Guide: Dissolved Oxygen in an Estuary

May 24, 2011, 7:13 pm
Source: NOAA


In this activity developed by NOAA, students learn about dissolved oxygen (DO) and its effects on life, with a focus on the chemistry. First, they are introduced to, and analyze data gathered from, water quality sensors in Narragansett Bay National Estuarine Research Reserve (NERR), observing how DO and chlorophyll-a change from the surface to the bottom and considering the relationships between DO and temperature. Then, in the unique environment of Azevedo Pond in the Elkhorn Slough NERR, CA, they analyze DO data and speculate about how hydrodynamics, abiotic factors, and biological processes cause extreme fluctuations in DO in the pond.


Students will be able to:

  1. Explain the relationships between dissolved oxygen and water depth, chlorophyll-a and water depth, and dissolved oxygen and temperature.
  2. Explain how these parameters interact during estuarine processes and in such phenomena as eutrophication, algal blooms, and supersaturationhypoxia fluctuations.
  3. Understand how photosynthesis, respiration, and decomposition affect dissolved oxygen.
  4. Explain the role of these processes in daily or seasonal dissolved oxygen fluctuations in some estuaries.
  5. Explain how hypoxia and anoxia occur, using data as evidence, and explain the affect on estuarine animals.


Teaching Time: 3 class sessions (55 minutes) + homework

Organization of the Activity: This activity consists of 2 parts which help deepen understanding of estuarine systems:

  1. Dissolved Oxygen in Narragansett Bay
  2. What’s Happening in Azevedo Pond?


Teacher Guide-Physical Science Module
Activity: Dissolved Oxygen in an Estuary



Nomack, M. (2011). Teacher Guide: Dissolved Oxygen in an Estuary. Retrieved from


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