Impacts—Ocean Acidification

Summary: The ocean is becoming more acidic because of carbon dioxide emissions. The change threatens the health marine organisms that depend on available calcium carbonate to make their shells. In this topic guide, students use models and real data to explore the relationship between atmospheric CO2 and ocean pH, and the impacts that pH changes have on marine organisms.

Concepts to teach:


  1. Increased levels of atmospheric CO2 leads to a decrease in ocean pH
  2. Ocean acidification leads to decreased amounts of available calcium carbonate that many marine organisms need to make their shells
  3. Scientists use data to create models that forecast future conditions

Standards: NGSS Performance Expectations

  • HS-ESS3-6. Use a computational representation to illustrate the relationships among Earth systems and how those relationships are being modified due to human activity

Specific Objectives:
Students will be able to:

  1. Use data to describe the process and driving factor behind ocean acidification
  2. Use online tools to recreate climate change model scenarios and examine effects of increased CO2 on ocean acidity and carbonate saturation levels
  3. Identify expected future impacts of ocean acidification on marine organisms and ecosystems

Activity Links and Resources:

  • Changing Ocean Chemistry Curriculum from Oregon Sea Grant – This 2019 resource includes five lessons to define and characterize OA is and its impacts, and describes what students can do to reduce the problem of OA.
  • On June 10, 2019, the Oregon Coordinating Council on Ocean Acidification and Hypoxia (OAH) released the Oregon’s DRAFT Ocean Acidification and Hypoxia Action Plan
  • Understanding Ocean Acidification from Data in the Classroom —Revised in 2019, this high school level curriculum uses NOAA data to help students learn about ocean acidification.
    • Level 1 Explore NOAA data to understand patterns and relationships that explain variation in ocean pH
    • Levels 2-4 helps students use NOAA data to explore the impacts of ocean acidification
  • The Power of pH: Changing Ocean Chemistry from Monterey Bay Aquarium – Review what pH is and how CO2 released from the burning of fossil fuels increases the acidity of the ocean
  • Virtual Urchin: Our Acidifying Ocean—With this interactive online laboratory experiment, students discover the effects of acidified sea water on sea urchin larval growth
  • Multimedia Resources about Ocean Acidification
    • Ocean Acidification—Short animation from North Carolina Aquarium at Fort Fisher introduces effects of OA on ecological interactions
    • This pH infographic summarizes findings from the Ocean Acidification Summary for Policy Makers 2013


  • The Data in the Classroom resource includes assessment components, including
    • Check for Understanding interactive questions at the end of Levels 1, 2, and 4
    • The Teacher Guide contains detailed questioning strategies, student worksheets and answer keys
    • Level 5 in the Data in the Classroom unit challenges students to come up with their own hypothesis about ocean acidification and then look for NOAA data that will support or reject that hypothesis.