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St. Petersburg Coastal and Marine Science Center

St. Petersburg Coastal and Marine Science Center > Ocean Acidification

Ocean Acidification

Arctic Cruise 2011: Educational Outreach

Carbon Dioxide (CO2) is a common gas in the Earth’s atmosphere. Plants "breathe" it in and make oxygen that gets released back into the atmosphere. It is also one of the major "greenhouse gases" released into the atmosphere during fossil fuel burning processes and even when we humans breathe. The concentration of carbon dioxide (CO2) in the atmosphere is now increasing at a faster rate than occurs naturally and the increased concentrations of CO2 are affecting global climate change.

The world's oceans naturally serve as a reservoir for CO2. At the surface of the oceans, CO2 mixes with the seawater and forms a weak acid called carbonic acid (H2CO3). When there is an increase in CO2, such as today, then more carbonic acid (H2CO3) is produced. An increase in carbonic acid (H2CO3) can, in turn, lower the pH (or increase the acidity) of the ocean.

Why does Ocean Acidification matter?

Simply put, some marine animals, such as shellfish and corals, make their own shell or skeleton. When the pH of seawater decreases, as the ocean becomes more acidic, shellfish and corals may have a difficult time making their shells and skeletons. This may cause slower growth, thinner shells, more brittle skeletons, or may prevent some species from thriving in their natural habitat. This process, in turn, could cause a disruption in the oceanic food chain.

Some other oceanic biota may benefit from OA. Marine plants such as sea grasses and algae, "breathe" in carbon dioxide, so the increased carbon dioxide (CO2) could make them grow faster.

What are we doing on the Arctic Cruise?

We will be testing seawater from many places and depths in the Arctic Ocean to take a more in depth look at ocean acidification in polar regions.

Classroom Resources

Video Podcast - Ocean Acidification: Research on Top of the World
Download video: MP4, OGG, WEBM, MOV | transcript

Ocean Acidification lesson plans and Power Point presentations

Coral Sand and Vinegar Activity (160 KB PDF)
School of Ocean and Earth Science and Technology, Univ. of Hawaii

Data in the Classroom teacher guide to Ocean Acidification and classroom activities
NOAA Ocean Data Education (NODE) Project

Ridgeway School Ocean Acidification Animation
European Project on OCean Acidification (EPOCA)

Hands on Ocean Acidification Experiments
European Project on OCean Acidification (EPOCA)

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