1. What are the possible impacts of ocean acidification?
Lesson 4 of 5
Developed by Brian Erickson ©2019

2. Ecosystems Impact video
Show Day 3 video, have students answer questions in notes. Following video, discuss

3. Humans and the Ocean are Interconnected
Say: So far, we’ve talked a lot about oysters at Whiskey Creek because they provide us with a well-studied example close to home. They also help show us that ocean acidification is about more than just pH.
Say: We are going to shift our focus and explore some other possible impacts of ocean acidification, which is an active area of scientific research.
Ask: in what ways do humans rely on the ocean? (food, minerals, climate, transportation, shipping, recreation, well-being) Does the ocean rely on humans for anything? (Many students will say no, the ocean doesn’t need humans. Some might say the ocean relies on humans to avoid polluting/overharvesting)
Now we are going to explore some of the many interconnections between different marine organisms and between the ocean and people.

4. Shell building takes more energy with ocean acidification
For those oysters that do survive, there can still be impacts. Take a look at the images in your notes. What differences do you see between oysters grown in “normal” waters and low omega/pH waters?
Oysters grown in unfavorable water, if they survive, are smaller, deformed, greater mortality, never fully recover even when put in “good” water later.
(Figure- A series of images of oysters grown in favorable (high Ω and pH) and unfavorable (low Ω and pH) conditions. (Notes- each image is of a different oyster. Photo credit- Brunner/Waldbusser))
Ω = 1.6 pH = 8.00
“favorable”
Ω = 0.5 pH = 7.49
Low Ω and pH

5. Small-group Presentations
You will divide into groups of 4-6
In 10 minutes, each student presents to the group
When not presenting, take notes in your handout
After 10 minutes, you will rotate to another group and repeat

6. How will ocean acidification impact marine ecosystems?
We don’t know
Ongoing research (lab and field)
We do know:
There will be winners & losers
It’s not just about shells: growth, respiration, reproduction, behavior…
Different life stages (larvae vs adult) respond differently
We just spent roughly an hour exploring some of the possible impacts of ocean acidification. I wanted to leave you with a few final thoughts…
Because ocean ecosystems are complex, and because there are many things changing at the same time, it is hard to tell exactly what the impacts of ocean acidification will be
This is a very active area of research that didn’t really get going until 2010
We know some organisms will probably be okay, even thrive (some marine plants) while others (especially those with calcium carbonate shells like oysters, mussels, clams, corals) will likely do poorly
There are many impacts beyond shell growth. And we're not just predicting that living things will die.
Different life stages (young vs adults) respond differently

7. Over 30% of Puget Sound marine species use calcium carbonate for shells, skeletons, & body parts
While we only talked about a few organisms, it is important to note that over 30% of organisms in Puget Sound (and thus likely around the same amount in Oregon) are in that most vulnerable category of organisms with shells of calcium carbonate.
Fact source: Washington State Blue Ribbon Panel on Ocean Acidification. Ocean Acidification : From Knowledge to Action, Washington State’s Strategic Response. (Adelsman H, Binder LW, eds.). Olympia, WA: Washington Department of Ecology; 2012.
Images- Barnacle: Sea urchin: Sea stars:
Oysters: Mussels: Clams: