1. Influences of Changes in Salinity on Release of Carbon by Phytoplankton Jessica Wagner Century High School OGI & OHSU Lab, Field, and Modeling Study Mentors: Tawnya Peterson Joe Needoba Karen Watanabe

2. 2 CMOP Field work Modeling In Situ Data Lab Experiments Center for Coastal Margin Observation & Prediction Project Relevance Water Samples, Carbon Model, Salinity Experiments

3. 3 Focus/Question Where fresh water meets salt water Has many changes in salinity over short periods of time Important for fish-creates a habitat Biologically very productive Question: How does the change in salinity affect the growth rate of freshwater Diatoms? Estuary

4. 4 CDOM Cast Data CDOM Colored dissolved organic matter http://www.gcrio.org

5. 5 Surirella sella Under salinity stress diatoms produce a larger amount of CDOM Eventually osmosis will cause the cell to shrink/burst Observations

6. 6 Analysis of Variants (ANOVA) Growth Rate vs. Salinity Salinity (PSU) Conclusion: Growth rates are significantly different on the salinity range

7. 7 Salinity affects growth What does this mean for the estuary and carbon cycling? Salinity experiments that can show effect of changes in salinity on carbohydrates are needed How do changes in salinity affect dissolved carbon release by phytoplankton?

8. 8 Salinity Experiment -May FW-Control ½ filtered fw ½ none filtered fw SW-Shock ½ Filtered sw ½ none filtered fw

9. 9 Salinity Experiment-July FW-Control ½ filtered fw ½ none filtered fw SW-Shock ½ Filtered sw ½ none filtered fw

10. 10 Summary Salinity affects growth of diatom CDOM release increased as salt water was added to fresh water phytoplankton However, No effect on July Salinity experiment –Different Seasons, Different Location in the river, Different species (Salt-tolerant) Future Hypothesis/Testing –Different salt tolerance on other species of diatoms

11. 11 Thank You -My Mentors Tawnya Peterson, Joe Needoba, and Karen Watanabe -K-12 Director Karen Wegner -CMOP -ASE