1. Melissa Apodaca Dr. A. Wijte CSULB
Oxygen Production by Sedimentary Microalgae in a Natural and Constructed Salt Marsh
Melissa Apodaca
Dr. A. Wijte
CSULB

2. Introduction Characteristics of tidal salt marshes
Variable conditions
Feeding and nursery grounds
Sedimentary microalgae
Diatoms, cyanobacteria, and filamentous green algae
Important in food webs, nutrient cycling, and as sediment stabilizers

3. Introduction Natural and constructed marshes Previous studies
Sediment characteristics
Nutrient availability
Previous studies
Focused on primary production
Sedimentary microalgae and oxygen production

4. Goals of the Study
Determine the standing stock of sedimentary microalgae and their rates of oxygen production in a natural and constructed salt marsh
Hypotheses
Areas with a higher chlorophyll content will have a higher rate of oxygen production
The constructed marsh will have a lower sedimentary algae biomass than the natural

5. Study Site Constructed marsh in San Pedro Natural marsh in Seal Beach
Length of sampling
Sampling habitats
Canopy and exposed sites

6. Study Site cont.

7. Study Site cont.
2000 by Lisa L. Ingram

8. Overview of Methods Transects in intertidal Sediment cores
8cm diameter, 5cm height
Chlorophyll a extraction
n=10
Oxygen production measurements

9. Sediment Chlorophyll a Content
Chlorophyll a extraction
Performed on top 5mm
Extraction with DMF (N,N-dimethyl formamide) at 4ºC overnight
Absorbency readings at 664nm
Chlorophyll a determination

10. Oxygen Production Measurements
Oxygen readings performed on top 5mm
Incubation chamber
Clear plastic container covered by a glass funnel
Incubation for 1 hour under light conditions normally experienced
Determination of oxygen production

11. Statistical Analysis Chlorophyll Content and Oxygen Production
Two-way ANOVA (α=0.05)
H0: μ1=μ2
Effect of chlorophyll content on oxygen production
Regression Analysis (α=0.05)
H0: β=0

12. Expected Summer Results

13. Expected Summer Results cont.

14. Expected Results cont.

15. Expected Long Term Results

16. Conclusions
Relationship between chlorophyll content and oxygen production
Constructed vs natural marsh
Importance of oxygen production by sedimentary microalgae

17. Future Studies
Comparison of chlorophyll and oxygen production for multiple natural marshes
Comparison of water column and sediment oxygen production

18. Acknowledgements
Dr. A Wijte
Siggi von Gesjen
HHMI