Melissa Apodaca Dr. A. Wijte CSULB Oxygen Production by Sedimentary Microalgae in a Natural and Constructed Salt Marsh Melissa Apodaca Dr. A. Wijte CSULB
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
Introduction Natural and constructed marshes Previous studies Sediment characteristics Nutrient availability Previous studies Focused on primary production Sedimentary microalgae and oxygen production
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
Study Site Constructed marsh in San Pedro Natural marsh in Seal Beach Length of sampling Sampling habitats Canopy and exposed sites
Study Site cont.
Study Site cont. 2000 by Lisa L. Ingram
Overview of Methods Transects in intertidal Sediment cores 8cm diameter, 5cm height Chlorophyll a extraction n=10 Oxygen production measurements
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
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
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
Expected Summer Results
Expected Summer Results cont.
Expected Results cont.
Expected Long Term Results
Conclusions Relationship between chlorophyll content and oxygen production Constructed vs natural marsh Importance of oxygen production by sedimentary microalgae
Future Studies Comparison of chlorophyll and oxygen production for multiple natural marshes Comparison of water column and sediment oxygen production
Acknowledgements Dr. A Wijte Siggi von Gesjen HHMI