Results

SPECIAL THANKS TO

Acknowledgments

Research Areas

Located at the east end of downtown Nantucket, The Creeks Marsh is a highly impacted marsh

system.

The UMass Boston Nantucket Field Station is home to Folger’s Marsh, a

natural, relatively undisturbed system.

A recent restoration project was done at Medouie Creek Marsh

aimed at allowing tidal waters to naturally flow into the back marsh.

Objective

Approaches and Methods

Salt Marsh Primary Productivity Jesse Bean

jdbean1125@gmail.com

School for the Environment

The LivingLabs: Nantucket

Major: Environmental, Earth and Ocean Science

The goal of this study was to assess human impacts in salt marsh creek systems. I compared primary productivity by phytoplankton in three salt marshes on Nantucket, MA. Measurements of chlorophyll a (chl a) , a pigment used during photosynthesis, were taken to determine levels of phytoplankton, which are the base of the marine food chain, in marsh waters and calculating relative fluorescence of the water samples. Chlorophyll a levels can be an indicator of the amount of primary productivity in salt marsh waters.

• Water samples from six sites at each marsh • Samples taken at high tide; 3/23, 3/29, 4/5 & 4/8 • Isolated chl a in acetone solution • Measured relative fluorescence (RF) with a

fluorometer • Calculated chl a concentrations from RF

measurements

FIGURES 1-3. Figure 1 shows that The Creeks Marsh has had a decrease in chl a over the study period. Figure 2 shows the same general trend at Folger’s Marsh; however, there was a spike at most sites on 3/29. Similarly at Medouie Creek Marsh, there was a decrease over time and a spike on 3/29. We see that Medouie had the lowest concentration of phytoplankton, even though it has been restored, the creeks have not recovered to levels of the other marshes. FIGURE 4. On average, The Creeks had the highest concentrations, followed by Folger’s and then Medouie. All three marshes show peak concentrations around 3/29 followed by a gradual decrease. The decrease could be due to a number of factors such as an increase in consumer activity or decrease in available nutrients. FIGURES 5 & 6. Figure 5 shows a trend where as salinity decreases so will chl a concentrations. This could be due to a number of variables. Figure 6 shows that as temperature increases, variability in chl a concentration decreases.

Discussion

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THE CREEKS MARSH

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• Dr. Elizabeth Boyle • Dr. Robyn Hannigan • Dr. Sarah Oktay • Dr. Anamarija Frankic • Ashley Bulseco-McKim • Steve Nye Jr. • Travis Lowery

FIGURE 1. FIGURE 2 FIGURE 3.

FIGURE 4. FIGURE 5. FIGURE 6.

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FIGURES 1-3.- The graphs show the average chl a concentrations at the six sites of the three marshes on each sampling date. Variability in phytoplankton densities are expressed with the use of black error bars. FIGURE 4.- Shows the average chl a concentrations at each marsh for each sampling date. FIGURES 5 & 6.- Help to visualize any correlations between variables and concentrations. They compare averages of concentrations and variables for all three marshes over the entire sampling period.

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