Friday, July 28, 2017

Marsh Edge Erosion - Fitzgerald Lab

Hi I’m Rachel and I am a rising sophomore majoring in Earth and Environmental Science and Public Relations. This summer I'm interning in the Fitzgerald lab. Our lab studies a variety of coastal processes but the project I’m working on focuses on marsh edge erosion on the north shore of Boston which is where I grew up.
I live in Beverly where the red arrow is pointing. The Great Marsh starts about 15 or 20 mins north of me and extends almost to the border of New Hampshire. We do a lot of work in Newbury, Rowley and Ipswich.

In front of the marsh edge there is usually a mudflat that is very sticky. Professor Fitzgerald believes that the entire marsh will eventually be mudflats. You're not part of the team until you've had to dig your boot out of the mud.


We are currently in the middle of an extended sample collection project involving sediment pads. Sediment pads are small mylar circles that we put out in the marsh at low tide and leave overnight. While the sed pads are in the marsh, the tide rises and inundates the marsh with water, washing loose sediment onto the pads for us to collect. The pads are placed at 5 m intervals moving away from the marsh edge, giving us continuous data on the amount of loose sediment in the marsh. For this particular experiment we are leaving the pads on the marsh for an entire tidal cycle which is about a month.

Miyu and I collected the sediment pads from our last experiment in petri dishes so no extra sediment would be introduced. The sed pads and cups are marked by orange flags which make them easy to spot from a distance.


When we set out sediment pads we also set out solo cups to collect water samples. When the water rises onto the marsh the cups fill with water and get trapped there. Then we collect the water in nonreactive bottles and run them through a filter back in the lab. The filters trap sediment, telling us how much sediment is suspended in the water.

I would like to say that no arthropods were harmed in the making of this science but they were. The ones that weren't dead after collection, storage and filtration were put in the -80° C freezer.



In addition to lab and field work, the interns are also responsible for conducting some literature research. Duncan has asked us to research rates of sea level rise in marshes all around the world. I am in charge of researching marshes in the United States. Carina and I spend most afternoons at the Kenmore Starbucks looking through databases and reading scientific articles. We skim the articles looking for the rate of sea level rise in a specific marsh and then input them into a data table.

Reading multiple scientific papers a day requires copious amounts of caffeine.


This week we also got a chance to process a different kind of sample: sand from Brazil. The samples were shipped to us so we could conduct grain size analysis. First we dried out the samples so they wouldn't stick to the equipment. Next we split each sample in half so we'd have a back up sample in case we messed up or needed additional analysis. Then we put the samples through a stack of sieves which were shook for 10 minutes by a machine, sorting the sand by grain size and allowing us to determine what percentage of the sample was fine grained and what percentage was course grained. The different components of the sand were all different colors and sizes which was very cool and a refreshing change from the marsh samples we usually process.

I'm having a lot of fun this summer learning about lab work, field work and scientific research. I can't wait to see what our data tells us at the end of the summer.


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