two researchers in marsh grasses

With sea level on the rise, researchers at UNH are looking into the best way to protect our coastal salt marshes. Working in collaboration with Great Bay National Estuarine Research Reserve, researchers are able to implement different techniques to prevent salt marsh erosion due to sea level rise. This post is the first of two, highlighting two graduate students working on salt marsh resiliency and restoration techniques.

The first student is Chloe Brownlie, who hails from New Jersey and graduated from Smith College as a Biology major in 2017. Chloe now works with Dr. Gregg Moore, studying Marine Biology at UNH. She is a long-time lover of the invertebrate world, bringing her expertise to the wonderful world of the insect larvae, scuttly amphipod, snails, and bivalve mollusks that call salt marshes home. Chloe studies a particular method of increasing salt marsh resiliency, called Thin Layer Placement, and how it affects invertebrate communities.

Thin Layer Placement, or TLP, was designed to combat flooding due to sea level rise by spreading a layer of sediment over the marsh; thick enough to reduce excess flooding, but thin enough to minimally impact marsh plants and animals. Typically, marshes are able to build vertically at a rate that keeps up with rising water levels, by means of plant growth through roots and leaf litter, or sediment being deposited from tidal flooding or from ice sheets which carry sediment to the marsh and then melt. With water rising at a faster rate from climate change, there are indications that natural mechanisms of sediment accumulation are not enough to keep marshes from ‘drowning’.

While much research is focused on how marsh plants are affected by TLP, its ecological effect on invertebrates are less known. Chloe is especially interested in recovery of the invertebrate community after TLP occurs. Her research will include two full summers of field work to monitor invertebrates in locations with and without TLP sediment. Her work so far indicates little difference in the invertebrate community between sites with sediment layers and sites without. Preliminary results from her work indicate that invertebrate communities recover quickly following TLP, or could be a response to a variety of other factors.

Chloe looks forward to her second summer of field work, and is hoping she doesn’t lose any boots in the mud. She recommends getting involved if you are concerned about coastal wetlands or are curious to learn more. She says a great place to start is by volunteering for efforts through the Great Bay Stewards or other citizen science programs. We look forward to keeping up with Chloe as her research progresses, and hearing more about how Thin Layer Placement can be used. You can follow her work here or on Twitter.

-Eliza Balch, Research Assistant

Picture 1: Chloe Brownlie is a Master of Science graduate student at the University of New Hampshire, studying marine biology. Photo courtesy of Chloe Brownlie.


Picture 2: Chloe is pictured at a field site with fellow graduate student Grant McKown, doing a transect survey of the salt marsh invertebrate community. Photo courtesy of Grant McKown.


Picture 3: Thin layer placement is a management tool used to prevent salt marsh erosion. This is the equipment used to place sediment, and is pictured here at Blackwater National Wildlife Refuge in Maryland. Photo courtesy of Dave Harp, Chesapeake Photos.

two researchers in marsh grasses