Research explores marsh migration process

As rising seas push coastal marshes inland, the yards and woodlands next door are changing.
But not much is known about how this happens. That’s why Shimon Anisfeld and colleagues at the Yale School of Forestry and Environmental Studies began trying to tease out some of the details of the process by looking at marsh migration at two state parks, Sherwood Island in Westport and Hammonassett Beach in Madison.
On Sept. 12, he presented findings thus far from his research, which is being funded by Connecticut Sea Grant, to the Long Island Sound Habitat Restoration & Stewardship Work Group at Connecticut College in New London. The group is part of the Long Island Sound Study, a partnership of Connecticut, New York and the Environmental Protection Agency.
At Sherwood Island, Anisfeld and his team compared migration patterns at marshes bounded by lawns verses those next to forests that were getting flooded by high tides more frequently in recent years. Since lawn areas tended to be flatter than the woodlands, determining how much of the change was due to differences in the slope was tricky, he said. The research did, however, find differences in the mix of marsh vegetation migrating inland into lawns versus woodlands, probably a result of soil and salinity differences.
In another phase of the work still underway, Anisfeld and his team are using marsh core samples and the presence of single-celled marine organisms called foraminifera to measure how far the marshes at Sherwood Island and Hammonassett have moved vertically and horizontally since 1963.
Overall, the research will help inform management practices at areas with tidal marshes, as land use officials seek the best ways to preserve these critical habitats in the face of sea level rise.
Two other presentations at the workshop dealt with other aspects of changing marsh habitats. Scott Graves of Southern Connecticut State University and Mark Paine, director of public works for West Haven, described restoration efforts at Cove River Marsh. Ron Rozsa, retired coastal ecologist for the state Department of Energy and Environmental Protection, shared his recent research into the long-term effects of ditches dug into the marshes at Barn Island Wildlife Management Area in Stonington that took place in Colonial times and in the 1930s.
After the presentations, the group toured the Mamacoke Island marsh in Waterford, which is owned by Connecticut College.
To read more about Anisfeld’s work, visit: