Global climate change will likely lead to sea level rise and more frequent severe coastal storms in the Northeast US. Coastal areas like Connecticut have experienced significant flooding and storm damage in recent years. One approach to address these impacts is developing "living shorelines" which use natural features like salt marshes, eelgrass beds, and mangroves to buffer storm surges and waves. These natural features can mitigate flooding but as sea levels rise, marshes must be able to migrate inland. Protecting coastal open spaces and allowing marsh migration will be important to maintain these ecosystems under climate change.

1. Climate Resilient Shorelines in the Northeast
Global climate change will likely impact shorelines in the Northeastern United States in multiple
ways. Significant impacts will likely include sea level rise and a greater frequency of severe
coastal storms, including hurricanes. Connecticut has experienced a variety of significant storm-
related impacts over the past several years, including record-setting flooding in March 2010,
Tropical Storm Irene on 24 August 2011, an extreme snowstorm on 30 October 2011 (figure
below), and Superstorm Sandy in August 2012 (figure below).
One potential response to these extreme short-term events and the longer-term impact of sea
level rise is developing “living shorelines.” This concept includes maintenance and enhancement
of such natural features as intertidal salt marshes (figure below), subtidal eelgrass beds or SAV
(submerged aquatic vegetation) (figure below), and in more tropical environments, mangrove

2. forests.
All these natural features have the ability to buffer extreme water motion such as storm surges
and strong waves. Additionally, salt marshes, like all wetlands, act as sponges and can mitigate
flooding events.
In the Northeast intertidal salt marshes exist between specific tidal levels that allow periodic
inundation by sea water (length of time tolerated depends on the species) and exposure to the
atmosphere. As sea level rises this elevational range moves vertically and the marsh must move
vertically and inland to compensate (figures below).

3. The ability of the marsh to move vertically is dependent upon accretion of sediment on the marsh
surface from tidal water and open space to move inland horizontally to accommodate this vertical
rise. Clearly this horizontal movement will require protection of significant areas of coastal open
space. Man-made structures, such as armored shorelines, rip rap, etc. that impede this inland

4. migration risk drowning the marsh because of excessive inundation times (figures below).
Therefore, protection and maintenance of salt marsh communities in order to maintain the many
ecological services they provide, including shoreline and flood mitigation, will require a variety
of approaches to allow for the shoreward migration of these communities. These tools should
include rolling easements to allow marsh migration, acquisition of coastal land to protect marsh
movement, zoning requirements that allow marsh migration under housing and other buildings
constructed on poles or pilling to allow marsh migration underneath the structure. Because the
northeast has already lost significant areas (up to 70%) of coastal salt marsh to historic dredging
and filling activities (e.g., much of the City of Boston) it is imperative to protect salt marshes in
the face fo rising sea level and other climate change effects. Implementation of living shorelines

5. (figures below) is an important strategy to allow for the continuation of these important intertidal
ecosystems.