Abstract
The outlet of Cape Cod’s Herring River has been restricted through the Chequessett Neck Road dike for roughly a century, and the salt marshes which make up the river’s estuary were extensively drained for mosquito control and land reclamation. These two manipulations have dramatically altered the basic functions of this ecosystem. The removal of tidal exchange and the atmospheric oxidation of sedimentary compounds in the Herring River Estuary (HRE) have caused up to one meter of subsidence in marshes upstream of the dike. Beyond the biochemical and ecological impacts of this long-standing intervention, the coastal engineering considerations necessary to restore this marsh present a case-study in sea level rise adaptation. In small watersheds like the Herring River, an unimpeded connection to the ocean is essential to deposit organic material and sediment onto salt marshes at high tide. Diking also decreases tide heights, causing marsh sediments to dry and pore spaces to collapse. The National Park Service’s restoration plan for the HRE involves the installation of a flood-control structure under an existing road to gradually raise the water level in the estuary and re-accrete its subsided marshes. This restoration project presents a microcosm of the challenges facing coastal wetland managers around the world – if sea level rises faster than coastal wetlands are able to accrete, these ecosystems will be lost along with the coastal resilience and carbon sequestration benefits they provide. This poster includes a cross-section of the dike’s impact and discusses multiple potential benefits of marsh restoration.
Presenters
Evan HeberleinStudent, Master of Environmental Science and Management, Bren School of Environmental Science & Management, University of California - Santa Barbara, California, United States
Details
Presentation Type
Theme
Assessing Impacts in Diverse Ecosystems
KEYWORDS
Sea Level Rise, Wetlands, Coastal Resilience, Engineering, Multiple Benefits, Adaptation
