Rapid Assessment Method for Evaluating Coastal Wetland Health

Find information on Massachusetts Office of Coastal Zone Management (CZM) efforts with this method.

Serious concerns for the need to provide better protection for wetlands emerged in Massachusetts about 50 years ago, leading to the passage of the state Wetlands Protection Act (1963). Substantial loss of wetlands had occurred for over 300 years of settlement as a result of filling and altering. Since the passage of the legislation, state and local protection efforts have worked to avoid, minimize, and mitigate further losses, including substantial acquisitions of wetlands for permanent protection and conservation. The regulatory framework put in place has largely eliminated all additional losses of tidal wetlands, and, since the 1990s, considerable efforts have attempted to restore tidal flow to isolated and fragmented marshes. A major challenge has been how to document the success of these restoration efforts and how to assess the impacts of ongoing threats to tidal marsh integrity.

The U.S. Environmental Protection Agency (EPA) has developed a three-tier framework for states to adopt for wetland assessment, where Tier 1 is a landscape assessment based on existing maps (primarily GIS), Tier 2 is a Rapid Assessment Method for evaluating condition using quick and simple methods to gather information from a short site visit, and Tier 3 is a detailed on-site measurement of biological and physical conditions.

The Massachusetts Office of Coastal Zone Management (CZM) worked to develop a primarily Tier 2 New England Rapid Assessment Method (NERAM) for coastal wetlands during 2004-2006. NERAM was developed to support the evaluation of the numerous coastal wetland restoration and mitigation projects that were being undertaken, as well as to support the state need to report on the overall health of coastal wetlands coastwide.

Through an intensive pilot project conducted in four coastal watersheds, CZM developed an assessment protocol (or methodology) comprised of a suite of biological, physical, and social indicators of estuarine marsh integrity for NERAM. Indicators were made up of three types of measurements: condition, disturbance, and characterization metrics that are used to analyze the information. The methodology was designed to allow for the collection of all needed information in about two to four hours, including desktop analysis and a site visit.

Characterization indicators are applied to the whole of a mapped wetland unit and are rated via desktop analysis using aerial photographs and other map products to then  classify the wetland for comparisons to other similar types. Verification of the characterization assessment is required for a few of the indicators, such as the slope of the site, which is done during the site visit. Disturbance indicators are used to identify stressors to the wetland, both to the entire wetland unit and to randomly selected points within the wetland. Some disturbance indicators can be identified via desktop analysis, while others need field verification, including some that are field measurements at the randomly selected points, such as specific land use surrounding the points. Condition indicators are field-based measurements of the biota, primarily the plant community. All of the disturbance indicators are rated with a score which, when summed, provides a final index score that can be compared to the range of condition metrics measured during the pilot project. The method was developed as an operational draft, and additional applications and data analysis will support the evaluation of the methodology.


Tell us what you think