The Massachusetts Bays National Estuary Program (MBP) and EPA’s Office of Research and Development have partnered to assess key vulnerabilities of Massachusetts Bays coastal systems to climate change impacts, as part of EPA’s Climate Ready Estuaries Program. The aim is to support coastal communities in management planning to protect important coastal resources from the impacts of climate change. Based on a review of priority goals in MBP’s Comprehensive Conservation and Management Plan, salt marshes were selected as a climate-sensitive ecosystem of special interest for vulnerability assessment. The assessment was framed through development of conceptual models exploring the linkages among key ecosystem processes, climate drivers, and interacting human stressors for salt marshes. Two key processes – sediment retention and plant/bird community interactions – were selected for more in-depth analysis. The objectives of the vulnerability analysis are to: 1) evaluate the influences of climate and human stressors on physical variables that regulate marsh development (and thus the ecosystem processes under consideration), 2) assess the relative sensitivity of each ecosystem process to key stressors under current conditions and under a range of future climate change scenarios, and 3) characterize the degree of knowledge/uncertainty about these relationships.

Results/Conclusions

For the analysis, an expert elicitation exercise was designed for use in a workshop setting. Expert elicitation is a process for obtaining the judgments of experts to characterize uncertainty and fill data gaps where traditional scientific research is not feasible or data are not yet available. Prior to the workshop, 5-10 local experts for each key process developed influence diagrams, which are simplified, graphical representations of a problem that are used to define the qualitative structure of causal relationships among variables that are believed to be most important for the problem under consideration. Preliminary results of the exercise include consolidated group influence diagrams that distill the full list of potential interactions to a more limited number of 10-15 critical stressor variables and response variables, along with the influences among them. In the workshop portion of the exercise, the experts make systematic qualitative judgments on the degrees of influence among the variables in the diagram, as well as on the uncertainty associated with each judgment. The judgments are first made for the variables under current conditions, and then under a range of climate scenarios. The full results of the comparative analysis, as well as emerging implications for adaptation management, will be presented here.