Salt Marsh Vulnerability Assessment and Adaptation Plan Development in San Francisco Bay, California
The San Francisco Estuary Partnership (SFEP) and the San Francisco Bay Conservation and Development Commission (BCDC) are assessing the vulnerabilities of local salt marsh ecosystems to climate change. Using conceptual models, the project leads are identifying the links between climate drivers, stressors, and ecosystem processes with the goal of developing an adaptation plan.
SFEP and BCDC, collaborating with the U.S. Environmental Protection Agency’s Office of Research and Development through a grant from the EPA’s Climate Ready Estuaries Program, are working to conduct a vulnerability assessment focused on salt marshes and to create a plan to adapt to climate change impacts. Sea levels have risen approximately eight inches over the last century in California. An additional 20 to 55 inch rise is expected by 2100; a 55 inch rise would flood about 150 square miles of wetlands in the area. Other impacts of concern to the Bay Area include wetland inundation, erosion, shifts in species range and composition, decreased water quality, alterations to freshwater flows, larger and more frequent storms, increased sedimentation, and warmer water temperatures.
Components of this project include:
- using management goals from the SFEP Comprehensive Conservation and Management Plan;
- identifying key ecosystem processes;
- conceptual modeling of climate drivers that will affect management goals;
- identifying baseline conditions and summarizing observed and projected climate change impacts in order to track any variation from the baseline;
- assessing climate change stressors, cumulative impacts, and interactions among stressors and ecosystem processes;
- identifying adaptation options;
- incorporating expert and stakeholder input; and
- developing a climate change adaptation plan.
SFEP and BCDC have brought together scientists and resource managers to discuss vulnerabilities, identify climate indicators, and cooperate on climate research and information-sharing; one such gathering was a workshop held in October 2008 to launch the project where scientists presented findings on actual and projected climate change impacts to Bay Area habitats and wildlife. Since then, progress has been made on three elements of the project:
- Salt marshes and mudflats in San Pablo Bay (a shallow tidal estuary in the northern part of San Francisco Bay) were selected as priority areas for assessment and adaptation planning.
- Sediment retention and community interactions were identified as the key ecosystem processes essential to adaptation efforts in the region.
- Several models have been developed: a) a general conceptual model for salt marshes, and b) conceptual models of sediment retention and community interactions.
These models demonstrate the links between climate drivers, stressors, ecosystem processes, and identified indicators (like the one developed and used by the Massachusetts Bays Program in their adaptation project). The next step is to use these models to assess climate change impacts and identify adaptation management strategies for the bay. Another workshop is planned to convene a panel of scientific experts to examine the models and identify the sensitivities of salt marsh processes (sediment dynamics and species interactions) under different climate change scenarios. With input from the expert panel, SFEP will make recommendations for specific management policies.
Outcomes and Conclusions
SFEP plans to develop a climate change adaptation plan for the area using lessons learned from the planning process for the California State Climate Adaptation Strategy and other research.
Gregg, R. M. (2010). Salt Marsh Vulnerability Assessment and Adaptation Plan Development in San Francisco Bay, California [Case study on a project of the San Francisco Estuary Partnership]. Product of EcoAdapt's State of Adaptation Program. Retrieved from CAKE: http://www.cakex.org/case-studies/salt-marsh-vulnerability-assessment-an... (Last updated March 2010)