Evaluating and ranking pressures threatening the recovery of the Puget Sound Ecosystem

The Puget Sound Partnership (PSP) and its partner agencies established ecosystem restoration goals to achieve recovery of the Puget Sound ecosystem by 2020. In support of effective ecosystem recovery planning, the PSP's Biennial Science Work Plan highlights the need for a clear and comprehensive understanding of the relative potential impacts of the various sources of stress (pressures) on ecosystem and human well-being components, which are described using a system of assessment endpoints. To address this need, members of the PSP Science Panel have led the development of a multi-scaled ecosystem pressures assessment approach that builds on a conceptual model of intrinsic ecosystem vulnerability. This conceptual model describes the vulnerability of ecosystem endpoints to individual stressors, within marine & nearshore, terrestrial, and freshwater aquatic ecosystem domains, at the scale of watersheds and marine sub-basins. This presentation will describe: 1) the basis for the ecosystem vulnerability approach, 2) the process used for choosing and defining assessment endpoints and stressors, 3) the structure of the underlying sub-models for intrinsic vulnerability, stressor intensity and distribution, and endpoint distribution, and 4) the expert elicitation process used to parameterize these models. The pressures assessment was designed to support the Partnership's complicated ecosystem recovery planning processes, which includes integrated basin-scale planning as well as multiple local watershed-scale planning processes. While this presentation focuses on the underpinnings of, and the processes used within, the approach, its workshop-driven implementation and the assessment results and interpretation will be discussed in a separate talk.