PARENT SESSION
PW11 - Site-Specific Risk Assessments
Wednesday, 20 November 2002
8:00 AM to 6:30 PM
Exhibit Hall
(P846) Ecological Risk Assessment of Cherry Point, Washington Using the Relative Risk Model.
Hart Hayes, Emily*,1, Markiewicz, April1, Landis, Wayne1, 1 Western Washington University, Bellingham, WA, USA
ABSTRACT- We conducted a regional ecological risk assessment for the Cherry Point region in northern Whatcom County, WA using the Relative Risk Model. The objectives of this study were twofold: (1) to analyze cumulative impacts from multiple sources of stress to assess risk to multiple biological endpoints that utilize the region and (2) to determine the utility of the Relative Risk Model applicability in the study area. We used Geographic Information Systems to compile and compare spatial data for sources of stressors and habitats in sub-regions within the study area. These data determined the ranks for each sub-region. By quantitatively integrating ranks with exposure and effects filters as defined in a conceptual model, we estimated relative risk in sub-regions, relative contribution of risk from sources, risk in habitat types and assessment endpoints most at risk within the Cherry Point area. Finally, we used Monte Carlo techniques to perform uncertainty analysis and applied an alternative ranking scheme to evaluate the effects of model and parameter uncertainty on the risk predictions. The Relative Risk Model and uncertainty analysis results suggest the major contributors of risk in the region are commercial and recreational vessel traffic, upland urban and agricultural land use and shoreline recreational activities. The biological endpoints most likely to be at risk are Great Blue heron and juvenile Dungeness crab. The majority of risk occurs in sandy inter-tidal, eelgrass and macro-algae habitats. The sub-regions where the most risk occurs are Lummi Bay, Drayton Harbor and Cherry Point.
Key words: regional risk assessment, relative risk model, multiple stressors