Marine Spatial Planning in Washington: A Spatial and Temporal Assessment of Current Uses and Potential Conflict

Abstract

As humanity’s capacity for developing new ways to extract and use resources proliferates, so does its use of ocean space and demand for ocean resources by an ever-growing pool of users. Anticipating disputes from this growth, Washington State initiated the process of Marine Spatial Planning (MSP) to protect existing uses by minimizing conflicts between current and future uses – most notably renewable energy – along Washington’s coastline. As part of this process, Washington State is currently assessing conflicts between existing and future marine uses, yet no baseline study has assessed the intensity of the current level of spatial and temporal use conflict between current marine users. This paper uses spatial, temporal, and use-intensity data for 27 major marine uses to quantify potential conflict and highlight high- and low-intensity areas within Washington’s MSP study area. A novel Marine Conflict Index (MCI), calculated by combining the degree of spatial and temporal overlap between pairs of uses and accounting for their intensities, is used to evaluate pairwise potential conflicts between uses. The spatial extent of uses varies widely throughout the designated MSP study area. 38 pairs of uses, about 10% of the total, did not overlap spatially and therefore are likely compatible with one another. Temporally the number of uses peaks in July and August and falls to a low during January and February. The MCI identified three important user groups with a substantial degree of potential conflict: commercial fishing with commercial fishing, commercial fishing with Tribal usual and accustomed fishing areas, and commercial fishing with shipping. A cumulative intensity analysis found that medium- to high-intensity use characterized much of the MSP study area, whereas low-intensity use characterized Grays Harbor, Willapa Bay, and the Northwestern corner of the MSP study area. By ground truthing results with external evidence of actual conflict, three cases highlight how MCI scores can represent potential conflict to understand compatibilities and actual conflict for marine managers. This report is the first representative use analysis on Washington’s existing marine uses that includes spatial, temporal, and intensity factors, providing a crucial first look at ongoing and potential conflicts between marine uses. These results are intended to inform the Washington MSP process to meet one of its core goals of protecting and preserving existing uses while planning for future uses. Beyond Washington, this study provides a template for examining potential use conflicts that incorporates space, time, and intensity and is applicable for any marine planning process.