A Socioecological Approach to Assessing Risks from and Threats to Freshwater Recreation to and from Invasive Species in the North Puget Sound Region

Recreationalists both impact and benefit from the numerous watersheds that feed Puget Sound. This study employs a socioecological approach to assess invasive species risks from, and threats to, freshwater recreation in Washington Department of Fish and Wildlife’s (WDFW) North Puget Sound Region. A survey of residents, combined with a census of freshwater fishing licensees, found that 76% participated in freshwater recreation during summer 2023, primarily through shoreline activities and non-motorized boating. Activity was concentrated in urban lakes and major rivers. We concurrently modeled habitat suitability for four key invasive species that can be transported by recreationalists, and/or may also affect recreational experiences: Eurasian watermilfoil (Myriophyllum spicatum), New Zealand mud snail (Potamopyrgus antipodarum), American bullfrog (Lithobates catesbeianus), and Japanese knotweed (Reynoutria japonica). We found waterbodies with WDFW access sites exhibited higher habitat suitability for these species. Integrating recreation use and habitat suitability models, we identified high-vulnerability sites for both invasion via recreational vectors and impacts to recreational quality. These findings demonstrate the importance of integrated social science and ecological methods for developing targeted management strategies in coastal regions to mitigate invasive species spread, protect recreational opportunities, and preserve freshwater ecosystem integrity.