Exciting news! Our paper, “Performance of salmon fishery portfolios across western North America,” is now available in the “early view” format in the Journal of Applied Ecology. Follow the link here. The article is open access so please check it out.
We found that the performance of salmon “portfolios” was greater in the higher latitudes of western North America (Alaska, Canadian Yukon, Transboundary AK-Canada) than in the lower latitude regions of British Columbia or the lower 48 (Washington, Oregon, California). Moreover, the performance of these portfolios had a strong negative relationship with human impact on watersheds (land use change) and the number of dams. These highly impacted regions also have a greater influence of hatchery populations although we did not specifically test their effect. Variables that describe the physical complexity of watershed were not well-correlated at our analysis scales. We often think the more complexity the better, but how well it correlates with performance may depend on the scale we measure the complexity and the scale at which we measure performance. The portfolios we assessed were for Chinook and sockeye salmon watersheds. Each portfolio had “assets”, just like a financial portfolio, that represented different sub-basins and their associated salmon populations in the larger watershed. Both Chinook and sockeye showed the same pattern of performance along the coastline of North America.
Sockeye salmon migrating upstream to spawn
Jennifer R. Griffiths 