June 5, 2026 — Fish that split their lives between fresh and salt water often face obstacles getting back and forth. Dams and roads fracture river networks and interfere with traditional migratory routes, sparking concerns about fish health and abundance, as well as biodiversity on a broader scale.
Efforts to restore fish passage are cropping up across the country, but these projects come with hefty price tags. In a new study, published June 3 in PLOS One, University of Washington researchers explore whether this money is being well spent by examining the process that determines which projects are prioritized.
The current standard, called score and rank, involves evaluating barriers one by one and assigning a score based on potential gains, such as habitat expansion. Top-ranking projects become leading candidates for funding, but score and rank systems don’t always account for barriers in the full river context. High-scoring projects can yield stranded investments, where removing the barrier doesn’t have the desired outcome because of other barriers downstream or immediately upstream.