A Legacy of Divergent Fishery Management Regimes and the Resilience of Rainbow and Cutthroat Trout Populations in Lake Crescent, Olympic National Park, Washington

Lake Crescent, within Olympic National Park, harbors three genetically distinct trout populations—one rainbow and two cutthroat—that have persisted despite decades of liberal sport harvest and extensive hatchery supplementation. Unlike nonnative species introduced elsewhere, these populations thrived without establishing dominance, showcasing remarkable resilience. The study, analyzing redd counts (1989–2012) and genetic data, revealed distinct spawning patterns: rainbow trout spawned in the outlet from January to May, while cutthroat trout exhibited unusual timing, spawning in both the inlet tributary (February to June) and outlet river (September to March). Catch-and-release regulations significantly boosted rainbow trout populations. Morphometric analyses showed no intraspecific differences between cutthroat populations, though interspecific hybridization was minimal (9–17%). Lake Crescent's rainbow trout are genetically divergent from nearby populations, representing a unique evolutionary legacy. This research underscores the adaptability of native species under divergent management regimes and highlights their conservation significance.

Brenkman, S. J., Duda, J. J., Kennedy, P. R., & Baker, B. M. (2014). A Legacy of Divergent Fishery Management Regimes and the Resilience of Rainbow and Cutthroat Trout Populations in Lake Crescent, Olympic National Park, Washington. Northwest Science, 88(4), 280–304. https://doi.org/10.3955/046.088.0404