Wild salmon populations have declined precipitously across their range due to dam construction, habitat degradation, overfishing, and climate change. Population collapse has welfare implications for individual fish and for ecosystems that depend on salmon.
Wild salmon welfare intersects with population ecology in ways that require considering both individual fish and system-level welfare. Individual salmon navigating inadequate fish passage in warming rivers experience thermal stress, exhaustion, and high pre-spawning mortality. At the population level, collapse removes the ecological services that salmon provide — nutrient transfer, prey availability for predators including orcas and bears — creating cascading welfare effects across entire ecosystems. Dam removal, river temperature restoration through riparian planting, and fishing management reforms address both individual welfare and the ecosystem welfare that salmon populations support.