Atlantic Salmon Migration Welfare: Rivers and Sea

How barriers, predators, and environmental changes affect the welfare of wild Atlantic salmon during their freshwater migration.

Key Facts

Atlantic salmon migrate thousands of kilometres between freshwater rivers and marine feeding grounds
Upstream migration to spawning grounds involves fasting and enormous energetic expenditure
River barriers including weirs, mills, and dams can prevent salmon reaching spawning sites
Elevated river temperatures cause physiological stress and sometimes pre-spawn mortality
Fish passes can restore migration routes but vary significantly in effectiveness

Welfare Considerations

Wild salmon migration involves extraordinary physiological challenge even under optimal conditions. Salmon fast during upstream migration, metabolizing their body reserves to fuel the journey. Barriers that prevent upstream passage cause behavioral frustration, injury from attempting to jump past obstacles, and energetic exhaustion. Elevated water temperatures during migration cause heat stress and can be lethal when salmon have no refuge to cool water. Pre-spawn mortality - dying before reaching spawning sites due to exhaustion, temperature, or disease - causes individual welfare harm and population-level conservation damage.

What You Can Do

Support river restoration organizations working on barrier removal
Advocate for fish pass installation and maintenance at existing river barriers
Support climate mitigation as essential for maintaining cold river temperatures
Report pre-spawn mortality events to national salmon monitoring programs
Donate to Atlantic salmon conservation organizations working on habitat and migration routes