Study Reveals Dual Nature of Pacific Salmon's Nutrient and Contaminant Transport
Over 40 years, Pacific salmon have significantly increased the movement of nutrients and contaminants across North America, impacting ecosystems and food webs.
- Researchers tracked the migration of Pacific salmon from 1976 to 2015, noting a 30% increase in nutrient and contaminant transport by 2015.
- The study highlights both the ecological benefits and risks of salmon biotransport, referring to nutrients as 'bright' and contaminants as 'dark' subsidies.
- Pink salmon, despite lower contaminant concentrations, contributed the largest share of contaminants transported due to their sheer numbers.
- Chinook salmon, feeding higher on the food chain, carry higher ratios of contaminants to nutrients compared to other salmon species.
- The research underscores the importance of considering both nutrients and contaminants together to fully understand the environmental impact of migratory species.