In Nova Scotia, Atlantic salmon are endangered, and many populations have already become extinct. Two major factors contribute to population declines—the impact of freshwater acidification on egg-to-smolt survival and a low survival rate once smolts reach the ocean. Researchers are investigating factors in migratory behaviour that may help predict ocean survival for this species.

Rivers with a low pH level may increase stress on salmon, impacting their behaviour when they avoid predators. Along the Eastern Shore of Nova Scotia, rivers treated with lime to increase pH and calcium concentrations have been shown to improve egg-to-smolt survival. However, smolts may still not survive once they reach the ocean.

Researchers are building on earlier studies that identified a relationship between a salmon’s physiological status and personality traits. This increased understanding will help determine how early experiences in the salmon’s life cycle may impact their behaviour in the future and identify factors associated with survival.