Publication Abstract

The effects of atrazine on Atlantic Salmon (Salmo salar) smolts in fresh water and after sea water transfer

C.P. Waring and A. Moore

Atlantic salmon smolts were exposed to low levels of atrazine (0 – 22.7 m g l^-1) for 7 days while in freshwater and measured the physiological effects of exposure. A second group of smolts were also exposed to atrazine in freshwater and then challenged with a 24 hour exposure to sea water. Atrazine in fresh water caused few physiological changes except for slightly elevated plasma cortisol concentrations and monovalent ion concentrations at and above 6.5 m g l^-1. However, a sea water challenge caused mortalities in smolts that had been pre-exposed to the highest water atrazine concentrations in fresh water. Moreover, surviving fish showed signs of major physiological stress: elevated plasma cortisol, thyroxine, osmolality, and monovalent ion concentrations. However, atrazine exposure had little effect on muscle or plasma water contents. The data suggests that atrazine may be a hazard for salmon smolts migrating between salinities.

Reference:

C.P. Waring and A. Moore. 2004. The effects of atrazine on Atlantic Salmon (Salmo salar) smolts in fresh water and after sea water transfer. Aquatic Toxicology 66: 93-104