Seawater survival and osmoregulation of Atlantic salmon (Salmo salar) parr-smolts exposed to four different pesticides

• Main Author: Hauta, Christopher Carl
• Other Authors: Newman, Lenore, Kennedy, Christopher, Dodd, Matt
• Language: unknown
• Published: 2014
• Subjects: Atlantic salmon; ATPase; current use pesticides; osmoregulation; seawater challenge; smolt; Salmo salar
• Online Access: http://hdl.handle.net/10170/676

Atlantic salmon (Salmo salar) parr-smolts were exposed to sublethal concentrations of cypermethrin, chlorothalonil, quintozene or atrazine to determine if they affected osmoregulation. After 96 h of exposure to a pesticide, Na+K+-ATPase, hematocrit, liver somatic index (LSI), plasma sodium, chloride, and cortisol concentrations were determined. There were no mortalities observed following a 24-h seawater challenge. No effects were seen with cypermethrin exposure. Chlorothalonil exposure resulted in increases in plasma Na+ concentrations following the seawater challenge in the 0.18 and 3.6 μg/L groups. For quintozene, decreases in LSI was seen at each concentration, and decreases in Na+K+-ATPase activity was seen at 0.55 μg/L as well as a decrease in Na+ concentrations at the highest exposure concentration. Atrazine exposure increased Na+K+-ATPase activity in the 1 and 100 μg/L groups, and plasma cortisol concentrations at100 μg/L. Overall, the pesticides examined had minimal effects on fish osmoregulation and stress at the concentrations tested.