Effects of High Environmental CO2 Levels on Atlantic Salmon Post‐Smolts

Abstract

Atlantic salmon has demonstrated the capacity to physiologically acclimate when exposed to increased pCO2 levels in aquaculture flow‐through systems. Less is known about tolerance to increased pCO2 in Recirculation Aquaculture System (RAS). In the present study, Atlantic salmon post‐smolt in a RAS were kept at 12 ppt (12°C) and exposed to six different pCO2 levels ranging from <5 mg/L (PCO2<1.83 mm Hg), 12 mg/L (PCO2=4.40 mm Hg), 19 mg/L (PCO2=6.94 mm Hg), 26 mg/L (PCO2=9.50 mm Hg), 33 mg/L (PCO2=12.06 mm Hg) and 40 mg/L (PCO2=14.61 mm Hg). After 12 week treatments fish were transferred to full strength seawater with the lowest tested pCO2 level. We found that post‐smolts demonstrated a classic transient physiological compensatory response to cope with elevated pCO2, despite a clear and persistent decrease in growth rate when reared above 19 mg/L CO2. After twelve weeks of variable pCO2 exposures post‐smolt were challenged with rapid changes from high (40 mg/L) to low (5 mg/L) pCO2 levels and vice‐versa. Here we also will present physiological compensatory responses 1 and 24 hours and up to 6 days following rapid changes in pCO2 exposure.Support or Funding InformationCenter for Research Based Innovation, “CtrlAqua” Project Number 237856/030This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.