The role of high carbon dioxide (CO2) levels on fish performance, bone structure/composition and as a potential cause of spinal
deformities was studied. Two groups of fish were exposed to a low (control) and a high level of CO2 for 135 days during the
freshwater period. After smoltification, the fish were transferred to seawater and followed up for 517 days until they reached
harvest weight (3.1 kg BW).