There are few studies that assess CO2 effects on fish tissues. To study these effects, young-of-year Arctic Charr (Salvelinus alpinus), Rainbow Trout (Oncorhynchus mykiss), and Brook Charr (S. fontinalis) were exposed to either control levels of CO2 (1,400 μatm) or elevated levels of CO2 (5,236 μatm) for 15 days. Fish were then sampled for gill, liver, and heart tissues and histologically analyzed. A species effect was observed for the length of secondary lamellae, as Arctic Charr had significantly shorter secondary lamellae than the other species. No notable changes within the gills and livers of Arctic Charr, Brook Charr, or Rainbow Trout exposed to elevated CO2 were observed. Generally, our results indicated that elevated CO2 levels over 15 days do not induce catastrophic tissue damage and it is unlikely that fish health would be seriously impacted. Ongoing research dedicated to examining how elevated CO2 long-term may affect internal tissues of fish will allow for a more comprehensive understanding of how fish may fair with ongoing climate change and in aquaculture facilities.
Traynor E. M. & Hasler C. T., in press. Elevated CO2 levels did not induce species- or tissue-specific damage in young-of-year salmonids. Journal of Aquatic Animal Health. Article.
