The effects of carbon dioxide on growth performance, welfare, and health of Atlantic salmon post-smolt (Salmo salar) in recirculating aquaculture systems

Highlights

• Atlantic salmon post-smolts were exposed to six CO2 concentrations (5–40 mg/L) for 12 weeks in 12 ppt salinity RAS
• Fish showed no mortality, cataracts, nephrocalcinosis or signs of external injuries.
• Skin dermis layer was significantly thinner in fish exposed to 40 mg/L of CO2.
• Body weight and growth were significantly lower at CO2 concentrations ≥12 mg/L.
• Effects of CO2 exposure during the RAS phase were carried over during an additional 6-week experimental period to mimic a seawater phase.

Abstract

High carbon dioxide (CO2) concentrations negatively impact fish, which makes data on its tolerance especially relevant for production systems that can accumulate CO2 such as recirculating aquaculture system (RAS). The current study evaluates the effect of CO2 on the growth performance, welfare, and health of Atlantic salmon post-smolts in RAS. This study consisted of two phases. The first was a CO2 exposure phase, where eighteen tanks were used with six treatments in triplicate: 5, 12, 19, 26, 33 and 40 mg/L of CO2 during 12 weeks in a 12 ppt salinity RAS (hereafter RAS phase). In the second phase, PIT-tagged fish were transferred to a 34 ppt salinity single flow-through tank at CO2 < 5 mg/L (hereafter seawater phase) for an additional 6-week experimental period mimicking a seawater phase. Overall, mortality of fish exposed to CO2 was low and not related to treatments. The mean final body weight was significantly higher in the 5 mg/L treatment compared to CO2 treatments ≥12 mg/L at the end of RAS phase and to CO2 treatments ≥33 mg/L at the end of seawater phase. Moreover, regressions showed that growth significantly decreased linearly with increasing CO2 in the water. Eye cataracts and visible external damage on skin, operculum, and fins were inexistent and similar among CO2 treatments. Kidneys showed no signs of mineral deposits in any of the structures of the tissue. However, skin analysis showed that fish exposed to high CO2 concentrations had a significantly thinner dermis layer (both at the end of RAS and seawater phase) and a significantly thinner epidermis layer and lower mucus cells count (at the end of seawater phase). In conclusion, Atlantic salmon post-smolts cultured in brackish water RAS showed a maximum growth performance at CO2 concentrations below 12 mg/L. Except skin, no major effects of health and welfare were observed, including cataracts and nephrocalcinosis. Further studies should evaluate the molecular and physiological responses to both short-term and long-term carbon dioxide exposure.

 

Mota V. C.,  Nilsen T. O.,  Gerwins J.,  Gallo M.,  Ytteborg E.,  Baeverfjord G.,  Kolarevic J.,  Summerfelt S. T. & Terjesen B. F., in press. The effects of carbon dioxide on growth performance, welfare, and health of Atlantic salmon post-smolt (Salmo salar) in recirculating aquaculture systems. Aquaculture. Article.

0 Responses to “The effects of carbon dioxide on growth performance, welfare, and health of Atlantic salmon post-smolt (Salmo salar) in recirculating aquaculture systems”



  1. Leave a Comment

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.




Subscribe to the RSS feed

Powered by FeedBurner

Follow AnneMarin on Twitter

Blog Stats

  • 1,119,143 hits

OA-ICC HIGHLIGHTS

Ocean acidification in the IPCC AR5 WG II

OUP book