Exposing Atlantic Salmon Post-Smolts to Fluctuating Sublethal Nitrite Concentrations in a Commercial Recirculating Aquaculture System (RAS) May Have Negative Consequences
Salmon farmers are interested in extending the time post-smolts are reared in recirculating aquaculture systems (RAS). However, there is a lack of knowledge regarding optimal water quality for post-smolts in RAS, and regarding potential consequences of long term exposure to different toxic compounds...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2022-07-01
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| Series: | Frontiers in Animal Science |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fanim.2022.886071/full |
| _version_ | 1818017318246023168 |
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| author | Heidi S. Mortensen Elin Jacobsen Jelena Kolarevic Amanda Vang |
| author_facet | Heidi S. Mortensen Elin Jacobsen Jelena Kolarevic Amanda Vang |
| author_sort | Heidi S. Mortensen |
| collection | DOAJ |
| description | Salmon farmers are interested in extending the time post-smolts are reared in recirculating aquaculture systems (RAS). However, there is a lack of knowledge regarding optimal water quality for post-smolts in RAS, and regarding potential consequences of long term exposure to different toxic compounds, such as nitrite, in the RAS water. To address this issue, we conducted a case study at a Faroese Atlantic salmon farm, that rears large post-smolts in fresh water RAS for 22 months before sea transfer, with no additional chloride salt, a known treatment for nitrite toxicity. The aim was to document the potential effects of long-term exposure of fluctuating sub-lethal nitrite concentrations in fresh water RAS on blood physiology of large post-smolts. The study was conducted over six weeks, at the end of the RAS production cycle. Our case study shows that after ~22 months in RAS with no additional chloride, the fish had accumulated a plasma nitrite concentration 8 to 16 times higher than the ambient water. Our results indicate that the accumulation may have resulted in extracellular hyperkaliemia, since there was a positive correlation between plasma nitrite and potassium levels (p=0.00095), with potassium levels almost twice as high than previously reported for Atlantic salmon. This could indicate that Atlantic salmon health is challenged due to prolonged sub-lethal nitrite exposure in fresh water RAS. Further research related to long-term nitrite exposure in RAS is needed to asses the potential negative impact, in order to optimize welfare and growth performance during production of Atlantic salmon post-smolts. |
| first_indexed | 2024-04-14T07:25:34Z |
| format | Article |
| id | doaj.art-90ac48fe927843a480b2b56cc6f80327 |
| institution | Directory Open Access Journal |
| issn | 2673-6225 |
| language | English |
| last_indexed | 2024-04-14T07:25:34Z |
| publishDate | 2022-07-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Animal Science |
| spelling | doaj.art-90ac48fe927843a480b2b56cc6f803272022-12-22T02:06:01ZengFrontiers Media S.A.Frontiers in Animal Science2673-62252022-07-01310.3389/fanim.2022.886071886071Exposing Atlantic Salmon Post-Smolts to Fluctuating Sublethal Nitrite Concentrations in a Commercial Recirculating Aquaculture System (RAS) May Have Negative ConsequencesHeidi S. Mortensen0Elin Jacobsen1Jelena Kolarevic2Amanda Vang3Fiskaaling, Við Áir 11, Hvalvík, Faroe IslandsFiskaaling, Við Áir 11, Hvalvík, Faroe IslandsThe Norwegian College of Fishery Science, Faculty of Biosciences, Fisheries and Economics, UiT, The Arctic University of Norway, Tromsø, NorwayFiskaaling, Við Áir 11, Hvalvík, Faroe IslandsSalmon farmers are interested in extending the time post-smolts are reared in recirculating aquaculture systems (RAS). However, there is a lack of knowledge regarding optimal water quality for post-smolts in RAS, and regarding potential consequences of long term exposure to different toxic compounds, such as nitrite, in the RAS water. To address this issue, we conducted a case study at a Faroese Atlantic salmon farm, that rears large post-smolts in fresh water RAS for 22 months before sea transfer, with no additional chloride salt, a known treatment for nitrite toxicity. The aim was to document the potential effects of long-term exposure of fluctuating sub-lethal nitrite concentrations in fresh water RAS on blood physiology of large post-smolts. The study was conducted over six weeks, at the end of the RAS production cycle. Our case study shows that after ~22 months in RAS with no additional chloride, the fish had accumulated a plasma nitrite concentration 8 to 16 times higher than the ambient water. Our results indicate that the accumulation may have resulted in extracellular hyperkaliemia, since there was a positive correlation between plasma nitrite and potassium levels (p=0.00095), with potassium levels almost twice as high than previously reported for Atlantic salmon. This could indicate that Atlantic salmon health is challenged due to prolonged sub-lethal nitrite exposure in fresh water RAS. Further research related to long-term nitrite exposure in RAS is needed to asses the potential negative impact, in order to optimize welfare and growth performance during production of Atlantic salmon post-smolts.https://www.frontiersin.org/articles/10.3389/fanim.2022.886071/fullpost-smoltAtlantic Salmonfresh water RASwater qualityfluctuating nitrite concentrationhyperkalaemia |
| spellingShingle | Heidi S. Mortensen Elin Jacobsen Jelena Kolarevic Amanda Vang Exposing Atlantic Salmon Post-Smolts to Fluctuating Sublethal Nitrite Concentrations in a Commercial Recirculating Aquaculture System (RAS) May Have Negative Consequences Frontiers in Animal Science post-smolt Atlantic Salmon fresh water RAS water quality fluctuating nitrite concentration hyperkalaemia |
| title | Exposing Atlantic Salmon Post-Smolts to Fluctuating Sublethal Nitrite Concentrations in a Commercial Recirculating Aquaculture System (RAS) May Have Negative Consequences |
| title_full | Exposing Atlantic Salmon Post-Smolts to Fluctuating Sublethal Nitrite Concentrations in a Commercial Recirculating Aquaculture System (RAS) May Have Negative Consequences |
| title_fullStr | Exposing Atlantic Salmon Post-Smolts to Fluctuating Sublethal Nitrite Concentrations in a Commercial Recirculating Aquaculture System (RAS) May Have Negative Consequences |
| title_full_unstemmed | Exposing Atlantic Salmon Post-Smolts to Fluctuating Sublethal Nitrite Concentrations in a Commercial Recirculating Aquaculture System (RAS) May Have Negative Consequences |
| title_short | Exposing Atlantic Salmon Post-Smolts to Fluctuating Sublethal Nitrite Concentrations in a Commercial Recirculating Aquaculture System (RAS) May Have Negative Consequences |
| title_sort | exposing atlantic salmon post smolts to fluctuating sublethal nitrite concentrations in a commercial recirculating aquaculture system ras may have negative consequences |
| topic | post-smolt Atlantic Salmon fresh water RAS water quality fluctuating nitrite concentration hyperkalaemia |
| url | https://www.frontiersin.org/articles/10.3389/fanim.2022.886071/full |
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