A comparison of two seawater adaptation strategies for Atlantic salmon post-smolt (Salmo salar) grown in recirculating aquaculture systems (RAS): Nitrification, water and gut microbiota, and performance of fish
The land-based production phase in Norwegian Atlantic salmon farming has the past years been extended to include post-smolt for an increasing number of farmers. Post-smolt production can involve introduction of brackish/seawater to a recirculating aquaculture system (RAS) that is acclimatized to fre...
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Language: | English |
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Online Access: | https://hdl.handle.net/11250/2686846 https://doi.org/10.1016/j.aquaculture.2020.735973 |
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ftntnutrondheimi:oai:ntnuopen.ntnu.no:11250/2686846 2023-05-15T15:32:21+02:00 A comparison of two seawater adaptation strategies for Atlantic salmon post-smolt (Salmo salar) grown in recirculating aquaculture systems (RAS): Nitrification, water and gut microbiota, and performance of fish Fossmark, Ragnhild Olsen Attramadal, Kari Kristian, Nordøy Østerhus, Stein Wold Vadstein, Olav 2021 application/pdf https://hdl.handle.net/11250/2686846 https://doi.org/10.1016/j.aquaculture.2020.735973 eng eng Elsevier Regionale forskningsfond Nord-Norge: 289950 urn:issn:0044-8486 https://hdl.handle.net/11250/2686846 https://doi.org/10.1016/j.aquaculture.2020.735973 cristin:1840379 Navngivelse 4.0 Internasjonal http://creativecommons.org/licenses/by/4.0/deed.no CC-BY 532 Aquaculture Peer reviewed Journal article 1478 ftntnutrondheimi https://doi.org/10.1016/j.aquaculture.2020.735973 2020-11-11T23:33:59Z The land-based production phase in Norwegian Atlantic salmon farming has the past years been extended to include post-smolt for an increasing number of farmers. Post-smolt production can involve introduction of brackish/seawater to a recirculating aquaculture system (RAS) that is acclimatized to freshwater for the earlier stages of salmon production. A change from freshwater to seawater shifts the environmental conditions for fish, bacteria and water treatment processes in RAS. Two regimes for salinity increase were studied to evaluate the effects on nitrification functionality, water and gut microbiota and fish performance on land and in the sea cages. A fish group of 200,000 salmon parr were stocked in a brackish water RAS (bRAS) at 3‰ salinity. After the fish had smoltified the group was split in two, one group was kept in bRAS and the other was moved to a RAS operated at 28‰ salinity (sRAS). The bRAS was operated with a gradual increase in salinity from 3 to 26‰ over a period of 28 days, whereafter both groups were moved to two separate sea cages. Bacterial communities of water, biofilter biofilm and fish faeces were characterized by 16S rRNA amplicon sequencing. Nitrification capacity tests at different salinities were performed on biofilter media from bRAS, to evaluate short term robustness to salinity changes. Ordination based on Bray-Curtis similarities showed that in water samples in bRAS, the bacterial communities were stable from 12 to 26‰ salinity increase. The faecal microbiota of the fish showed high inter-individual variation within fish tanks, suggesting stochastic processes/drift to affect the community structures in addition to salinity increase. The same nitrifying bacteria were present in bRAS (throughout the salinity increase) and in sRAS, showing that these nitrifiers could adapt to salinities from 3 to 26‰, and 28‰. After the sea cage phase, fish from the sRAS system had in total 2.9% higher weight than the fish from bRAS, however the mortality was 15% higher in the sRAS group. Salinity was a driver for succession in RAS, and other factors such as organic load in the water and stochastic processes in the host also affected the bacterial community dynamics. publishedVersion Available online 30 September 2020 0044-8486/ © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). DOI:10.1016/j.aquaculture.2020.735973 Article in Journal/Newspaper Atlantic salmon Salmo salar NTNU Open Archive (Norwegian University of Science and Technology) Bray ENVELOPE(-114.067,-114.067,-74.833,-74.833) Aquaculture 532 735973 |
institution |
Open Polar |
collection |
NTNU Open Archive (Norwegian University of Science and Technology) |
op_collection_id |
ftntnutrondheimi |
language |
English |
description |
The land-based production phase in Norwegian Atlantic salmon farming has the past years been extended to include post-smolt for an increasing number of farmers. Post-smolt production can involve introduction of brackish/seawater to a recirculating aquaculture system (RAS) that is acclimatized to freshwater for the earlier stages of salmon production. A change from freshwater to seawater shifts the environmental conditions for fish, bacteria and water treatment processes in RAS. Two regimes for salinity increase were studied to evaluate the effects on nitrification functionality, water and gut microbiota and fish performance on land and in the sea cages. A fish group of 200,000 salmon parr were stocked in a brackish water RAS (bRAS) at 3‰ salinity. After the fish had smoltified the group was split in two, one group was kept in bRAS and the other was moved to a RAS operated at 28‰ salinity (sRAS). The bRAS was operated with a gradual increase in salinity from 3 to 26‰ over a period of 28 days, whereafter both groups were moved to two separate sea cages. Bacterial communities of water, biofilter biofilm and fish faeces were characterized by 16S rRNA amplicon sequencing. Nitrification capacity tests at different salinities were performed on biofilter media from bRAS, to evaluate short term robustness to salinity changes. Ordination based on Bray-Curtis similarities showed that in water samples in bRAS, the bacterial communities were stable from 12 to 26‰ salinity increase. The faecal microbiota of the fish showed high inter-individual variation within fish tanks, suggesting stochastic processes/drift to affect the community structures in addition to salinity increase. The same nitrifying bacteria were present in bRAS (throughout the salinity increase) and in sRAS, showing that these nitrifiers could adapt to salinities from 3 to 26‰, and 28‰. After the sea cage phase, fish from the sRAS system had in total 2.9% higher weight than the fish from bRAS, however the mortality was 15% higher in the sRAS group. Salinity was a driver for succession in RAS, and other factors such as organic load in the water and stochastic processes in the host also affected the bacterial community dynamics. publishedVersion Available online 30 September 2020 0044-8486/ © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). DOI:10.1016/j.aquaculture.2020.735973 |
format |
Article in Journal/Newspaper |
author |
Fossmark, Ragnhild Olsen Attramadal, Kari Kristian, Nordøy Østerhus, Stein Wold Vadstein, Olav |
spellingShingle |
Fossmark, Ragnhild Olsen Attramadal, Kari Kristian, Nordøy Østerhus, Stein Wold Vadstein, Olav A comparison of two seawater adaptation strategies for Atlantic salmon post-smolt (Salmo salar) grown in recirculating aquaculture systems (RAS): Nitrification, water and gut microbiota, and performance of fish |
author_facet |
Fossmark, Ragnhild Olsen Attramadal, Kari Kristian, Nordøy Østerhus, Stein Wold Vadstein, Olav |
author_sort |
Fossmark, Ragnhild Olsen |
title |
A comparison of two seawater adaptation strategies for Atlantic salmon post-smolt (Salmo salar) grown in recirculating aquaculture systems (RAS): Nitrification, water and gut microbiota, and performance of fish |
title_short |
A comparison of two seawater adaptation strategies for Atlantic salmon post-smolt (Salmo salar) grown in recirculating aquaculture systems (RAS): Nitrification, water and gut microbiota, and performance of fish |
title_full |
A comparison of two seawater adaptation strategies for Atlantic salmon post-smolt (Salmo salar) grown in recirculating aquaculture systems (RAS): Nitrification, water and gut microbiota, and performance of fish |
title_fullStr |
A comparison of two seawater adaptation strategies for Atlantic salmon post-smolt (Salmo salar) grown in recirculating aquaculture systems (RAS): Nitrification, water and gut microbiota, and performance of fish |
title_full_unstemmed |
A comparison of two seawater adaptation strategies for Atlantic salmon post-smolt (Salmo salar) grown in recirculating aquaculture systems (RAS): Nitrification, water and gut microbiota, and performance of fish |
title_sort |
comparison of two seawater adaptation strategies for atlantic salmon post-smolt (salmo salar) grown in recirculating aquaculture systems (ras): nitrification, water and gut microbiota, and performance of fish |
publisher |
Elsevier |
publishDate |
1478 |
url |
https://hdl.handle.net/11250/2686846 https://doi.org/10.1016/j.aquaculture.2020.735973 |
long_lat |
ENVELOPE(-114.067,-114.067,-74.833,-74.833) |
geographic |
Bray |
geographic_facet |
Bray |
genre |
Atlantic salmon Salmo salar |
genre_facet |
Atlantic salmon Salmo salar |
op_source |
532 Aquaculture |
op_relation |
Regionale forskningsfond Nord-Norge: 289950 urn:issn:0044-8486 https://hdl.handle.net/11250/2686846 https://doi.org/10.1016/j.aquaculture.2020.735973 cristin:1840379 |
op_rights |
Navngivelse 4.0 Internasjonal http://creativecommons.org/licenses/by/4.0/deed.no |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1016/j.aquaculture.2020.735973 |
container_title |
Aquaculture |
container_volume |
532 |
container_start_page |
735973 |
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1766362865772527616 |