Metabolic and functional impacts of hypoxia vary with size in Atlantic salmon
The most capricious environmental variable in aquatic habitats, dissolved O2, is fundamental to the fitness and survival of fish. Using swim tunnel respirometry we test how acute exposure to reduced O2 levels, similar to those commonly encountered by fish in crowded streams and on commercial aquacul...
Published in: | Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology |
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ftunivtasmania:oai:eprints.utas.edu.au:29417 2023-05-15T15:31:02+02:00 Metabolic and functional impacts of hypoxia vary with size in Atlantic salmon Oldham, TMW Nowak, B Hvas, M Oppedal, F 2019 https://eprints.utas.edu.au/29417/ unknown Elsevier Science Inc Oldham, TMW orcid:0000-0002-8994-0052 , Nowak, B orcid:0000-0002-0347-643X , Hvas, M and Oppedal, F 2019 , 'Metabolic and functional impacts of hypoxia vary with size in Atlantic salmon' , Comparative Biochemistry and Physiology. Part A, vol. 231 , pp. 30-38 , doi:10.1016/j.cbpa.2019.01.012 <http://dx.doi.org/10.1016/j.cbpa.2019.01.012>. Salmo salar aquaculture stress critical swimming speed oxygen swim tunnel respirometry metabolic scaling cortisol lactate Article PeerReviewed 2019 ftunivtasmania https://doi.org/10.1016/j.cbpa.2019.01.012 2021-09-13T22:19:10Z The most capricious environmental variable in aquatic habitats, dissolved O2, is fundamental to the fitness and survival of fish. Using swim tunnel respirometry we test how acute exposure to reduced O2 levels, similar to those commonly encountered by fish in crowded streams and on commercial aquaculture farms, affect metabolic rate and swimming performance in Atlantic salmon of three size classes: 0.2, 1.0 and 3.5 kg. Exposure to 45–55% dissolved O2 saturation substantially reduced the aerobic capacity and swimming performance of salmon of all sizes. While hypoxia did not affect standard metabolic rate, it caused a significant decrease in maximum metabolic rate, resulting in reduced absolute and factorial aerobic scope. The most pronounced changes were observed in the smallest fish, where critical swimming speed was reduced from 91 to 70 cm s−1 and absolute aerobic scope dropped by 62% relative to the same measurement in normoxia. In normoxia, absolute critical swimming speed (Ucrit) increased with size, while relative Ucrit, measured inbody lengths−1, was highest in the small fish (3.5) and decreased with larger size (medium = 2.2). Mass specific metabolic rate and cost of transport were inversely related to size, with calculated metabolic scaling exponents of 0.65 for bSMR and 0.78 for bMMR. Metabolic O2 demand increased exponentially with current speed irrespective of fish size (R2 = 0.97–0.99). This work demonstrates that moderate hypoxia reduces the capacity for activity and locomotion in Atlantic salmon, with smaller salmon most vulnerable to hypoxic conditions. As warm and hypoxic conditions become more prevalent in aquatic environments worldwide, understanding local O2 budgets is critical to maximizing the welfare and survival of farmed and wild salmon. Article in Journal/Newspaper Atlantic salmon Salmo salar University of Tasmania: UTas ePrints Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology 231 30 38 |
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Open Polar |
collection |
University of Tasmania: UTas ePrints |
op_collection_id |
ftunivtasmania |
language |
unknown |
topic |
Salmo salar aquaculture stress critical swimming speed oxygen swim tunnel respirometry metabolic scaling cortisol lactate |
spellingShingle |
Salmo salar aquaculture stress critical swimming speed oxygen swim tunnel respirometry metabolic scaling cortisol lactate Oldham, TMW Nowak, B Hvas, M Oppedal, F Metabolic and functional impacts of hypoxia vary with size in Atlantic salmon |
topic_facet |
Salmo salar aquaculture stress critical swimming speed oxygen swim tunnel respirometry metabolic scaling cortisol lactate |
description |
The most capricious environmental variable in aquatic habitats, dissolved O2, is fundamental to the fitness and survival of fish. Using swim tunnel respirometry we test how acute exposure to reduced O2 levels, similar to those commonly encountered by fish in crowded streams and on commercial aquaculture farms, affect metabolic rate and swimming performance in Atlantic salmon of three size classes: 0.2, 1.0 and 3.5 kg. Exposure to 45–55% dissolved O2 saturation substantially reduced the aerobic capacity and swimming performance of salmon of all sizes. While hypoxia did not affect standard metabolic rate, it caused a significant decrease in maximum metabolic rate, resulting in reduced absolute and factorial aerobic scope. The most pronounced changes were observed in the smallest fish, where critical swimming speed was reduced from 91 to 70 cm s−1 and absolute aerobic scope dropped by 62% relative to the same measurement in normoxia. In normoxia, absolute critical swimming speed (Ucrit) increased with size, while relative Ucrit, measured inbody lengths−1, was highest in the small fish (3.5) and decreased with larger size (medium = 2.2). Mass specific metabolic rate and cost of transport were inversely related to size, with calculated metabolic scaling exponents of 0.65 for bSMR and 0.78 for bMMR. Metabolic O2 demand increased exponentially with current speed irrespective of fish size (R2 = 0.97–0.99). This work demonstrates that moderate hypoxia reduces the capacity for activity and locomotion in Atlantic salmon, with smaller salmon most vulnerable to hypoxic conditions. As warm and hypoxic conditions become more prevalent in aquatic environments worldwide, understanding local O2 budgets is critical to maximizing the welfare and survival of farmed and wild salmon. |
format |
Article in Journal/Newspaper |
author |
Oldham, TMW Nowak, B Hvas, M Oppedal, F |
author_facet |
Oldham, TMW Nowak, B Hvas, M Oppedal, F |
author_sort |
Oldham, TMW |
title |
Metabolic and functional impacts of hypoxia vary with size in Atlantic salmon |
title_short |
Metabolic and functional impacts of hypoxia vary with size in Atlantic salmon |
title_full |
Metabolic and functional impacts of hypoxia vary with size in Atlantic salmon |
title_fullStr |
Metabolic and functional impacts of hypoxia vary with size in Atlantic salmon |
title_full_unstemmed |
Metabolic and functional impacts of hypoxia vary with size in Atlantic salmon |
title_sort |
metabolic and functional impacts of hypoxia vary with size in atlantic salmon |
publisher |
Elsevier Science Inc |
publishDate |
2019 |
url |
https://eprints.utas.edu.au/29417/ |
genre |
Atlantic salmon Salmo salar |
genre_facet |
Atlantic salmon Salmo salar |
op_relation |
Oldham, TMW orcid:0000-0002-8994-0052 , Nowak, B orcid:0000-0002-0347-643X , Hvas, M and Oppedal, F 2019 , 'Metabolic and functional impacts of hypoxia vary with size in Atlantic salmon' , Comparative Biochemistry and Physiology. Part A, vol. 231 , pp. 30-38 , doi:10.1016/j.cbpa.2019.01.012 <http://dx.doi.org/10.1016/j.cbpa.2019.01.012>. |
op_doi |
https://doi.org/10.1016/j.cbpa.2019.01.012 |
container_title |
Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology |
container_volume |
231 |
container_start_page |
30 |
op_container_end_page |
38 |
_version_ |
1766361528174379008 |