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Oxygen gradients affect behaviour of caged Atlantic salmon Salmo salar


Oldham, T and Dempster, T and Fosse, JO and Oppedal, F, Oxygen gradients affect behaviour of caged Atlantic salmon Salmo salar, Aquaculture Environment Interactions, 9 pp. 145-153. ISSN 1869-7534 (2017) [Refereed Article]


Copyright Statement

The authors 2017. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0)

DOI: doi:10.3354/aei00219


Dissolved oxygen (DO) conditions in marine aquaculture cages are heterogeneous and fluctuate rapidly. Here, by temporarily wrapping a tarpaulin around the top 0 to 6 m of a marine cage (~2000 m3), we manipulated DO to evaluate the behavioural response of Atlantic salmon Salmo salar to hypoxia. Videos were recorded before, during and after DO manipulation at 3 m depth while vertical profiles of temperature, salinity, DO and fish density were continuously measured. The trial was repeated 4 times over a 2 wk period. Temperature and salinity profiles varied little across treatment periods; however, DO saturation was reduced at all depths in all replicate trials during the tarpaulin treatment compared to the periods before or after. In 3 out of 4 trials, swim speeds were 1.5 to 2.7 times slower during the tarpaulin treatment than the before or after periods. Significant changes in vertical distribution of fish density and DO were observed between treatment periods in all replicate trials; salmon swam either above or below the most hypoxic depth layer (59 to 62% DO saturation). In a regression tree analysis, the relative influence of DO in determining fish distribution was 17%, while temperature (39%) and salinity (44%) explained the majority of variation. Our results demonstrate that salmon are capable of modifying their distribution and possibly activity levels in response to intermediate DO levels, but that DO is not a primary driver of behaviour at the saturation levels examined in this study.

Item Details

Item Type:Refereed Article
Keywords:salmon, oxygen, hypoxia, behaviour, aquaculture, fish distribution
Research Division:Agricultural, Veterinary and Food Sciences
Research Group:Fisheries sciences
Research Field:Aquaculture
Objective Division:Animal Production and Animal Primary Products
Objective Group:Fisheries - aquaculture
Objective Field:Aquaculture fin fish (excl. tuna)
UTAS Author:Oldham, T (Mrs Tina Oldham)
ID Code:119975
Year Published:2017
Web of Science® Times Cited:21
Deposited By:Fisheries and Aquaculture
Deposited On:2017-08-08
Last Modified:2018-03-22
Downloads:89 View Download Statistics

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