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The effects of constant and cyclical hypoxia on the survival, growth and metabolic physiology of incubating Atlantic salmon (Salmo salar)

Citation

Wood, AT and Clark, TD and Elliott, NG and Frappell, PB and Andrewartha, SJ, The effects of constant and cyclical hypoxia on the survival, growth and metabolic physiology of incubating Atlantic salmon (Salmo salar), Aquaculture, 527 Article 735449. ISSN 0044-8486 (2020) [Refereed Article]

Copyright Statement

Copyright 2020 Elsevier B.V.

DOI: doi:10.1016/j.aquaculture.2020.735449

Abstract

Salmonids reared in aquaculture incubation systems are susceptible to periods of cyclical or fluctuating hypoxia caused by embryo crowding, water flow rates and management protocols. Hypoxia during early development can reduce salmon growth, development and survival, and delay hatching, potentially impacting future performance and survival in subsequent phases of life. However, salmon embryos can also limit the effects of hypoxia by metabolic depression, premature hatching or physiological modifications to improve oxygen delivery. Here, we investigated the effects of constant and cyclical hypoxia on the growth, development, hatching, survival, oxygen uptake rate (O2) and hypoxia tolerance (O2crit) of Atlantic salmon (Salmo salar) from fertilisation, through hatching, until 113 days post-fertilisation (DPF). We incubated salmon in either normoxia (100% dissolved oxygen [DO; as percent air saturation]), moderate hypoxia (∼63% DO), severe hypoxia (∼27% DO) or cyclical hypoxia (∼100-25% DO daily). At the eyed-egg stage routine oxygen uptake (O2rout) was reduced by ~20% in salmon from the cyclical and moderate hypoxia treatments, although reduced O2rout was not associated with a reduction in O2crit. Moderate hypoxia did not affect growth, development, survival or hatching. However, at 113 DPF cyclical hypoxia-incubated salmon were ∼12% smaller and developmentally delayed by ∼5 days compared to normoxia-incubated salmon as a result of reduced growth and development prior to the eyed-egg stage (∼39 DPF). Survival was unaffected by moderate or cyclical hypoxia, but hatching was delayed by ∼2-3 days in cyclical hypoxia incubated salmon. Severe hypoxia produced deformed embryos, greatly decreased growth and development and resulted in 99.3% mortality by 113 DPF. This study demonstrates that Atlantic salmon have a considerable capacity to survive daily bouts of extreme hypoxia, however, the consequent reductions in growth, development and hatching may still have implications in aquaculture systems.

Item Details

Item Type:Refereed Article
Keywords:Atlantic salmon, cyclical hypoxia, early development, metabolic rateoxygen, development, aquaculture, larvae, alevin, egg, metabolism, red blood cell
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:Elliott, NG (Dr Nick Elliott)
UTAS Author:Frappell, PB (Professor Peter Frappell)
UTAS Author:Andrewartha, SJ (Dr Sarah Andrewartha)
ID Code:139793
Year Published:2020
Web of Science® Times Cited:5
Deposited By:Agriculture and Food Systems
Deposited On:2020-07-06
Last Modified:2020-08-06
Downloads:0

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