The effects of acute and long-term exposure to CO 2 on the respiratory physiology and production performance of Atlantic salmon ( Salmo salar ) in freshwater

Javed Rafiq Khan*, D. Johansen, Peter Vilhelm Skov

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

A high-level of free CO2 is a prevalent feature of intensive RAS and chronic exposure is common for most species during the production process. Currently, standard operating procedures, regulations and “safe” levels of CO2 are based on values that do not necessarily represent a point at, up to which, production and fish performance are unaffected. The high solubility of CO2 in water and the large input from fish respiration also means that current practices for the removal of CO2 are often inadequate for the scale of production. High CO2 levels can be addressed by the control of alkalinity, thereby creating a scenario where the majority of CO2 exists as carbonate and bicarbonate. Any acute reduction in pH can shift the equilibrium towards a large and sudden conversion of inorganic carbon to free CO2, which can have a detrimental effect on fish. The current investigations aimed to determine the effects of both; acute increases in dissolved CO2 on the physiological capacity of Atlantic salmon, as well the effects of chronic exposure to different CO2 concentrations on production in freshwater. Results show that acute exposure (up to 40 mg L−1) significantly reduces aerobic capacity and the rate of recovery from stress. They also show that these effects are driven primarily by CO2 exposure, and to a much lesser extent by the associated reduction in pH. Growth and feed conversion experiments during chronic exposure suggest that there is no CO2 concentration where production performance is unaffected.
Original languageEnglish
JournalAquaculture
Volume491
Pages (from-to)20-27
ISSN0044-8486
DOIs
Publication statusPublished - 2018

Keywords

  • Carbon dioxide
  • Atlantic salmon
  • Recirculating aquaculture systems
  • Growth
  • Metabolic rate

Cite this

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title = "The effects of acute and long-term exposure to CO 2 on the respiratory physiology and production performance of Atlantic salmon ( Salmo salar ) in freshwater",
abstract = "A high-level of free CO2 is a prevalent feature of intensive RAS and chronic exposure is common for most species during the production process. Currently, standard operating procedures, regulations and “safe” levels of CO2 are based on values that do not necessarily represent a point at, up to which, production and fish performance are unaffected. The high solubility of CO2 in water and the large input from fish respiration also means that current practices for the removal of CO2 are often inadequate for the scale of production. High CO2 levels can be addressed by the control of alkalinity, thereby creating a scenario where the majority of CO2 exists as carbonate and bicarbonate. Any acute reduction in pH can shift the equilibrium towards a large and sudden conversion of inorganic carbon to free CO2, which can have a detrimental effect on fish. The current investigations aimed to determine the effects of both; acute increases in dissolved CO2 on the physiological capacity of Atlantic salmon, as well the effects of chronic exposure to different CO2 concentrations on production in freshwater. Results show that acute exposure (up to 40 mg L−1) significantly reduces aerobic capacity and the rate of recovery from stress. They also show that these effects are driven primarily by CO2 exposure, and to a much lesser extent by the associated reduction in pH. Growth and feed conversion experiments during chronic exposure suggest that there is no CO2 concentration where production performance is unaffected.",
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author = "Khan, {Javed Rafiq} and D. Johansen and Skov, {Peter Vilhelm}",
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The effects of acute and long-term exposure to CO 2 on the respiratory physiology and production performance of Atlantic salmon ( Salmo salar ) in freshwater. / Khan, Javed Rafiq; Johansen, D.; Skov, Peter Vilhelm.

In: Aquaculture, Vol. 491, 2018, p. 20-27.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - The effects of acute and long-term exposure to CO 2 on the respiratory physiology and production performance of Atlantic salmon ( Salmo salar ) in freshwater

AU - Khan, Javed Rafiq

AU - Johansen, D.

AU - Skov, Peter Vilhelm

PY - 2018

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N2 - A high-level of free CO2 is a prevalent feature of intensive RAS and chronic exposure is common for most species during the production process. Currently, standard operating procedures, regulations and “safe” levels of CO2 are based on values that do not necessarily represent a point at, up to which, production and fish performance are unaffected. The high solubility of CO2 in water and the large input from fish respiration also means that current practices for the removal of CO2 are often inadequate for the scale of production. High CO2 levels can be addressed by the control of alkalinity, thereby creating a scenario where the majority of CO2 exists as carbonate and bicarbonate. Any acute reduction in pH can shift the equilibrium towards a large and sudden conversion of inorganic carbon to free CO2, which can have a detrimental effect on fish. The current investigations aimed to determine the effects of both; acute increases in dissolved CO2 on the physiological capacity of Atlantic salmon, as well the effects of chronic exposure to different CO2 concentrations on production in freshwater. Results show that acute exposure (up to 40 mg L−1) significantly reduces aerobic capacity and the rate of recovery from stress. They also show that these effects are driven primarily by CO2 exposure, and to a much lesser extent by the associated reduction in pH. Growth and feed conversion experiments during chronic exposure suggest that there is no CO2 concentration where production performance is unaffected.

AB - A high-level of free CO2 is a prevalent feature of intensive RAS and chronic exposure is common for most species during the production process. Currently, standard operating procedures, regulations and “safe” levels of CO2 are based on values that do not necessarily represent a point at, up to which, production and fish performance are unaffected. The high solubility of CO2 in water and the large input from fish respiration also means that current practices for the removal of CO2 are often inadequate for the scale of production. High CO2 levels can be addressed by the control of alkalinity, thereby creating a scenario where the majority of CO2 exists as carbonate and bicarbonate. Any acute reduction in pH can shift the equilibrium towards a large and sudden conversion of inorganic carbon to free CO2, which can have a detrimental effect on fish. The current investigations aimed to determine the effects of both; acute increases in dissolved CO2 on the physiological capacity of Atlantic salmon, as well the effects of chronic exposure to different CO2 concentrations on production in freshwater. Results show that acute exposure (up to 40 mg L−1) significantly reduces aerobic capacity and the rate of recovery from stress. They also show that these effects are driven primarily by CO2 exposure, and to a much lesser extent by the associated reduction in pH. Growth and feed conversion experiments during chronic exposure suggest that there is no CO2 concentration where production performance is unaffected.

KW - Carbon dioxide

KW - Atlantic salmon

KW - Recirculating aquaculture systems

KW - Growth

KW - Metabolic rate

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