University of Tasmania

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Oxygen removal from water versus arterial oxygen delivery: calibrating the Fick equation in Pacific salmon

journal contribution
posted on 2023-05-18, 13:20 authored by Farrell, AP, Eliason, EJ, Clark, TD, Steinhausen, MF
While it is well known that O2 is directly removed from the water by skin and gill tissues of fish, the mismatch between O2 removal from water (O2 uptake; V·O2) and the O2 delivered to tissues by the primary circulation (O2 consumption; V·aO2) has never been measured directly. Using data from four recent studies that simultaneously measured V·O2 and V·aO2 in 2–5 kg Pacific salmon, our analysis revealed that sockeye salmon can remove an additional 12–48 % more O2 from the water than the primary circulation delivers to the systemic tissues. This percentage did not change significantly during swimming activity, a result that contradicts an earlier prediction that the difference should decrease when V·O2 increases during exercise. In resting Chinook salmon, a similar percentage difference in simultaneously measured V·O2 and V·O2 was observed, yet the difference tended to disappear during acute heat stress to a near lethal temperature. These results emphasize that caution should be exercised when using the Fick equation to estimate cardiac output because the overestimate of cardiac output that results from using the Fick equation in Pacific salmon is not small, may not be fixed and may exist in other teleosts.


Publication title

Journal of Comparative Physiology. B










Institute for Marine and Antarctic Studies



Place of publication

175 Fifth Ave, New York, USA, Ny, 10010

Repository Status

  • Restricted

Socio-economic Objectives

Coastal or estuarine biodiversity