PNNL

Abstract

Blood plasma analyses can provide researchers, aquaculture facilities, and fisheries managers with valuable insight into the physiological state and welfare of fish. For example, glucose and lactate are part of the secondary stress response system and elevated concentrations are indicators of stress. However, blood plasma analyses from field sites can be logistically difficult and typically involves sample storage and transport to quantify concentrations in a laboratory setting. Portable glucose and lactate meters offer an alternative to laboratory assays and have shown to be relatively accurate in fish, but these tools have only been validated for a few fish species. The objective of this study was to investigate if portable meters could be reliably used in juvenile Chinook salmon (Oncorhynchus tshawytscha). As part of a larger stress response study, Chinook salmon (157 ± 17 mm fork length [mean ± standard deviation; SD]) were exposed to stress-inducing treatments and sampled for blood. Laboratory reference glucose concentrations (milligrams per deciliter; mg/dL; n=70) were 1.21 ± 0.21 (mean ± SD) times higher than the Accu-Check Aviva™ meter. Linear regression analysis showed an R2 = 0.79. Lactate concentrations (milliMolar; mM; n =52) of the laboratory reference were 2.55 ± 0.50 (mean ± SD) times higher than the Lactate Plus™ meter with linear regression yielding an R2 = 0.76. Our results indicate both meters could be used to measure relative glucose and lactate concentrations in Chinook salmon and provide fisheries professionals with a valuable tool, especially in remote field settings.