The efficacy of field techniques for obtaining and storing blood samples from fishes

Abstract

Prompted by the dramatic increase in the use of blood analyses in fisheries research and monitoring, this study investigated the efficacy of common field techniques for sampling and storing blood from fishes. Three questions were addressed: (1) Do blood samples taken via rapid caudal puncture (the 'grab-and-stab' technique) yield similar results for live v. sacrificed groups of fishes? (2) Do rapidly obtained caudal blood samples accurately represent blood properties of fishes prior to capture? (3) Does storage of whole blood in an ice slurry for a working day (8·5 h) modify the properties of the plasma? It was shown that haematocrit, plasma ions, metabolites, stress hormones and sex hormones of caudal blood samples were statistically similar when taken from live v. recently sacrificed groups of adult coho salmon Oncorhynchus kisutch. Moreover, this study confirmed by using paired blood samples from cannulated O. kisutch that blood acquired through the caudal puncture technique (mean ±s.e. 142 ± 26 s after capture) was representative of fish prior to capture. Long-term (8·5 h) cold storage of sockeye salmon Oncorhynchus nerka whole blood caused significant decreases in plasma potassium and chloride, and a significant increase in plasma glucose. Previous research has suggested that these changes largely result from net movements of ions and molecules between the plasma and erythrocytes, movements that can occur within minutes of storage. Thus, blood samples from fishes should be centrifuged as quickly as practicable in the field for separation of plasma and erythrocytes to prevent potentially misleading data.

Refuge-Seeking Impairments Mirror Metabolic Recovery Following Fisheries-Related Stressors in the Spanish Flag Snapper (Lutjanus carponotatus) on the Great Barrier Reef

“…The respirometers were cylindrical, had an internal diameter of 25 cm and a length of 80 cm, and were submerged in a large tank to ensure thermal stability (∼28ЊC). The functioning of the respirometers was similar to that described previously (Clark et al 2011(Clark et al , 2012. Briefly, each respirometer was equipped with a closedcircuit recirculation loop to ensure appropriate water mixing, and an automated flush pump refreshed the respirometer water for 5 min in every 10-min period.…”

“…RAMP was evaluated immediately before blood sampling, and then fish were placed supine in a water-filled trough ) before a 21-gauge sodium-heparinized needle and a 1-mL syringe were used to withdraw 0.5 mL of blood nonlethally from the caudal vasculature. The entire procedure took less than 3 min, which should have provided a blood sample from the control fish that was uninfluenced by the netting event (see Turner 2004;Clark et al 2011). Blood was placed in a water-ice slurry for up to 1 h. Blood glucose and lactate were measured with a portable diagnostic meter (Accutrend Plus, Roche) that has been previously validated for use on fish (Beecham et al 2006).…”

Resilience of Pink Salmon and Chum Salmon to Simulated Fisheries Capture Stress Incurred upon Arrival at Spawning Grounds

“…By rapidly dipnetting control fish and sampling blood within 1 min of initial contact, we anticipated that the blood sample would be uninfluenced by the capture event (Clark et al 2011a). Therefore, control values ( Figure 2) were probably representative of the fish's physiological state prior to capture in the channel raceway.…”

Validation of a portable, waterproof blood pH analyser for elasmobranchs

“…Still, while conventional laboratory blood chemistry analysers are more accurate than field instruments, such as the i-STAT or the Hanna pH meter used here (Harrenstein et al ., 2005; Gallagher et al ., 2010; Harter et al ., 2015), they are often impractical because they require the storage and transport of samples out of a field setting (Clark et al ., 2011; Stoot et al ., 2014). Additionally, analysing blood acid-base properties must occur within minutes of blood sampling to ensure accuracy (Stoot et al ., 2014), making the use of field-worthy instruments a necessity.…”