Evaluation and use of a portable field kit for measuring whole-blood lactate in sharks

Abstract

Abstract. Measurement of lactate is becoming a common procedure in assessing the physiological effects of capture stress in sharks, although the necessity to measure the concentrations in the laboratory limits the ability for field assessments. Portable lactate analysers offer an alternative, but await validation against laboratory assays for sharks. The present study assessed the reliability of a portable Lactate Pro analyser for measuring whole-blood lactate in the school shark, Galeorhinus galeus, in the field. Laboratory determination of whole-blood and plasma lactate obtained by spectrophotometry was highly correlated with field determinations. Because shark lactate concentration can exceed the upper detection limit of the portable analysers, which were designed for mammalian use, a method for dealing with values greater than the maximum detection limit was evaluated. Whole-blood diluted by 50% with acidified saline solution, tap water and distilled water gave measured values of 55, 56 and 52%, respectively, of the original values, allowing accurate estimation of concentrations exceeding the upper detection limit of the analyser. These findings indicated that the Lactate Pro can be used to rapidly and reliably measure lactate for sharks in the field.

Meta‐analysis of post‐release fishing mortality in apex predatory pelagic sharks and white marlin

“…temperature, dissolved oxygen, salinity, temperature–depth gradients) and biological factors (e.g. species, respiratory mode, habitat class, sex, body size, skin thickness, predation, soak time or time spent hooked/fight time, hooking location, vitality or condition code, biochemical correlates of morbidity and mortality) to influence survival outcomes (Awruch et al., ; Braccini et al., ; Butcher et al., ; Campana, Joyce & Manning, ; Carruthers et al., ; Dapp et al., , , ; Davis, ; Diaz & Serafy, ; Gallagher, Orbesen et al., ; Gallagher, Serafy et al., ; Marshall et al., ; Morgan & Carlson, ; Moyes et al., ; Musyl, Brill et al., ; Musyl et al., ). Moreover, there are also data that suggest sharks may suffer from gas emboli from rapid temperature changes (Garner, ) accompanied during retrieval from deep‐set longline gear (Rodríguez‐Cabello & Sánchez, ).…”

“…But to assess the performance and efficacy of these measures and others (e.g. fin‐to‐carcass ratios, bans on wire leaders, shark lines and hook shape), the fate of discards must be ascertained (Awruch, Simpfendorfer & Pankhurst, ; Dapp, Huveneers, Walker, Mandelman & Kerstetter, ; Gilman, Chaloupka, Swimmer & Piovano, ; Graves, Luckhurst & Prince, ; Gray & Kennelly, ; Moyes, Fragoso, Brill & Musyl, ; Uhlmann, Ulrich & Kennelly, ). Davis () suggested mortality of discards was a major component in fisheries management.…”

The importance of research and public opinion to conservation management of sharks and rays: a synthesis

“…Human activities can also have delayed or sublethal effects, and research to develop and evaluate tools that enhance the ability to identify them can provide useful data. For example, Awruch et al (2011) validated a cheap portable field kit for determining lactate concentrations in sharks, a method that will allow researchers to quickly and easily determine the level of stress of sharks in a variety of conditions. Human effects do not always come from fisheries, but can still have significant implications.…”

Tonic immobility in the zebra shark, Stegostoma fasciatum, and its use for capture methodology

“…Further investigation therefore is needed in order to assess whether the use of tonic immobility is better for the stress and welfare of captured sharks opposed to other techniques. For example, examining secondary metabolites from blood samples from sharks caught using different techniques, as per Awruch et al (2011).…”