Controlled experiments to explore the use of a multi-tissue approach to characterizing stress in wild-caught Pacific halibut (Hippoglossus stenolepis)

Abstract

The integration of multiple tissues in physiological and ecological analyses can enhance methodological approaches, increase applications for data and extend interpretation of results. Previous investigations of the stress response in fish have focused primarily on cortisol levels in a single matrix—blood plasma—which confines interpretations of cortisol levels to a short temporal frame. Epidermal mucus has been proposed as an alternative or complement to plasma that may provide a view to cortisol levels over a different temporal window allowing comparative assessment. Here, we explore the potential for multi-tissue cortisol analysis using both plasma and epidermal mucus in Pacific halibut (Hippoglossus stenolepis). The relative timing at which cortisol increased and decreased in the two matrices as well as cortisol concentrations at estimated peak levels were compared in two trials after (i) inducing cortisol synthesis by adrenocorticotropic hormone (ACTH1–24) administration and (ii) inducing cortisol elimination using cortisol (hydrocortisone, 98%) injection. The ACTH treatment elicited a peak plasma cortisol response approximately 12 hours post-injection, while mucus cortisol concentrations peaked later at approximately 62 hours post-injection. Exogenous cortisol treatments suggested relatively little transfer of cortisol from plasma to mucus, potentially reflecting differential effects of endogenous and exogenous cortisol. Our results suggest the potential utility of mucus as a sampling matrix that provides an extended window for detection of the stress response as compared to plasma. Results also suggest the utility of a multi-tissue approach to cortisol analysis with potential applications to applied fisheries research. Increased understanding of the relative scale of the cortisol response to stress (e.g. capture) will allow researchers and managers to better interpret the physiological condition and survival outcome of fish subjected to regulatory discard.

The gene expression profile of the glucocorticoid receptor 1 (gr1) but not gr2 is modulated in mucosal tissues of gilthead sea bream (Sparus aurata) exposed to acute air-exposure stress

“…cortisol in epidermal mucus, as it has been suggested in previous studies for gilthead sea bream (Guardiola et al, 2016) and other fish species (Kroska et al, 2021). In line with this idea, the very low concentrations of cortisol detected in skin mucus makes it very sensitive to the determination of significant differences.…”

A new era for science-industry research collaboration – a view towards the future

“…There are also many instances of effective collaboration towards the development and improvement of gear (Walsh et al, 2002;Harley and Robinson, 2008;Feekings et al, 2019;Merrifield et al, 2019), assessment of the selectivity of gear (Graham et al, 2007;Baker et al, 2011;Baker et al, 2014;O'Neill et al, 2019), analysis of selectivity in catch and surveys (Rose et al, 2010;Somerton et al, 2011;Veiga-Malta et al, 2019), analyses of management approaches (Smith et al, 2007;Smeltz et al, 2019) and conservation engineering solutions to mitigate fisheries impacts on marine environment (Kaiser et al, 2016;Österblom et al, 2020) or benthic substrates and communities (Rose et al, 2000;Rooper et al, 2011). Additionally, there are many examples of effective collaborative approaches to minimize or reduce bycatch and incidental mortality in protected or non-target species (Gauvin and Rose, 2001;Carruthers and Neis, 2011;Arkhipkin et al, 2021;Kroska et al, 2021;Yochum et al, 2021). There are also examples of effective scienceindustry collaboration to inform harvest control rules and management planning (Davis, 2008;Heller-Shipley et al, 2021).…”

Co-creating Knowledge with Fishers: Challenges and Lessons for Integrating Fishers' Knowledge Contributions into Marine Science in Well-Developed Scientific Advisory Systems

“…There are also many instances of effective collaboration towards the development and improvement of gear (Walsh et al, 2002;Harley and Robinson, 2008;Merrifield et al, 2019), assessment of the selectivity of gear (Graham et al, 2007;Baker et al, 2011;, analysis of selectivity in catch and surveys (Rose et al, 2010;Somerton et al, 2011;Veiga-Malta et al, 2019), analyses of management approaches (Smith et al, 2007;Smeltz et al, 2019) and conservation engineering solutions to mitigate fisheries impacts on marine environment (Kaiser et al, 2016;Österblom et al, 2020) or benthic substrates and communities (Rose et al, 2000;Rooper et al, 2011). Additionally, there are many examples of effective collaborative approaches to minimize or reduce bycatch and incidental mortality in protected or non-target species (Gauvin and Rose, 2001;Kroska et al, 2021;Yochum et al, 2021). There are also examples of effective scienceindustry collaboration to inform harvest control rules and management planning (Davis, 2008;Heller-Shipley et al, 2021).…”