Emily A. Hardison's research while affiliated with University of California, Santa Barbara and other places

Publications (6)

Article
Full-text available
Although most animals live in complex, thermally variable environments, the impact of this variability on specific physiological systems is still unresolved. The ectotherm heart is known to change in both structure and function to ensure appropriate oxygen delivery under different thermal regimes, but the plasticity of the upper thermal limits of t...
Article
Full-text available
Thermal acclimation is a key process enabling ectotherms to cope with temperature change. To undergo a successful acclimation response, ectotherms require energy and nutritional building blocks obtained from their diet. However, diet is often overlooked as a factor that can alter acclimation responses. Using a temperate omnivorous fish, opaleye (Gi...
Article
Female-biased mortality has been repeatedly reported in Pacific salmon during their upriver migration in both field studies and laboratory-holding experiments, especially in the presence of multiple environmental stressors, including thermal stress. Here we used coho salmon (Oncorhynchus kisutch) to test whether females exposed to elevated water te...
Article
Both laboratory and field respirometry are rapidly growing techniques to determine animal performance thresholds. However, replicating protocols to estimate maximum metabolic rate (MMR) between species, populations, and individuals can be difficult, especially in the field. We therefore evaluated seven different exercise treatments-four laboratory...
Article
Full-text available
Adult female Pacific salmon can have higher migration mortality rates than males, particularly at warm temperatures. However, the mechanisms underlying this phenomenon remain a mystery. Given the importance of swimming energetics on fitness, we measured critical swim speed, swimming metabolism, cost of transport, aerobic scope (absolute and factori...

Citations

... For instance, it can be assessed by measuring thermal performance curves (TPC) for fH max and/or aerobic scope (McKenzie et al., 2021), with the first being performed more easily and within a shorter timeframe than the latter. The fH max can be measured from slightly anesthetised fish if the vagal control is removed by using atropine and stimulating the β-receptors with isoproterenol, as it has been done in wide variety of fish species Anttila et al., 2013a;Casselman et al., 2012;Chen et al., 2015;Ferreira et al., 2014;Gilbert et al., 2019;Gilbert and Farrell, 2021;Hardison et al., 2021;Safi et al., 2019). The fH max values using the above-mentioned method are similar to fH max values measured from fish chased to exhaustion (Casselman et al., 2012). ...
... Most studies comparing metabolic rates between sexes have focused on mass-specific oxygen requirements rather than scaling coefficients (Kraskura et al., 2021;Tomlinson & Phillips, 2015;Weldon et al., 2013). Such an approach allows for misinterpretation because mass-specific metabolic rates systematically underestimate metabolic rate and may lead to misunderstandings about differences in metabolic rate across or within species (Hayes, 2001;Müller et al., 2021). ...
... More specifically, SOD, CS activity, LDH activity all increased temporally, either after single or multiple heatwaves, implying post-heatwave compensation costs. Besides temporal changes, the lower SOD in white muscle from 32°C to 34°C represents a reduced energy investment in antioxidant defence (Little et al., 2020). However, with higher respiratory requirements during extreme heatwaves, excessive oxidative stress from the production of reactive oxygen species should be buffered with more antioxidant agents (Heise et al., 2006). ...
... Individual fish were manually chased by hand for 3 min to exhaustion in a large cooler (45.4 L). This is a standard protocol that has been frequently used to exhaust fish (Norin and Clark, 2016;Little et al., 2020). The fish were then air-exposed for 30 s before being immediately placed in a respirometry chamber at which time measurement of oxygen consumption began and continued for 18-24 h (Eliason et al., 2008) (Fig. 2). ...