The effects of elevated potassium, acidosis, reduced oxygen levels, and temperature on the functional properties of isolated myocardium from three elasmobranch fishes: clearnose skate (Rostroraja eglanteria), smooth dogfish (Mustelus canis), and sandbar shark (Carcharhinus plumbeus)

Stress related blood values in Scyliorhinus canicula as live-indicators of physiological status after bottom trawling capture activity

“…Previous work by Cliff and Thurman (Cliff and Thurman, 1984) investigating the physiology consequences of stress in in Carcharhinus obscurus during hand net captures, reported that potassium plasma values above 7 mmol/ l could generate myocardial disruption. Although, the potential levels of K + that may impact cardiac function in sharks remain unknown (Schwieterman et al, 2021) the dogfish captured in deeper waters in our study had elevated levels of K + an may have experienced a larger osmotic disruption than those captured in shallower waters as reported by (Skomal and Mandelman, 2012) (Whitney et al, 2021).…”

Capture heats up sharks

“…Catch-and-release fishing is considered a multi-stressor interaction for individuals ( Gale et al, 2013 ), with the negative impacts broadly categorised as lethal or sub-lethal, with potential sub-lethal impacts including altered blood chemistry ( Gallagher et al, 2014 ; Dapp et al, 2016 ), behavioural impairments ( Raoult et al, 2019 ), reduced growth and reproductive rates and increased disease vulnerability ( Gale et al, 2013 ). Fish can experience oxygen deprivation ( Schwieterman et al, 2021 ), handling-related injuries ( Cooke et al, 2013 ; French et al, 2015 ) and heat stress ( Wosnick et al, 2018 , 2019 ).…”

“…Many studies investigating the impacts of catch-and-release fishing have highlighted the potential importance of temperature in these interactions ( Meka and McCormick, 2005 ; Gale et al, 2013 ; Schlenker et al, 2016 ; Bouyoucos et al, 2018 ; Schwieterman et al, 2021 ), whereby water temperature (T a ) can have a significant effect on post-release survival and a variety of sub-lethal impacts ( Gale et al, 2013 ). Furthermore, body temperature (T b ) is considered an important parameter when assessing an individual’s response to stress, their metabolic rate and their energy budgets; all of which may be affected by catch-and-release interactions.…”

“…When hooked, sharks often exhibit intensive swimming acceleration ( Gallagher et al, 2017 ) and periods of exhaustive exercise (i.e. anaerobic exercise) ( Schwieterman et al, 2021 ), as they attempt to escape. Capture-related exercise and the resulting physiological stress can elevate the metabolic rate ( Kieffer, 2000 ; Mohan et al, 2020 ) resulting in, among other things, the generation of heat.…”

“…In addition to altered thermal dynamics, hooked fish may undergo altered blood biochemistry as a result of the event ( Gallagher et al, 2014 ; Dapp et al, 2016 ; Mohan et al, 2020 ; Schwieterman et al, 2021 ). Capture can often result in hyperkalemia, metabolic and respiratory acidosis ( Schwieterman et al, 2021 ) and declines in blood oxygen concentration, as a result of the often exhaustive exercise and apneic asphyxia associated with capture ( Schwieterman et al, 2021 ). Lactate and glucose are two metabolites widely examined in studies investigating stress in sharks ( Cliff and Thurman, 1984 ; Hoffmayer and Parsons, 2001 ; Mandelman and Skomal, 2008 ; Gallagher et al, 2014 , 2017 ).…”