Fecal glucocorticoids and anthropogenic injury and mortality in North Atlantic right whales Eubalaena glacialis

Chronic stress from fishing gear entanglement is recorded in baleen from a bowhead whale (Balaena mysticetus)

“…The fecal corticosterone level was consistent with the range of fecal GC concentrations reported for chronically entangled North Atlantic right whales (Rolland et al 2017). Entanglements in this right whale population have been well documented, and persist from months to years (mean of 6 mo), resulting in severe physical trauma, highly elevated stress hormones, poor body condition, reduced reproduction and often a prolonged health decline prior to death (Cassoff et al 2011;Schick et al 2013;Rolland et al 2016Rolland et al , 2017. Bycatch in fishing gear is among the most significant anthropogenic threats to large whales globally (Cassoff et al 2011, Knowlton et al 2012, Reeves et al 2013.…”

“…The fecal corticosterone level was consistent with the range of fecal GC concentrations reported for chronically entangled North Atlantic right whales (Rolland et al . ). Entanglements in this right whale population have been well documented, and persist from months to years (mean of 6 mo), resulting in severe physical trauma, highly elevated stress hormones, poor body condition, reduced reproduction and often a prolonged health decline prior to death (Cassoff et al .…”

“…Serum GCs from a physically debilitated, live‐stranded North Atlantic right whale had much higher concentrations of cortisol compared to corticosterone, suggesting that a cortisol response was also predominant in this highly stressed right whale (Rolland et al . ). However, Lysiak et al .…”

“…Cortisol is believed to be the predominant form of circulating GC in cetaceans ("cortisol-dominant"; Ortiz and Worthy 2000, Atkinson et al 2015, and the results of the current study indicate a primary role for cortisol in the adrenal response to this chronic entanglement. Serum GCs from a physically debilitated, live-stranded North Atlantic right whale had much higher concentrations of cortisol compared to corticosterone, suggesting that a cortisol response was also predominant in this highly stressed right whale (Rolland et al 2017). However, Lysiak et al (2018) found that baleen corticosterone concentrations were highest, and cortisol levels were actually lower than the baseline during a chronic entanglement in an adult female North Atlantic right whale.…”

“…Assessing stress responses in marine wildlife by quantifying adrenal steroid hormones (i.e., glucocorticoids; cortisol, corticosterone, and/or their metabolites) has been a valuable tool for evaluating the physiological impacts of anthropogenic disturbance (Ayres et al 2012;Rolland et al 2012Rolland et al , 2017Atkinson et al 2015;Kellar et al 2015), and for monitoring the impacts of ecological changes Wikelski 2001, Bechshøft et al 2012). Glucocorticoid hormones (GCs) have been analyzed in several sample types in marine mammals, including blood (i.e., serum, plasma), blubber, feces, hair, saliva, exhaled respiratory 1 vapor ("blow"), cerumen (i.e., earwax, ear plug), and baleen (e.g., Hogg et al 2005Hogg et al , 2009Amaral 2010;Rolland et al 2012Rolland et al , 2017St. Aubin et al 2013;Trumble et al 2013;Hunt et al 2014;Kellar et al 2015;Champagne et al 2016;Robeck et al 2017;Burgess et al 2018).…”