Physiological stress response of Mountain Whitefish (Prosopium williamsoni) and White Sucker (Catostomus commersoni) sampled along a gradient of temperature and agrichemicals in the Oldman River, Alberta

Abstract

Species differences in tolerance to environmental stressors can contribute to differences in species distribution and abundance along river gradients. Climate change and intensive agriculture are likely to have major effects on fish populations in temperate zones, yet understanding of the interactions between temperature and chemical stressors on fish physiology is limited. The objective of this study was to compare the stress responses of the Mountain Whitefish, (Prosopium williamsoni, a cold-water fish) and White Sucker (Catostomus commersoni, a cool-water fish), along a temperature and pesticide gradient in the Oldman River, Southern Alberta in spring and summer. Fish were seined, placed into an enclosure, and plasma cortisol, glucose, liver glycogen, and condition factor were measured. Plasma acetylcholinesterase (AChE) activity was used as an indicator of exposure to organophosphate and carbamates pesticides. Whitefish had lower plasma AChE activity and lower liver glycogen reserves compared to suckers at all sites and all sampling times but the differences in plasma cortisol were not species-specific and there were no differences in plasma glucose levels, except at one site. Plasma cortisol increased, and plasma glucose decreased along a downstream river gradient in whitefish in both spring and summer; in sucker only plasma cortisol fluctuated and only in the summer. Liver glycogen decreased along the river gradient in both species at both seasons. Our study detected important species-specific differences in AChE activities and responses of the physiological stress axis, suggesting that whitefish are more sensitive to temperature and pesticide stress than suckers.

Variation in scale cortisol concentrations of a wild freshwater fish: Habitat quality or seasonal influences?

“…Interestingly, events such as drought are known to trigger stress responses in many vertebrate species (Baker et al, 2013;Jessop et al, 2003;Tokarz and Summers, 2011;Wikelski et al, 2001). Variation in water temperature is another environmental variable that should be considered when studying wild fish, since several authors have demonstrated its influence on cortisol stress responses (Blevins et al, 2012;Cook et al, 2011;Meka and McCormick, 2005;Quinn et al, 2010). In order to cope with subtle changes in the environment, such as the above mentioned, healthy individuals are predicted to increase GC secretion (Wikelski and Cooke, 2006), leading to higher circulating cortisol levels (Bonier et al, 2009).…”

Metabolic traits of westslope cutthroat trout, introduced rainbow trout and their hybrids in an ecotonal hybrid zone along an elevation gradient

“…Blood samples from ten fish were taken from four sites along the elevational gradient [a Crowsnest R tributary 1234 m, two Racehorse Creek tributaries (1478 and 1539 m), and the Oldman River mainstem (1722 m)] in July 2006. Plasma AchE activity [(µmol min) ml −1 ], liver glycogen, plasma glucose and cortisol, and gill Na + /K + ATPase activity were measured in tissue and blood samples from these fish (Chuiko, 2000; Levesque et al ., 2002, 2003; Quinn, Rasmussen & Hontela, 2010).…”

Reproductive Ecology, Spawning Behavior, and Juvenile Distribution of Mountain Whitefish in the Madison River, Montana

“…The exact mechanisms for declines are often unknown. Studies have documented mechanisms of Mountain Whitefish mortality including whirling disease (Schisler 2010;Pierce et al 2012), high temperatures (Boyd 2008;Brinkman et al 2013), pollutants (Brinkman et al 2008;Quinn et al 2010), decreased discharge, and entrainment (Kennedy 2009). However, little is known about the effects of these stressors on populations (but see IDFG 2007; Kennedy 2009).…”