| Title: | Behavioural responses of Pacific salmon to chemical disturbance cues during the spawning migration |
| Author(s): | Bett NN; Hinch SG; Yun SS; |
| Address: | "Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC V6T 1Z4, Canada. Electronic address: nolanbett@gmail.com. Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, BC V6T 1Z4, Canada. Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC V6T 1Z4, Canada" |
| DOI: | 10.1016/j.beproc.2016.10.001 |
| ISSN/ISBN: | 1872-8308 (Electronic) 0376-6357 (Linking) |
| Abstract: | "Many fish that are exposed to a threat release disturbance cues, which are chemicals that alert conspecifics to the presence of the threat. The release of disturbance cues has been well demonstrated in various species of laboratory-reared fish. Migratory fish species often exhibit increased cortisol levels and are exposed to numerous stressors during their migrations, which could trigger the release of disturbance cues. We tested the responses of wild migrating sockeye salmon (Oncorhynchus nerka) and pink salmon (O. gorbuscha) to the odours of disturbed and undisturbed conspecifics to determine whether these fish release disturbance cues following exposure to a simulated stressor. Furthermore, we tested the responses of sockeye salmon to water-borne cortisol, following evidence from past studies that this chemical is excreted through the gills of stressed fish, and speculation that endogenous correlates of stress might function as disturbance cues. We found that sockeye salmon avoid the odour of disturbed conspecifics, whereas pink salmon do not. Avoidance occurred in both female and male sockeye salmon, and was associated with an increase in plasma cortisol levels in females, but not in males. We also found no behavioural response to water-borne cortisol, which suggests this chemical does not act as an exogenous disturbance cue in sockeye salmon. Avoidance of disturbed conspecifics could limit exposure to risks during the sockeye salmon spawning migration, but could also delay the rate of migration and thereby accrue reproductive costs" |
| Keywords: | Animal Migration/*drug effects Animals Avoidance Learning *Cues Female Hydrocortisone/blood/*pharmacology Male Maze Learning/drug effects Pheromones/*pharmacology Reproduction/*drug effects Salmon/blood/*physiology Anadromous fish Dichotomous choice Odour; |
| Notes: | "MedlineBett, Nolan N Hinch, Scott G Yun, Sang-Seon eng Netherlands 2016/10/27 Behav Processes. 2016 Nov; 132:76-84. doi: 10.1016/j.beproc.2016.10.001. Epub 2016 Oct 5" |
