Impaired detection of chemical alarm cues by juvenile wild Atlantic salmon ( Salmo salar ) in a weakly acidic environment

Many prey fishes rely on damage-released chemical alarm cues to detect and avoid predators. The ability to use these cues has been shown to confer considerable survival benefits to individuals. While several laboratory studies and a single field study have demonstrated that an ambient pH of 6.0 impa...

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Bibliographic Details
Published in:Canadian Journal of Fisheries and Aquatic Sciences
Main Authors: Leduc, Antoine Olivier Henri Claude, Roh, Ellie, Harvey, Mark Charles, Brown, Grant Edwin
Format: Article in Journal/Newspaper
Language:English
Published: Canadian Science Publishing 2006
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Online Access:http://dx.doi.org/10.1139/f06-128
http://www.nrcresearchpress.com/doi/pdf/10.1139/f06-128
Description
Summary:Many prey fishes rely on damage-released chemical alarm cues to detect and avoid predators. The ability to use these cues has been shown to confer considerable survival benefits to individuals. While several laboratory studies and a single field study have demonstrated that an ambient pH of 6.0 impairs fishes in their ability to detect these alarm cues, no study had yet compared the response to alarm cue exposures across populations residing in multiple streams of a different acidity level. In our study, we conducted live behavioural observations in five nursery streams, ranging in pH from 5.71 to 7.49 on two age classes (young of the year and parr) of wild juvenile Atlantic salmon (Salmo salar). We aimed to assess if the detection of these chemical alarm cues was constantly dependant on the ambient pH or if variations in the detection occurred among populations of the different streams regardless of the ambient acidity level. Our results demonstrated that salmon present in any acidic stream did not respond to alarm cues, while those in neutral streams exhibited typical alarm responses.