Environmental factors correlate with hybridization in stocked brook charr (Salvelinus fontinalis)

• Published in: Canadian journal of fisheries and aquatic sciences Vol. 69; no. 5; pp. 884 - 893
• Main Authors: MARIE, Amandine D, BERNATCHEZ, Louis, GARANT, Dany
• Format: Journal Article
• Language: English
• Published: Ottawa, ON NRC Research Press 01.05.2012; National Research Council of Canada; Canadian Science Publishing NRC Research Press
• Subjects: Animal and plant ecology; Animal populations; Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; Dissolved oxygen; Distribution; Environmental aspects; Environmental effects; Environmental factors; Exploitation and management of natural biological resources (hunting, fishing and exploited populations survey, etc.); Fish populations; Fish stocking; Fresh water ecosystems; Freshwater; Fundamental and applied biological sciences. Psychology; Habitats; Hybridization; Identification and classification; Oxygen; Population biology; Salvelinus fontinalis; Synecology; Temperature; Trout; Wildlife; Zoology; Canada; Quebec Canada; Canada, Quebec; Freshwater environment; Aquatic environment; Vertebrata; Salvelinus fontinalis; Pisces; Environmental factor; Hybridization; Stock
• ISSN: 0706-652X; 1205-7533
• DOI: 10.1139/f2012-027

Stocking is a common practice throughout the world that may increase hybridization between wild and domesticated populations. Stocking intensity alone does not always fully explain the observed patterns of hybridization, suggesting that the intensity of hybridization may be modulated by environmental factors. Using brook charr (i.e., brook trout, Salvelinus fontinalis ) as a model, the objective of this study was to assess the relative effect of environmental factors and stocking intensity on the level of hybridization observed within brook charr from 15 lacustrine populations of two wildlife reserves in Quebec, Canada. The level of hybridization significantly increased with (i) the number of stocking events, (ii) a reduction in both surface area and maximum depth of lakes, and (iii) a reduction in dissolved oxygen and an increase in temperature and pH. These results suggest that levels of hybridization were affected by the availability and quality of lacustrine habitats as well as by the extent of propagule pressure. Our study provides the first demonstration that knowledge of environmental features may help predict the effects of stocking on the genetic integrity of wild populations.