Development of habitat suitability indices and bioenergetics models for Arctic grayling (Thymallus arcticus)

Larocque, S.M., Hatry, C., and Enders, E.C. 2014. Development of habitat suitability indices and bioenergetics models for Arctic grayling (Thymallus arcticus). Can. Tech. Rep. Fish. Aquat. Sci. 3097: vi + 57 p. Fish habitat models are often used as tools to evaluate habitat quality for aquatic organisms. Habitat suitability indices are a commonly used in habitat models, while others, such as bioenergetics models, are beginning to utilize them more frequently. Recent legislative changes to the Canadian Fisheries Act have led to a focus on the conservation of the sustainability and the ongoing productivity of Canada’s commercial, recreational, and Aboriginal fisheries rather than the former protection of fish habitat. Whereas the methods to evaluate the quantity and quality of fish habitat based on habitat suitability indices are well established, new methods have to be developed to assess the ongoing productivity of fisheries. Here, we explore the use of bioenergetics habitat models to assess habitat quality using the net energetic gain (NEG) of fish. Furthermore, we relate the NEG to the productivity and investigate the predictive power of bioenergetics habitat modelling in regards to flow and climate changes. Using Arctic grayling (Thymallus arcticus), a well-documented species sensitive to changes in habitat quality, we developed habitat suitability indices and a bioenergetics habitat model. When appropriate, assumptions were documented at each stage throughout the development of the model. RÉSUMÉ Larocque, S.M., Hatry, C., and Enders, E.C. 2014. Development of habitat suitability indices and bioenergetics models for Arctic grayling (Thymallus arcticus). Can. Tech. Rep. Fish. Aquat. Sci. 3097: vi + 57 p. Les modèles d’habitat du poisson sont souvent utilisés comme outils afin d’évaluer la qualité de l'habitat. Dans ces modèles, les indices de qualité de l’habitat (IQH) sont couramment utilisés. D’autres modèles, tel que les modèles bioénergétiques, commencent à les utiliser plus fréquemment. Les récents changements législatifs à la Loi sur les pêches du Canada mettent l’accent sur la durabilité et la productivité continue des pêches commerciales, récréatives et autochtones ; plutôt que la protection de l’habitat du poisson. Considérant que les méthodes d’évaluation de la quantité et de la qualité de l’habitat du poisson en fonction des IQH sont bien