Régime alimentaire du béluga, Delphinapterus leucas, de l'estuaire du Saint-Laurent, Canada, tel que révélé par l'analyse des acides gras du lard
|Advisor:||Guderley, Helga; Lesage, Véronique|
|Abstract:||Knowledge of diet is an important element for understanding the ecology of species. Currently, there are few techniques to examine the contemporary diet of St. Lawrence belugas considering the precarious status of the population and the rarity of prey remains in the stomach of stranded individuals. Fatty acid analyses of prey and blubber may provide the tools to indicate diet. It was with this purpose that a comparative study of fatty acid profiles was undertaken. As a first step, about 60 potential prey species for belugas were collected in the Estuary and Gulf of St. Lawrence and were examined for their fatty acid profiles. The analysis revealed the need to consider the effects of lipid content, size, season, and sampling location when evaluating species fatty acid profiles in order to improve evaluations of prey profiles of a predator such as the beluga. Blubber fatty acid analyses were subsequently compared between belugas and four species of pinnipeds that are encountered in the Estuary and the Gulf. Species along with other classes such as sex and age could be distinguished on the basis of their fatty acid signatures. A suite of multivariate analyses confirmed the role of diet-linked fatty acids in differentiating the groups, thereby confirming the potential for these techniques to conduct a comparative analysis of diets among these marine mammals. The characterization of fatty acid signatures of potential prey and predators represents essential steps on the path towards a better understanding of trophic ecology in these animals.|
|Document Type:||Mémoire de maîtrise|
|Open Access Date:||12 April 2018|
|Collection:||Thèses et mémoires|
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