Within-population heterogeneity of habitat use by lake trout Salvelinus namaycush

• Published in: Journal of fish biology 2006-12, Vol.69 (6), p.1675-1696
• Main Authors: Morbey, Y. E., Addison, P., Shuter, B. J., Vascotto, K.
• Format: Article
• Language: English
• Subjects: Agnatha. Pisces; Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; Fresh water ecosystems; Fundamental and applied biological sciences. Psychology; individual variation; Lake Louisa; Salvelinus namaycush; Synecology; telemetry; trophic flexibility; Vertebrates: general zoology, morphology, phylogeny, systematics, cytogenetics, geographical distribution
• ISSN: 0022-1112; 1095-8649
• DOI: 10.1111/j.1095-8649.2006.01236.x

To learn more about the degree of individual variation in resource use by lake trout Salvelinus namaycush, ultrasonic telemetry was used to study their habitat use in a lake without pelagic schooling fish prey. Individuals spent most of their time within the metalimnion in favourable water temperatures. They also made frequent excursions, however, into lake temperatures exceeding their optimum for physiological performance at all temporal scales considered. Their frequent use of nearshore habitats suggested that feeding in littoral areas may be common. Habitat use was highly variable among individuals, but spatial habitat use by individuals showed remarkable consistency between years. In particular, some lake trout exhibited high site fidelity to shallow, nearshore areas, whereas others used deep areas extensively. This level of between‐individual variation indicated niche partitioning by depth and the possibility of alternative foraging strategies.