Populations of northern Dolly Varden (Salvelinus malma malma) exhibit partial seaward migration, yet little is known about this phenomenon in Dolly Varden populations. Our study analyzed data from three different Dolly Varden populations in the western Canadian Arctic in order to determine if: (1) differences in size-at-first seaward migration exist between fish that migrate at early and late ages among populations inhabiting different river systems, and (2) annual growth influences anadromous or resident life history choice. Otolith strontium analysis and back-calculation were used to determine age- and size-at-first seaward migration, respectively. Differences in age- and size-at-first seaward migration were determined across river system and migration age. Back-calculated fish lengths were compared using a mixed effect model to determine how early growth influences migratory tactics (early or late aged smolt, or resident). Our results indicate that fish exhibiting faster early growth migrated in earlier years and at smaller sizes than slower growing fish, however size- and age-at first seaward migration varied by river system. Faster growing Dolly Varden tended to become either residents or early smolts, while slower growth was associated with smolting later in life. This is contrary to life history theory where the fastest growing fish in a population should mature as a resident. Our results indicate factors other than growth may be influencing life history ‘decisions’ in Dolly Varden. Future work on growth efficiencies and metabolic rates is needed to assess how they affect migratory behaviours.

北多莉瓦登（Salvelinus malma malma ）的种群) 表现出部分向海迁移，但对 Dolly Varden 种群中的这种现象知之甚少。我们的研究分析了来自加拿大西部北极地区三个不同 Dolly Varden 种群的数据，以确定：(1) 在早期和晚期迁移的鱼类之间是否存在首次向海迁移的大小差异，这些鱼类在居住在不同河流系统的种群中， (2) 年增长影响回溯或居民生活史选择。耳石锶分析和反算分别用于确定首次向海迁移的年龄和大小。跨河流系统和迁移年龄确定了首次向海迁移的年龄和大小的差异。使用混合效应模型比较反向计算的鱼的长度，以确定早期生长如何影响洄游策略（早年或晚年的黑鲑鱼，或居民）。我们的结果表明，早期生长速度较快的鱼在较早的几年迁移，而且比生长较慢的鱼的体型更小，但首次向海迁移时的体型和年龄因河流系统而异。生长速度较快的多莉·瓦登倾向于成为常住者或早期的幼鱼，而生长缓慢则与晚年的幼鱼有关。这与生活史理论相反，即种群中生长最快的鱼应该成熟为居民。我们的结果表明，增长以外的因素可能会影响 Dolly Varden 的生活史“决定”。未来需要在生长效率和代谢率方面开展工作，以评估它们如何影响迁徙行为。