Migratory Variation in Mackenzie River System Broad Whitefish: Insights from Otolith Strontium Distributions

• Published in: Transactions of the American Fisheries Society
• Main Authors: Harris, L. N., Loewen, T. N., Reist, J. D., Halden, N. M., Babaluk, J. A., Tallman, R. F.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2012
• Subjects: Northwest Territories; Mackenzie River; Mackenzie river
• Online Access: http://dx.doi.org/10.1080/00028487.2012.713885; https://afspubs.onlinelibrary.wiley.com/doi/pdf/10.1080/00028487.2012.713885

Abstract There is growing recognition of the global importance of preserving biodiversity. While many organisms show immense variation in intraspecific biodiversity, for example in life history variation and migratory strategies among conspecific populations, accurate descriptions of such variation are lacking for the majority of contemporary species. One such example is the broad whitefish Coregonus nasus of the lower Mackenzie River system in Canada's Northwest Territories, where anadromous, lacustrine, and putative riverine populations are thought to exist. In this study we resolve migratory variation exhibited by lower Mackenzie River broad whitefish by employing otolith microchemistry and find that (1) anadromous, lacustrine, and riverine populations exist in this system, (2) a high degree of variability exists within anadromous broad whitefish (e.g., varying degrees of marine and estuarine use), and (3) lacustrine populations are not composed solely of resident fish as anadromous broad whitefish occasionally migrate to, and stay in, lacustrine habitat. Overall, our results are consistent with the suggestion that there may be a higher level of migratory complexity in this system than previously reported and these results will be important in guiding the conservation of intraspecific biodiversity in Mackenzie River system broad whitefish.