Assessing genetic diversity of lake trout (Salvelinus namaycush) populations in Saskatchewan

Climate change may lead to declines in lake trout (Salvelinus namaycush) populations and change the structure of the ecosystem in which they live. The lake trout is a keystone species in ecosystems of northern temperate lakes and these declines may subsequently reduce the genetic diversity found in these salmonids. Populations that contain greater genetic variation may have an increased capacity to adapt to changes in the ecosystem. Therefore, an understanding of the genetic diversity found in lake trout populations is required for their effective conservation and management. As a result, this study aimed to examine the genetic diversity and phylogeography of lake trout populations in north central Canada.The genetic diversity of lake trout from 19 lakes in Saskatchewan was examined using partial regions of the ND2 and ND5 mtDNA genes. A total of 607 tissue samples were analyzed using PCR-based single stranded conformation polymorphism (SSCP) and DNA sequencing. Although the ND5 gene fragment had minimal intraspecific variation, eleven sequence types were detected in the ND2 gene. Each sequence type differed in relative frequency between and among the lake trout populations sampled. One particular southern lake trout population, Crean Lake, had markedly different genetic composition in comparison to other lakes in the region. In the 1950’s and 1960’s, Crean Lake was stocked with lake trout from neighbouring Wassegam Lake in an attempt to increase population numbers. The sequence types of Crean Lake trout and their relative frequencies were dramatically different to those in Wassegam Lake. This suggests that the stocked fish may have been unsuccessful in their establishment/reproduction within Crean Lake. Lake trout from this lake also contained the highest frequency (44%) of rare ND2 sequence type “B”. Sequence type B was only detected in one other lake (La Ronge), at a very low frequency. The mutational changes in the eleven ND2 mitochondrial DNA sequence types represented three different amino acid sequence types. Substitutions of Threonine and Isoleucine occurred, resulting in two polar amino acids with much different hydropathy indexes. This may affect the tertiary structure of the protein, possibly indicating functional differences. Functionally different proteins may be exhibiting characteristics that allow lake trout to flourish in their environment. The fragments of both the ND2 and ND5 genes proved to be valuable for phylogenetic analyses within the Salmonidae. The genetic markers established in the present study provide the basis for future work on population genetics of lake trout. It would be advantageous to broaden the area of study in order to compare the genetic diversity found within the study area to other regions of Canada. This would determine whether the genetic diversity detected in this study is significantly greater than in other populations at a national scale. Management strategies should ultimately attempt to conserve the genetic diversity found within the lake trout populations of north central Saskatchewan

2017 Research & Innovation Day Program

A one day showcase of applied research, social innovation, scholarship projects and activities.https://first.fanshawec.ca/cri_cripublications/1004/thumbnail.jp

Variation in the intensity and prevalence of macroparasites in migratory caribou: a quasi-circumpolar study

Comparative studies across time and geographical regions are useful to improve our understanding of the health of wildlife populations. Our goal was to study parasitism in migratory caribou (Rangifer tarandus L., 1758) of North America and Greenland. A total of 1507 caribou were sampled across twelve herds to assess seven of their main helminth and arthropod macroparasites between 1978 and 2010. We sought to determine which factors such as sex, age class, herd size, and season best explained the prevalence and intensity of those parasites. Intensity of Hypoderma tarandi (L., 1758) increased with age for males while the opposite was observed in females. Prevalence of Fascioloides magna (Bassi, 1875), Taenia hydatigena (Pallas, 1766), and Cephenemyia trompe (Modeer, 1786) was higher in adults than in calves. Prevalence of F. magna and T. hydatigena were higher at high herd size than at lower herd size. Greenland herds had the lowest prevalence of T. hydatigena and Taenia krabbei (Moniez, 1879), a higher intensity of H. tarandi and a higher prevalence of C. trompe than the other herds. Of the herds from QuÊbec and Labrador, the Rivière-George herd had a higher prevalence of F. magna than the Rivière-aux-Feuilles herd. Our research provides the first comparative survey of these parasites of caribou across a broad spatial-temporal range.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author