Author: Carolyn T. Knapper
Sockeye Salmon from Gitanyow Lake in the Skeena River watershed of British Columbia are recognized as a significant conservation unit under Canada’s Wild Salmon Policy. The population, an important cultural resource for the Gitanyow First Nation (GFN), has experienced drastic declines in the last two decades despite the GFN having ceased fishing decades earlier over conservation concerns. The GFN has also implemented initiatives to better understand and protect the population. As part of this work, I examined metrics of smolt quality for Gitanyow Sockeye Salmon compared to smolts migrating from Babine Lake, the largest Sockeye Salmon population in the Skeena watershed. Although smolts from both populations migrate predominantly as 1-year olds, Gitanyow smolts were significantly larger and had higher condition factor. The smolt marker, gill Na+,K+ -ATPase activity, however, did not differ between the populations. I also used two OpenArray (OA) transcriptional profiling chips: an osmoregulation (oSTP) chip, with 28 genes, was used for gill tissue and a Stress Transcriptional Profile (STP) OA chip, with 112 genes, was used for liver tissue. The chips targeted genes involved in osmoregulation, stress response, detoxification, endocrine disruption, apoptosis, hypoxia, circadian rhythm, growth, metabolism, and immune function. I found no difference in osmoregulatory, stress response, endogenous control or immune function related genes between the populations in sampled gill tissue. Significant differences in growth and metabolism-related genes, however, were observed for both gill and liver tissues. My results indicate that smolting is not a bottleneck for Gitanyow Sockeye Salmon viability. Further analysis will examine juvenile Sockeye Salmon caught in Gitanyow Lake during the summer in response to high temperature and low dissolved oxygen. My research has informed ongoing conservation efforts and may offer insights applicable to other small, genetically distinct Sockeye Salmon populations in British Columbia.