Pacific salmon ecology & conservation laboratory





Ken Jeffries, Postdoctoral Investigator

Centre for Applied Conservation Research
3606 Forest Sciences Centre
University of British Columbia
Vancouver, BC  V6T 1Z4  CANADA

Office: +001 604 822-1969

kenmjeffries (at)



2012 - Ph.D. - University of British Columbia

2007 - M.Sc. in Environmental Physiological Ecology - University of Calgary

2004 - B.Sc. (First Class Honour's) - University of Calgary


Broad Research Interests:

I am interested in how environmental stress (either anthropogenic or natural) can affect an individual’s fitness. As freshwater systems are continually being altered by human activity and climate change, many fish within a population may have a reduced ability to successfully spawn or to survive until maturation. I am interested in how sub-lethal stressors can alter physiological processes for an individual and potentially lead to reduced reproductive output, which may scale up to population-level consequences.


Pacific Salmon Research:

In recent years, Fraser River Pacific salmon have been migrating through warmer river temperatures than what they have historically experienced. Migration during periods of elevated water temperature can lead to increased rates of en route and prespawn mortality. The goals of my research are to determine the potential impacts of elevated water temperatures on sockeye and pink salmon survival, blood properties and gene expression. With microarray technology, researchers can simultaneously measure the expression of thousands of genes and determine which genes are ‘turned on’ or ‘turned off’ during periods of temperature stress. This allows us to understand which biological pathways are influenced by water temperature. By studying changes in the transcriptome, blood properties, and survival affected by high water temperature, I was able to determine the effects of water temperature on Pacific salmon scaling up from the cellular level to the level of the individual. My research has contributed to the understanding of potential impacts of warming river water temperatures on Pacific salmon.

Another complicating factor in studying Pacific salmon spawning migrations is that they are semelparous, which means they spawn once and then die. Pacific salmon cease feeding up to six months before they migrate into freshwater and therefore must use endogenous energy stores to fuel migration and reproductive development. During these spawning migrations, Pacific salmon are more susceptible to disease and parasites, suffer degeneration of some internal organs, begin to lose the ability to osmoregulate, all due to the natural senescence process. Essentially, salmon are dying while they migrate. Using microarray appoaches and blood physiology, I was able to generate some of the first data examining the mechanisms of mortality and senescence in adult Pacific salmon. 


Jeffries, K.M., Hinch, S.G., Sierocinski, T., Pavlidis, P., Miller, K.M. Transciptomic responses to high water temperature in Pacific salmon. In review.

Jeffries, K.M., Hinch, S.G., Sierocinski, T., Clark, T.D., Eliason, E.J., Donaldson, M.R., Li, S., Pavlidis, P., Miller, K.M. (2012) Consequences of high temperatures and premature mortality on the transcriptome and blood physiology of wild adult sockeye salmon (Oncorhynchus nerka). Ecology and Evolution 2: 1747-1764.

Jeffries, K.M., Hinch, S.G., Martins, E.G., Clark, T.D., Lotto, A.G., Patterson, D.A., Cooke, S.J., Farrell, A.P., Miller, K.M. (2012) Sex and proximity to reproductive maturity influence the survival, final maturation, and blood physiology of Pacific salmon when exposed to high temperature during a simulated migration. Physiological and Biochemical Zoology 85: 62-73.

Jeffries, K.M., Hinch, S.G., Donaldson, M.R., Gale, M.K., Burt, J.M., Thompson, L.A., Farrell, A.P, Patterson, D.A., Miller, K.M. (2011) Temporal changes in blood variables during final maturation and senescence in male sockeye salmon Oncorhynchus nerka: reduced osmoregulatory ability can predict mortality. Journal of Fish Biology 79: 449-465.


I have also been fortunate to have collaborated with some wonderful salmon ecologists and physiologists within our research group looking at various aspects of Pacific salmon biology that was not part of my doctoral research.


Cooke, S.J., Hinch, S.G., Donaldson, M.R., Clark, T.D., Eliason, E.J., Crossin, G.T., Raby, G.D., Jeffries, K.M., Lapointe, M., Miller, K., Patterson, D.A., Farrell, A.P. (2012) Conservation physiology in practice: How physiological knowledge has improved our ability to sustainably manage Pacific salmon during up-river migration. Philosophical Transactions of the Royal Society of London B 367: 1757-1769.

Clark, T.D., Jeffries, K.M., Hinch, S.G., Farrell, A.P. (2011) Exceptional aerobic scope and cardiovascular performance of pink salmon (Oncorhynchus gorbuscha) may underlie resilience in a warming climate. Journal of Experimental Biology 214: 3074-3081.

Eliason, E.J., Clark, T.D., Hague, M.J., Hanson, L.M., Gallagher, Z.S., Jeffries, K.M., Gale, M.K., Patterson, D.A., Hinch, S.G., Farrell, A.P. (2011) Differences in thermal tolerance among sockeye salmon populations. Science 332: 109-112.


Ecotoxicology Research:

Impacts of anthropogenic and agricultural activities are common in rivers globally. However, relatively little is known about the cumulative effects of these inputs on river water quality and the corresponding effects on native fish populations. My Honour’s and M.Sc. research involved studying physiological changes in a widely distributed native minnow, the longnose dace, along natural river gradients in Southern Alberta. I was able to detect the up-regulation of the gene that codes for the female-specific egg yolk precursor protein, vitellogenin, in male longnose dace, which indicates exposure to compounds with estrogen-like activity. I also found that in some regions of rivers in Southern Alberta, the sex-ratios for longnose dace populations were heavily skewed towards females, which suggests severe endocrine disruption. This research demonstrated that the combined impacts of municipal wastewater and agricultural run-off are affecting longnose dace populations and established the longnose dace as a sensitive indicator of exposure to compounds with estrogen-like activity in agricultural watersheds.


Jeffries, K.M., Jackson, L.J., Ikonomou, M.G., Habibi, H.R. (2010) Presence of natural and anthropogenic organic contaminants and potential fish health impacts along two river gradients in Alberta, Canada. Environmental Toxicology and Chemistry 29: 2379-2387.

Jeffries, K.M., Nelson, E.R., Jackson, L.J., Habibi, H.R. (2008) Basin-wide impacts of compounds with estrogen-like activity on longnose dace (Rhinichthys cataractae) in two prairie rivers of Alberta, Canada. Environmental Toxicology and Chemistry 27: 2042-2052.

Jeffries, K.M., Jackson, L.J., Peters, L.E., Munkittrick, K.R. (2008) Changes in population, growth and physiological indices of longnose dace (Rhinichthys cataractae) associated with land-use in the Red Deer River, Alberta, Canada. Archives of Environmental Contamination and Toxicology 55: 639-651.



Pacific salmon come in all shapes and sizes.....


The underappreciated and also awesome longnose dace (this is a huge dace!)