Northern fisheries monitoring

DSC_2402Populations of species found in the world’s remaining isolated regions are challenging to monitor with traditional demographic techniques for logistic reasons. Our lab is highly active in applying multidisciplinary scientific approaches towards the effective monitoring of harvested fish populations in northern Canada. Research projects commonly involve a combination of genetic, genomic and life history metrics/approaches, and traditional ecological knowledge of local fishers. Our focal field site is Mistassini Lake, Quebec’s largest (2,335 km2) natural lake and one of its deepest (180 m), and found within Cree First Nations territory.

Large, pristine lakes that are non-impacted by human activity such as Mistassini Lake are very rare. Mistassini is home to several fish species characterized by divergent populations in sympatry  that are of socio-economic and cultural importance (e.g. brook trout, lake trout and walleye). These populations provide an excellent model for understanding the process of population divergence and incipient speciation, and are important to recognize for sustainable fisheries management and conservation.

Here is a synopsis of current and past research studies:

Life history and demographic monitoring of walleye using population genomics (2002 – ongoing)

We are currently conducting long-terMistassini walleyem monitoring of four breeding walleye populations in Mistassini Lake, in order to document any changes to catch efficiency, age and size structure and breeding population size. By combining these ecological data with genomics (genotyping by sequencing) and traditional ecological knowledge, our research will provide the Cree Nation of Mistissini with critical information on the health of its harvestable walleye populations, and on any trends in these populations that may have implications for sustainable fishing practices or the restoration of traditional fishing practices.

Management implications of sympatric population differentiation in lake trout (2013 – ongoing)  

lake trout morphsWe have conducted molecular and morphological analyses to determine that Mistassini Lake is home to several genetically-distinct lake trout populations, which primarily occupy different depths and to a lesser extent different lake basins. The extent of weak (yet biologically relevant) population divergence was somewhat associated with body size, colouration, and fish community structure but inconsistently associated with differences in body or head shape that are normally linked to trophic ecology. The research has implications for local management of the species and for the restoration of lake trout in other large postglacial lakes where the species is extirpated (e.g. Great Lakes).

Life history and demographic monitoring of brook trout using population genomics (2000 – ongoing)

DSC_1862Mistassini Lake is world renowned by anglers for its large brook trout (fish over 8lbs are captured annually). Past population genetic and genomic studies have documented that three genetically-distinct populations inhabit the lake and spawn in different tributaries and the outlet PDF. The populations exhibit a number of life history, behavioural and growth differences, and occupy different spatial areas of the littoral zone PDF. One population in particular (Pepeshquasati) contributes disproportionately to the annual harvest. A successful collaborative research program for 15 years, we monitor life history characteristics, population sizes (based on genetic approaches) and trends in traditional ecological knowledge to assist the Cree Nation of Mistassini with maintaining a sustainable brook trout fishery PDF.

Check out our Mistassini Lake field research in HD: