A genetics-based approach for the determination of Phalacrocorax auritus diet on Lake Nipissing

Abstract

The decline in Sander vitreus population on Lake Nipissing (LN) has become an increasing cause for concern for the city of North Bay and the surrounding communities. Double-crested cormorants (Phalacrocorax auritus) have been suggested as a possible cause for the decline of these fish stocks. Using a combination of molecular and bioinformatic techniques, I have developed a non-invasive genetics-based method for the determination of Double-crested Cormorant (DCCO) diet using the 16S ribosomal RNA gene. I observed general trends that were consistent over the overall two year-long study. I observed small differences in diet dependant on the location of the island being studied, as well as time of year. Overall, I was able to determine that DCCO consisted of the following relative abundance of prey: 43% yellow perch (Perca flavescens), 27% troutperch (Percopsis omniscomaycus), 12% pumpkinseed (Lepomis gibbosus), 7% walleye (Sander vitreus), 4% rainbow smelt (Osmerus mordax), 4% unresolved, and 3% other species. The data collected from this thesis can be applied to statistical modelling analysis to possibly determine the impact DCCO have on the overall population of walleye, and the methods could be applied for long-term monitoring of overall diet