Michelle Charest

M.Sc. Candidate, Department of Biology, University of New Brunswick
Hometown: Kegdwick River, New Brunswick 

Michelle Charest

Contact information 

Dept. of Biology, University of New Brunswick
PO Box 4400
Fredericton, NB E3B 5A3
Tel: (506) 447-3450
Email Michelle  


B.Sc. (Hons) in Biology, University of New Brunswick, 2010


Co-supervisors: Dr. Rick Cunjak and Dr. Brittany Graham
Started March 2011

The change in the δ34S stable isotope ratio in the tissues of four-spined stickleback, Apeltes quadracus, in response to a change in diet.

In stream ecology, stable isotope analysis (SIA) is a method used to measure the stable isotope values of stream components. The stable isotope ratios of nitrogen (15N:14N) and carbon (13C:12C) are commonly used. Stable isotope ratios act as chemical tracers and can be used to track the flow of nutrients through stream ecosystems. In fish ecology, inferences on migration patterns and food sources and trophic positions of fish can be made using SIA of carbon and nitrogen. These inferences can be made because the relationship between the stable isotope composition of fishes' tissues and the stable isotope composition of the fishes' diet is known.

The focus of my study is to determine the relationship between fish and their diet in terms of sulphur stable isotope composition.

Sulphur is another element, besides carbon and nitrogen, that naturally occurs in animals tissues. The relationship between fish tissue sulphur isotope ratios and their food source is unknown. Because this relationship is unknown, it is not possible to make inferences on food web structure or food sources using sulphur stable isotope analysis. Also, by adding sulphur results to carbon and nitrogen results we can strengthen the reliability of our interpretations of food web structure and migration patterns when using the method of stable isotope analysis.