Open Collections

Barbier, Laurelyne

I adapted and developed a modelling tool to assess the risk for microplastic (MP) bioaccumulation and biomagnification in the St. Lawrence Estuary (SLE) beluga whale food web. The diet preferences, dietary uptake rates, and MP elimination rates of 21 species were retrieved from existing literature, along with abiotic water and sediment concentrations, to project the MP concentration in each species in grams of MPs per kilograms of tissue over time. From these time series, three other metrics were calculated. First, the biomagnification factor (BMF), a ratio indicating how much greater the MP concentration in a predator is compared to that in a prey, therefore revealed insights on MP biomagnification to the beluga. Second, the biota-sediment accumulation factor (BSAF), a ratio between the MP concentration in a species compared to that in the sediments, was used to analyze accumulation from ingesting sediments. Finally, the trophic magnification factor (TMF), calculated from the relationship between species’ trophic level and the logarithm of MP concentration, speaks on the risk for biomagnification over the entire food web. Model predictions suggest MP bioaccumulation in all species of the food web. However, no bioaccumulation was observed from the sediments to the beluga. MP biomagnification in the beluga occurred from consuming some, but not all, of its most important prey. Finally, the relationship between species’ trophic levels and their MP concentrations were deemed insignificant. These results call for improved management of contaminants in the SLE. To increase the reliability of the model’s predictions, research must be conducted to find better empirical values specific to the SLE and its species to enter as the various parameters.

Text

University of British Columbia. ENVR_V 449

Vancouver : University of British Columbia Library

10.14288/1.0449129

Science, Faculty of; Earth, Ocean and Atmospheric Sciences, Department of

Undergraduate

DSpace