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Boardman, Anya; Chelswick, Kailey; Collins, Sophia; Law, Pui Yi

Fecal contamination in shellfish harvesting areas in British Columbia affects human health, ecosystem function, and industry. Previous studies have investigated fecal contamination of marine environments, however, sources of contamination and the dispersal of contaminants throughout marine environments is contingent on the specific environmental conditions at a given site. In collaboration with the BC Centre for Disease Control (BCCDC), this report addresses fecal contamination in marine waters across three vital shellfish harvesting locations on Vancouver Island (Saanich Inlet, Comox Harbour, and Baynes Sound), through the analysis of fecal coliform concentration data obtained from Environment and Climate Change Canada. FC concentration data spans from 1982 to 2022, and was analyzed in relation to environmental factors including rainfall, salinity, air temperature, land use, flushability and streamflow at the three study sites. Our findings highlight significant seasonal FC concentration variations, with peaks during fall, closely linked to increased precipitation and runoff. Land use analysis points to agriculture, residential development, and mining as key contamination sources. In addition, this study examined the relationship between river streamflow, proximity to river mouths, and FC concentration, providing nuanced insights into how freshwater inputs affect marine water quality and how this varies by river. This research also investigates coastal flushability, which refers to the ability of an area to clear pollutants through the movement of tidal waters. Results indicate that regions with increased water flow have reduced FC concentrations, highlighting how hydrodynamics play a role in dispersing contaminants. Conversations with stakeholders and investigation into regional sewage management practices suggest that private and central sewage management practices are likely an important source of fecal contamination. Elevated FC concentrations across all study areas reinforce concern regarding fecal contamination in this region. The results of our study lead us to recommend 1) increased regulation and monitoring of sewage infrastructure, 2) alternative sampling methods to identify sources of contamination, and 3) continued monitoring of FC concentration patterns in conjunction with the specific environmental factors in this region. These actions can maintain longevity of shellfish harvesting enterprises, improve the health of the marine environment, and decrease health risks to Indigenous Peoples practicing traditional harvesting.

Text

University of British Columbia. ENVR 400

Vancouver : University of British Columbia Library

10.14288/1.0442324

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

Undergraduate

DSpace