St. Lawrence, Canada

Despite the long history of intense human use of the EGSL, especially through incessant fishing since the 18th century and a number of significant stock collapses, it still supports diverse and productive fish and invertebrate fisheries that sustain the local economy. This case study will focus primarily on economic valuation of fisheries and their vulnerability to scenarios of change. The bottom water layers of the St. Lawrence Estuary have shown declining oxygen concentrations and rising acidification, likely linked to carbon and nitrogen flux from freshwaters, with inputs from farmland exceeding municipal sources. Coastal erosion, invasive species and maritime traffic are additional stressors that the St. Lawrence experiences. A better comprehension of the cumulative effects of stressors and the identification of tipping points is essential for conservation and management of habitats, communities and populations.