Ocean pollution indicators for the Strait of Georgia

In the Salish Sea, pollution represents an anthropogenic pressure which would clearly benefit from a methodical tracking of contaminant types, levels and trends in the environment and in valued biota. A surprising lack of regimented, ecosystem-based pollution monitoring efforts presently constrains the ability to track trends in priority pollutants in the Strait of Georgia. However, datasets for certain pollutants are available from different agencies, reflecting their legislated need to monitor discharges to the environment. These datasets are captured in articles and reports. Seldom are they made available in an integrated manner to decision makers or the general public, with the result that it is difficult to construct a ‘state of the environment assessment’ for coastal British Columbia. We are collating available datasets in support of a series of ocean pollution indicators, which will contribute to a new coast-wide ‘ocean health’ initiative being launched by the Vancouver Aquarium’s new Coastal Ocean Research Institute. We will present here our conceptual framework, and illustrate its utility by drafting case studies. These examples will capture priority pollutant topics and provide for an overview of trends. We will then develop a cumulative index of pollution which integrates concentrations of different contaminant classes and affords insight into trends by trophic level, marine fisheries catches, and in species of concern. This ‘Marine Pollution Trophic Index (MPTI)’ will track pollutant responses to past or present emissions histories, thereby providing insight into the overall health of food webs and potential risks for human health. MPTI trends for a given species or aggregate of species can then be compared against toxic effect thresholds and human consumption guidelines. These indicators will then be applied to forward-looking, climate-driven scenarios to inform marine and climate policies in Canada