The trade-off analysis for the mitigation of underwater noise pollution from commercial vessels: Case study – Trans Mountain project, Port of Vancouver, Canada

Although shipping has significant positive effect on human civilization, it introduced negative environmental impacts such as oil, air, and plastic pollutions. Many negative externalities through international and local regulations have been in place, and preventive actions have been taken to monitor and control. However, underwater noise pollution as an emerging negative shipping impact has not been well introduced to society nor appropriately regulated in international scale. Because of traffic density and the presence of sensitive marine species in some parts of the world, the negative social and environmental impacts of underwater noise pollution become more critical. Haro Strait due to high shipping traffic and presence of vulnerable marine species such as Southern Resident Killer Whale is a good example. The majority of ocean-going vessels transiting to Vancouver and vice versa pass through the corridor which includes Haro Strait. Tankers currently represent about 2% of total ship traffic visiting the Port of Vancouver; however, regarding the Trans Mountain Pipeline Expansion Project, the traffic density will grow by 11%, which will enhance the adverse impacts of underwater noise pollution on marine mammals. This study, by considering the features and characteristics of the area and the project, proposed four scenarios and modelling. The article by developing simulations and utilizing the Multiple Criteria Decision Making (Multiple Attribute Decision Making) algorithms and Technique for Order of Preference by Similarity to Ideal Solution techniques strives to trade-off between the environmental (noise and CO₂ emission) and economical (fuel cost) aspects of the project to enhance the Decision Support System to promote sustainable development. This will help the decision makers to have a multi-dimensional thinking instead of the single-dimensional thinking in addressing and tackling the negative externalities of the Trans Mountain project in the area. Moreover, at the end of each scenario, a sensitivity analysis will be conducted to provide a clean environment for decision makers.