Marine Environmental Quality in the Pacific North Coast Integrated Management Area (PNCIMA), British Columbia, Canada: A Summary of Contaminant Sources, Types, and Risks

Abstract

Under the terms of Canada’s Oceans Act (1997), Fisheries and Oceans Canada has embarked on an approach to Ecosystem-Based Management (EBM) which aims to protect the structure, function, and quality of marine ecosystems from human impacts. This report aims to provide the reader with an overview of the contaminant sources, types, and risks in the Pacific North Coast Integrated Management Area (PNCIMA) as these relate to marine environmental quality (MEQ), and builds on two previously published reports generated for sub-regions of the PNCIMA, namely the central coast (Haggarty et al. 2003) and the north coast and Queen Charlotte Islands (Johannessen et al. 2007).

The PNCIMA includes 102,000 km2 of ocean, covering roughly two-thirds of the BC coast. While sparsely populated (3.3% of BC’s total population), the PNCIMA is faced with a growing list of threats to MEQ. The PNCIMA extends from the southern end of Johnstone Strait and the Brooks Peninsula on Vancouver Island northwards to the British Columbia (BC) – Alaska border and includes the marine area out as far as the base of the continental slope, and the Queen Charlotte Islands (Figure 1.1). The region is rugged, with a steep, glaciated mainland covered in dense rainforest and bisected by numerous fjords and inlets, while the coast is dominantly rocky and strewn with islands. The influence of two semi-permanent atmospheric pressure cells (the Aleutian Low and the North Pacific High) over the Pacific Ocean provides this area with some of the highest rainfall amounts in Canada, along with mild winters and cool summers.

The remote location and low population would suggest that there are few anthropogenic stresses in the area. However, a number of human activities take place in the area that can affect MEQ. Key among the past and present activities are aquaculture, vessel traffic, ports / harbours / marinas, forestry, pulp and paper, mining / smelting, ocean dumping, Coast Guard / military sites, oil and gas, and global pollutants. In many cases, source control and regulations have mitigated some of these activities, including a reduction in the by-production of dioxins and furans by pulp mills, the elimination of polychlorinated biphenyls (PCBs) and many organochlorine (OC) pesticides, and restrictions on the use of tributyltin on ship hulls as an antifoulant. However, a number of emerging threats to MEQ in the PNCIMA reflect growing industrial sectors, and include the potential exploration and extraction of offshore oil and gas, a significant increase in cruise ship traffic, expanding port facilities, and the expanding aquaculture sector.