Social-Ecological Context and Management: BC and the Northern Shelf Bioregion

In BC, the productive coastal marine food web supports rich First Nations and non-First Nations communities, cultures, and economies. Human communities have lived in this region for thousands of years, supported by abundant terrestrial and marine ecosystems and resources. These also shaped human socio-cultural values, as exhibited by the close co-existence that First Nations cultures have with the landscape and the place-based stewardship that still exists today, despite the modern history of colonization.  

The BC coast is managed at a range of scales including bioregions, eco-sections, and habitats [3]. The four bioregions include: 1) Offshore Pacific; 2) Northern Shelf; 3) Southern Shelf; and 4) Strait of Georgia [3]. This report focuses on the MaPP planning region, which is largely the same region as the NSB, with some exceptions (Figure 1). The NSB is one of Canada’s five Large Ocean Management Areas (LOMAs) that are used to implement Canada’s Oceans Act and is the focus of ongoing initiatives for marine resource and marine conservation planning in BC. The NSB assumes the same footprint as the Pacific North Coast Integrated Management Area (PNCIMA)[2]. Existing and ongoing research in the NSB has fewer research initiatives than the other southern bioregions in BC [4], but the combination of ongoing management and planning in the NSB suggest that this could change. 

Ecologically speaking, Canada’s Pacific coast is a highly dynamic and complex transition zone where three large ocean currents converge: the upwelling (southward flowing) California Current, the down welling (northward flowing) Alaska Coastal Current, and the eastward flowing North Pacific Current (Figure 2). In addition, the California Undercurrent transports warm ocean waters from the tropical latitudes to intersect with southern Vancouver Island, and a wind driven coastal countercurrent – the Davidson Current – flows seasonally northwards into BC waters from Mexico [5]. These currents are important drivers of marine nutrient richness and ecological diversity in BC’s waters. 

Recent summaries of the ecological status of the marine coastal system of BC emphasize that the ecological complexity and diverse species dynamics within the region are supported by high primary productivity and highly variable oceanography, hydrology, and geomorphology [5,6]. Ecological productivity in the NSB is driven by upwelling and down-welling patterns that vary seasonally and episodically; variable seasonal patterns of freshwater and tidal mixing also affect oceanographic conditions. Regional bathymetry also affects marine ecological conditions, as deep-water troughs and canyons separate shallow banks in the center of Hecate Strait [5]. Oceanographic conditions are also influenced by the El Niño Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO). The El Niño phase of the ENSO tends to enhance the flows of southern warm currents that tend to correlate with the arrival of southern tropical marine species in these waters [5,7,8]. El Niño also affects the natural variability in air temperature in BC, and year-to-year and decade-to-decade variability in climate and weather across the province may mask observations of long-term climate change during some periods and in some regions [9,10]. The PDO is a long-term pattern of Pacific climate variability that affects oceanographic conditions across the Northeast Pacific. The variation in the PDO (warm/cool) patterns can affect the region for a decade or longer. 

Along the coast of BC, ocean water temperatures are warming, and nearshore waters are becoming less salty, less oxygenated, and more acidic (a chemical process resulting from them becoming enriched in carbon dioxide) [11]. These changes are contributing to biological changes such as shifting species distributions [12,13]. In order to understand and anticipate climate change impacts, a range of modeling approaches have been used to characterize and predict ecological and biological responses along the BC coast and the surrounding marine area. Research focused on and within the NSB has included descriptions of the ecological communities and context, trophodynamic modeling, and the effects of climate change on fisheries and ecosystems [14–20].


Figure 2: Coastal region of British Columbia showing the main current patterns and ocean dynamics. From Okey et al. 2014, “Effects of climate change on Canada’s Pacific marine ecosystems: A summary of scientific knowledge.”
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