The unique geography of the region, says Canadian Wildlife Service scientist John Elliott. Almost two-thirds of B.C.'s 3.3 million people live near the shores of the Strait of Georgia. Planners estimate that by the year 2021 almost three million people will live in the Greater Vancouver Regional District, while across the strait, the population of Vancouver Island will increase by nearly 40 per cent, to about 900,000. Along with humans come environmental impacts. As land is cleared, drained and paved to make way for subdivisions, highways, and commercial and industrial sites, birds lose nesting, foraging and roosting habitat.
Environmental pollution poses another serious threat.
Landfills, industrial and vehicle emissions, and runoff from urban storm drains release toxins into the air, water and soil. The result is a veritable witch's brew of chemicals, including dioxins, furans, PCBs, DDE and PAHs. The problem, says Laurie Wilson, Canadian Wildlife Service biologist, is not just that these substances are toxic, but that they are highly stable. At each ascending level, as large predators eat numerous small prey, the contaminants become concentrated in their tissues. Fish-eating birds such as eagles and herons sit at the top of the food chain, so they end up with the highest concentrations.