Environmental and risk assessments for projects that would increase tanker traffic in southwestern B.C. fail to consider billions of dollars in potential social, economic and environmental impacts, according to a new report on the region by the Raincoast Conservation Foundation.

The environmental assessments required by senior governments are much too narrow and fail to consider the broader impacts of marine traffic on the ecological health of the region, which includes the Strait of Georgia, Juan de Fuca Strait and Puget Sound, argue the authors of the 108-page report Our Threatened Coast. The Salish Sea's 7,000 kilometres of intricate coastline support ecosystem services from tourism and recreation to flood protection, climate regulation and fish habitat worth tens of billions of dollars, according to studies cited by the authors.

"A fuller, honest assessment would make most people wonder whether a hydrocarbon export economy makes sense for the region," said lead author Misty MacDuffee. "Even the federal government acknowledges that southern Vancouver Island is Canada's highest-risk traffic area, and that's under past levels of shipping."

Kinder Morgan Canada is seeking National Energy Board approval to increase the capacity of its Trans Mountain Pipeline to 890,000 barrels a day from 300,000. The expansion could increase the number of tanker trips through the region from about 70 per year to more than 400.

The $1.6-billion Woodfibre liquid natural gas facility proposed near Squamish would add several dozen more tanker trips each year, while the expansion of coal exports at Fraser Surrey Docks could see the number of loaded barges moving through the Salish Sea grow into the hundreds.

Washington state's planned Gateway Pacific Terminal could add hundreds more shipments per year, mainly coal.

"Port expansions and the coal terminals and LNG will triple the number of ships passing through. Those are huge increases," said MacDuffee. "No one has looked at the Salish Sea as a region, and that is the scale at which we have to consider the impacts of major port traffic expansions."

In 2008, then-B.C. environment minister Barry Penner told the Pacific States/British Columbia Oil Spill Task Force that "given the high marine traffic and topography of our coastline, it simply is not possible to completely prevent spills from happening."

The risks of additional tanker traffic may include major oil spills, which are relatively rare, but also chronic small spills and acoustic pollution affecting marine life from herring to dolphins and whales.

rshore@postmedia.com