For years, members and elders of Tsleil-Waututh Nation (TWN) have detected erosion on the shores of Burrard Inlet corresponding with elevated marine traffic.
In February 2021, TWN published new research reporting the contributions of wakes from tugboats and tanker boats to the overall wave energy of Burrard Inlet, with technical support from MarineLabs and Kerr-Wood Leidal. The Wild Bird Trust of BC caretakes the Conservation Area at Maplewood Flats, which is in the heart of TWN lands and waters, and directly impacted by the shipping routes involved in this study.
The findings of the research state that vessel wakes increase the overall wave energy of Burrard Inlet by a factor of 1.2 up to 4.6 times the natural, wind-induced wave levels.
The Trans Mountain pipeline expansion, a new oil pipeline proposed to twin the existing 1,150-kilometre-long pipeline from Alberta’s tarsands to Burnaby, will increase vessel traffic in Burrard Inlet. An analysis in TWN’s new report reveals that the expansion will facilitate an additional 300+ tugboat trips per month, more than doubling the waves from current tugboat traffic. The expansion will also introduce an estimated 60 tanker transits per month, which would create a potential 900% increase in waves from tankers.
The research found that vessel traffic does significantly contribute to wave energy in Burrard Inlet, despite the fact that Trans Mountain regulators have previously dismissed TWN’s worries about rising tanker traffic.
The corresponding increase in wave energy creates undue risk to the cultural and archaeological landscape of Burrard Inlet. It disrupts calm waters and cultural activities, such as canoeing and ceremonies. It erodes cultural sites and floods TWN’s reserve lands. It also disrupts nearshore ecosystems and beaches, a risk further exacerbated by rising sea levels from climate change.
Future research is required to understand and quantify the specific impacts of these numerous losses. But this research determines that local vessel traffic needs to be considered in its entirety in order to understand the generational, climate, and cumulative impacts, rather than on a project-by-project basis.