How will ocean acidification and bottom water hypoxia affect the natural resilience of British Columbia’s fjords to oil spills?

Abstract:

Dramatically increased tanker traffic through Douglas Channel, transporting Liquefied Natural Gas and possibly diluted bitumen products from the port of Kitimat to international markets, greatly enhances the risk of oil spills affecting Canada’s pristine Pacific coast. Environmental concerns prompted the current Tier restrictions that limit the maritime transport of Canadian resources. In addition, existing and planned infrastructures (e.g., LNG Canada) will operate over several decades; however, the effects of ocean acidification and hypoxia, increasingly concerning in BC’s waters, on natural oil degradation rates have never been assessed.

The Geological Survey of Canada (GSC), in collaboration with many partners including DFO, NRC and the U. of Minnesota, is leading a 5-year project to study oil spills in the Kitimat area. The project aims to establish a baseline of current and past variability in physico-chemical properties and microbial/microplanktonic populations in Douglas Channel, and to evaluate the ability of the system to self-mitigate oil spills under a range of reconstructed and forecast conditions. Palynology will be used primarily for Holocene paleoenvironmental reconstructions in the area, based on sediment trap and sediment cores recovered from the channel. Oil degradation rates under past and forecast pH and O₂ conditions will be tested in laboratory-based “microcosm” experiments, using freshly sampled local microbial communities. The project will also attempt mapping of bottom oxygen concentrations in surficial sediment along the channel using Mo isotopes, and detect possible anthropogenic disturbances recorded in sedimentary archives (e.g., PAHs).