Risk of Enbridge Northern Gateway Pipeline Project to Eulachon (Thaleichthys pacificus)

Abstract

Eulachon, (Thaleichthys pacificus), is an anadromous species that spawns in the Kitimat River, British Columbia. The proposed Enbridge Northern Gateway Pipeline travels alongside this waterway and will put this species at risk. Eulachon are a unique species, and are important to freshwater and riparian ecosystems. Spawning runs occur at the end of winter, and they provide marine-derived nutrients that are essential to the functioning of these ecosystems. Species such as bears, gulls, eagles, and piscivorous fish all rely on eulachon for sustenance. The status of the central BC population of eulachon is “critically endangered”, with Kitimat River populations being “virtually extirpated” with fewer than 1000 members per run. Since 1992, eulachon runs of the Kitimat River have dropped substantially, and an oil spill at the most inopportune time could potentially eliminate this population. Haisla First Nations rely on eulachon runs for food, social, and ceremonial purposes. The elimination of these populations would have devastating effects on their way of life. The pipeline project puts eulachon at risk during all life stages; eulachon may be exposed as embryos incubating in the Kitimat River, as juveniles in the Kitimat Arm of the Douglas Channel, or as spawning adults running up the Douglas Channel. Should there be a tanker spill in the ocean, adult eulachon may also be exposed. There has been no research into the toxicological effects of crude oil or bitumen on eulachon during any life stage. Pink salmon (Oncorhynchus gorbuscha), Pacific herring (Clupea pallasii), and rainbow trout (Oncorhynchus mykiss) are three species that are most similar to eulachon. Toxicity of crude oil to pink salmon and Pacific herring embryos is observed at concentrations as low as 18 µg/L and 0.4 µg/L respectively. Liver lesions are observed in pink salmon juveniles exposed to ≥ 25 µg/L crude oil. Adult Pacific herring exposed to crude oil exhibit immunosuppression. Eulachon may have similar effects upon exposure to diluted bitumen.