Eulachon | Oceana Canada

Ocean Fishes

Eulachon

Thaleichthyes pacificus

Also known as

Oolichan, ulichan, ooligan, candlefish, oilfish, salvation fish

Distribution

Throughout the northern Pacific; in the northeastern Pacific from the Bering Sea to California

Ecosystem/Habitat

Nearshore ocean floor and coastal inlets

Feeding Habits

Filter feeder

Conservation Status

Special concern/threatened/Endangered

Taxonomy

Order Osmeriformes (true smelts & allies); Family Osmeridae (true smelts)

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Eulachon are a small, schooling fish that have an extremely high oil content in their bodies. This oil content has led to the nickname “candlefish” because they can be dried, fitted with a wick and used as a candle. They are a forage fish, or prey species, and play an important role in Pacific northwest food webs as food for numerous other fish species, marine mammals and seabirds.  They have also been an important fish for centuries to many First Nations along British Columbia’s coast for food, social and ceremonial purposes. Their oils were extracted for “grease” production and the trails that were traditionally used to reach the fisheries and carry the rendered oil back for trade were known as “grease trails.” To this day eulachon are still a highly important fish species for many First Nations communities on the Pacific coast.

Eulachon are a slender, silvery fish that have a bluish back and a white belly. During spawning season, they change colour to a greyish-brown. Their fins are transparent and, like most forage (prey) fish, they have a highly forked tail. They also have large, distinct canine-like teeth that they lose with age. They typically grow to be 20 centimetres in length but can be found at lengths of up to 25 centimetres.

Eulachon are anadromous, which means they spend some of their lives in freshwater and some in saltwater environments. Their lifecycle is typically two to six  years in total. They begin as eggs and larvae in river systems and coastal streams where, shortly after hatching, the larvae are carried downstream to saltwater ecosystems. The larvae will spend some time in the shallow, coastal waters but quickly move deeper into the marine environment where they spend most of their adult lives. The primary food source for adult eulachon are small, shrimp-like crustaceans called euphasiids.

Once they have reached the adult stage, eulachon migrate inland in the spring to freshwater streams for spawning, with most fish returning to their natal springs. There are three main populations in Pacific Canadian waters; these populations include the Nass/Skeena River population, the Central Pacific Coast population and the Fraser River population. Eulachon are semelparous, meaning that the adults die after spawning. Due to their high fatty oil content, they are an extremely important food source for both animals in the marine realm and as well terrestrial animals once they die upstream after spawning.

Eulachon have been harvested for centuries by First Nations for food, social and ceremonial purposes, and can be traced back to early trading for their high oil content between First Nations communities and early settlers. The oil was extremely labour intensive to extract and fetched a high price or high trade value.  A commercial fishery for eulachon began in the Fraser River area in the 1870’s, and from 1903 to 1917 was the fifth largest commercial fishery in British Columbia. As catches grew and eulachon populations declined, the commercial fishery was closed in 1997 and remains closed to this day.

Today, Fisheries and Oceans Canada (DFO) negotiates treaty agreements to fish for eulachon with several First Nations communities in British Columbia and in the Yukon, which are harvested when the eulachon return to spawn in the spring. Eulachon are typically harvested by gillnet but can also be harvested by dip nets or eulachon rakes in traditional fishing areas upon request.

In 2011 and 2013, the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) assessed and designated the Fraser River and Central Pacific Coast populations as Endangered, and the Nass/Skeena River population as Special Concern, respectively. They were assessed as such due to drastic population declines in the 1990’s that occurred due to unknown circumstances. Certain regions have seen a complete loss of spawning populations as the eulachon fail to return to their natal rivers to spawn. Factors that potentially negatively affect eulachon populations include overfishing, dredging, coastal development, damming of river systems, logging and subsequent erosion, other land use practices that degrade water quality and broad consequences of climate change.  Under the Precautionary Approach Framework set out by Fisheries and Oceans Canada, all three eulachon populations in Canada have been listed as Unknown due to limited, sufficient scientific data to accurately assess the populations.

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