Eulachon are small marine fish (8-9 inches in length) that feed on plankton in the eastern Pacific, from Alaska to northern California. In late winter, they move into estuaries and coastal rivers to spawn; most adults die after this process. Fertilized eggs, which sink to the gravel beds, hatch in a month and the fry head to sea; there they will live in offshore waters for 3-5 years before returning to spawn.
Heavily laden with fat, the spawning eulachon are known as candlefish (since dried specimens can be lit like candles) and were called "salvation fish" by Native Americans of the Pacific Northwest since their calorie-rich bodies provided vital nutrition during the leans months of late winter and early spring. Of course, Steller's sea lions, dolphins and sea birds also welcome their spawning runs.
Unfortunately, eulachon have all but disappeared from the coastal rivers of northern California, Oregon and Washington and their numbers have decreased significantly farther north. Global warming, overfishing, water pollution and altered river sediments (due to hydroelectric dams) are all thought to be playing a role in the population decline of this smelt.