Capelin (Mallotus villosus) are pelagic fish of the smelt family that spawn on the coasts of the Northern Hemisphere each summer. In Alaska, they appear in early June and continue their spawn through July, rolling up on the beach in large schools. The fish are small, no more than 6-7 inches, but they are prey for whales, larger fish, and seabirds. They spawn in gravel beds at shoreline, and they often become trapped above the water. 
Capelin spawn on many coasts on the Northern Hemisphere, but in subarctic Alaska, they seem to be one of the first substantial food sources in spring. They are referred to by locals as “cigar fish” due to their extremely oily flesh, which is rumored to be so flammable that it may be lit up like a cigar. They are a valuable source of food for many species, including humans.
Relatively little is known about the populations of capelin in the Bering Sea because commercial harvest there has been uncommon. In Atlantic waters, commercial fishers are beginning to take capelin as the larger species become less available; their populations are monitored through the Capelin Observers Network. There is no such monitoring in the Pacific, but capelin are generally known as a key forage species in the ecosystem.
The size and duration of the spawn varies changes year to year due to fluctuations in ice cover and winter temperatures. During some decades, the populations have apparently crashed. Capelin eggs are adapted to survive very low temperatures, so the fish thrive and reproduce in cold Arctic waters. Warmer ocean water has been blamed for some of these population decreases, but without a study targeting these fish, we don’t know the overall trend of the population.
The vast quantity of capelin, and the diversity of species seen feeding on them, would seem to show they have at least some importance as a food source. We would gain a valuable understanding of the North Pacific marine ecosystem from a study tracking the population over time.
Ellen Whittle
Nome, Alaska
Brown, E. D. 2002. Life history, distribution, and size structure of Pacific capelin in Prince William Sound and the northern Gulf of Alaska. ICES Journal of Marine Science, 59: 983–996.