Roadless Areas
Home/Species/ Eulachon

Thaleichthys pacificus

(Richardson, 1836)

Eulachon

G4Apparently Secure Found in 6 roadless areas NatureServe Explorer →
G4Apparently SecureGlobal Rank
Least concernIUCN
PS:LTESA Status
Medium - lowThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.100935
Element CodeAFCHB04010
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVertebrate Animal
IUCNLeast concern
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomAnimalia
PhylumCraniata
ClassActinopterygii
OrderOsmeriformes
FamilyOsmeridae
GenusThaleichthys
USESAPS:LT
COSEWICPS: E,SC
Other Common Names
Eulakane (FR)
Concept Reference
Robins, C.R., R.M. Bailey, C.E. Bond, J.R. Brooker, E.A. Lachner, R.N. Lea, and W.B. Scott. 1991. Common and scientific names of fishes from the United States and Canada. American Fisheries Society, Special Publication 20. 183 pp.
Taxonomic Comments
See Begle (1991) for a classification and phylogeny of osmeroid fishes based on morphology. Common name eulachon is derived from the Chinook language, a synthetic trading language made of combined French, English, and various Native American languages (Hay and McCarter 2000).
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2025-04-11
Change Date2025-04-11
Edition Date2025-04-11
Edition AuthorsGotthardt, T. A. (2005); rev. R. L. Gundy (2025)
Threat ImpactMedium - low
Number of Occurrences81 - 300
Rank Reasons
This species is abundant and widespread in the northeastern Pacific Ocean. However, the population has suffered range contractions and declines in abundance. It is threatened by rising seawater and freshwater temperatures due to climate change, mortality from by-catch in commercial fisheries, dams preventing access to historical spawning sites and reducing the quality of currently accessible spawning sites, and industrial and commercial pollution in spawning rivers.
Range Extent Comments
This species is found in the eastern Pacific in coastal waters of the United States and Canada. Spawning sites extend from Mad River, California north to Nushagak River and Pribilof Islands, Bering Sea, Alaska (Gustafson et al. 2010). Distribution coincides closely with coastal temperate rainforest, although there may not be a functional linkage (Hay and McCarter 2000).

Historically spawned in the Sacramento River system and farther south along the California and Baja California coast but have been extirpated from those locations (Hay and McCarter 2000, Mecklenburg et al. 2002, Willson et al. 2003). Surveys of Washington State rivers (outside the Columbia River watershed) in 2011 and 2012 found eggs/larvae in two rivers in the Willapa Bay system and the Chehalis River in the Grays Harbor system (Storch et al. 2014). In Alaska, seasonally abundant in most major drainages from Southeast Alaska west to Cook Inlet and become less abundant westward toward the Aleutian Islands and the Pribilof Islands in the Bering Sea (Fritz et al. 1993, Willson et al. 2003).
Occurrences Comments
There are several occurrences in northern California, at least 15 in Oregon, approximately 15 in Washington, at least 33 in British Columbia, and at least 35 rivers in Alaska (Gustafson et al. 2010).
Threat Impact Comments
This species faces several threats including mortality related to bycatch from commercial shrimp fisheries, dams preventing access to historical spawning sites and reducing habitat quality of accessible spawning sites, increasing seawater and freshwater temperatures due to climate change, and industrial pollution reducing water quality (Drake and Wilson 1991, Anderson and Piatt 1999, Hay and McCarter 2000, Willson et al. 2003, Gustafson et al. 2010, Schweigert et al. 2012, NMFS 2017, NMFS 2022).
Ecology & Habitat

Description

Generally distinguished from other smelts by having the front of the dorsal fin begin well behind where the pelvic fin attaches to the body. Dorsally bluish to bluish black or brown, with fine black speckling; silvery white laterally and ventrally. Large pair of canine teeth on the vomer, 18-23 rays in the anal fin (Morrow 1980, Mecklenburg et al. 2002).

Maximum length recorded is 254 mm, generally <200 mm (Morrow 1980, Mecklenburg et al. 2002).

Habitat

Nearshore ocean bottom, coastal inlets. Adults live at moderate sea depths (commonly 20-200 m but have been recorded as deep as 625 m) in echo-sounding layer not far from shore; young apparently occur in deeper water (Lee et al. 1980, Page and Burr 1991, Willson et al. 2003). Spawns in coastal freshwater streams over bottoms of silt, sand, gravel, cobble or detritus but apparently prefer bar and riffle habitat containing sand or pea-gravel, seldom more than a few miles inland (Estes and Vincent-Lang 1984, Willson et al. 2003). Presence of spring freshets is a factor common to nearly all spawning streams or rivers; typically characteristic of rivers that drain large snowpacks or glaciers (Hay and McCarter 2000, Willson et al. 2003).

Ecology

A valuable food source for many animals because of extremely high oil content (about 20%, or 4-5 times higher than most other fish of comparable size) (Payne et al. 1999 in Hay and McCarter 2000). Predators include sea birds and ducks, marine and terrestrial mammals, and humans (Lee et al. 1980, Willson et al. 2003). Predators often congregate at eulachon spawning runs. Used historically and currently for an essential source of oil and food by Native Americans throughout their range (Drake and Wilson 1991). Called candlefish because a dried fish threaded with a wick will burn like a candle (Hay and McCarter 2000).

Reproduction

Spawns in the spring. Females produce 17,000- 40,000 eggs (Scott and Crossman 1973); average fecundity is around 25,000 eggs per female (Drake and Wilson 1991). Eggs incubate in sediment for 2-3 weeks, depending on water temperature, then hatch and larvae are carried downstream to the sea (Willson et al. 2003). Most adults die soon after spawning, may live 5 years. Generally semelparous, with sexual maturity reached at around age 3 or 4 (Hay and McCarter 2000, Willson et al. 2003). Spawning occurs at night, and males and females must synchronize activity closely because eulachon sperm remain viable for only a short time, possibly minutes (Hay and McCarter 2000, Willson et al. 2003). Spawning migration timing is variable and appears to be related to water temperature and the occurrence of high tides. Runs occur from February to June throughout species range, but generally occur in April or May; in some rivers more than one run occurs (Willson et al. 2003).
Other Nations (2)
CanadaN2B,N2N
ProvinceRankNative
British ColumbiaS2Yes
United StatesN5
ProvinceRankNative
OregonS1Yes
CaliforniaS1Yes
AlaskaS3Yes
WashingtonS4Yes
Threat Assessments
ThreatScopeSeverityTiming
5 - Biological resource useRestricted - smallSlight or 1-10% pop. declineHigh (continuing)
5.4 - Fishing & harvesting aquatic resourcesRestricted - smallSlight or 1-10% pop. declineHigh (continuing)
5.4.1 - Intentional use: subsistence/small scale (species being assessed is the target) [harvest]Restricted (11-30%)Moderate or 11-30% pop. declineHigh (continuing)
5.4.4 - Unintentional effects: large scale (species being assessed is not the target) [harvest]Large (31-70%)UnknownHigh (continuing)
7 - Natural system modificationsLarge (31-70%)Moderate - slightHigh (continuing)
7.2 - Dams & water management/useLarge (31-70%)Moderate - slightHigh (continuing)
9 - PollutionPervasive - largeUnknownHigh (continuing)
9.2 - Industrial & military effluentsPervasive - largeUnknownHigh (continuing)
11 - Climate change & severe weatherPervasive (71-100%)Moderate - slightHigh (continuing)
11.1 - Habitat shifting & alterationPervasive (71-100%)Moderate - slightHigh (continuing)

—

Roadless Areas (6)
Alaska (6)
AreaForestAcres
Bering LakeChugach National Forest965,076
Boston BarChugach National Forest53,617
Copper River WetlandsChugach National Forest85,972
Kenai MountainsChugach National Forest306,600
Sheridan GlacierChugach National Forest224,683
Twenty MileChugach National Forest198,775
References (39)
  1. Anderson, P. J., and J. F. Piatt. 1999. Community reorganization in the Gulf of Alaska following ocean climate regime shift. Marine Ecology Progress Series 189: 117-123.
  2. Bartlett, L. 1994. Eulachon. Wildlife notebook series. Alaska Department of Fish and Game. Anchorage, Alaska.
  3. Begle, D. P. 1991. Relationships of the osmeroid fishes and the use of reductive characters in phylogenetic analysis. Systematic Zoology 40:33-53.
  4. Blahm, T. H., and R. J. McConnell. 1971. Mortality of adult eulachon (<i>Thaleichthys pacificus</i>) subjected to sudden increases in water temperature. Northwest Science 45(3):178-82.
  5. Committee on the Status of Endangered Wildlife in Canada (COSEWIC). 2011a. COSEWIC Assessment Results. May 2011.
  6. Drake, A. and L. Wilson. 1991. Eulachon: a fish to cure humanity. Museum Note No. 32, UBC Museum of Anthropology, Vancouver, BC, Canada.
  7. Estes, C.C. and D.S. Vincent-Lang (eds.). 1984. Report no. 3: Aquatic habitat and instream flow investigations (May-October 1983): chapter 5: Eulachon spawning habitat in the lower Susitna River. Alaska Department of Fish and Game, Susitna hydro aquatic studies report series.
  8. Eulachon Biological Review Team (BRT). 2010. Status review update for eulachon in Washington, Oregon, and California. 443 pp. Online. Available: http://www.nwr.noaa.gov/Other-Marine-Species/Eulachon.cfm
  9. Fritz, L.W., V.G. Wespestad and J.S. Collie. 1993. Distribution and abundance trends of forage fishes in the Bering Sea and Gulf of Alaska. Pp. 30-44 in: Is it food? Addressing marine mammal and seabird declines: workshop summary. Alaska Sea Grant College Program, University of Alaska Fairbanks, Fairbanks, Alaska.
  10. Gustafson, R. G., M. J. Ford, D. Teel, and J. S. Drake. 2010. Status review of eulachon (<i>Thaleichthys pacificus</i>) in Washington, Oregon, and California. U.S. Dept. Commer., NOAA Tech. Memo. NMFS-NWFSC-105, 360 p.
  11. Hay, D.E. and P.B. McCarter. 2000. Status of the eulachon <i>Thaleichthys pacificus</i> in Canada. Department of Fisheries and Oceans Canada, Canadian Stock Assessment Secretariat, Research Document 2000-145. 92 pp
  12. Hay, D.E., J. Boutillier, M. Joyce, G. Langford. 1997. The eulachon (<i>Thaleichthys pacificus</i>) as an indicator species in the North Pacific. Pp. 509-530 in: Forage Fishes in Marine Ecosystems. Proceedings of the International Symposium on the Role of Forage Fishes in Marine Ecosystems. Alaska Sea Grant College Report No. 97-01. University of Alaska Fairbanks.
  13. Lee, D. S., C. R. Gilbert, C. H. Hocutt, R. E. Jenkins, D. E. McAllister, and J. R. Stauffer, Jr. 1980. Atlas of North American freshwater fishes. North Carolina State Museum of Natural History, Raleigh, North Carolina. i-x + 854 pp.
  14. Master, L. L. 1996. Synoptic national assessment of comparative risks to biological diversity and landscape types: species distributions. Summary Progress Report submitted to Environmental Protection Agency. The Nature Conservancy, Arlington, Virginia. 60 pp.
  15. Master, L. L. and A. L. Stock. 1998. Synoptic national assessment of comparative risks to biological diversity and landscape types: species distributions. Summary Report submitted to Environmental Protection Agency. The Nature Conservancy, Arlington, VA. 36 pp.
  16. Mecklenburg, C. W., T. A. Mecklenburg, and L. K. Thorsteinson. 2002. Fishes of Alaska. American Fisheries Society, Bethesda, Maryland. xxxvii + 1,037 pp.
  17. Morrow, J.E. 1980. The freshwater fishes of Alaska. Alaska Northwest Publishing Company, Anchorage, AK. 248 pp.
  18. Moyle, P. B. 1976a. Inland fishes of California. University of California Press, Berkeley, California. 405 pp.
  19. Moyle, P. B. 2002. Inland fishes of California. Revised and expanded. University of California Press, Berkeley. xv + 502 pp.
  20. National Marine Fisheries Service (NMFS). 1999. 90-day finding for a petition to list Columbia River eulachon (<i>Thaleichthys pacificus</i>) as endangered or threatened. Federal Register 64(228):66601-66603.
  21. National Marine Fisheries Service (NMFS). 2008. Listing endangered and threatened species: notification of finding on a petition to list Pacific eulachon as an endangered or threatened species under the Endangered Species Act. Federal Register 73(49):13185-13189.
  22. National Marine Fisheries Service (NMFS). 2009. Endangered and threatened wildlife and plants: proposed threatened status for southern Distinct Population Segment of eulachon. Federal Register 74(48):10857-10876.
  23. National Marine Fisheries Service (NMFS). 2010. Endangered and threatened wildlife and plants: threatened status for southern Distinct Population Segment of eulachon. Federal Register 75(52):13012-13024.
  24. National Marine Fisheries Service (NMFS). 2017. Recovery Plan for the Southern Distinct Population Segment of eulachon (<i>Thaleichthys pacificus</i>). National Marine Fisheries Service, West Coast Region, Protected Resources Division, Portland, OR, 97232.
  25. National Marine Fisheries Service (NMFS). 2022. 2022 5-year review: summary & evaluation of eulachon, Southern DPS. National Marine Fisheries Service, West Coast Region. 63 pp.
  26. Nelson, J. S., E. J. Crossman, H. Espinosa-Perez, L. T. Findley, C. R. Gilbert, R. N. Lea, and J. D. Williams. 2004. Common and scientific names of fishes from the United States, Canada, and Mexico. American Fisheries Society, Special Publication 29, Bethesda, Maryland. 386 pp.
  27. Page, L. M., and B. M. Burr. 1991. A field guide to freshwater fishes: North America north of Mexico. Houghton Mifflin Company, Boston, Massachusetts. 432 pp.
  28. Page, L. M., and B. M. Burr. 2011. Peterson field guide to freshwater fishes of North America north of Mexico. Second edition. Houghton Mifflin Harcourt, Boston. xix + 663 pp.
  29. Page, L. M., H. Espinosa-Pérez, L. T. Findley, C. R. Gilbert, R. N. Lea, N. E. Mandrak, R. L. Mayden, and J. S. Nelson. 2013. Common and scientific names of fishes from the United States, Canada, and Mexico. Seventh edition. American Fisheries Society, Special Publication 34, Bethesda, Maryland.
  30. Page, L. M., K. E. Bemis, T. E. Dowling, H.S. Espinosa-Pérez, L.T. Findley, C. R. Gilbert, K. E. Hartel, R. N. Lea, N. E. Mandrak, M. A. Neigbors, J. J. Schmitter-Soto, and H. J. Walker, Jr. 2023. Common and scientific names of fishes from the United States, Canada, and Mexico. Eighth edition. American Fisheries Society (AFS), Special Publication 37, Bethesda, Maryland, 439 pp.
  31. Payne, S. A., B. A. Johnson, and R. S. Otto. 1999. Proximate composition of some north-eastern Pacific forage fish species. Fisheries Oceanography 8(3):159-77.
  32. Robins, C.R., R.M. Bailey, C.E. Bond, J.R. Brooker, E.A. Lachner, R.N. Lea, and W.B. Scott. 1991. Common and scientific names of fishes from the United States and Canada. American Fisheries Society, Special Publication 20. 183 pp.
  33. Rodriguez, M. A. 2002. Restricted movement in stream fish: the paradigm is complete, not lost. Ecology 83(1):1-13.
  34. Schweigert, J., C. Wood, D. Hay, M. McAllister, J. Boldt, B. McCarter, T. W. Therriault, and H. Brekke. 2012. Recovery potential assessment of eulachon (<i>Thaleichthys pacificus</i>) in Canada. DFO Can. Sci. Advis. Sec. Res. Doc. 2012/098. vii + 121 p.
  35. Scott, W. B., and E. J. Crossman. 1973. Freshwater fishes of Canada. Fisheries Research Board of Canada, Bulletin 184. 966 pp.
  36. Storch, A.J., E.S. Van Dyke, O.O. Langness, P.E. Dionne, C. W. Wageman, and B.J. Cady. 2014. Freshwater distribution of Eulachon in Oregon and Washington. Report B, In C. Mallette (Ed.), Studies of Eulachon Smelt in Oregon and Washington, prepared for the National Oceanic and Atmospheric Administration, Washington, DC, by the Oregon Department of Fish and Wildlife and the Washington Department of Fish and Wildlife. Grant No.: NA10NMF4720038.
  37. U.S. Environmental Protection Agency (EPA). 1999. Endangered and threatened wildlife and plants; 90-day finding for a petition to list Columbia River eulachon (<i>Thaleichthys pacificus</i>) as endangered or threatened. Federal Register, November 29, 1999 64(228): 66601-66603.
  38. Washington Department of Fish and Wildlife (WDFW). 2004. Species of concern in Washington State. http://wdfw.wa.gov/wlm/diversty/soc/soc.htm. (Accessed 7/29/04).
  39. Willson, M.F., R.H. Armstrong, M.C. Hermans, and K. Koski. 2006. Eulachon: a review of biology and an annotated bibliography. Alaska Fisheries Science Center Processed Report 2006-12. National Marine Fisheries Service. Juneau, Alaska. 229 pp.