Changes in Run-Timing and Abundance of ESA-Threatened Eulachon in the Columbia River: Analysis of Two Centuries of Historical Records

Eulachon, Thaleichthys pacificus, is an anadromous osmerid smelt that spends greater than 95% of its life at sea yet spawns in the lower portions of rivers draining into the northeastern Pacific Ocean ranging from northern California to the Bering Sea coast of southeastern Alaska.  The earliest mention of eulachon in the Columbia River occurs in the journals of the Lewis and Clark Expedition in February and March of 1806.  Several contemporary narratives in memoirs and journals of settlers, fur trappers, and explorers indicate a major decline in Columbia River eulachon abundance occurred from the mid to late 1830s to the mid to late 1860s.  Based on newspaper accounts of eulachon in the fish markets of Portland, Oregon from 1867 to 1923, the mean date of initial appearance of eulachon in the Columbia River was 12 February.  Average initial landings in the Columbia River commercial eulachon fishery for the years 1949 to 2008 were more than one month earlier, averaging around 8 January.  These data, and others, indicate that the eulachon run in the Columbia River and its tributary streams currently begins and ends much earlier than historically.  Commercial fishery landings were first recorded in 1888 and local newspapers record landings in the Columbia River as early as 1867.  Commercial landings were consistently high (>500 metric tons [mt] and often >1,000 mt) for three quarters of a century from about 1915 to 1992.  Landings declined greatly from 233 mt in 1993 to an average of <40 mt between 1994 and 2000.  From 2001 to 2004, landings increased to an average of 266 mt before falling to <5 mt from 2005 to 2010.  Eulachon in the southern portion of their range were listed as a threatened species under the U.S. Endangered Species Act in March of 2010.