Research Document - 2005/077

Using an Eulachon Indicator Framework to Provide Advice on Fraser River Harvest Opportunities for 2006

By Therriault, T.W., and P.B. McCarter

Abstract

The Fraser River eulachon fishery has an important cultural significance, especially to local First Nations. These small anadromous smelt return annually to the Fraser River to spawn and are targeted by First Nation, recreational and commercial fishermen at this time. Although eulachon populations have declined gradually coastwide since the mid-1960s, a sudden and synchronous population decline occurred around 1993-94 among several major eulachon-bearing rivers. Continued low returning biomass in the Fraser River prompted a review of research and management considerations with a traffic light approach for making management decisions adopted in 2003. This approach considered four independent measures of stock status: 1) spawning stock biomass (SSB) based on the Fraser River egg and larval survey; 2) an offshore biomass index derived from the shrimp research survey off the south-west coast of Vancouver Island; 3) Columbia (and Fraser) River catch; and 4) the Fraser River test fishery catch. After compiling and interpreting each of these indicators, we recommend no harvest of Fraser River eulachon in 2006. Each of the four indicators suggests conservation concerns are warranted, especially the SSB estimate that has been below a response point of 150 tonnes in each of the past two years. In fact, the 2005 SSB estimate was only 16 tonnes. After considering these results in conjunction with record low catches in the test fishery (less than 900 cumulative pieces), negligible commercial catch in the Columbia or Fraser Rivers in 2005 due to low abundance, and continued low abundance in offshore waters, we recommend that all eulachon returning to the Fraser River in 2006 be allowed to spawn. Also, in light of these extremely low indicators, we suggest that careful consideration be given to any potential harvest opportunities in 2007 as stock rebuilding should be a priority of fisheries managers.

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