There is limited biological information available to guide management decisions regarding Fraser River eulachon. A 2003 PSARC paper (2003/051) provided direction for using this limited information. The PSARC paper recommended a management approach using three pre-season indicators and one in-season indicator as reference points to guide management actions. The three pre-season indicators are:
- Spawning stock biomass from the previous two years.
- The offshore biomass index from the previous year.
- Same year Columbia River catches.
The spawning stock biomass provides an estimate of how many tonnes of eulachon successfully spawned the previous year. Although eulachon abundance is subject to considerable annual fluctuations PSARC recommends that a low spawning stock biomass for one year is cause for caution and a low spawning stock biomass for two consecutive years indicates a conservation concern. A low spawning stock biomass has been defined as less than 150 tonnes.
The 2007 results are "complete" however, revisions can occur within a year or so due to water discharge adjustments as measured by the Water Survey of Canada. In the past, you may have noticed a previous year's SSB revised by a ton or two. Flow volume revisions are the primary reason for this. Early this spring, Environment Canada Water Survey experienced unusual difficulties (possibly related to potential flood threat) and so they were extremely reluctant to release, even preliminary figures hence there is some SSB uncertainty this year. In addition, each computer program run of a bootstrap mean biomass estimate is also slightly different. The good news is that we are confident that we obtained accurate egg and larval counts and sampling representation.
The 2007 eulachon SSB is 44 tonnes (up from a 29 tonnes estimate in 2006). As this is two consecutive years of low biomass this is considered a conservation concern and due to this concern the recreational fishery for eulachon will not open in 2008.
Information related to eulachon can be found on the following DFO's websites to assist those to become familiar with the Fraser River survey:
http://www.pac.dfo-mpo.gc.ca/sci/herring/herspawn/pages/river1_e.htm http://www.pac.dfo-mpo.gc.ca/sci/herring/pages/eulachon_e.htm
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Topic: 2008 eulachon information: No recreational opening expected (Read 1311 times)