Fraser River Sockeye Fisheries and Fisheries Management - Cohen ...

ebuilding plan in the early 2000’s. In 2003, DFO conducted a review of the 1985rebuilding strategy resulted in the initiation of a new process, the Fraser River SockeyeSpawning Initiative (FRSSI), for setting annual escapement goals and target exploitationrates for Fraser sockeye. A detailed description of the FRSSI process and models can befound in a number of DFO workshop reports (e.g., DFO 2009b) and one published report(Pestal et al. 2008). Staley (2010) provides a review of the FRSSI process and themethods used to set the interim conservation benchmarks and Fraser sockeye spawningtargets for the 2007-2010 fishing seasons.Current Escapement GoalsTwo types of escapement goals or reference points for Fraser sockeye have been definedthrough the FRSSI process: (1) low escapement benchmark, and (2) fixed escapementtarget. The definition of these escapement goals is complicated by the historical patternof cyclic dominance for several of the largest sockeye stocks. This cyclic dominancepattern can result in returns being more than 1500-fold larger on the dominant cycle linethan off-cycle lines (e.g., Quesnel run size was estimated to be ~6,000 in 1984 and ~10Min 1993). Since most Fraser sockeye return at age four, the dominant, sub-dominant andoff-cycle patterns have been maintained for these cyclic dominant stocks over manyyears. Consequently, DFO has defined the “reference points” for Fraser sockeye relativeto the average of the 4-year sequence of escapements for each of the 19 indicator stocks(Table 24, DFO 2009b). The MSC certification process, recently completed for Frasersockeye (Devitt et al. 2010), requires fisheries managers to define Limit Reference Points(LRPs) and Target Reference Points (TRPs) for each stock management unit. DFO hasinitiated a formal process under the WSP to define these reference points for Frasersockeye (Holt et al. 2009). In the interim, DFO has been using their “low escapementbenchmarks” as the operational equivalent of LRPs and their “fixed escapement target”as the operational equivalent of TRPs.The low escapement benchmark (LEB) values have been defined through the FRSSIprocess as the highest value out of the following five alternatives, calculated for each ofthe indicator stocks:20% of the average of the 4-year sequence of escapements that maximizesrecruitment (Bayesian estimate, Larkin fit);40% of the average of the 4-year sequence of escapements that maximizesrecruitment;100