Fraser River sockeye salmon: data synthesis and cumulative impacts

instead of migrating directly out into the Strait, though we don’t know very much aboutthem.Pickard: When we do the cumulative effects project and we use your data, there is concern thatthe findings will be out of whack if we use Kalman filter data for when the impacts areactually happening.Peterman: You shouldn’t just use one data series; instead, examine different assumptions (i.e.use multiple dependent variables and compare results).Dorner: If the series changes slowly, probably the lag doesn’t matter as much.Staley: Re the little evidence for delayed density-dependent effects question, using cyclic vs. notcyclic models will make a significant difference – there will be a debate on this.Peterman: The difference in data from using Ricker vs. Larkin can be substantial (Larkindelayed density dependent effect across brood years). The productivity parameter stayedhigh in recent years for Quesnel with Larkin, but with Ricker it went down. We foundthere was quite a difference between the models, but in this analysis it was only importantfor Quesnel. Larkin seems better for Quesnel only. Carl Walters appears to have backedoff on his previous conclusions about the prevalence of the advantage of the Larkin overthe Ricker model and he agrees that Quesnel is about the only stock where delayeddensity dependence makes a difference. We have to do sensitivity analysis for everythingwe do because we don’t know what the true underlying dynamics are. So we use raw andprocessed data and if they are different, we examine why.Conservation Unit Status AssessmentKatherine Wieckowski, ESSAThis analysis reviewed several methods for assessing conservation status, using the 36 Frasersockeye Conservation Units (CUs) proposed by Holtby et al (DFO is still considering reducingthese.)The approaches reviewed included the DFO paper on indicators of status and benchmarks forCUs. This was developed by Carrie Holt et al, and elements of it are included in the paper by SueGrant. The second approach was Pestal and Cass’s paper on the use of qualitative riskevaluations to prioritize assessment activities for Fraser sockeye. The third approach was themore generic NatureServe paper by Feber-Langendoen et al, which was eliminated as notviable/ideal.Recognizing that all methods have strengths and weaknesses, four evaluation criteria were usedfor the analysis: ecological relevance (to life history, habitat usage, etc.; the method for settingbenchmarks; the data needs for that method and how available is the data required for all CUs;and feasibility of implementation (how realistic is it for DFO to implement).Ecological relevance: Holt et al and Pestal/Cass both address abundance, trends in spawners,distribution and fishing mortality. Holt does not address genetic diversity, only life historydiversity. This raises the question of indirect methods and whether it is okay to have proxyindicators, and with limited resources, this should be considered. Pestal included habitatcondition but didn’t specify what the habitat condition indicator was. Holt did not addresshabitat, which is covered under Strategy 2 of the WSP.33