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

Expansion line (x1000)90807060504030201007-Jul12-Jul 17-Jul 22-Jul 27-Jul 1-Aug 6-Aug 11-AugArea 20 Date2.502.001.501.000.500.00Coefficient of variationFigure I-3 Time series of mean expansion line for combined Area 12 and 20 gillnet(red circles) and coefficient of variation (blue dashed line) for thecombined Early Stuart, Early Summer and Summer Run stock groups.The predictive estimates of expansion lines for the marine gillnets are used to estimateabundance with uncertainty (Table I-1) for Early Stuart, Early Summer and Summer runsockeye. These projections of abundance are used in run-size models but aresubsequently replaced at t+6 days with reconstructions of abundance from Missionhydroacoustic estimates and en-route catch. The predictive estimates are also used toproject abundances entering the Fraser River, to assess potential catch and for themanagement of fisheries inside the assessment sites (Johnstone Strait, Juan de FucaStrait, United States Panel Areas and in-river fisheries).Table I-1 Mean and median values for gillnet expansion lines by period. The meanvalues were used in 2010. The upper and lower probability levels areestimated using Markov Chain Monte Carlo simulation in Winbugs.Lower 10% Upper 90%mean median sd MC error p Level p Level10-Jul 11.7 10 7.05 0.1 4.9 20.615-Jul 14.6 13 7.56 0.11 7.0 24.120-Jul 17.7 16 8.15 0.11 9.2 28.325-Jul 27.4 25 11.83 0.16 14.7 42.830-Jul 40.5 38 16.45 0.22 21.7 62.94-Aug 41.3 38 16.87 0.23 22.4 64.79-Aug 56.5 55 19.38 0.24 31.9 84.5I-5