Results of preliminary runs of the cmsy-method against data limited iccat stocks

Name and region: Bluefin Tuna , North Atlantic

Catch data used from years 1950 - 2013 , biomass = observed

Prior initial relative biomass = 0.5 - 1

Prior intermediate rel. biomass= 0.5 - 1 in year 1960

Prior final relative biomass = 0.2 - 0.6

If current catches continue, is the stock likely to crash within 3 years? Possible

Prior range for r = 0.15 - 0.4 , prior range for k = 35.4 - 347

Results from Bayesian Schaefer model using catch & observed biomass

r = 0.144 , 95% CL = 0.121 - 0.172 , k = 87.8 , 95% CL = 74.3 - 105

MSY = 3.16 , 95% CL = 2.75 - 3.65

Biomass in last year = 45.7 or 0.52 k

Results of CMSY analysis with altogether 1997 viable trajectories for 993 r-k pairs

765 r-k pairs above r = 0.185 and 1069 trajectories within r-k CLs were analyzed

r = 0.273 , 95% CL = 0.191 - 0.389 , k = 72.5 , 95% CL = 47.2 - 111

MSY = 4.94 , 95% CL = 4.29 - 5.69

Predicted biomass last year= 0.482 , 2.5th = 0.222 , 25th = 0.38 , 97.5th = 0.594

Predicted biomass next year= 0.523 , 2.5th = 0.244 , 25th = 0.415 , 97.5th = 0.635

Species: Thunnus thynnus , stock: BFT

Name and region: Bluefin Tuna , North Atlantic

Catch data used from years 1950 - 2013 , biomass = CPUE

Prior initial relative biomass = 0.5 - 1

Prior intermediate rel. biomass= 0.5 - 1 in year 1960

Prior final relative biomass = 0.2 - 0.6

If current catches continue, is the stock likely to crash within 3 years? No

Prior range for r = 0.15 - 0.4 , prior range for k = 35.4 - 347

Prior range of q = 4.16e-05 - 0.000136

Results from Bayesian Schaefer model using catch & CPUE biomass

r = 0.322 , 95% CL = 0.248 - 0.512 , k = 86.3 , 95% CL = 49.3 - 154

MSY = 7.13 , 95% CL = 3.99 - 13

q = 4.08e-05 , lcl = 3.35e-05 , ucl = 4.89e-05

Biomass in last year from q*CPUE = 55.7 or 0.645 k

Results of CMSY analysis with altogether 1879 viable trajectories for 926 r-k pairs

714 r-k pairs above r = 0.179 and 1075 trajectories within r-k CLs were analyzed

r = 0.266 , 95% CL = 0.182 - 0.389 , k = 74.3 , 95% CL = 47.2 - 117

MSY = 4.94 , 95% CL = 4.28 - 5.7

Predicted biomass last year= 0.48 , 2.5th = 0.221 , 25th = 0.377 , 97.5th = 0.596

Predicted biomass next year= 0.519 , 2.5th = 0.242 , 25th = 0.412 , 97.5th = 0.637

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Graphical output of CMSY analysis and BSM analysis based on catch and CPUE (here: combined Atlantic longline indices LL_ind for Bluefin tuna, ATUN) (red curve in lower middle panel). The red curve in the lower right panel is the catch/biomass ratio relative to the ratio compatible with MSY as estimated by BSM.

CMSY management graph for BFT (ATUN), showing in the upper left panel catches relative to MSY and its lower 95% confidence limit. The upper right graph shows estimated biomass with 2.5th and 97.5th percentiles relative to B_msy and half of B_msy; the circle indicates the 25th percentile of predicted biomass in the last year; the red dashed curve shows reported CPUE relative to B_msy estimated by BSM. The lower left panel shows the exploitation rate relative to the one compatible with MSY; the red dashed curve shows results from the BSM analysis of catch and CPUE data. The lower right panel shows the trajectory of relative biomass over relative exploitation, for CMSY (black) and BSM (red).