Scalefish Southern Calamari Catch MSY

Catch-MSY Results

Catch-MSY results based on the assumption of “high” resilience are presented below for the northeast and northwest coast regions. Results suggest that Southern Calamari biomass is depleting in both regions (Figure 1, Figure 4). Estimates of harvest rates and catch indicate that fishing pressure may have started exceeding sustainable limits (northeast coast Ftarget = 0.43 MSY = 26.8, see Figure 2 and Figure 3; and northwest coast Ftarget = 0.47 and MSY = 25.0, see Figure 5 and Figure 6). Median estimates of biomass depletion in the northeast peaked at 38% of unfished levels (lower 90% CI = 30%) in 2019/20 (Figure 7). Median estimates of biomass depletion in the northwest peaked at 54% of unfished levels in 2017/18 (lower 90% CI = 49%) and were at 55% of unfished biomass in 2019/20 (lower 90% CI = 46%) (Figure 4). Results for initial key fishing grounds on the south-east coast and east coast are not shown here but indicate possible depletion beyond limit reference points (20% of unfished levels) associated with substantially reduced catches and harvest rates. Overall, the results indicate that Southern Calamari populations in these regions might be in a depleted state and that populations on the north coast might follow the same trajectory.

Northeast Coast

Figure 1: Trends in estimated biomass depletion (biomass divided by unfished biomass) and associated confidence intervals (CIs). The dotted red line marks a common target reference point, which is the biomass assumed to deliver the maximum sustainable yield (Btarget). The continuous red line marks a limit reference point (Blimit).
Figure 2: Trends in harvest rate and associated confidence intervals (CIs) relative to the estimated target fishery mortality (Ftarget).
Figure 3: Trends in catch relative to the estimated maximum sustainable yield (MSY) and associated confidence intervals (CIs).

Northwest Coast

Figure 4: Trends in estimated biomass depletion (biomass divided by unfished biomass) and associated confidence intervals (CIs). The dotted red line marks a common target reference point, which is the biomass assumed to deliver the maximum sustainable yield (Btarget). The continuous red line marks a limit reference point (Blimit).
Figure 5: Trends in harvest rate and associated confidence intervals (CIs) relative to the estimated target fishery mortality (Ftarget).
Figure 6: Trends in catch relative to the estimated maximum sustainable yield (MSY) and associated confidence intervals (CIs).

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