Evaluating harvest control rules for lake whitefish in the Great Lakes: Accounting for variable life-history traits

Control rule performance for intermixing lake whitefish populations in the 1836 Treaty waters of the Great Lakes: A simulation-based evaluation

“…Based on deterministic models sharing the same stockrecruitment parameters and fishery characteristics used in this analysis, the estimated maximum sustainable yield instantaneous fishing mortality rate on the most selected age class for each productivity level was 0.258 (low productivity), 0.393 (medium-low productivity), 0.631 (medium-high productivity), and 1.15 (high productivity). The range of the recruitment parameter coefficients used to characterize the different productivity levels was similar to what has been estimated for lake whitefish fisheries in the 1836 Treaty waters (Deroba and Bence, 2012), indicating that the values selected were reasonable for lake whitefish in the Great Lakes.…”

“…In both cases, constant mortality control rules were found to perform adequately with respect to producing near maximum fishery yield (Deroba and Bence, 2012;Jacobson and Taylor, 1985), although Deroba and Bence (2012) found that biomass-based control rules produced larger yields and were better at minimizing risk of depletion if stock-specific levels of unfished biomass were known. Neither of these previous research studies accounted for population intermixing when conducting their harvest evaluations, although Deroba and Bence (2012) did account for substantial complexity and uncertainty in lake whitefish life-history characteristics.…”

“…The performance of harvest control rules for managing lake whitefish fisheries in the Laurentian Great Lakes was previously evaluated by Jacobson and Taylor (1985) and Deroba and Bence (2012). In both cases, constant mortality control rules were found to perform adequately with respect to producing near maximum fishery yield (Deroba and Bence, 2012;Jacobson and Taylor, 1985), although Deroba and Bence (2012) found that biomass-based control rules produced larger yields and were better at minimizing risk of depletion if stock-specific levels of unfished biomass were known.…”

“…Originally, the 65% total annual mortality control rule was adopted based on research that indicated that this level of mortality was sustainable, and substantially higher mortality rates were not (Ebener et al, 2008). Deroba and Bence (2012) found that the 65% total annual mortality control rule allowed significant harvest without high risk of overexploitation even with changes in life history characteristics of lake whitefish in recent years. However, intermixing among populations was not evaluated by Deroba and Bence (2012).…”

“…Deroba and Bence (2012) found that the 65% total annual mortality control rule allowed significant harvest without high risk of overexploitation even with changes in life history characteristics of lake whitefish in recent years. However, intermixing among populations was not evaluated by Deroba and Bence (2012). Furthermore, their focus was on the overall distribution of performance metrics, and not on the fate of individual spawning populations.…”