Marine closures are commonly used as a fishery and biodiversity conservation management tool. The consequent spatial structuring and reduction of data to inform assessments of status is known to bias assessments.

Both data-rich and data-poor based management strategies were evaluated for their ability to attain biomass targets and have reasonable biomass risk profiles (the probability of the biomass falling below a limit reference point). Our results suggest that full quantitative assessments generally performed well in terms of meeting target biomass levels for the open area. In contrast, data-poor management strategies perform less well with increased biomass risk.

If managers choose a stock-wide target, then the open area biomass target can be less than the stock–wide target, due to the protection of stock within the closure. A stock-wide biomass target strategy also tends to maintain catches irrespective of mixing level. Alternatively, a harvest strategy based on a biomass target for the open area alone led to higher catch rates and stock-wide biomass for a particular mixing rate, but with potentially less annual catch than a strategy based on maintaining stock-wide biomass.