The use of reserves as conservation tools is widespread. However, evaluating the effectiveness of reserve implementation for long‐lived species has been problematic as it requires sampling programmes over long timescales that are appropriate to species' longevity and recovery rates. In the sea, towed bottom fishing gears alter the biodiversity and ecosystem services provided by benthic communities and habitats. Marine reserves have been used to manage these impacts but our understanding of the drivers of their effectiveness for the conservation of temperate reefs is incomplete. We examined the effectiveness of marine reserves for recovery of temperate reef fauna in relation to their life history. We used an underwater video to sample six species with different life histories across 60 sites that varied in the duration of protection from towed mobile fishing gear at 0, 1, 8 and 10 years. Species with a high dispersal potential and less habitat specific requirements such as soft corals and king scallops recovered to close to their carrying capacity in <3 years. In contrast, the longer‐lived Ross coral and pink seafans increased in abundance but had not fully recovered; with their projected recovery time being 17–20 years. Ongoing recovery was evident for long‐lived species as their mean body size increased significantly across all treatments, whereas shorter‐lived species such as queen scallops did not change in size and were assumed to have fully recovered. Synthesis and applications. This study shows that the recovery rates of biota depend on life‐history factors, such as larval longevity and dispersal potential. Recovery for species that had low dispersal potential and specific habitat requirements was slow and could take >20 years. This suggests activities such as bottom trawling or dredging should be avoided where such species occur if their conservation is an objective. In contrast, species with high dispersal potential and less habitat specific requirements had shorter recovery timescales of c. 2‐3 years and would be more amenable to managed trawl frequencies in areas where activities such as fishing occur.

The ecological effects of seabed-penetrating fishing gears depend, in part, on the seabed penetration (P) of the gear. We present a gear impact tool that utilizes published data to provide estimated P of globally utilized seabed-penetrating fishing gears in different sediments and their resulting impact on biological communities. As P correlates with the depletion (d) of benthic fauna caused by fishing gears, we use P to calculate d, which can be used to estimate the relative benthic status (RBS; the community biomass of benthic fauna relative to carrying capacity) of the seabed. The tool can provide an objective appraisal of different fisheries management scenarios or interventions (e.g., gear modification, gear substitution, or fishing effort limits) on seabed status, particularly in situations of limited data or resources. For otter trawling in mud, gear modification may provide greater ecological benefits than reducing fishing effort; mean RBS increased by 29% in fished areas by removing the impact from the otter trawl sweeps; this is comparable to reducing fishing effort by approximately 70%. In contrast, modification of beam trawl gear in sand resulted in marginal improvements (6%) in RBS. Modification or removal of gear components with high seabed penetration could result in greater improvements in RBS than spatial management, dependent on gear type and sediment. We provide a quantitative method for estimating the effectiveness of different management scenarios in reducing the benthic impact of seabed-penetrating fishing gears, enabling an objective evaluation of the trade-off between spatial management measures (closures or effort reductions) versus technical modifications. This article met the requirements for a Gold-Gold JIE data openness badge described at http://jie.click/badges