Management regime influences the recovery of subtidal kelp forests following harvesting

Physical disturbances, especially those that reduce or remove foundation species, have complex effects on ecosystem functioning. Evaluating resilience to predict these impacts requires long-term research over large temporal and spatial scales.
This study investigates the recovery of the subtidal kelp (Lessonia trabeculata) to simulated kelp harvesting in areas under different fisheries management regimes (Territorial Use Rights for Fisheries (TURF) vs. Open Access (OA) sites) along the Northern–Central Chilean coast.
The managed TURF sites demonstrated significantly faster recovery of adult kelp densities following harvesting, while OA sites exhibited consistently lower kelp densities and delayed recovery. However, the generality of this pattern varied across regions.
Morphological traits such as holdfast diameter were larger at TURF sites, where kelp exhibited larger size. Delayed size recovery was evidenced at OA sites.
Herbivore densities were higher in OA than in TURF sites, potentially contributing to differences in kelp density, size and recovery. These patterns highlight the interaction between herbivory and management efficacy.
Synthesis and applications. Our findings highlight the critical role of local fisheries management in enhancing kelp recovery after harvesting. The faster recovery of kelp at most TURF sites demonstrates how spatially explicit management can buffer ecological impacts of herbivore density and promote kelp recovery. To improve outcomes, managers should prioritize the implementation and enforcement of management plans in the TURF to promote herbivore control measures and invest in long-term monitoring programmes to support adaptive strategies that sustain kelp forest ecosystems and the valuable services they provide to coastal communities.