Evaluating Spatial Compliance of Protected Areas by Recreational Fishers and Resulting Ecological Responses of Temperate Rocky Reefs

Protected areas (PA) are widely used to mitigate overfishing, but their conservation value depends on their size, age, take/no‐take regulations, compliance and enforcement. We evaluated fisher compliance of PAs within Barkley Sound, Canada, using recreational fishing effort location data from aerial surveys (2021–2023). We used these data to identify differences in fishing pressure between protected and unprotected reefs, allowing us to link fishing effort with ecological monitoring data to study shallow rocky reef community responses to protection. We assessed ecological patterns using 4 years (2021–2024) of SCUBA surveys at 27 protected and unprotected sites. PAs had high compliance: Only 1.1% of 7524 observed fishing boats were inside boundaries, with most illegal activity in the seasonally closed PA. Kernel density analyses identified fishing hotspots in sheltered waters near access points (e.g., marinas), suggesting fishers target areas that reduce time and financial costs and are protected from offshore waves. Despite 10–37× higher boat densities near unprotected reefs, the SCUBA survey data showed ecological responses were taxon‐specific and often weak. Fish species richness and biomass of fish ≥ 20 cm were slightly higher with protection, but total fish abundance showed opposite trends. Macroinvertebrates returned mixed responses: Red turban snails were more abundant at protected sites and sea urchins less abundant, whereas other groups showed no clear effects. Overall, we show PAs can effectively reduce fishing effort, but this does not guarantee PAs will significantly increase community biodiversity against the backdrop of natural variability unless other aspects of PA design (e.g., size and age) are adequate.