Marine Protected Areas (MPAs) have been implemented worldwide as a tool for improving the overall health and function of fisheries and marine ecosystems impacted by fishing activity. Monitoring the performance of MPAs in a comprehensive way is crucial for the effective management and thoughtful implementation of new MPAs. In California, mesophotic (30-100m) rocky reef fish communities are a valuable commercial/recreational resource, though the effects of MPAs on this community remain relatively understudied. This is at least partially a result of depth restricted sampling tools that do not typically overlap; SCUBA surveys are generally limited to shallow depths (<30 m) and Remotely Operated Vehicle/Autonomous Underwater Vehicle surveys are often used for deep water (>100m). Additionally, traditional extractive techniques like trawl surveys are limited by their inability to effectively sample high relief rocky habitats, and are not commonly used in MPAs due to their destructive nature. With this study we tested the effects of two MPAs on demersal fish communities living on mesophotic rocky reefs utilizing Baited Remove Underwater Video (BRUV) surveys. We deployed BRUV landers annually from 2019 to 2021 at Anacapa State Marine Reserve/State Marine Conservation Area (SMR/SMCA) and Carrington Pt. SMR. We observed significant positive reserve effects on the total biomass of targeted (i.e., fished) species and on the size structure of individual focal species at both study sites. Relative abundance (MaxN) proved to be a less sensitive metric than biomass for detecting MPA effects, underscoring the utility of a stereo-video camera system that is capable of capturing highly accurate fish measurements. Dissimilar rocky habitat abundance for the deepest depth zones at Anacapa Island, where rockfish (Sebastes spp.) represent the largest proportion of the fish community, is likely one explanation for the negative reserve effect we observed for targeted rockfish abundance at this site. The results of this study provide useful information on how two California MPAs affect valuable fish communities that have historically been understudied and emphasize the importance of accurate fish measurement to detect these effects. This work also highlights the significance of habitat availability on the distribution of species with high habitat affinity. The continued monitoring of demersal fish communities on mesophotic rocky reefs would provide resource managers a more comprehensive understanding of MPA performance in California.