High-resolution Planet Dove data identify local drivers of kelp canopy persistence

Abstract In many regions, kelp forests have experienced losses due to ocean warming and other stressors, with negative impacts on ecosystems and fisheries. Detailed maps of kelp canopy extent are needed to understand the drivers of these losses, factors promoting resilience, and vulnerability to climate change. While moderate-resolution satellite data have been used to map kelp canopies over large scales, they often miss small, sparse, or nearshore canopies. We developed a convolutional neural network to map kelp canopy using Planet Dove imagery and created annual 3 m resolution maps from 2017 to 2024 across California. We show that kelp persistence during this post-disturbance period, following a marine heatwave, was positively associated with persistence before the heatwave, cooler sea surface temperatures, shallow habitats, and reduced fragmentation. There was high latitudinal variability in the effect of these drivers on persistence, highlighting the importance of data that capture ecological complexity from local to regional scales.