We study ecological relationships among key players in kelp forest and coral reef communities. Our work often focuses on spatial ecology of predators and prey. Understanding how organisms move in relation to one another as well as their habitat is critical for spatial management and population dynamics.  We use acoustic telemetry to measure short- and long-term movements, home range sizes and site fidelity for a number of reef fish species in temperate and tropical ecosystems.  Recent work from my group on herbivorous parrotfishes has demonstrated that spatial variation in habitat use, even over small spatial scales, can have fundamentally different impacts on benthic communities.