Grazing by terrestrial macro- and mega-herbivores has been shown to alter rates of plant growth and species diversity, primary production, nutrient cycling, energy flow and age distribution in terrestrial plant communities, and there is also the potential for cascading effects through the ecosystem. The role of large herbivores in aquatic systems has not been studied as extensively as in terrestrial systems, yet the available data suggest that aquatic mega-herbivores may exert as much, if not more, influence on plant and animal communities as their terrestrial counterparts. Our research examines the impacts of large marine herbivores (dugongs and green turtles) and benthic excavators (loggerhead turtles and rays) on seagrass communities and associated fauna. This research gives us an understanding of the resilience of coastal marine system to small and larger scale disturbances, and informs us of the ways in which grazers may shape ecosystems.

Examples of projects

• Impacts of grazing by dugongs on seagrass communities
• Impacts of grazing by dugongs on benthic invertebrate communities
• Impacts of grazing by green turtles on seagrass diversity and production
• Impacts of foraging by loggerhead turtles on seagrass and reefal communities.