Research on the levels of light needed to sustain seagrass communities is being applied in infrastructure development in rapidly-growing coastal communities in Australia’s north. Seagrass meadows are a vital yet often overlooked component of the Great Barrier Reef ecosystem, providing food, shelter and breeding areas to many key species, in addition to acting as a major carbon sink. Reduced light reaching the seafloor – caused by, for example, increased sediment loads associated with coastal development and dredging – can have a negative effect on seagrass health. The Queensland Government used seagrass light threshold data developed under a NESP Tropical Water Quality Hub project as part of the environmental impact conditions needed to be met by proponents of the Cairns Shipping Development Project, due to start later in 2019. Queensland’s Ports North are also using the guidelines to ensure any impacts to seagrass are minimized. This project, led by Dr Catherine Collier and Dr Michael Rasheed at James Cook University, synthesized all available knowledge on how much light different species of seagrasses need in order to stay healthy and grow.