Few studies have examined how gastrointestinal disease affects the gut microbiome and long-term health of sea turtles. In contrast, research in humans has shown that disease can disrupt the gut microbiota, leading to dysbiosis, a microbial imbalance in the gastrointestinal tract. Dysbiosis is commonly associated with disease in animals but can also be exacerbated by environmental stressors and dietary changes. The gut microbiota plays a critical role in regulating nutrient uptake, metabolism, and overall physiological health. This PhD project aims to address key knowledge gaps regarding the impact of disease on gut health in green sea turtles. It will also contribute to understanding what constitutes a healthy gut flora across three green turtle populations along the east coast of Queensland, Australia.