Biodiversity in estuaries Estuaries are often referred to as the nurseries of the sea. They contain a diversity of plants and provide shelter, nutrient-rich food and nesting sites for juvenile and adult animals.photo_cameraOpen description A green and golden bell frog on a tree branch closeClose descriptionImage Credit: Rosie Nicolai/DCCEEW Plants in estuaries The dominant plant groups in our estuaries are seagrass, mangroves, saltmarsh, macroalgae and microalgae.east Fish in estuaries Estuaries play a major role in the lifecycle of many freshwater and marine fish species.east Birds in estuaries Huge numbers of birds live in our estuaries and use them to provide habitat, food and a place to rest.east Invertebrates in estuaries A diverse range of ecologically and commercially valuable invertebrates live in our estuaries.east Aquatic vertebrates in estuaries Sea turtles, frogs and other aquatic animals live in our estuaries and use them for food, rest and shelter.east