The Grand Bay Reserve is one of the most biologically productive estuarine ecosystems in the Gulf of Mexico region, supporting several rare or endangered plant and animal species, numerous important marine fishery resources, diverse habitat types and important archaeological sites. The reserve is of major ecological significance because of its diverse range of habitats. It encompasses coastal bay, expansive saltwater marshes, maritime pine forest, pine savanna and pitcher plant bogs. It supports extensive and productive oyster reefs and seagrass habitats. It serves as nursery area for many of the Gulf of Mexico's important recreational and commercial marine species, such as shrimp, blue crab, speckled trout, red fish. The area is used for recreational and commercial fishing, birding and aesthetic enjoyment.