Brown Lake

Brown Lake, also known as Bummeria, is a perched lake located on North Stradbroke Island in South-East Queensland, Australia.

The lake is 1 km long and is situated 4 km east of Dunwich, a small town on the island. The ecosystem of the lake represents a coastal non-floodplain sand lake with acidic water, nutrient-poor sandy soil, as well as shrub-like vegetation and wet heathlands. Besides, Brown Lake holds great geographical significance and ecological value.

Brown Lake is situated in a subtropical climatic region with a wet season in the winter and a dry season in the summer. It has a mean daily temperature of 15°–29°C in summer and 9°–20°C in winter. The lake has an average annual rainfall of around 1668 mm. The ecosystem of Brown Lake is located on a parabolic sand ridge system formed during the Quaternary glacials and interglacials of the Pleistocene epoch.

Brown Lake is a perched lake, and its hydrological operations are highly diverse and complex. It has high levels of dissolved organic matter, which gives its water acidic characteristics with a pH level less than 6. The lake's water system is characterized by very low nutrient levels.

Brown Lake supports a diverse population of aquatic fauna, which includes vibrant macroinvertebrates, fish, and decapods crustacea that are representative of rare acid-adapted marine life existing in humic water systems.

The flora surrounding the Brown lake looks characterized by riparian grasses and small plant species, typical of a coastal wet heathland and shrub-dominated area. Besides, the environment has larger trees such as Gahnia sieberiana,