Lake Matano ( id, Danau Matano), also known as Matana, is a natural

lake A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...

in East Luwu Regency, South Sulawesi province,

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...

. With a depth of , it is the deepest lake in Indonesia (ranked by maximum depth), the 10th deepest lake in the world and the deepest lake on an island by maximum depth. The surface elevation from

mean sea level There are several kinds of mean in mathematics, especially in statistics. Each mean serves to summarize a given group of data, often to better understand the overall value (magnitude and sign) of a given data set. For a data set, the '' ari ...

is only , which means that the deepest portion of the lake is below sea level (

cryptodepression A cryptodepression is a depression in the Earth's surface that is below mean sea level, and which is filled by a lake. The term is derived from the Ancient Greek word ('hidden') and depression. Description A cryptodepression is often due to ...

). It is one of the two major lakes (the other being

Lake Towuti Lake Towuti () is a lake in East Luwu Regency, South Sulawesi province, Indonesia. Surrounded by mountains, it is the largest lake of the island of Sulawesi and one of the five lakes of the Malili Lake system (the other being Lake Matano, Matano, ...

) in the Malili Lake system.

Endemic animals and plants

Lake Matano is home to many species of

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

fish and other animals (e.g. ''

Caridina ''Caridina'' is a genus of freshwater atyid shrimp. They are widely found in tropical or subtropical water in Asia, Oceania and Africa. They are filter-feeders and omnivorous scavengers. They range from 0.9–9.8 mm ('' C. cantonensis'') t ...

'' shrimps, Parathelphusid crabs and '' Tylomelania'' snails) as well as many plants. The endemic fishes of Matano have been compared to the species swarms of the

Rift Valley Lakes The Rift Valley lakes are a series of lakes in the East African Rift valley that runs through eastern Africa from Ethiopia in the north to Malawi in the south, and includes the African Great Lakes in the south. These include some of the world's ...

of Africa. While not as diverse, they are thought to have all arisen from a single ancestor species and diversified into numerous different species, which now fill many of the previously vacant

ecological niche In ecology, a niche is the match of a species to a specific environmental condition. Three variants of ecological niche are described by It describes how an organism or population responds to the distribution of resources and competitors (for ...

s, as can be seen in the family Telmatherinidae. Endemic and near-endemic fishes from other families include '' Glossogobius matanensis'', '' Mugilogobius adeia'', '' Nomorhamphus weberi'' and '' Oryzias matanensis''. Many of the endemics are seriously threatened due to pollution and predation/competition from a wide range of introduced fishes, including

flowerhorn cichlid Flowerhorn cichlids are ornamental aquarium fish noted for their vivid colors and the distinctively shaped heads for which they are named. Their head protuberance is formally called a nuchal hump. Like blood parrot cichlids, they are hybrids tha ...

s. The water snake '' Enhydris matannensis'' is only known from the vicinity of Lake Matano and on

Muna Island Muna (Pulau Muna) is an island in the Southeast Sulawesi province of Indonesia with an area of and had a population of 316,293 at the 2010 Census and 368,654 at the 2020 Census.Badan Pusat Statistik, Jakarta, 2021. It is just southeast of the i ...

Chemistry

Below the top layer of oxygenated water, Lake Matano's depths are

anoxic The term anoxia means a total depletion in the level of oxygen, an extreme form of hypoxia or "low oxygen". The terms anoxia and hypoxia are used in various contexts: * Anoxic waters, sea water, fresh water or groundwater that are depleted of diss ...

, free of sulfates, and rich in iron. These conditions make Lake Matano an analog for Earth's oceans during the

Archean The Archean Eon ( , also spelled Archaean or Archæan) is the second of four geologic eons of Earth's history, representing the time from . The Archean was preceded by the Hadean Eon and followed by the Proterozoic. The Earth during the Arc ...

Eon, which is useful for studying relationships between anoxygenic

phototroph Phototrophs () are organisms that carry out photon capture to produce complex organic compounds (e.g. carbohydrates) and acquire energy. They use the energy from light to carry out various cellular metabolic processes. It is a common misconcep ...

s and

banded iron formation Banded iron formations (also known as banded ironstone formations or BIFs) are distinctive units of sedimentary rock consisting of alternating layers of iron oxides and iron-poor chert. They can be up to several hundred meters in thickness ...

s. The lake contains a population of

green sulfur bacteria The green sulfur bacteria are a phylum of obligately anaerobic photoautotrophic bacteria that metabolize sulfur. Green sulfur bacteria are nonmotile (except ''Chloroherpeton thalassium'', which may glide) and capable of anoxygenic photosynthe ...

that conducts photosynthesis with

bacteriochlorophyll Bacteriochlorophylls (BChl) are photosynthetic pigments that occur in various phototrophic bacteria. They were discovered by C. B. van Niel in 1932. They are related to chlorophylls, which are the primary pigments in plants, algae, and cyanoba ...

''e''.

Lake Matano Festival

To lure foreign tourists of the beauty of Lake Matano and surrounding as a new icon of South Sulawesi, the first annually Lake Matano Festival was held in May 2015 with some attractions such as competition of running, cycling and swimming.

References

{{Authority control Matano Landforms of South Sulawesi

Endemic animals and plants

Chemistry

Lake Matano Festival

See also

References