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
East Luwu Regency is the most easterly of the twenty-one regencies in South Sulawesi Province of Indonesia. Malili is the capital of East Luwu Regency. The population of East Luwu Regency was 243,069 at the 2010 Census and 296,741 at the 2020 C ...
,
South Sulawesi
South Sulawesi ( id, Sulawesi Selatan) is a province in the southern peninsula of Sulawesi. The Selayar Islands archipelago to the south of Sulawesi is also part of the province. The capital is Makassar. The province is bordered by Central Sula ...
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
Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. ...
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 elsew ...
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
''Tylomelania'' is a genus of freshwater snails which have an operculum, aquatic gastropod mollusks in the family Pachychilidae. In the aquarium hobby, snails from this genus are commonly known as "rabbit snails" (not to be confused with sea ...
'' 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
The Telmatherininae, the sail-fin silversides are a subfamily of Atheriniformes, atheriniform fish from the rainbowfish family, the Melanotaeniidae, inhabiting fresh and brackish water. All but the species ''Kalyptatherina helodes'' are restricte ...
. 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 lines, nuchal hump. Like blood parrot cichlids, they ar ...
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
Earth ...
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 a ...
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 photosynthesi ...
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 cyanobact ...
''e''.
Lake Matano Festival
To lure foreign tourists of the beauty of Lake Matano and surrounding as a new icon of
South Sulawesi
South Sulawesi ( id, Sulawesi Selatan) is a province in the southern peninsula of Sulawesi. The Selayar Islands archipelago to the south of Sulawesi is also part of the province. The capital is Makassar. The province is bordered by Central Sula ...
, the first annually Lake Matano Festival was held in May 2015 with some attractions such as competition of running, cycling and swimming.
See also
*
List of lakes of Indonesia
This is a list of the notable lakes of Indonesia. Indonesia has 521 natural lakes and over 100 reservoirs, covering approximately 21,000 km². The total volume of water held is approximately 500 km³. The largest lake, by both area an ...
References
{{Authority control
Matano
Landforms of South Sulawesi