Betsiboka River
Encyclopedia
Betsiboka River is a 525 kilometres (326.2 mi) long river in central-north Madagascar
. It flows northwestward and empties to Bombetoka Bay
, forming a large delta
. The river is distinct for its red-coloured water, which is caused by river sediments. The river carries an enormous amount of reddish-orange silt to the sea. Much of this silt is deposited at the mouth of the river or in the bay.
It is dramatic evidence of the catastrophic erosion of northwestern Madagascar. Removal of the native forest for cultivation and pastureland during the past 50 years has led to massive annual soil losses approaching 250 metric tonnes per hectare (112 tons per acre) in some regions of the island, the largest amount recorded anywhere in the world. Several fish species are endemic to the river basin, including the three cichlid
s Paretroplus petiti
, P. tsimoly
and P. maculatus
.
The Betsiboka's largest tributary, the Ikopa River
, drains the capital city of Antananarivo
.
Madagascar
The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...
. It flows northwestward and empties to Bombetoka Bay
Bombetoka Bay
Bombetoka Bay is a bay on the northwestern coast of Madagascar near the city of Mahajanga, where the Betsiboka River flows into the Mozambique Channel...
, forming a large delta
River delta
A delta is a landform that is formed at the mouth of a river where that river flows into an ocean, sea, estuary, lake, reservoir, flat arid area, or another river. Deltas are formed from the deposition of the sediment carried by the river as the flow leaves the mouth of the river...
. The river is distinct for its red-coloured water, which is caused by river sediments. The river carries an enormous amount of reddish-orange silt to the sea. Much of this silt is deposited at the mouth of the river or in the bay.
It is dramatic evidence of the catastrophic erosion of northwestern Madagascar. Removal of the native forest for cultivation and pastureland during the past 50 years has led to massive annual soil losses approaching 250 metric tonnes per hectare (112 tons per acre) in some regions of the island, the largest amount recorded anywhere in the world. Several fish species are endemic to the river basin, including the three cichlid
Cichlid
Cichlids are fishes from the family Cichlidae in the order Perciformes. Cichlids are members of a group known as the Labroidei along with the wrasses , damselfish , and surfperches . This family is both large and diverse. At least 1,300 species have been scientifically described, making it one of...
s Paretroplus petiti
Kotso
The kotso is a species of cichlid fish from northwestern Madagascar. Currently rated as data deficient by the IUCN, this species is virtually unknown. The only known specimen is a juvenile that was collected more than 80 years ago...
, P. tsimoly
Paretroplus tsimoly
Paretroplus tsimoly is a species of cichlid fish from the Betsiboka River basin in northwestern Madagascar. Like other members of the lamena group, it is a rheophile . This relatively elongate Paretroplus reaches about in length, and is closely related to P. lamenabe and P. nourissati....
and P. maculatus
Damba mipentina
The damba mipentina is a critically endangered species of cichlid fish from turbid, shallow flood-plain lakes in the Betsiboka and Ikopa River basins in northwestern Madagascar. It has declined drastically because of habitat loss, overfishing and invasive species...
.
The Betsiboka's largest tributary, the Ikopa River
Ikopa River
The Ikopa River is the second longest waterway in Madagascar and passes through the capital, Antananarivo. It is the largest tributary of the Betsiboka River....
, drains the capital city of Antananarivo
Antananarivo
Antananarivo , formerly Tananarive , is the capital and largest city in Madagascar. It is also known by its French colonial shorthand form Tana....
.