Lake Itasy (6579)
Madagascar, Africa

Site overview

KBA status: confirmed

Year of last assessment: 2014

National site name: Lac Itasy

Central coordinates: Latitude: -19.0740, Longitude: 46.7840

System: freshwater, terrestrial

Elevation (m): 1221 to 1221

Area of KBA (km²): 29.63559

KBA classification: Global/Regional TBD

Legacy site: Yes

Site details

Site description: Lake Itasy is located 10 km south-east of Analavory and 25 km north-west of Soavinandriana. It is a freshwater crater-lake with marshy areas in its southern and eastern parts, lying within a steep-sloped volcanic massif. It is permanent, with seasonal variations in the water-level, having an average depth of 4 m but reaching up to 10 m at its centre. The Andranomena and Mariandrano rivers feed the lake in the east, while the Lily river flows out of the lake. The lake receives a lot of sediment from the rivers and from the eroded adjacent slopes. There is marginal vegetation of reedbeds Phragmites and clumps of Cyperus (up to 2 m), and floating mats of the non-native water-hyacinth Eichhornia. Submerged plants include Ceratophyllum and Potamogeton. Near the middle of the lake, there is dense vegetation of various very tall aquatic plants.

Rationale for qualifying as KBA: This site qualifies as a Key Biodiversity Area of international significance because it meets one or more previously established criteria and thresholds for identifying sites of biodiversity importance (including Important Bird and Biodiversity Areas, Alliance for Zero Extinction sites, and Key Biodiversity Areas) KBA identified in the CEPF Ecosystem Profile of the Madagascar and Indian Ocean Islands Hotspot (2014). Taxonomy, nomenclature and threat status follow the 2013 IUCN Red List.

Additional biodiversity: See Box and Tables 2 and 3 for key species. Forty-four species are known from the lake, of which 10 are endemic to Madagascar. The dense vegetation near the middle of the lake is a refuge for herons (Ardeidae) and rails (Rallidae). A locally resident population of Anas melleri is probably of national importance. Ardea humbloti is infrequently recorded.

Habitats

Land use: agriculture

Threats

Summary of threats to biodiversity at KBA: The escarpments around the lake are completely bare of vegetation as a result of bush-fires and agriculture, and the significant erosion that ensues is accelerating the silting-up of the lake.

Additional information