Mahajamba Bay - Anjavavy Complex (6544)
Madagascar, Africa
Site overview
KBA status: confirmed
Year of last assessment: 2014
National site name: Complexe de la Baie de Mahajamba - Anjavavy
Central coordinates: Latitude: -15.4280, Longitude: 47.0670
System: freshwater, marine, terrestrial
Elevation (m): 0 to 40
Area of KBA (km2): 1866.36915
KBA classification: Global/Regional TBD
Legacy site: Yes
Site details
Site description: This large bay is located 95 km north of Mahajanga. The bay is shallow and is generally less than 5 m deep at low tide, although the main drainage channel at its mouth is 20–90 m deep at low tide. Five rivers flow into the bay: the Sofia and the Tsiribihina rivers in the north-east, the Mahajamba river in the centre, and the Andranoboka and Masokoenja rivers in the south-east. There are 47,500 ha of mangroves, located at the mouths of the five rivers and dominated by Rhizophora and Avicennia. Those located along the sea are well developed (8–10 m high) and show no signs of exploitation. Tongue-shaped mudflats, c.750 m long and 500 m wide, occur along the edge of the mangroves. Some small rocky islets are present in the channel. Parts of the bay shore are rocky, and inland there are more or less wooded hills.
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. The following KBA trigger species occur at this site but are not yet available in WBDB, either because they have only been globally Red-List-assessed recently (in 2012-2013; global Red List category is given in brackets, where triggering the Vulnerability KBA criterion) or because they have not yet been globally Red-List-assessed (most of these taxa are nevertheless listed as valid in Catalogue of Life or Tropicos); many of the latter species may prove to be globally threatened, or are already listed as regionally or nationally threatened, and nearly all of the following species are also likely to be endemic to the Hotspot, often with very restricted known ranges, thus also triggering the Irreplaceability 1 KBA criterion: PLANTAE: Acampe loheriana; Terminalia rhopalophora var. analavensis.
Additional biodiversity: See Box and Tables 2 and 3 for key species. Thirteen species are known from the site, of which one is endemic to Madagascar. The site holds the largest congregation of Egretta dimorpha known. Non-bird biodiversity: Lemur: Propithecus verreauxi coquereli (EN).
Threats
Summary of threats to biodiversity at KBA: One of the rocky islets is a sacred site to which access is forbidden, and is this protected against human disturbance. Haliaeetus vociferoides and Propithecus verreauxi coquereli are also protected by ‘fady’ (taboos). The colonies of breeding waterbirds are exploited by local people, especially the employees of an industrial aquaculture installation.
Additional information
References: Langrand (1987), Rabarisoa (1994), Rabarisoa et al. (1995), Ségalen (1956), Watson et al. (1993).