Current view: Text account
Site description (2001 baseline):
Site location and context
The site lies 20 km from Mahajanga. Bombetoka Bay is delimited, in the north, by a line from Katsepy in the west to the headland just north of Boanamary in the east, and, in the south, by the Marovoay flood-plain. The bay consists of mangrove islets (c.43,500 ha) separated by channels (c.21,500 ha at high tide) and mudflats (c.8,500 ha at low tide), with shallow subtidal waters in the estuary. The water is shallow (less than 5 m deep at low tide), except towards the mouth, and is very turbid. Northern mangroves are relatively degraded (3–4 m high), while those toward the south are in better condition; likewise, those on the coast are more intact than those in brackish, inland areas, where the canopy is 6–8 m high. The largest mudflats lie immediately seaward of the mangrove islets. A muddy bar crosses the mouth of the estuary, c.10 m wide and covered with scattered mangroves. The Marovoay wetlands comprise a vast area of rice-fields, marshes with Cyperaceae, and a large reservoir, Lake Amboromalandy.
See Box and Tables 2 and 3 for key species. Sixty species are known from the site, of which 10 are endemic to Madagascar. The occurrence of a large, seasonal congregation of
Anas bernieri (the largest known), and of several individuals of
Threskiornis (aethiopicus) bernieri, in the Bombetoka estuary, is notable. The eastern part of Lake Amboromalandy is very rich in waterbirds.
Non-bird biodiversity: Sirenian: Dugong dugon (VU; present, according to local people).
Pressure/threats to key biodiversity
Except near Mahajanga, the mangroves are relatively intact. A proposed plan for the industrialization and further development of Mahajanga city and harbour (for example, a proposal to set up shrimp-farms) includes potential pollution risks. Hunting, and the destruction of waterbird colonies on the Marovoay flood-plain, are both known threats.
Recommended citation
BirdLife International (2024) Important Bird Area factsheet: Bombetoka Bay - Marovoay NPA (Madagascar). Downloaded from
https://datazone.birdlife.org/site/factsheet/bombetoka-bay--marovoay-npa-iba-madagascar on 22/11/2024.
