Lake Victoria: Mara Bay and Masirori swamp

Country/territory: Tanzania

IBA Criteria met: A4i (2001)
For more information about IBA criteria please click here

Area: 50,000 ha

Nature Tanzania
Most recent IBA monitoring assessment
Year of assessment Threat score (pressure) Condition score (state) Action score (response)
2017 high not assessed low
For more information about IBA monitoring please click here

Site description
Mara Bay is situated at the entrance to Musoma town and harbour on the eastern shore of Lake Victoria. At the eastern edge of the bay is the mouth of the Mara river, backed by Masirori swamp, an extensive area of papyrus Cyperus papyrus. There are a number of islands at the entrance to the bay including Lukuba, Kyameto, Ngoche, Bugambwa and Myonyo. The shore in this area of the lake is generally well-settled with little natural vegetation.

Key biodiversity
See Box for key species. Chlidonias leucopterus use the area in large numbers on a regular basis. In January 1995 a roost on Ryamugasire island, immediately to the east of Musoma town, contained a minimum of 3,500 Phalacrocorax carbo, 1,500 Phalacrocorax africanus and 924 Egretta garzetta. Some of these birds may have been included in counts of birds along a 5 km stretch of shoreline which revealed 500 Phalacrocorax carbo and 1,500 Phalacrocorax africanus. The islands at the entrance of the bay may provide significant roost and breeding sites for these species. Further work is required to refine the boundaries of the site, especially at Masirori swamp. A single Balaeniceps rex has been reported from this site and surveys are likely to reveal that species of the Lake Victoria Basin biome occur.

Non-bird biodiversity: None known to BirdLife International.

Recommended citation
BirdLife International (2022) Important Bird Areas factsheet: Lake Victoria: Mara Bay and Masirori swamp. Downloaded from on 08/08/2022.