Distribution of Seagrasses and Common Seaweeds Around Nampula Province (Northern Mozambique) with Emphasis on Moçambique Island

Abstract

The diversity and distribution of seagrasses and common seaweeds in Nampula province was studied. The field work took place between January and April 2002. 11 seagrasses and 53 common seaweed species were identified at Mocambique Island. From all studied sites, Fernao Veloso and Mocambique were the most diverse in seagrasses whereas Relanzapo and Ilha-dos-Sete-Paus in seaweeds. Seagrasses and seaweeds were mapped in Mocambique Island and grouped in nine community types namely: Thalassia hemprichii/ Halodule wrightii, Thalassia hemprichii/ macroalgae, Sargassum spp. / Cystoseira spp, Nanozostera capensis/Cymodocea rotundata/ Halodule wrightii, Cymodocea rotundata, Thalassodendron ciliatum/ Macroalgae, Thalassodendron ciliatum/Syringodium isoetifolium, Thalassodendron ciliatum , and Syringodium isoetifolium . All the above communities covered up to 70% of the total intertidal area, with Thalassia hemprichii /macroalgae being the largest community in Mocambique Island. Common species such as Thalassodendron ciliatum, Syringodium isoetifolium , and Sargassum spp. occur mainly in sublittoral fringe; while Thalassia hemprichii, Cystoseira myrica Laurencia papillosa at midlittoral and Enteromorpha and some Ulva sp. close to the shoreline. The present study contributes to fill up the lack of information regarding the community ecology of seagrass and seaweed in the Nampula province. Keywords : Seagrass, seaweed, diversity and distribution, Northern Mozambique, Western Indian West Indian Ocean Journal of Marine Science Vol. 4 (2) 2005: pp. 175-184