Abstract:
The assemblages of benthic macroinvertebrates in mangroves and open intertidal areas of the Dar es Salaam coast,
Tanzania, was investigated in 2013–2014, revealing 56 species. Higher density, species richness and diversity were
recorded in open intertidal areas, compared to nearby mangrove forests. Non-metric multidimensional scaling
indicated differences in assemblages between mangrove and open intertidal samples. These differences were
confirmed by analysis of similarity. SIMPER identified an average dissimilarity of 97.24% between mangroves and
open intertidal samples, most of which were due to the malacostracan Uca annulipes and the gastropod Cerithidea
decollata. PRIMER RELATE indicated significant correlation between macroinvertebrate assemblages and the
measured physico-chemical parameters salinity, pH, redox potential and sediment particle size, whereas BIOENV
and the Monte Carlo permutation test indicated that redox potential, sediment particle size and pH contributed
significantly to variation in species composition. Mangroves were dominated by the gastropod C. decollata, and by
the malacostracans Neosarmatium africanum and U. annulipes, and open intertidal areas by the bivalves Dosinia
hepatica and Eumarcia paupercula. Due to the rich biodiversity in open intertidal ecosystems, it is recommended
that conservation efforts along the Tanzanian coast should focus here.
