Patterns of colonisation of meiobenthos as an indicator of recovery of reforested Rhizophora mucronata mangroves in Gazi Bay, Kenya.

Abstract

Recolonisation patterns of meiobenthos in restored Rhizophora mucronata forests were investigated by assessing their densities, community composition and diversity. This was done in 5- and 10- year reforested mangroves and natural and a degraded controls. MDS and ANOSIM on meiofauna community composition, showed a separation of the natural and the 10 years reforested sites from the 5- year reforested and degraded sites. Nematodes were the dominant meiofauna taxon in all the sites. The natural and the 10 years reforested sites rich in silt/clay sediments and organic matter, recorded the highest meiofauna and nematode densities. The degraded site recorded significantly higher Shannon Diversity index than all the other sites, which was linked to the relatively higher dominance by nematodes in the natural, 10- year reforested and the 5- year reforested sites. The study showed that degradation of mangroves leads to changes in the habitat conditions, which leads to a strongly impoverished meiofauna community in terms of density and community composition. It is also evident that recovery of the meiofauna community and in particular nematodes takes place between 5 and 10 years of reforestation.