The Impact of Indirect Effects of Climate Change on Mangrove Associated Biodiversity.

Abstract

Periodic episodes arising out of global climate changes seem to pose a reasonable threat to the integrity of mangrove ecosystem. Mangrove macrofauna, which are residents of mangrove areas throughout their adult life, stand to be highly affected by the Periodic episodes arising out of global climate changes. During the 1997/8 8 El- Niño event, massive sedimentation due to erosion of terrigenous sediments caused mangrove dieback in many areas along the Kenyan coast. Mwache Creek a peri-urban mangrove forest in Mombasa was the most affected resulting in mangrove death covering about 200ha. Biodiversity in El-Niño impacted sites was compared to reference (natural forests) sites in order to assess the impact of climate change to mangrove associated biodiversity. Transects (sea-landward transect) were laid in both impacted and natural sites where relevant physico-chemical variables were measured and mangrove biodiversity determined as an indicator of ecosystem change. Molluscs densities and diversity were found not to be significantly different between treatments (impacted and reference sites) while crabs diversities was significantly higher in reference sites than impacted sites. Faunal diversity of Molluscs in impacted sites was found to be sustained by invasive shrubs while crab densities and diversity was highly reduced by the mangrove dieback.