Effects of Mangrove Zonation and the Physicochemical Parameters of Soil on the Distribution of Macrobenthic Fauna in Kadolkele Mangrove Forest, a Tropical Mangrove Forest in Sri Lanka

The ecology of the macrobenthic fauna of the mangrove forests has received little attention compared to the mangrove flora. The present study was aimed at filling this information gap and investigated if the diversity and distribution of macrobenthic fauna at Kadolkele mangrove forest, a pristine mangrove forest situated at the Negombo estuary in Sri Lanka, are governed by the mangrove zonation and variation of physicochemical parameters of the mangrove soil. Since the aerial photographs identified three distinct mangrove zones at Kadolkele, namely, Rhizophora, Avicennia, and Lumnitzera zones, fauna were sampled and physicochemical parameters of the soil were measured in belt transects that were established at each mangrove zone. Data were collected and analyzed using appropriate field sampling techniques and statistical methods, respectively. Results revealed that the physicochemical parameters in soil varied between the three mangrove zones and that the distribution of benthic fauna followed the mangrove zonation. Further, the diversity measures of epifauna were found to be higher than those of the infauna of this tropical estuary.