Impact of Mangrove Deforestation on Fiddler Crab Distribution and Soil Physico-chemistry at Eagle Island, Rivers State

Abstract

Mangrove forest in the Niger Delta and its associated biotic and abiotic has been greatly impacted by several factors, some natural and others anthropogenic in nature. Anthropogenic activities have negatively affected the organisms that inhabit the forest resulting in the decrease in size of population of fiddler crabs (Uca tangeri). To investigate the influence of anthropogenic activities on the mangrove habitat, burrow distribution and population of fiddler crabs and soil physico-chemistry were determined in forested and deforested sites. Burrows and number of crabs outside burrows were counted while samples of soil were retrieved and moved to the laboratory for the determination of cadmium (Cd), lead (Pb), total hydrocarbon content (THC) and Zinc (Zn) using atomic absorption spectrophotometer. The conclusions show a lack of significant difference in burrow distribution between forested and deforested areas (P>0.05). Contrastingly there is significance in the difference in crab population in forested and deforested sites. (P<0.05), which showed that there were more crabs in deforested areas than forested areas. There was also a significant difference in chemical and microbial population (P<0.05). There was higher THC in deforested areas, which was probably impacted by the heavy-duty vehicles used to cut down the trees. The result implies that human activities of deforestation and pollution influence crab population and soil physicochemistry in mangrove forest.