Preliminary wildlife assessment of selected gas producing communities in Ogba-Egbema area of Rivers State, Nigeria

Abstract

The Niger Delta region of Nigeria is a beehive of oil production activities for almost fifty years. The exploration of this important resource with its attendant gas flaring has impacted negatively on biodiversity of the area. A baseline study was therefore, conducted to ascertain the level of wildlife abundance in selected communities (Obrikom, Mgbede, Ebocha, Aggah and Okwuzi all in Ogba-Egbema Local Government Area of Rivers State) impacted by gas flaring. A total of 7 transects were used for the study. Species density and diversity indices were estimated from data generated. The mammalian order Rodentia was more in abundance than other species. Two rodents, the giant-pouched rat (Cricetomys emini) and cane rat (Thryonomys swinderianus) recorded 7.336±0.0068 and 6.146±0.036 individuals/km² respectively. The mona monkey (Cercopithecus mona) and putty-nosed monkey (Cercopithecus nictitans) with average densities of 0.496±0.018 and 0.324±0.006 troop/km² are the only recorded primates in the study sites. The agama lizard (Agama agama) with average density of 0.192±0.014 individuals/km² was found to be more in abundance than other reptiles. Species recorded for avifauna belong to thirteen families and Ploceidae family was found to be more in abundance. Species Richness (d), Shannon- Wiener (HꞋ) and Evenness (E) indices for mammals in Okwuzi were 1.821, 1.415 and 0.727 respectively and were higher than other sites. Obrikom had the highest Simpson Dominance (C) of 0.456 though not significantly different (p ≥ 0.05) from Okwuzi. Diversity indices for reptiles showed that Obrikom and Okwuzi had the highest d, HꞋ, E and C of 1.820, 1.099, 1.000 and 0.333 each respectively. Highest values of d (2.889) and HꞋ (1.835) were recorded for Obrikom while E (0.963) and C (0.355) were highest values for Okwuzi and Aggah respectively in relation to avifauna diversity. Many of the species encountered have ethno zoological values. The findings indicate that there is loss of wildlife occasioned by anthropogenic impacts especially oil and gas exploration.