Abstract

Kayode G. Bengamin

The ecological impact of petroleum sludge on fresh water shrimp (Desmoscaris trispinosa) and brackish water shrimp (Palaemonetes africanus) in the Niger Delta area was compared using the Organization of Economic Co-operation and Development (OECD) No. 218 protocol for sediment toxicity test. The shrimp were exposed to sediments treated with petroleum sludge at concentrations of 625, 1250, 2500, 5000 and 10000 mgkg-1 . The LC50 value obtained with D. trispinosa (1100 ± 160 mgkg-1 ) was lower than that obtained with P. africanus (1590 ± 336 mgkg-1 ). This was an indication that the petroleum sludge was more toxic to the fresh water shrimp than the brackish water shrimp. However, the observed mean LC50 values were not significantly different at levels of p <0.01. These values indicated that petroleum sludge can have adverse effects on the fauna in the shoreline/benthic sediment of the Niger Delta ecological zone. Consequently, there is the need to protect sensitive invertebrates representing the major proportion of the diet of many species and humans.