he aim of this study was to assess the toxicity of dispersants (OSD/SEACARE and OSD/LT) with different concentrations on the growth of Aspergillus and Rhizopus species in fresh water (Ocdee River) in KegbaraDereGokana Local Government Area, Rivers State. The Fresh water sample was collected by submerging 10liters of jerry Can (sterile) into a depth of 30cm in K-Dere River in Gokana Local Government Area, Rivers State. The samples were transported to the laboratory in sterile containers packed in coolers in an ice pack for analyses within six hours of collection. Oil spill dispersants; OSD/SEACARE and OSD/LT were obtained from Barker and Hughes Nig. Ltd (formally Mil Park Nigeria Limited) in Port Harcourt Rivers State. The toxicity testing was done for the period of days at room temperature. Standard microbiological techniques were used; toxicity testing was prepared by setting up conical flask aseptically covered with cotton wool. For each dispersant (toxicant), the test was carried out in five (5) separate conical flasks containing appropriately sterile habitat water (freshwater). In each of the conical flask, four toxicant concentrations (%); 10, 25, 50, and 75 were added separately. These concentrations were obtained by aseptically transferring 10, 25, 50 and 75 ml of the dispersant into 90, 75, 50, and 25 ml of sterile freshwater. The control contained the water sample (habitat water) and the organism without toxicant. One millilitre (1ml) of the test organism was added to each toxicant concentration in test tubes containing (10, 25, 50, 75% and control respectively). | Response of Aspergillus and Rhizopus species to the toxicity of dispersants
