Toxicology Study of Dispersant Corexit 9527 to 14-day Tilapia Guineensis Fingerlings

Ifezue Obianuju Appolonia; Felix. E. Okieimen

Ifezue Obianuju Appolonia
Felix. E. Okieimen

Keywords: sensitivity, probit, lethal, asymptotic, threshold, tolerant, tilapia, static, bioassay, corexit 9527

Abstract

The sensitivity of 14-day old fresh water tilapia guineensis fingerlings to dispersant corexit 9527 was studied in static renewal bioassay glass tank, using tap water to access the lethal concentrations of the chemical on the test organisms. The test organisms were collected from a fish pond in Warri, Delta State of Nigeria. In the most predictive applications, the LC50 is normally used as an estimate of the incipient lethal level, also known as the lethal threshold concentration, asymptotic LC50 or tolerant limit. In fish tests, the incipient lethal level often occurs within 4 days, and this is one rationale behind the 96-hr length for a standard acute fish test. The median lethal concentration LC50 of dispersant corexit 9527 on tilapia guineensis was determined using a computerized probit analysis. This research showed that the median lethal concentration, LC50 for the 14-day old tilapia guineensis fingerlings were 54.82mg/l, 24.21 mg/l and 16.47mg/l for 2, 3 and 4 days respectively; and the 14-day old tilapia guineensis showed high sensitivity to the different lethal concentrations of corexit 9527 at 96-hr duration.

References

ASTM International. (1999). Standard guide for use of oil spill dispersant application equipment during spill response: Boom and nozzle systems. F1737/F1737M-15. In Annual book of ASTM standards, 1(1). Philadelphia, PA, USA.
Barron, M. G., Hemmer, M. J., & Jackson, C. R. (2013). Development of aquatic toxicity benchmarks for oil products using species sensitivity distributions. Integrated Environmental Assessment and Management, 9(4), 610-615.
Bejarano, A. C., & Farr, J. K. (2013). Development of short, acute exposure hazard estimates: A tool for assessing the effects of chemical spills in aquatic environments. Environmental Toxicology and Chemistry, 32(8), 1918-1927.
EMSA. (2005). Inventory of national policies regarding the use of dispersants in the EU member states. November 2005.
Ezemonye, L.I.N & Olomukoro, J.O. (2000). Bioassay toxicity trial 1: Effects of residual chlorine on biological test organisms. Nigeria Journal of Applied Science, 1(8), 53-56.
George-Ares, A. & Clark, J. R. (2000). Aquatic toxicity of two Corexit® dispersant. Chemosphere, 40(8), 897-906.
Hansen, B. H., Altin, D., Bonaunet, K., & Øverjordet, I. B. (2014). Acute toxicity of eight oil spill response chemicals to temperate, boreal, and arctic species. Journal of Toxicology and Environmental Health, Part A, 77(9-11), 495-505.
Hemmer, M. J., Barron, M. G., & Greene, R. M. (2011). Comparative toxicity of eight oil dispersants, Louisiana sweet crude oil (LSC), and chemically dispersed LSC to two aquatic test species. Environmental Toxicology and Chemistry, 30(10), 2244-2252.
Mitchell, F. M. & Holdway, D. A. (2000). The acute and chronic toxicity of the dispersants Corexit 9527 and 9500, water accommodated fraction (WAF) of crude oil and dispersant enhanced WAF (DEWAF) to Hydra viridissima (green hydra). Water Research, 34(1), 343-348.
National Oceanic and Atmospheric Administration (NOAA). (2018). Response link-web-based emergency response communications system.
National Research Council (NRC). (2005). Oil spill dispersants: Efficacy and effects. National Academy Press, Washington, DC, USA.
Ohonba, S.I. & Oronsaye, J.A. (1999). The Toxicity of cadmium, to oreochromis niloticus. Nigeria Journal of Applied Science, 1(7), 91-96.
Swannel, R.P.J & Daniel, F. (1999). Effects of dispersant on oil biodegradation under stimulated marine conditions. In Proceedings: 1999 international oil spill, Washington. US, pp. 169-176.
Wise, J. & Wise, J. P. (2011). A review of the toxicity of chemical dispersants. Reviews on Environmental Health, 26(4), 281-300.