Q. Karam1*, M. Ali1, M.N.V.
Subrahmanyam1,4, K. Al-Abdul Elah1, M. Bentley2,3 and
Life Sciences Research Center, Kuwait Institute for Scientific Research,
2Dove Marine Laboratory,
School of Marine Science and Technology, Newcastle University, Newcastle upon
Tyne, NE1 7RU, United Kingdom
University, Singapore, 567 739, Singapore
Organization for the Protection of the Marine Environment (ROPME),
Safat 13124, Kuwait
Author Email :
Aim: The objective of
the present study was to investigate the effects of dispersed and undispersed
Kuwait crude oil on egg hatching and larval survival of Epinephelus
Methodology: In the present study,
the toxic effects of crude and dispersed oil using three formulations of oil
dispersants against multiple life stages of Epinephelus coioides was
assessed. The lethal concentration was calculated by ToxCal®
software developed by Tidepool Scientific, LLC.
Results: Specifically, the
following life stages were investigated: embryonated eggs (EE), larvae
hatched during exposure (LHE) and hatched larvae (HL). Chemical analysis
showed that Total Petroleum Hydrocarbon (TPH) concentrations were higher in
dispersed than undispersed oil solutions, indicating accommodation of more
petroleum hydrocarbons in the aqueous phase. Acute static toxicity tests
produced variable LC50 values for all chemical preparations and all fish life
stages. Crude oil dispersed with both Corexit® EC 9500A and Corexit® EC 9527A
separately was more toxic to both EE and LHE stages than undispersed oil, but
crude oil dispersed with Slickgone® NS resulted in lower toxicity.
Furthermore, all three types of dispersed oil exerted higher toxicity than undispersed
oil at HL stage.
Interpretation: A life stage
dependent effect demonstrated variation in the toxicity of both dispersed and
undispersed crude oil to fish. Few life stages were more sensitive than
others to either dispersed or undispersed crude oil toxicity. While
dispersion of an oil slick with oil dispersant has proved to be an effective
tool in the oil response strategy, the fate of dispersed oil can exert lethal
effects on embryo-larval stages of marine fish present near the spill.
Key words: Embryo-larval stages, Epinephelus coioides, Kuwait
crude oil, Total petroleum hydrocarbons