Effects of Crude Oil and Spent Oil on &lt;i&gt;Clarias garipinus&lt;/i&gt;: A Typical Marine Fish

Gbadebo Gbadebo

doi:10.3844/ajessp.2009.753.758

Abstract

Problem statement: Petroleum hydrocarbon and petroleum residue (i.e., spent oil) remains the foremost pollutants to the fish communi ties in various aquatic media-ponds, streams, rivers, creeks, coastal and marine environments thr ough indiscriminate disposal of oil contaminated drilling muds, cutting and oil spillages. Approach: Also, the spent oil enters into aquatic media through run-off following unguided disposal. Both t he petroleum hydrocarbon and spent oil, on getting to the water bodies spread fast and produce lethal, sub-lethal and even acute effect of petroleum hydrocarbon and spent oil on the fingerli ngs and other juvenile fishes. Results: Since this group of fish constitutes about 60% of the fish pop ulation in any aquatic medium, a green house study was carried out to assess the effects of crud e oil and spent oil on fingerlings of Clarias garipinus-a typical marine fish. In this study, fingerlings of Clarias garipinus were exposed to 2-10% concentration of crude oil and spent oil for 96 h p eriod. Readings were taken every 24 h. From concentration of 4-10%, high mortality rate averagi ng 10 out of 10 fingerlings were recorded. Conclusion/Recommendations: The deaths were attributed to reduced dissolved ox ygen and blockage of the water surface by the oils. Concentr ations of 2% showed a reduced level of mortality, which even lapsed over the 96 h period. The mortali ties were owed to impairment in neurologically dysfunction. Changes in physiological character suc h as changes in skin color and reduced locomotive actions were also observed.

Highlights

Petroleum hydrocarbon in its crude, refined or spent form has negative impact on both the human, animal and plant species[2,5]
After the 96 h period, the LC50 determined from Table 1c using arithmetic graph methods was 40.3 mL (i.e., LC50 = 40.3 mL) for spent oil
In the crude oil experiment, there was no mortality(i.e., mean-mortality = 0.0) at all in the concentration levels within the first 24 h as in the spent oil and no mortality was recorded at concentration of 0.25 and 0.50% for both 48, 72 and 96 h periods

Summary

Introduction

Petroleum hydrocarbon in its crude, refined or spent form has negative impact on both the human, animal and plant species[2,5]. Evaluation of such hazards can be carried out using various toxicological substances in order to establish the various effects on the aquatic species. Such toxicological observation may be acute/lethal or chronic/sub-lethal. The lethal concentration of a substance is that urged to observe the short term effect over a test population. Oil spillage has caused destruction of food resources[17] Impacts of such oil spills on different aquatic organisms and species need to be assessed on a regular basis in order to ascertain its immediate effects and predict its possible effects on physiological characteristics of these animals. The simplest of the laboratory toxicity test is one in which an organism especially the fish is placed in a standard

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Discussion

Conclusion