|1.Research Institution||Hiroshima University|
|2.Research Area||Integrated Fields|
|3.Research Field||Causes and Effects of Environmental Loading its Reduction|
|4.Term of Project||FY 1997 〜 FY 2001|
|6.Title of Project||Evaluation and Restoration of the Effects of Oil Pollution on Coastal Ecosystem|
|Name||Institution,Department||Title of Position|
|Mitsumasa Okada||Hiroshima University, Graduate School of Engineering||Professor|
|Names||Institution,Department||Title of Position|
|Kouichi, Ohwada||Prefectural University of Kumamoto, Environmental and Symbiotic Sciences||Professor|
|Eiichi, Baba||Hiroshima University, Information Exchange Office||Professor|
|Kenji, Takeuchi||Kobe University, Graduate School of Economics Faculty of Economics||Professor|
9.Summary of Research Results
The following results were found in this research.
1) Quantitative analysis of the impact of oil pollution on the coastal ecosystem was done using the mesocosm and microcosm experiments. Change in the cluster of bacteria and fluctuation of a vegetation network has occurred. In addition, differences in the recovery speed of the different species of seaweed, shellfish and marine plants were observed. On the other hand, there is almost no direct impact of oil pollution on eelgrass except for some effects including shading and change in the species of macro benthos by oil drifting ashore.
2) It was found that the oil penetration in the beach sand was affected by wave movement, and there is much difference between penetration of oil and that of water. The economical method was used for the evaluation of tideland environmental value aggregated among Kanto area households, and a societal benefit value was estimated as [yen per hectare].
3) It was confirmed that the dispersant treatment was one of the effective methods for oil treatment, because it increases the solubility of oils which increase biological degradation of oils. However, the dispersant also increases the solubility of high molecular PAHs, leading to the increase of toxicity. The dispersant should be used carefully.