Development of eco-engineering system using technique of reproduction and inhabitation of benthos on tideland and shallow sea area.

通过建立滩涂实验室模型，研究了作为环境污染指标的重油对由沙蚕、短颈蛤和滩涂细菌组成的围隔生态系统性能的影响，结果表明，与沙蚕相比，短颈蛤对环境负荷的敏感性更高。结果表明，由于有机物的存在，系统中的水质下降，而在沙蚕的存在下，水质下降并不严重。这表明生活在底栖生物中的沙蚕在稠油存在的情况下具有保持净化能力的可能性。此外，可以认为，细菌因可作为有机物处理的重油而增加，并且有机物在被细菌分解和净化后被沙虫捕食而进一步减少。通过对加塞人工潮滩和SANNBANNSE天然潮滩的调查研究，结果表明：SANNBANNSE天然潮滩对COD的净化能力、深度小于3 m区域的微生物种类和生物量均高于加塞人工潮滩。天然滩涂对COD的净化能力是人工滩涂的2倍。从生物学、物理学和化学的角度来看，适当的结构对于滩涂的净化功能是很重要的。根据前一年的研究结果，还表明，通过设计底栖生物的繁殖/固定技术，可以加强潮滩系统的净化功能。

Tideland bench-scale experimental model was established to evaluate the influence of heavy oil as an index of environmental pollution substance on the performance of mesocosm systems that consist of lugworms and short-neck clams and bacteria living in tideland.As a result, compared with lugworms, a littleneck clam's susceptibility was higher to environmental load. It was found that water quality in the system declined due to the presence of the organic mater from the carcass, whereas, with the existing of lugworm, water quality decline was not so serious. It suggested that lugworm living in benthos, has the possibility of maintaiuing purification capability under existence of heavy oil. Moreover, it was thought that bacteria increased by heavy oil that can be treated as an organic matter, and the organic matter was further reduced by predation of lugworms after decomposition and purification by bacteria. The results investigated in KASAI artificial tideland and SANNBANNSE natural tideland showed that COD purification ability, the species of microorganisms and the amount of biomass in the area which the depth is less than 3-meter in SANNBANNSE natural tideland were higher than those in KASAI artificial tideland. The COD purification ability in the natural tideland is two-fold higher than that in the artificial one. It is clear that the proper structure is important for the tideland purification function from a biological, physical and chemical point of view. From the results conducted in preceding year, it also suggested that by devising reproduction/fixing technology of benthos purification function could be strengthened in the tideland system.