In Japan, a number of various types of artificial reefs have been developed and settled to create fishery ground for the fishery production enhancement in coastal and off shore marine areas. There are many issues to be clarified about the suitable installation of artificial reefs, such as the relation between flow conditions and the biological effect of them. In this paper, a set of technologies newly developed to enhance marine resources is introduced. It consists of a hydraulic experiment and field research to select out the most appropriate shape for marine habitat restoration and a new fisheries resources enhancement structure that embodies multiple functions. The authors examined that the strong upward flow exists to the front of the panel specially designed for the generation of the upwelling water. Also, behind the structure, there are exists difference of the velocity between bottom and middle layer, besides the upward flow has been generated from the bottom layer as it was drawn into the fast current in the middle layer. Concerning the effective area of the structure, the main axis of the vortex generated by the structure has a tendency to be parallel to the direction of the mainstream, therefore it was confirmed that the effective area of vertical mixing reaches 20 times longer rearward than the structure height in length. The set of technologies was applied to coastal areas and was verified to improve biological environment in and around the fisheries resources enhancement structure.

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We tried a new approach to develop substantial amounts of phytoplankton-derived carbon biomass using incubations of unaltered deep-sea waters from 100 m, 400 m and 700 m depths in Suruga Bay, Japan. Incubations were run in 20 to 30 liters polycarbonate bottles for 11 days in 2002 and for 14 days in 2003, in land-based incubators under attenuated natural irradiance and at ambient temperature. Nutrients declined rapidly in all incubations. Nitrate (initially the main species of nitrogen) was depleted about midway through both incubations but silicate and phosphate were never depleted until the end. Diverse blooms of phytoplankton dominated by diatoms developed in all incubations except for controls. Phytoplankton carbon biomass increased by as much as 3-4 orders of magnitude. Bacteria and heterotrophic nano- and picoflagellates biomasses also increased during incubations but their contributions to living carbon biomasses were lower than phytoplankton in most of the incubations. Zooplankton developed sporadically but during their peak biomasses, their contribution to total living carbon biomasses was greater than phytoplankton. Particulate organic carbon (POC) also increased by as much as 2 orders of magnitude. The development of POC was not exclusively determined by the development of phytoplankton carbon. Our results demonstrate that incubations of unaltered deep-sea water are useful for generating substantial phytoplankton biomass of different size and species composition for ecological and physiological studies.

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To confirm whether dioxins are able to be degraded by non-oxidative high temperature heating, we examined the degradation of polychlodibenzodioxin (PCDDs), polychlorodibenzofurane (PCDFs), coplanar polychlorobiphenyl (PCB) contained in fly ashes discharged from a refuse-burner of a waste incineration plant by using a non-oxidative high temperature heating experimental system under reduced pressure. Fly ashes especially contained highly chlorinated PCDDs, such as 1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin and octa-chlorodibenzo-p-dioxin. All dioxins were completely degraded by non-oxidative high temperature heating more than 900°C without reproduction of dioxins. These results suggest that the non-oxidative high temperature heating is a useful method for removal of dioxins from fly ashes, soil and industrial waste materials polluted by dioxins.

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Wet oxidation treatment involves dissolution, ionization, gasification, and re-crystallization of elements in wastes during reaction, and thus these processes must be understood to reveal the material cycles in a closed system. In this study, monitoring methods of nitrogen, which is a major component of organic substances, were investigated for the first time to understand its behavior and balance using the wet oxidation unit for decomposing the plant materials at CEEF. The rice straw used as experimental material was cultivated at CEEF and contained 9.816 mg/g of nitrogen. In each operation, about 30 g of nitrogen was input from the specimen, of which 60 ∼ 67% was collected during the decomposition reaction in the form of nitrates in the processed solution. This percentage was much higher than the designed value, and the result was favorable, since the load on the ammonia and ammonium nitrate synthesis unit for treating excess nitrogen gas could be reduced less than we had predicted. The total amount of nitrogen in the system during operation was 124 ∼ 292 g. Some certain pattern was not seen in the relationship between the progress of treatment and the amount of total nitrogen in any of the three operation trials. This was found to be attributable to the fact that 80 ∼ 90% of total nitrogen was in gaseous form and the presence affected its behavior. The measurements showed precisely the actual amounts of input material, input nitrogen, and nitrogen collected in the processed solution. On the other hand, no stable balance was obtained for nitrogen gas, which accounts for the major proportion of total nitrogen, so methods should be optimized by increasing the number of gas sampling and sampling points.

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The sustainable development of an oasis-style ecological and economic system, making good use of the water resource of northwestern China, is suggested to develop the aquaculture. The project is in Yuanyang Lake area, located in the city of Jiuquan, Gansu province, and is concerned with the development of the sturgeon recirculating culture and fish farming, the establishment of a sturgeon germplasm resource lab, sturgeon broodstock pool, and ultimately a sturgeon industry. In addition, integrating aquaculture in lakes and reservoirs (culturing Chinese domestic fishes as well as other aquatic species) with agriculture on the arid lands near lakes and reservoirs (planting xerophytes, such as liquorice, diversifolious popular and Haoana Fang) will contribute to the bioremediation of the arid ecosystem, to the improvement of the biological diversity, and to the stabilization of an oasis ecosystem of Jiuquan City and its surrounding areas. Moreover, the development of aquaculture and plantation can result in not only economic and ecological benefits, but also profound changes to the industrial structure of Jiuquan City. It could become a practical model for the sustainable development of an oasis-style ecological and economic system in the arid areas of Western China.

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