Among the functions of ecosystem, nutrients cycle is the most important for sustaining natural system. But in modernized and industrialized countries, the product consumes the resources and make wastes. This means that valuable resources are turning to waste through product. Waste water is one of the product from the valuable resources, so waste water is no more waste and it can be used as valuable resources for other process by using natural ecosystem. By the conventional wastewater treatment systems, the “zero discharge” could not be achieved by several factors. Shortage of resources is one of the reasons. Secondly, by the environmental engineering, the pollutants are only transformed from one medium to another. Thirdly, for eliminating the pollutants, fossil fuel must be used, which means another pollution. Self-designed and solar energy based ecotechnology could be an alternative method which solve the local, regional and global environmental problems properly should be found out. Already ecotechnology was defined as “the design of human society with it natural environment for the benefit of both”. By using the functions of ecosystem, such as food web, energy flow, nutrients cycles and homeostasis, pollutants can be eliminated, concentrated and transformed to nature. The major purpose of mechanical wastewater treatment systems is focused on the large quantity of domestic wastewater. But, small quantity of domestic wastewater is not concerned by public treatment because economic and technical difficulty. However, for improvement of water quality of streams and rivers, the small quantity of domestic wastewater must be purified. Here, some eco-technologies for water quality improvement installed in Korea are introduced. The artificial wetland, artificial food web and artificial vegetation island are installed in polluted and ecologically disturbed areas. These methods are not perfectly solving the environmental problems, and they are acting as alternative methods for clean up of polluted and restoration of disturbed ecosystems.

Purpose of CH4 reference gases Intercomparison is to evaluate measurement ability among different laboratories and to improve problems in analyzing reference gases. As a result, the goal is for being reached a scale within the limits of the possibility in intercomparison. Korea Meteorological Administration (KMA) and Korea Research Institute of Standards and Science (KRISS) carried out CH4 reference gases intercomparison of the Far East Asia managed by Japan and CH4 intercomparison among standard institutions managed by Consultative Committee for Amount of Substance (CCQM) respectively. CH4 reference gas and standard gases is injected to calibrate instrument drift by turns and checked uncertainty of measurement additionally. Expanded uncertainty in intercomparison among meteorological administrations in the Far East Asia showed 1784.3 ppb±0.26%, 1935 ppb±0.29% respectively. Expanded uncertainty in the case of one point calibration and multipoint calibration showed 1903 ppb±0.11%, 1904 ppb±0.32% respectively. One point calibration obtained better result than mult-point calibration because of having an extent of different manufacturing uncertainty in the case of using various standard gases and having an instrument drift caused by long-time analysis. Through these intercomparison experiment, we could know that concentration of CH4 standard gases produced in CMDL was higher about 1.3~1.4% (about 24~26 ppb) than those of KRISS. This is reason caused a difference between manufactured by gravimetric method and manometric method. Therefore, the standard gases is required to intervalidation with standard institutions and GAW observatories. Also, a low level standard gases need to be calibrated by upper level standard gases periodically.

The Cheongju Wonheung Ecological Park was constructed to help the multiplication of toads, following the beginning of the development of surrounding areas. A great number of CCA (Chromated Copper Arsenate)- treated wood structures were included in the construction around the pond and the migration passage to the nearby mountain (Guryong Mountain). Noticeable malformation, however, occurred in toad tadpoles and most of them were found to be dead after all. This study was conducted to find the cause of the incidence, focusing on the contamination of the area with heavy metals. CCA-treated wood, soil, and water samples were collected around the pond and they were analyzed for heavy metals. The results showed that teratogenic copper concentrations were highly elevated in pond water and soil samples, suggesting that CCA-treated wood may be a potential source of toad malformation.

The species composition and phylogeographical features of marine algal flora of Dok island are investigated. A total of 253 species, 26 green, 67 brown, 160 red, were counted cumulatively since first report by Kang and Park (1969) from Dok island. Among them Ectocarpus corticulatus Saunder, Antithamnion okiense Kajimura are first reported from Korea and Feldmannia irregularis, F. globifera, Spatoglossum crassum newly added by this study. And also, a candidated new species, Dictyota sp. (Dictyotaceae, Phaeophyceae) is collected in this study. A remarkable increasing of warm water brown algal species, eg. Nemacystus decipiens, Sphaerotrichia divaricata, Tinocladia crassa, Petrospongium rugosum, Sargassum yezoense, are observed recently studies. This phenomenon is presumed to be closely related with global warming. For phylogeographical study of marine algae of Dok island we selected two species, one red alga Griffithsia japonica Okamura and one brown alga Dictyota coriacae (Holmes) Hwang, Kim et Lee, which have low dispersal capacity by their Oogamious sexual reproduction. The Dok island's haplotype of G. japonica is clearly distinguished from Oki island haplotype but closely related to the Korean type's haplotypes which distributed in south and east coast of Korea. And also, the Dok island's haplotype of D. coreacea is a unique Korean type which discriminated from Japanese and Taiwanese type. From these results, we proposed the marine algae of Dok island, at least in case of warm water species, were originated from Korean coasts rather than western coast of Japan by the Korean warm current.

Samples were taken from the surface waters around Dokdo Island to measure the physico-chemical and microbiological water qualities from June 23 to 26, 2007. Water temperature and dissolved oxygen were in the range of 20.7~20.9oC and 7.01~7.74, respectively. Salinity and pH were in the range of 34.5~34.8‰ and 8.23~8.37, respectively. Population densities of aerobic oligotrophic bacteria and heterotrophic bacteria by plate counting method were in the range of 2.4±0.5×103~3.0±0.3×103 and 4.4±0.6×103~6.0±0.9×103 cfu ml−1, respectively. Among thirty-seven isolates isolated from surface waters around Dokdo island by using 16S rDNA analysis, dominant species were closely related to Actionobacteria (7 clones), α-proteobacteria group (6 clones), and γ-proteobacteria group (4 clones).

This study aims at the importance of Dok-do island which is located in the most eastern part of Korea. The field study was conducted during 2005. 6 and 2006. 8 at the site of Dong island of Dok-do and a total of 16 species were identified. The large breeding colony of Larus crassirostris, Oceanodroma monorhis, Calonectris leucomelas were identified and the total population of L. crassirostris was more than 10,000 individuals and signifies the largest breeding colony in the east coast. This study also attempts to collect all the information since 1978 when the bird survey was done in Dok-do for the first time. A total of 102 species were identified and this includes Falco peregrinus as Endangered species I and 9 species of Endangered II by Ministry of Environment. Dok-do also served as a habitat designated by Natural Monument #336 by Cultural Properties Administration (CPA), but CPA have not made any detailed study and conservation efforts thus far. This study also identified the potential importance of the island as a place not only for rescue island but for information center for migratory bird species in the east coastal areas.