지속적인 환경변화에 따른 중형저서동물 군집의 변동을 살펴보기 위하여, 시화호 방조제 배수갑문 부근의 대부도 방아머리 조간대의 5정점과 인근 조하대 3정점을 택하여, 2000년 3월부터 2001년까지 계절별로 수행되었다. 표층퇴적물의 평균 입도는 조간대에서 사질 퇴적 환경으로 3.16~3.73 Φ, 조하대에서 주로 니질 퇴적 환경으로 5.81~6.67 Φ, 의 퇴적 환경 특성을 나타냈다. 전체 19개의 중형저서동물 분류군이

조하대 각 정점에서 중형저서동물의 그룹별 조성을 보면 총 22개의 그룹이 출현하였다. 배수갑문 바로 앞의 정점에서는 방류 하루 후, 방류 일주일 후가 방류 하루 전에 비해 중형저서동물군집의 각 개체군의 개체수가 다른 정점에 비해 현저하게 감소함을 나타냈다. 우점하고 있는 분류군은 방류 하루 전에는 저서성 요각류가 가장 우점하고 있었고, 방류 하루 후에는 거의 출현하지 않는 현상을 보였다. 배수 갑문으로부터 약간 떨어진 정점에서는 앞의 정점과 같이 급격한

The present study investigated the effect of ammonia load on microbial communities in mesophilic anaerobic digestion of propionic acid. A laboratory-scale continuous anaerobic digester treating propionic acid as a sole organic substrate was operated under non-inhibitory condition and inhibitory conditions with ammonia (1.5 g and 3.5 g ammonia-N/L, respectively), and bacterial and archaeal communities in the steady states of each ammonia condition were analyzed using high-throughput sequencing. Thirteen bacterial families were detected as abundant bacterial groups in mesophilic anaerobic digestion of propionic acid. Increase in ammonia concentration resulted in significant shifts in microbial community structures. Syntorophobacter, Pelotomaculum, and Thermovigra were determined as the dominant groups of (potential) propionate oxidizing bacteria in the non-inhibitory condition, whereas Cryptanaerobacter and Aminobacterium were the dominant groups of (potential) propionate oxidizing bacteria in the ammonia-inhibitory condition. Methanoculleus and Methanosaeta were the dominant methanogens. Acetate-oxidation coupled with hydrogenotrophic methanogenesis might be enhanced with increases in the relative abundances of Methanoculleus and Tepidanaerobacter acetatoxydans under the ammonia-inhibitory condition. The results of the present study could be a valuable reference for microbial management of anaerobic digestion systems that are exposed to ammonia inhibition and propionic acid accumulation.

In this study, the intra-seasonal fluctuation (ISF) of wintertime temperature change in East Asia was classified by a cluster analysis of complete linkage. A ISF of temperature change was defined as a difference of synthesized harmonics (1 to 36 harmonic) of daily temperature averaged for 30 years (1951~1980, 1981~2010). Eight clusters were gained from the ISF curves of 96 stations in East Asia. Regions of the cluster C, G and A1 seem to be affected by the Siberian High (SH) center, whereas the cluster A1, A2, D, B and F by the SH main pathways. Regions of the cluster E are apart from the SH main pathways and appear to be in the area of influence of other factors. Wintertime temperatures in Northwest China (clusters C, G) and Northeast China (cluster A1) were increased very largely. In most clusters, around late January there were less warming periods than the winter mean of the mean ISF of the clusters, before and after this time there were more warming periods than the winter mean.

도시화 및 기후변화에 의한 물순환 특성의 변동 분석을 도시지역별로 평가하고 특성이 유사한 지역별로 대상 집단을 분류하여 낙동강 유역 내 도시 지역을 도시화 및 기후의 변화로 발생되는 유사 특성을 나타내는 지역별로 그룹화하였다. 본 연구는 도시화에 따른 불투수면적의 증가에 따른 물순환 변동의 특성을 분석하기 위하여 낙동강 유역을 대상으로 1975년, 1990년, 2009년의 토지이용도 자료를 수집하였다. 또한 기후변화의 영향을 고려하기 위하여 기상청에서 제공하는 AR5 시나리오 기반의 RCP 8.5 시나리오를 선정하였다. 낙동강 유역 내 지역별 물순환 변동 지수를 산정하기 위하여 SWAT 모형을 구축하여 토지이용시나리오 및 기후변화 시나리오를 적용함으로써 소유역별 발생되는 물순환 결과를 도출하였다. 낙동강 유역은 표준단위유역을 기준으로 145개 소유역으로 분할하였으며, 산정된 물순환 결과 및 토지피복별 변화 정도의 결과를 이용하여 군집분석의 입력자료로 활용하였다. 물순환 및 토지피복별 변화 정도를 면적대비 변화율로 정의하여 지수를 도출하고 지수 간의 Spearman's rank-order 상관분석을 통하여 상관분석을 실시하였다. 지수 간 상관 정도가 높은 지역별 지수를 군집분석 기법 중 k-means clustering analysis 기법에 적용하여 145개 소유역에 대하여 3 가지 cluster로 분류하였다. cluster1의 경우는 도시화의 증가율이 비교적 적은 지역으로 산림 및 농지가 대부분을 차지하였고, cluster2는 도시화 진행 정도가 5 % 미만인 지역이며, cluster3은 도시화가 5 % 이상으로 면적 대비 증가율이 비교적 크고 산림 및 농지의 면적의 비율이 작은 지역으로 분류되었다. 유역 내 도시 단위별 도시화 및 기후변화에 따른 물순환 특성의 변동이 유사한 지역으로 군집화 함으로써 수자원 개발 또는 도시 개발 계획 시 유사한 지역의 사례를 통한 기초 조사·분석에 활용이 가능하다.

We analyzed with HPLC (High Performance Liquid Chromatography) analysis photosynthetic pigments and environmental factors, microscopic observations of the phytoplankton and zooplankton in the seawater every month from February 2009 to November 2010 in Haengam Bay. The level of dissolved inorganic nutrients was the highest between July and September, when freshwater influx was at its peak, whereas chlorophyll a levels were the highest in April and August. Also, phytoplankton pigment concentration increased when dissolved inorganic nutrients are carried into nearshore waters by rainfall runoff. Based on identification of phytoplankton and photosynthetic pigments results, diatoms were mainly dominant while dinoflagellate populations increased at July and August 2009, May 2010. The zooplankton communities are dominated in terms of Noctiluca scintillans. The contribution of Noctiluca scintillans in 2010 accounts for approximately 77.3% of the total zooplankton. Distribution patterns over time of zooplankton in the seasonal distribution of phytoplankton showed a different pattern.

Benthic macroinvertebrates were seasonally sampled from upstream and downstream of the Gunwi Dam construction site from 2006 to 2012. Totally 148 and 165 species were collected at the upstream and downstream sampling sites, respectively. At the upstream area after dam construction, there was no significant change of the numbers of non-insect taxa, but at the downstream area, the non-insect taxon numbers were increased gradually. The individual ratio of Ephemeroptera and Diptera had higher value than the other taxa in both of up and downstream. The trichopteran individual ratios were increased in upstream sites, but decreased in downstream sites from 2010. Also, non-insects and coleopteran individual ratios were decreased in upstream, but increased in downstream after completion of dam construction. The annual range of fluctuation in community indices narrowed after construction. According to a functional feeding group analysis, the individual ratios of FC (Filtering Collector) were increased, and GC (Gathering Collector) and SC (Scraper) were decreased in upstream sites annually. In contrast, the annual individual ratios of FC were decreased, and GC and SC were increased in the downstream sites.

This study presented seasonal changes of the phytoplankton community in Junam reservoir by pollution and water quality of the lake. The water storage of the reservoir is 5.3 million ton, most of which are being utilized for agricultural, industrial and residential purposes. The annual precipitation during the investigation period was 1,868.9 ㎜, increasing by 20% from the average annual level of 1,506.7 ㎜ in 2009. The annual average water storage was 57.3%. It decreased during agricultural season and then increased again after monsoon rainfall. The loads of BOD were 3,799 ㎏day -1 , and 81% of them came from livestock and household. The TN and TP loads were 1,164 ㎏day -1 and 170 ㎏day -1 , respectively, and 76% of them came from livestock. We assessed water quality of the Junam reservoir using 17 variables. According to the result, the reservoir met the fourth grade, meaning slightly bad, because of high concentration of COD, SS and chlorophyll-a. Eutrophication assessment was conducted by revised Carlson's Index (TSIm, Aizaki), and it was found that the entire lake was eutrophicated with high chlorophyll-a concentration all through the year, except during February to April and in July. A total of 76 phytoplankton species were identified from the samples. Among them, the largest number of species were Chlorophyceae with 33 species(43.4%), followed by Bacilliophyceae with 27 species(35.5%), Cyanophyceae with 8 species(10.5%), and Cryptophyceae with species(10.5%). The total cell number of phytoplankton was the highest in October(7,884 cells mL -1 ) among Cyanophyceae and Bacilliophyceae. The seasonal succession of Chlorophyceae (Chlamydomonas spp.), Cyanophyceae(Microcystis aeruginosa) and Cryptophyceae(Rhodomonas spp.) was observed during January to May, July to September and October to December respectively.

The short-term variations of the mesozooplankton community structure were investigated in Gamak Bay during summer season, 2006. The study was based on a comprehensive survey constituting from 12 stations on June 19, July 28, August 4, and August 29, respectively. Mean of temperature and chlorophyll a concentrations in the surface layer were significantly higher than those in bottom layer, and those concentrations were significantly higher in the inner bay than those in the outer bay. A total of 40 taxa including 19 copepods were observed in Gamak Bay during summer season. Mean abundance of total mesozooplankton varied from 1,859 to 26,111 indiv. m-3. The dominant species were Noctiluca scintillans, Penilia avirostris, Evadne tergestina, Paracalanus parvus s. l., Acartia omorii and Cirriped nauplii and cyprii in Gamak Bay, and they contributed 90% of mean abundance of total mesozooplankton. Noctiluca scintillans was high after the rainfall. Cluster analysis showed that the mesozooplankton community could be divided into 4 distinct groups, indicating rapid change of the community in the short-term of this survey. The relative contribution of each group of the N. scintillans, P. avirostris, E. tergestina, and P. parvus s. l. showed differences during the phytoplankton bloom period. The mesozooplankton community compositions were highly associated with water temperature, and salinity in physical conditions, and food organisms affect short-term variations in mesozooplankton composition. Interestingly, protozoa N. scintillans, and Cladocera appeared to be one of the key organisms to extinguish the phytoplankton bloom. Therefore, this study suggests that N. scintillans, and Cladocera could be a key player to control the mesozooplankton community structure during summer season, 2006.

In order to study on the variational characteristics of water quality and chlorophyll a concentration, the water samples were collected daily or three times a week during the period from April 1990 to November 1991 at Kukdong port located in the Northern Kamak bay of Southern Korea I made an analysis on biological factor as chlorophyll a concentration as well as physico-chemical factors such as water temperature, salinity, sigma-t, dissolved oxygen, nutrients (ammonia, nitrite, nitrate, phosphate, and silicate), N/P ratio and chemical oxygen demand. In Northern Kamak bay seasonal variations in physical factors such as water temperature, salinity and sigma-t were very marked. On the other hand, chemical factors such as nutrients concentration and COD were not so. Chemical factors, in particular, silicate were influenced by input of freshwater. And the roles of silicate on the seasonal succession of phytoplankton species composition was very low. Phytoplankton biomass as measured by chlorophyll a concentration was very high all the year round, and it was controlled by the combination of several factors, especially of N/P ratio determined by dissolved inorganic nitrogen.

The community of phytoplankton and water quality were investigated 5 times from October, 1994 to October, 1995 in the east area of Chinhae Bay. Seasonal changes of environmental parameters were shown general pattern and related to the red tide mechanism of phytoplankton community. Seasonal variations of dissolved oxygen concentrations were affected by the photosynthetic activity of phytoplankton community and the increase of COD at the bottom water was occurred after the red tide. The standing stocks of phytoplankton in this study area ranged 202 - 1616 Cells·ml^-1 and the bloom(red tide) was formed from April to July. The diatom species, Skeletonema costatum was a dominant species all the year round and the dinoflagellate species, Alexandrium tamarense and Prorocentrum triestinum were red tide species increased standing stocks in phytoplankton bloom.

A study was carried out on the distribution of chlorophyll a and water quality in the dry season in Yosuhae bay and adjoining sea, Southern Korea, in July of 1994. Concentration of salinity and phosphate were lower in the outer bay than in the inner bay. While nitrate and silicate were higher in the former than in the latter. We were identified with coastal water of origin from China with the lower salinity in outer bay. The China coastal water was characteristic of high nutrients and phytoplankton biomass, such as chlorophyll a. The principal component analysis (PCA) on the analytical data proved that high density of phytoplankton biomass occurred under the condition of low salinity and high concentration of dissolved inorganic nutrients. It is thought that the thermoharine structure and biological produtions of Yosuhae bay were controlled by the China coastal water in the outer bay.