만경강 하류의 환경과 식물플랑크톤 군집

심재형,신윤근,이원호 ( Jae Hyung Shim,Yoon Keun Shin,Won Ho Lee ) 한국하천호수학회 1991 생태와 환경 Vol.24 No.1

The community of phytoplankton was investigated 11 times from October, 1989 to August, 1990 on monthly interval in lower Mankyeong River. During the surveys, distribution patterns were studied for species composition of phytoplankton, standing stocks, species diversity, temperature, salinity, dissolved oxygen, pH, nutrients. The environments of study area differentiated distinct low-discharge and high-discharge periods. During low-discharge period (Fall-early spring), salinity in the study area was relatively high due to sea water penetrated, while in high-discharge season, low salinity was observed contribute to high discharge of fresh water. Ratios and distribution patterns of phytoplankton species showed a close correlation with environmental characteristics which correspond with that of general fresh water environment. Species composition, standing stocks, species diversity of phytoplankton in the higher river showed large variation in time, may be resulted from pollution of water caused by several pollutants in higher parts of river. On the contrary, Jeonjupo environmental condition kept probably stable because of dilution of pollutant concentation by sea water. Decrease of phytoplankton standing stocks in very low salinity regions may be resulted from mortality of fresh water phytoplankton caused by changes in osmotic pressure.

Primary Production System in the Southern Waters of the East Sea, Korea I. Biomass and Productivity

심재형,여환구,박종규,SHIM, JAE HYUNG,YEO, HWAN GOO,PARK, JONG GYU The Korean Society of Oceanography 1992 韓國海洋學會誌 Vol.27 No.2

For the study on the structure and characteristics of the primary production system in the southern waters of the East Sea, chlorophyll, phytoplankton standing stocks. nutrients and hydrographic properties were investigated and analyzed in conjunction with measurement of C-14 based primary productivity. The primary productivity was relatively high in comparison with the previous studies, ranging from 284 to 4,574 mgC$.$m/SUP -2/$.$day /SUP -1/ and averaged to be 2,000 mgC$.$m/SUP 02/$.$day/SUP -1/. The standing stocks within the euphotic zone were fairly high, but ambient inorganic nitrogenous nutrient concentrations were too low to support the high production. This implied that there might be active recycling of nitrogenous nutrients by heterotrophic processes and the upward flux of nutrients by vertical mixing. Subsurface chlorophyll maxima were continuously observed in the lower parts of the euphotic layer and the depth coincided with the nutricline rather than isopycnal surfaces, supporting the view that chlorophyll distributions and primary production were primarily influenced by nutrient supply. Despite low nutrient concentrations, phytoplankton standing stocks and production were fairly high and the fraction of autotrophic nano- and picoplankton production was significant.

Spatial and Temporal Variations of Phytoplankton in Ch$\check{o}$nsu Bay

심재형,여환구,Shim, Jae Hyung,Yeo, Hwan Goo The Korean Society of Oceanography 1988 韓國海洋學會誌 Vol.23 No.3

Spatial distribution and temporal variations of phytoplankton population were investigated in Ch$\check{o}$nsu Bay, the Korean western coast. Diurnal fluctuations of phytoplankton standing crop are associated with semidiurnal tidal cycle, as high concentration at low tide and low at high tide. In monthly variations of phytopolankton standing crop, the 1st peak occurrs in March and the 2nd one in August. The study area could be divided into two parts, outer bay and inner bay according to the physical and biological factors such as water temperature and salinity, and phytoplankton distribution patterns. The northern waters of the bay, however, may be affected by irregular fresh water influx through the lock of the dike. Because of the hydrographical differences among the surveyed stations, phytoplankton species succession patterns of each station have some differences. On the whole in this study area, Paralia sulcata and Skeletonema costatum are dominant species all the year round. However, except June, Paralia sulcata, a tychopelagic diatom is not dominant species at Station 6 (northern end of the bay). This seems to be caused by the fact that the waters of northern part of the bay is less turbulent than that of the outer bay. The result of principal component analysis (PCA) indicates that Ch$\check{o}$nsu Bay is normal coastal ecosystem where the environmental conditions are cycled in a year, and water temperature and nitrogenous nutrients such as nitrate, nitrite and ammonia are major factors to influence the annual cycle of environmental conditions.

Phytohydrography and the Vertical Pattern of Nitracline in the Southern Waters of the Korean East Sea in Early Spring

심재형,앙성렬,이원호,Shim, Jae Hyung,Yang, Sung Ryull,Lee, Won Ho The Korean Society of Oceanography 1989 韓國海洋學會誌 Vol.24 No.1

A study on quantitative phytoplankton samples, hydrographic conditions (temperature, salinity, dissolved oxygen), and nutrients has been performed in the southern waters of the Korean East Sea in early spring. Phytoplankton community showed close correlation with hydrographic conditions. This study area could be divided into three phytohydrographic regions; 1) East Korean Warm Water Region (a branch of Tsushima Current), 2) North Korean Cold Water Region, and 3) offshore water region not affected by other two water regions. Vertical distribution of phytoplankton is dependent upon stability of water column and nutrient concentration. Nutrient concentration shows characteristic distribution according to water masses. N/P ratio of ca. 3 in surface layer indicates that nitrogen is the major limiting nutrient in this area. N/P removal ratio was 12.54 ($r^2$ = 0.96), consistent with the Redified ratio. Primary nitrite maxima at the nitracline depths are thought to be formed by phytoplankton exudation. Secondary nitrite maximum was observed in coastal area with dissolved oxygen content of >5.2 ml/l much higher than <0.25 ml/l in other areas. The mechanism of secondary maximum is different from that of other regions, and whether it may be due to in situ degradation of organic matter by bacterial activity is still open to discuss.

한강하류에 있어서 부유성 조류군집의 구조 및 기능변화에 관한 연구

심재형,최중기,Shim, Jae Hyung,Choi, Joong Ki 한국해양학회 1978 韓國海洋學會誌 Vol.13 No.2

The planktonic algal communities of the Han River with a particular emphasis on water pollution was studied over a twelve month of period. Results of observing many algal communities from 7 stations of the Han River have shown that these communities are generally composed of many species, most of which have relatively small populations with a few exceptional dominant species. The distribution of the total standing crop of phytoplankton in the studid area is characteristic, summer in the polluted zone. Diversity indices of all samples were computed and have shown that the H values of 7 stations are relatively low. However, a detailed examination of these H values reveals that the seasonal fluctuations of the species diversity remarkably coincide with those fo phytoplankton standing crop.No reduction in the species diversity at stations 4, 5, 6, and 7 where the water is heavily polluted indicates that a great number of species capable of invading stations, 4, 5, and 6 from the various tributaries, and the station 7 from the contaminated with sea water are probably more important in the functional changes of the communities than the size of sampling area. It is evident that the diversity index in a lotic environment does not indicate water quality as far as phytoplankton communities are concerned.

서해 천수만의 식물플랑크톤에 대하여

심재형,이원호,Shim, Jae Hyung,Lee, Weon Ho 한국해양학회 1979 韓國海洋學會誌 Vol.14 No.1

Monthly observations of phytoplankton and physico-chemical properties of sea water were made from October, 1977 to December, 1977 and from June, 1978 to August, 1978 at four stations in Cheonsu Bay. 141 taxa of phytoplankton(diatoms and dinoflagellates) representing 17 families, 40 genera have been identified in this study, and 11 taxa of the number are found to be new to Korea. Nitzschia longissima, Coscinodiscus occulus-iridis, Biddulphia sinensis, were the major species in the phytoplankton communities of the Bay. Leptocylindrus danicus, which was one of the dominant species in June, 1978, showed a distinct pattern of distribution;in June its abundance varied from 89.05% to 1.67% of total abundance along 4 stations. During summer months phytoplankton standing crops were ranged between 25,492 and 129,459 cells/l and the values of species diversity index (H) varied from 0.648 to 3.597. A brief taxonomic account is given.

光陽灣 植物 플랑크톤 分布에 관한 硏究

심재형,신윤근,이원호,Shim, Jae Hyung,Shin, Yoon Keun,Lee, Won Ho 한국해양학회 1984 韓國海洋學會誌 Vol.19 No.2

Phyroplankton samples were collected seasonally from March to December, 1982 in order to study the distribution of phyroplankton and their relation to environmental factors in Kwang-yang Bay. A total of 211 taxa of phyroplankton representing 67 genera, 196 species, 14 varieties, and 1 forma have been identified. Seasonal succession of dominant species is evident in this bay; Rhiwosolenia deiicatula, Chroomonas sp. being predominant in spring, Chroomonas sp. in summer, Chaetoceros debilis, C. socialis in autumn, and Skeletonema costatum, Chroomonas sp. in winter, repectively. The standing crops of the phyroplankton vary with time, and hare relevance to NH$\_$3/-N concentration, grazing pressure, and temperature. In spring, diatom blooming is relatively well correlated with the NH$\_$3/-N concentration. The species diversity is rather low in general. The fraction of nanoplankton total cell number represents an annual average of 36.5%, showing a meaningful contribution to the primary production and food web in this water system. Spatial distribution of phytoplankton indicates that this bay could e divided into three chracteristic areas; Seomjin-river mouth area heavily influenced by fresh water, western-half area scarecely affected by the oceanic water, and eastern-half area heavily influenced by the oceanic water. The industrial effluents from the YeochunIndustrial Complex also affected the spatial distribution of phyroplankton.

韓國 東南 海域의 플랑크톤 硏究(I) -1981年 9月의 植物플랑크톤 分布-

심재형,이원호,Shim, Jae Hyung,Lee, Won, Ho 한국해양학회 1983 韓國海洋學會誌 Vol.18 No.2

Qualitative and quantitative phytoplankton samples collected during a cruise in the southeastern sea of Korea in September 1981, were analysed. A total of 185 species of phytoplankters were identified in the present study. Of the numbers 14 species of diatoms and 56 dinoflagellate forms were found. The rest were 3 silicoslagellate forms, a cryptomonad and a euglenoid each. On the bases of the analyses of the phytoplankton communities, two vegetation areas were recognized. It is demonstrated that the extent of each vegetation area largely depends on hydrographical features. In southeastern coastal waters, the vegetation was fairly rich, and consisted of small celled diatoms and minute flagellates. In the northern part of the area, abundant phytoplanktons were present consisting of various diatoms and dimofalgellates. The size of standing stock of phytoplankton was compared with hydrography and the specific composition of phytoplankton. The importance of mixing between the Tsushima warm current water and North Korean cold water in distributing phytoplankton stocks was stressed.

초여름 韓國 西南海域 植物플랑크톤의 群集構造와 分布

심재형,박용철,Shim, Jae Hyung,Park Yong Chul 한국해양학회 1984 韓國海洋學會誌 Vol.19 No.1

To characterize community structure and distribution of phytoplankton, cluster analyses are performed on quantitative data of phytoplankton collected from the southwestern sea of Korea in early summer, 1980. The cluster analysis shows that the phytoplankton of the study area consists of three distinct characteristic communities, representing different water masses. The species of the first community, predominant in the southwestern coastal were of the main land, are mostly neritic and cold water diatoms. The second community consists of neritic and oceanic diatoms, a few flagellates and an euglenoid. These species are predominant in the vicinity of Jeju Island with warm and high saline waters which seems to be a branch of the Kuroshio Current. The species of the last community, consisting primarily of small-sized dinoflagellates, are predominant in the rest part of the study area with warm and low saline water. Addition, the vertical distributions of phytoplankton and environmental factors show that high concentration of phytoplankton cells, chlorophyll-a and dissolved oxygen are observed near the seasonal pycnocline in the off-coastal area. Fraction of nanoplankton take the above 90% of the total cell concentration in the surface mixed layer of off-coastal area where the seasonal pycnocline develops in summer.

여수 근해의 쌍편모조류에 관한 분류학적 연구

심재형,신은령,최중기,Shim, Jae Hyung,Shin, Eun-Young,Choi, Joong Ki 한국해양학회 1981 韓國海洋學會誌 Vol.16 No.2

This study deals with the marine dinoflagellates observed in 50 samples collected in the vincinity of Yeosu from August 1979 to May 1980. Forty-nine species were identified and these taxa are attributed to 10 genera, of which 2 are infraspecific taxa. Two families, 3 genera, and 32 species are new records for the Korean coastal waters. Small dinoflagellates recorded in this study are ascribed to the use of volumetric samplers instead of nets. In this area, the armored forms are the most important components of the dinoflagellates (39 taxa). All species are illustrated by photomicroscopy. There are 49 pictures of taxa. An attempt has been made to provide more correct references to each species. There are comparative descriptive information, taxonomic comments, and distributional data for each species.