• Title/Summary/Keyword: Red-Tide

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The Outbreak of Red Tides in the Coastal Waters off Kohung, Chonnam, Korea: 1. Physical and Chemical Characteristics in 1997 (전남 고흥 해역의 유해성 적조의 발생연구: 1.물리${\cdot}$화학적인 특성)

  • Yang, Jae-Sam;Choi, Hyun-Yong;Jeong, Hae-Jin;Jeong, Ju-Young;Park, Jong-Kyu
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.5 no.1
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    • pp.16-26
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    • 2000

  • Physical characteristics and nutrient distributions in seawater were investigated to understand the mechanism of red tide outbreak in coastal waters off Kohung area. To identify any physical and chemical differences before, during and after the red tide outbreaks, 6 times of field observations have been carried out from May to October, 1997. We found that major environmental properties of the seawater in the study area were determined not by the local meteoric conditions or nearby-land influences, but by the intrusion of seawater from offshore. In particular, extreme environmental variations in seawater were found during the period of red tide outbreak from August to September. Before the red tide outbreak, high concentrations of DIN(Dissolved Inorganic Nitrogen)were found in seawater, but they decreased during the outbreak. Whereas no significant variations of DIP(Dissolved Inorganic Phosphate) were found. For the water mass in the semienclosed northern part of the study area, local nutrient sources originated from nearby-lands were estimated to cover 70% of total DIN input, but the rest part of the water mass in the study area, sporadic intrusion of offshore water mass could account for the major source of DIN supply. An offshore water mass influenced by Yangtze river effluent was suggested as one of the candidates with its high nitrate contents, high seawater temperature and low salinity. A red tide related phytoplankton, Gyrodinium impudicum, was found in seawater on the 21th day of August and, on the same day, a unique water mass with high temperature and extremely low salinity suddenly appeared in the study area. On the 22th day of September, after one and half month duration of red tide we found that red tide had disappeared simultaneously with the intrusion of new water mass with different characteristics.

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Morphology and Ecology of Peridinium bipes var. occultatum Lindem.(Dinophyceae) Forming Freshwater Red Tides in Korean Dam Reservoirs

  • Lee, Jung-Joon;Jang, Sung-Hyun;Lee, Joo-Heon;Lee, Jung-Ho
    • ALGAE
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    • v.21 no.4
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    • pp.433-443
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    • 2006

  • This study was performed to understand the morphological and ecological characteristics of Peridinium bipes var. occultatum Lindem., which is the organism responsible for freshwater red tides in Sangsa dam and Miryang dam reservoirs. The samples were collected from April to July 2004 when the freshwater red tides occurred. In the study, we were able to differentiate P. bipes var. occultatum from P. bipes, a closely related species, by its smaller antapical horn size. In Miryang dam reservoir the red tide occurred only within the area of the upstream, but it was well developed in all of the water area in Sangsa dam reservoir. In 2004 average LTSI (Lake Trophic Status Index; Yang and Dickman, 1993) of Miryang dam reservoir was 3.53 of mesotrophic state and Sangsa dam reservoir was 8.59 of eutrophic state. It was determined, through culture experiments under various conditions that vitamins, trace elements, phosphorus and nitrogen were important contributing factors to the growth of P. bipes var. occultatum. A rapid toxic effect of P. bipes var. occultatum on aquatic organisms such of Daphnia magna and Oryzias latipes was not identified in this study.

  • https://doi.org/10.4490/ALGAE.2006.21.4.433 인용 PDF KSCI

A Numerical Simulation on Red Tide Formation

  • Yanagi, Tetsuo
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 1993.07a
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    • pp.14-19
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    • 1993

  • Gymnodinium mikimotoi is one of several species of flagellates that cause harmful red tides. The red tides of G. mikimotoi have occurred only along $33-35^{\circ}$ N, e.g. Chinhae Bay in Korea, tile Seto Inland Sea and Kumane-Nada in Japan. I try to reproduce the formation of red ties of G. mikimotoi at Suo-Nada and Iyo-Nada, the western part of Seto Inland Sea, Japan in July 1985 with the use of four-dimensional assimilation model including the biological process of G. mikimotoi in this paper. (omitted)

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