The Spatio-Temporal Progress of Cochlodinium polykrikoides Blooms in the Coastal Waters of Korea

한국연안의 Cochlodinium polykrikoides 적조 발생과 변천

  • KIM Hak Gyoon (Dept. of Marine Environment Oceanography and Harmful Algal Blooms Department National Fisheries Research & Development Institute) ;
  • JUNG Chang-Su (Dept. of Marine Environment Oceanography and Harmful Algal Blooms Department National Fisheries Research & Development Institute) ;
  • LIM Wol-Ae (Dept. of Marine Environment Oceanography and Harmful Algal Blooms Department National Fisheries Research & Development Institute) ;
  • LEE Chang-Kyu (Dept. of Marine Environment Oceanography and Harmful Algal Blooms Department National Fisheries Research & Development Institute) ;
  • KIM Sook-Yang (Dept. of Marine Environment Oceanography and Harmful Algal Blooms Department National Fisheries Research & Development Institute) ;
  • YOUN Sung-Hwa (Dept. of Marine Environment Oceanography and Harmful Algal Blooms Department National Fisheries Research & Development Institute) ;
  • CHO Yong-Chul (Chongppyong Inland Fisheries Institute, National Fisheries Kesearch & Development Institute) ;
  • LEE Sam-Geun (Dept. of Marine Environment Oceanography and Harmful Algal Blooms Department National Fisheries Research & Development Institute)
  • 김학균 (국립수산진흥원 어장환경부) ;
  • 정창수 (국립수산진흥원 어장환경부) ;
  • 임월애 (국립수산진흥원 어장환경부) ;
  • 이창규 (국립수산진흥원 어장환경부) ;
  • 김숙양 (국립수산진흥원 어장환경부) ;
  • 윤성화 (국립수산진흥원 어장환경부) ;
  • 조용철 (청평내수면연구소) ;
  • 이삼근 (국립수산진흥원 어장환경부)
  • Published : 2001.11.01

Abstract

The first bloom of Cochlodinium polykrikoides was observed in the estuary of Nak-dong river near Pusan in Korea in 1982. Since then, there have been irregular blooms, sometimes spread over the adjoining .to Jinhae Bay even though it was confined to the bay and its vicinites until 1988. It had been outbroken frequently in the adjacent to Tongyeong, Geoje, Namhae and Yeosu coast since 1989. It became widespread along the coast of the South Sea to the East Sea of Korea in 1995. And in October in 1998 and 1999, the bloom had been taken place in Kunsan coast of Yellow Sea. According to the observations in situ, the frequency of occurrence has been increased year by year. The prevailing bloom season was from July to October with peak in September. The duration of the bloom became longer with the year, and sometimes lasted more than one month. The density of the bloom did not exceed 5,000 cells $mL^{-1}$until 1991, but it increased year by year to the highest of 43,000 cells $mL^{-1}$ in 1999. With respect to the assembleges of species in dinoflagellate blooms, C. polykrikoides was one of the important species with diatoms and the other dinoflagellates in 1980s. But since then, C. polykrikoides made an almost monospecific bloom. Based on two decadal observations of C. polykrikoides blooms, it became widespread throughout whole coast of the Korea, persistent for about one or two month long in some year, and monospecisc high density blooms. It was reported that significant fish mortalities were caused by this harmful dinoflagellate blooms especially in the fishfarms accomodating intensive fish cages such as Tongyeong, Namhae-do, Geoje, Yeosu and Geomun-do fishfarming yards. This widespread and persistent harmful algal blooms impede the development of marine aquaculture industries.

우리나라 연안에서 Cochlodinium polykrikoides 적조는 1982년 낙동강하구에서 최초로 발생하였으며, 1988년까지는 진해만과 그 부근해역에서 발생하였다. 그러나 1989년 이후부터는 진해만에서는 거의 발생하지 않고 충무, 거제, 남해, 여수 둥의 남해안의 중부해역에서 주로 발생하였고, 1995년부터는 동해연안까지 발생해역이 확대되었다. 그리고, 1998, 1999년도에는 서해연안에서도 이종에 의한 적조가 발생하였다. C. polykrikoides 적조 발생건수는 매년 증가하는 추세를 보였으며, 발생시기는 $7\~10$월로 특히 9월에 집중 발생하는 것으로 나타났다. 적조지속기간도 매년 증가하여 처근에는 한달 이상 지속되는 양상을 보이고 있으며, 적조밀도 역시 '91년까지는 최고 5,000cells $mL^{-1}$를 초과하지 않았으나, '99년도에는 43,000 cells $mL^{-1}$까지 나타나 매년 증가하는 추세를 보였다. 한편 C. polykrikoides적조는 '82년과 '84년에는 다양한 규조류 및 편모조류와 함께 발생하는 혼합적조로 출현하였으나, 이후에는 주로 단독적조로 출현함으로써 C. polykrikoides 적조가 혼합적조에서 단독적조로 발전해 갔음을 알 수 있었다. 이와 같이 C. polykrikoides 적조는 발생해역이 우리나라 전연 안으로 확대되고, 적조밀도가 높아지며, 발생기간이 $1\~2$개월로 장기간 지속하고 있는 양상을 나타내고 있으며 특히 양식산업이 성행하고 있는 충무, 남해도, 거제도, 여수 및 거문도 연안에서 $8\~9$월에 자주 적조를 형성하므로서 양식산업 발전에 큰 위협이 되고 있다.

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