Korean Journal of Ecology and Environment (생태와환경)

The Korean Society of Limnology (한국수생태학회)
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Modeling the Effects of Periodic Intrusions of Outer Water on the Variation in the Phytoplankton Biomass and Productivity in a Small Embayment

작은 만에서 식물플랑크톤 생체량과 생산력 변화에 대한 외부 물의 정기적인 침입 효과의 모델링

  • Ougiyama, Shu (Graduate School of Science and Engineering, Ehime University) ;
  • Koizumi, Tsuneyoshi (Center for Marine Environmental Studies, Ehime University, (present address) ECOH Co.LTD.) ;
  • Takeoka, Hidetaka (Center for Marine Environmental Studies, Ehime University) ;
  • Yuichi, Hayami (Faculty of Engineering, Ehime University)
  • Published : 2004.12.31
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Abstract

Effects of the different strengths and intervals of the periodic outer water intrusions (kyuchos and bottom intrusions) on the dynamics of phytoplankton biomass in a small embayment were examined with a simple numerical model. Environmental conditions of Kitanada Bay in the Bungo Channel were applied to the model. As the interval of the intrusion became longer and the amplitude became smaller, phytoplankton biomass In the bay became higher. On the other hand, as the interval became shorter and the amplitude became larger, the growth rate of the phytoplankton became higher. It suggested that when the intrusion was weaker, water exchange of the bay decreased and the phytoplankton in the bay accumulated at a high density, When water exchange was improved by active intrusions, availability of light would become more efficient and the growth rate of the phytoplankton was enhanced.

본 연구는 Kitanada 만에 있어서 식물플랑크톤 생체량의 변동기구에 대한 세기와 주기성이 다른 두 가지 형태의 외양수유입 (급조(急潮) 및 bottom intrusion)의 영향을 만의 환경조건을 고려한 수식모델을 이용하여 분석하였다. 외양수 유입의 간격이 길어지고 진폭이 작아짐에 따라 만 내의 식물플랑크톤 생체량이 커졌으나, 이와는 반대로, 유입간격이 짧아지고 진폭이 커질수록 식물플랑크톤의 성장률은 높아졌다. 이 결과는 유입이 약해짐에 따라 만의 해수교환이 감소하고 만내의 식물플랑크톤이 높은 밀도로 축적됨을 시사하였다. 또한, 외양수유입에 의해 해수교환이 활발해짐에 따라 빛의 효율적 이용이 가능하여 식물플랑크톤의 성장률이 향상되었다.

Keywords

References

  1. Hayami, Y., S. Ougiyama, M. Yamada, M. Yamada, K. Takemura and H. Takeoka. (in press.) Seasonal and inter-annual variation in chlorophyll a concentration in Kitanada Bay, Uwa Sea. Bulletin of the Japanese Society of Fisheries Oceanography
  2. Kaneda, A., H. Takeoka, E. Nagaura and Y. Koizumi. 2002. Periodic intrusion of cold water from the Pacific Ocean into the bottom layer of the Bungo Channel in Japan. Journal of Oceanography 58: 547-556
  3. Koizumi, Y. 1999. Kyucho events and the mechanism of phytoplankton growth in the eastern coast of the Bungo Channel. Doctorial Thesis, University of Tokyo, 145 pp
  4. Koizumi, Y. and Y. Kohno. 1994. An influence of the Kyucho on a mechanism of diatom growth in Shitaba Bay in summer. Bulletin on coastal oceanography 32: 81-89
  5. Koizumi, Y., J. Kohno, N. Matsuyama, T. Uchida and T. Honjo. 1996. Environmental features and the mass mortality of fish and shellfish during the Gonyaulax polygramma red tide occurred in and around Uwajima Bay, Japan, in 1994. Nippon Suisan Gakkaishi 62: 217-224
  6. Nakata, K. 1993. Ecosystem Model; its formulation and estimation method for unknown rate parameters. J. Adv. Mar. Tech. Conf. 8: 99-138
  7. Takeoka, T. and T. Yoshimura. 1988. The kyucho in Uwajima Bay. J. Oceanogr. Soc. Japan 44: 6-16
  8. Takeoka, H., Y. Koizumi and A. Kaneda. 2000. Yearto-year variation of a kyucho and a bottom intrusion in the Bungo Channel, Japan. In Interactions between Estuaries, Coastal Seas and Shelf Seas, ed. T. Yanagi, Terra Scientific Publishing Company, Tokyo
  9. Tett, P., A. Edwards and K. Jones. 1986. A model for the growth of shelf-sea phytoplankton in summer. Estuarine, Coastal and Shelf Science 23: 641-672
  10. Yamamoto, T., O. Matsuda, T. Hashimoto, H. Imose and T. Kitamura. 1998. Estimation of benthic fluxes of dissolved inorganic nitrogen and phosphorous from sediments of the Seto Inland Sea. Oceanography in Japan 3: 151-158