Three embankments, namely Changpo, Bokkil and Guil, in Chunggye Bay were investigated to assess the influence of environmental changes to phytoplankton size structure, distribution of species and standing crops. Three stations was sampled near at each embankment in Nov. 2006, Feb. 2007, May 2007 and Aug. Phytoplankton were classified into net-size (>20㎛) and nano-size (<20㎛). In summer, the freshwater discharge seemed to have influence in the decrease of salinity and in the increase of turbidity, ammonium and phosphorus concentrations. Chl a concentration and phytoplankton abundance in Feb. 2007 were observed to be generally higher in all stations compared to other periods. Net-size phytoplankton was observed to be higher in Feb. 2007 and May 2007 compared to nano-sized phytoplankton. However, there was shift in phytoplankton composition in Nov. 2006 and Aug. 2007. Phytoplankton under seven class (Bacillariophyceae, Chlorophyceae, Chrysophyceae, Cryptophyceae, Cyanophyceae, Dinophyceae, Euglenophyceae) was identified during the study period. It was found out that the major phytoplankton class was Bacillariophyceae. Phytoplankton was more diverse in autumn compared to any other season. Cyanophyceae was increased in summer. In rainy season, change in physical factors (salinity, transparency) seemed to have more influence on phytoplankton growth compared to inorganic nutrients.

Abstract
 1. 서 론
 2. 재료 및 방법
  2.1. 물리화학적 환경인자
  2.2. 엽록소 a 측정
  2.3. 식물플랑크톤 군집
  2.4. 통계분석
 3. 결 과
  3.1. 기후요인
  3.2. 물리적 환경인자
  3.3. 무기영양염류
  3.4. 크기별 엽록소 a와 개체수
  3.5. 군집구조 및 우점종
  3.6. 통계분석
 4. 고 찰
 5. 결 론
 참 고 문 헌

• 정병관(목포해양대학교 해양시스템공학부) | Byung-Kwan Jeong (Division of Ocean System Engineering, Mokpo Maritime National University)
• 지성(목포해양대학교 해양시스템공학부) | Sung Ji (Division of Ocean System Engineering, Mokpo Maritime National University)
• 신용식(목포해양대학교 해양시스템공학부) | Yong-Sik Shin (Division of Ocean System Engineering, Mokpo Maritime National University) Corresponding author