Characteristics of Horizontal Community Distribution and Nutrient Limitation on Growth Rate of Phytoplankton during a Winter in Gwangyang Bay, Korea

Abstract

: To estimate the effects of limitation nutrients for phytoplankton growth and its influences on short-term variations of a winter phytoplankton community structure, we investigated the abiotic and biotic factors of surface and bottom waters at 20 stations of inner and offshore areas from 6 to 7 February in Gwangyang Bay, Korea. Also, several algal bio-assay studies were conducted to identify any additional nutrient effects on phytoplankton assemblage using surface water for the assay. The dominant species in the bay was diatom Skeletonema costatum, which occupied more than 70% of total species in most stations (St.1-16) of the inner bay. According to a cluster and multidimensional scaling (MDS) analysis based on phytoplankton community data from each station, the bay was divided into three groups. The first group included stations from the south-western parts of Myodo lsland, which can be characterized as a semienclosed eutrophic area with high phytoplankton abundance. The second group included most stations from the north-eastern part of Myodo lsland, influenced indirectly by surface water currents from offshore of the bay. The standing phytoplankton crops were lower than those of the first group. The other cluster was restricted to samples collected from offshore of the bay. In the bay, silicon (Si) and phosphorus (P) were not a major limiting factor for phytoplankton production. However, since the DIN: DIP and DSi: DIN ratios clearly demonstrated that there were potential stoichiometric N limitations, nitrogen (N) was considered as a limiting factor. Based on the algal bio-assay, in vivo fluorescence values in N (+) added experiments were higher compared to control and P added experiments. Our results suggested that nitrogen may act as one of the most important factors in controlling primary production during winter in Gwangyang Bay.

Seasonal Variations in the Bacterial Community of Gwangyang Bay Seawater

“…Gwangyang bay, which receives freshwater via Seomjin River, is semi-closed and linked to the South Sea via two channels, Yeosu and Noryang, to the south and the east, respectively. The surface area of the bay is 230 km 2 and contains 20 islets. A large-scale steel works, container port, and heavy-chemical estate were constructed in the coastal region of the bay.…”

“…In recent years, this area has been designated as a special management area for coastal pollution, receiving great attention from the public due to its increasing environmental problems. There have been several investigations into the functions of environmental factors, water quality, and planktons and benthos [2,6,22], whereas studies on microorganisms are few. Therefore, we carried out systematic cataloguing of the microbial community of Gwangyang bay seawater.…”

Seasonal Variation of Bacterial Community in the Seawater of Gwangyang Bay Estimated by Amplified Ribosomal DNA Restriction Analysis

“…There have been several investigations into the functions of environmental factors, water quality, and planktons and benthos [1,3,20], whereas studies on microorganisms are few. Therefore, we investigated the seasonal variation of bacterial community of Gwangyang bay seawater.…”

The Influence of Nutrients Addition on Phytoplankton Communities Between Spring and Summer Season in Gwangyang Bay, Korea

“…광양만 해역에서 해양환경과 식물플랑크톤에 관한 연구는 지금 까지 다양하게 수행되어 왔다. 이들 대부분의 연구는 식물플랑크 톤의 분포와 군집구조 (Lee et al, 2007;Baek et al, 2011), 오염 원특성 , 염분 경사에 따른 식물플랑크톤의 종조 성과 입자성 유기물의 분포에 관한 연구 (Kwon et al, 2001;Lee et al, 2007), 와편모조류 시스트 분포특성 (Kim et al, 2003), 부 유입자물질 분포와 거동 (Lee et al, 2010), 식물플랑크톤의 영양 염 제한특성 (Lee et al, 2001;Kwon et al, 2002;Baek et al, 2011) )으로 정점간에 큰 차이를 보였고, 정점 11, 12, 13, 14 와 외해 쪽 정점 19, 20를 제외한 모든 정점에서 높게 관찰되었다 (Fig. 4).…”

“…본 종은 계절에 관계 없이 내만 뿐만 아니라 기수 역의 저염분 조건에서 활발한 증식을 하는 것으로 보고되고 있다 (Han et al, 1992;Baek and Kim, 2010;Baek et al, 2011). (Curl and MeLeod, 1961;Hitchock, 1980), 염분 또한 5~45 psu 로 기수역뿐만 아니라 고염분 조건에서 내성이 강한 것으로 보고되고 있다 (Brand, 1984;Rijstenbil, 1989).…”