Characteristics of Benthic Chlorophyll a and Sediment Properties in the Tidal Flats of Kwangyang Bay, Korea

doi:2009.24.3.149

Algae > Volume 24(3); 2009 > Article

Algae 2009;24(3): 149-161. doi: https://doi.org/10.4490/algae.2009.24.3.149

Yongsik Sin¹^*, Sang Ock Ryu² and Eunsook Song³

¹Division of Ocean System Engineering, Mokpo Maritime National University, Mokpo, Chonnam 530-729, Korea
²Institute of Tidal-Flat Research, Mokpo National University, Muan, Chonnam 534-749, Korea
³Coastal Estuarine Research Center, Mokpo National Maritime University, Mokpo, Chonnam 530-729, Korea

*Corresponding Author

Email: yongsik@mmu.ac.kr

ABSTRACT

Characteristics of benthic microalgae and sediment properties were investigated for the intertidal flats of Kwangyang Bay, Korea. Sampling stations were selected every 100 m in the intertidal flats from land-side to open ocean at two different sampling sites. Samples were collected in June 2004, July, September, November, February and May 2005. Sediments properties were measured including temperature, water contents, sediment bulk density, nutrient concentrations in porewater. Chlorophyll a concentrations in surface sediment (0.5 cm) were measured and relationships between the chlorophyll a and various sediment properties were analyzed to identify major mechanisms regulating biomass of benthic microalgae in the intertidal flats using simple linear regression analysis. Sediment chlorophyll a concentrations were maximum during winter and minimum during warm seasons ranging from 4.4 mg m?2 to 81.2 mg m?2. No clear spatial variations were observed for the sediment chlorophyll a in the study sites. Results from regression analysis suggested that benthic microalgae biomass was affected by sediment temperature and nutrients especially ammonium and silicate. Grazing effect was estimated using chlorophyll: pheopigments ratio, indirect indicator of grazing activity, and the positive correlation of the ratio and chlorophyll a implied that microalgae biomass is affected by grazing of zoobenthos although direct measurement of grazing activity is required to determine the importance of top-down controls in the benthic microalgae dynamics.

Key words: intertidal flats, Kwangyang Bay, microalgae, nutrients, sediment