Spatial-temporal dynamics of biogenic silica in the southern Yellow Sea

Concentrations of biogenic silica (BSi) in the southern Yellow Sea were determined during four cruises (spring: April-May 2014; autumn: November 2014; summer: August-September 2015; winter: January 2016). Samples of BSi were measured using the double extraction method. Seasonal and spatial variations of BSi and the potential correlation between chlorophyll a (Chi a) content and BSi in four seasons were measured in this study. Significant spatial variability was observed in seawater BSi concentrations. The average concentration of BSi was highest in winter and lowest in spring. Furthermore, the relationships between concentrations of BSi and hydrological parameters were also discussed. There was a significant positive correlation between Chi a and BSi. The concentrations of BSi showed significant relationships with temperature and the concentrations of silicates, total inorganic nitrogen and total inorganic phosphorus, indicating that distribution of BSi was affected by temperature and nutrient level.