Margins seas play an important role in the global oceanic carbon, which were contribute approximately 30% of global primary production. The spring phytoplankton blooms showeda recurrent feature in the East China Sea recorded in the past over decade.Phytoplankton blooms can lead to the substantial carbon sink due to the high productivity and large sinking export in phytoplankton bloom area.we report their contributions to POC flux in coast of the East China Sea during a spring bloom. Sinking rates of phytoplankton during bloom was 12.22±1.57 m day-1, which was more than 10 times (about 12 times) than non-bloom sites (1.04±0.78 m day-1). The highest of phytoplankton POC flux during bloom was 23952.5 mg C m-2 day-1, which was about 100 times than non-bloom control sites (256.48 mg C m-2 day-1). In this study, sinking rates increased significantly because of extremely high cell abundance, which impel cells aggregated. Actually, a massive phytoplankton sinking in the form of aggregation rather than individual cell. Average sinking rates of fecal pellets was 191.41±77.45 m day-1 during the bloom, which was not significantly higher than control sites (143.55±73.05 m day-1). Fecal Pellets POC flux in bloom sites in site ECS1 (1985.6 ± 142.1 mg C m-2 day-1) and ESC2 (2114.1± 151.9 mg C m-2 day-1) were about 3 times than non-bloom sites ESC3 (654.4±45.6 mg C m-2 day-1) and ESC4 (782.2±63.4 mg C m-2 day-1). Therefore, POC sinking sequesters carbon to the deep ocean faster than anticipated, and should be incorporated into biogeochemical of export via the biological carbon pump during the spring bloom.
Keyword: bloom ; phytoplankton ; sinking rates; POC flux; aggregation;
