Posters

Poster Session 1, Monday,  October  3, 15:40–18:00

Poster 101

Challenging red Noctiluca scintillans bloom detection

The dinoflagellate Noctiluca scintillans is one of the most widely distributed and abundant harmful algal bloom organisms world-wide, with two types of green and red Noctiluca . In China seas, it is red Noctiluca scintillans (RNS) dominated. During recent years, RNS bloom events in China seas have been increasing, either in terms of frequency or intensity. Efficient monitoring approaches are highly demanded. Here in this study, an intense bloom of RNS occurring in the western Taiwan Strait in late April, 2020 was investigated. Microscopic analysis of water samples in the bloom area showed maximum RNS density as high as 5.6 × 10 5 cells/L, while chlorophyll a (Chla) fluorometer detected no difference in and out of the bloom area. Similarly, Chla concentration in the whole study area from MODIS was low. These were consistent with the notion that RNS was heterotrophic, containing no pigments for photosynthesis. However, pCO 2 decreased substantially (~50-100 matm) in the bloom area, suggesting usage of CO 2 for photosynthesis. It looks like that autonomous detection of RNS bloom is still challenging, in particular from space. An integrated approach with optical and chemical proxies would be necessary. And, more specific in situ surveys of RNS blooms and RNS culture experiments are certainly desired.

Jingyu Wu, Xiamen University, [email protected]

Shaoping Shang, Xiamen University, [email protected] 

Yanshuang Xie, Xiamen University, [email protected] 

Ke Liu, Xiamen University, [email protected]

Famei Lei, Xiamen University, [email protected] 

Guomei Wei, Xiamen University, [email protected] 

Qiang Dong, Xiamen University, [email protected] 

Zhigang He, Xiamen University, [email protected]