Program  
 
Marine pollution, ecotoxicology and sustainability
 
 
 
Poster
Effects of Asian Dust Input on Eukaryotic Phytoplankton Community Structure in the open areas in Northwestern Pacific Ocean
P-E1-13
Weimin Wang* , 1. Center for Ocean and Climate Research, First Institute of Oceanography, State Oceanic Administration, Qingdao, China; 2. Laboratory for Regional Oceanography and Numerical Modeling, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China; 3. The Key Laboratory of Marine Environmental and Ecology, Ministry of Education, Ocean University of China, Qingdao, China
Huan Zhang, 1. The Key Laboratory of Marine Environmental and Ecology, Ministry of Education, Ocean University of China, Qingdao, China; 2. Department of Marine Sciences, University of Connecticut, Groton, Connecticut, USA
Hongju Chen, 1. The Key Laboratory of Marine Environmental and Ecology, Ministry of Education, Ocean University of China, Qingdao, China; 2. College of Environmental Science and Engineering, Ocean University of China, Qingdao, China
Yunyun Zhuang, 1. The Key Laboratory of Marine Environmental and Ecology, Ministry of Education, Ocean University of China, Qingdao, China; 2. College of Environmental Science and Engineering, Ocean University of China, Qingdao, China
Yousong Huang, 1. The Key Laboratory of Marine Environmental and Ecology, Ministry of Education, Ocean University of China, Qingdao, China; 2. College of Environmental Science and Engineering, Ocean University of China, Qingdao, China
Guangxing Liu, 1. The Key Laboratory of Marine Environmental and Ecology, Ministry of Education, Ocean University of China, Qingdao, China; 2. College of Environmental Science and Engineering, Ocean University of China, Qingdao, China
Presenter Email: wangweimin@fio.org.cn

As the major source of atmospheric deposition in the Northwestern Pacific Ocean (NWPO), Asian dust modulated the community structure and nutrient utilization of phytoplankton. In order to study the effects of Asian dust input on the eukaryotic phytoplankton community structure, we conducted deck-board incubation experiments were at 2 stations (K3, 26°11'15.48"N, 136°43'38.46"E; B1, 37°56'12.90"N, 146°59'55.26"E) in the open areas of NWPO in spring 2015. Different amount of Asian dust, 0.2 mg L-1 (Dust-1) and 2 mg L-1 (Dust-2) were added into the incubation system.Daily changes in chlorophyll-a, nutrients and eukaryotic phytoplankton abundance were monitored. On the 0th, 2nd, 4th and 7th day, water samples were collected for metabarcoding sequencing.

The results showed that the NO3--N concentration increased significantly while concentrations of NO2--N, PO43--P and SiO32--Si did not changed due to the dust input. During the incubation, concentration of NO3--N and SiO32--Si decreased dramatically in dust-2. Simultaneously, no significant difference was found in concentration variation of NO2--N and PO43--P among control and dust groups. Concentration of chlorophyll-a of nano- and micro- eukaryotic phytoplankton increased significantly in dust-2 at 2 stations. However, there was no significant difference of the chlorophyll-a concentration of pico- eukaryotic phytoplankton among control and dust groups. By the end of the cultivation, the eukaryotic phytoplankton abundance in dust-2 was 3.0 and 7.5 folds higher than that in control at K3 and B1. The species number in dust groups decreased at K3 because the diatom bloom interfered the growth of other groups. However, the species number in dust groups increased at B1 because when the dust was added, the N-limited condition was remitted and the hypnospore of diatoms germinated. Diatom growth was promoted in dust-2 at 2 stations and the promoting extent was much more dramatic at B1. The growth of dinoflagellates was interfered at K3 and not changed significantly at B1 in dust groups. Moreover, growth of larger sized groups such as Pseudo-nitzschia, Chaetoceros and Thalassionema were promoted significantly, while growth of smaller sized groups such as Thalassiosira, Prorocentrum, Heterocapsa, and Scrippsiella were interfered or not changed in dust groups at 2 stations.

The results indicated that Asian dust addition could increase the marine productivity and alter the eukaryotic phytoplankton community structure. This research provides important reference for further investigating the effects of dust input on phytoplankton community structure.

 
 
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