BIO-03 Diversity of marine host-associated microbiomes
Study of communities living on plastic in mesocosms shows ocean acidification has a strong effect
Xu Zhang, State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
Ping Zhang, State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
Zichao Deng, State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
Ruiping Huang, State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
Di Zhang, School of Ocean, Yantai University, Yantai, China
Yang Tian, State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
Jason Hall-Spencer, Marine Biology and Ecology Research Centre, University of Plymouth, Plymouth, UK；Shimoda Marine Research Center, University of Tsukuba, 5-10-1 Shimoda, Shizuoka 415-0025, Japan
Guang Gao, State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
Kunshan Gao, State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
Xin Lin* , State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China

We conducted a mesocosm experiment to examine how ocean acidification (OA) affects communities of prokaryotes and eukaryotes growing on single use drinking bottles in subtropical eutrophic waters of the East China Sea. Based on 16S rDNA gene sequencing, OA significantly altered the prokaryotic community, with the relative abundance of the phylum Planctomycetota increasing by 49 % under high CO2. In the acidified conditions, plastisphere prokaryotes significantly enhanced nitrogen dissimilation and ureolysis, opening up the possibility that OA may modify nutrient cycling and subsequently influence the oceanic nitrogen cycle. The relative abundance of pathogenic and animal parasite bacteria also increased under OA, so cuts in CO2 emissions may reduce the risk of spreading infectious diseases via marine plastic pollution. Our results show that OA significantly affected some secondary producers based on 18S rDNA gene sequencing. For example, Mayorella amoebae were highly resistant to OA whereas labyrinthulids were sensitive to OA. This shows that OA may alter plastisphere food chains.