The bacterial abundance and production in the East China Sea： seasonal variations and relationships with the phytoplankton biomass and production

• Published in: Acta oceanologica Sinica Vol. 33; no. 9; pp. 166 - 177
• Main Authors: Chen, Bingzhang, Huang, Bangqin, Xie, Yuyuan, Guo, Cui, Song, Shuqun, Li, Hongbo, Liu, Hongbin
• Format: Journal Article
• Language: English
• Published: Heidelberg The Chinese Society of Oceanography 01.09.2014; Springer Nature B.V; Fujian Provincial Joint Key Laboratory of Coastal Ecology and Environmental Studies and State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361102, China%Division of Life Science, Hong Kong University of Science and Technology, Hong Kong, China%Key Laboratory of Marine Ecology and Environmental Science, Institute of 0ceanology, Chinese Academy of Sciences, Qingdao 266071, China%National Marine Environmental Monitoring Center, State 0ceanic Administration, Dalian 116023, China
• Subjects: Additives; Atmospheric models; Bacteria; Biomass; Carbon dioxide; Chlorophyll; Chlorophylls; Climatology; Cold; Continental shelves; Depth; Earth and Environmental Science; Earth Sciences; Ecology; Engineering Fluid Dynamics; Environmental Chemistry; Environmental science; Growth rate; Heterotrophic bacteria; Laboratories; Marginal seas; Marine; Marine & Freshwater Sciences; Mathematical analysis; Nutrients; Oceanography; Offshore; Organic matter; Phytoplankton; Plankton; Primary production; Respiration; River discharge; River flow; Salinity; Seasonal variation; Seasonal variations; Spatial distribution; 东中国海; 叶绿素浓度; 地球化学动力学; 季节变化; 植物生产; 浮游植物生物量; 浮游植物生长; 细菌丰度; Changjiang River; Hong Kong China; East China Sea; China; INW, Donghai Sea; INW, China, People's Rep., Changjiang Estuary; bacterial production; chlorophyll; temperature; East China Sea; generalized additive model
• ISSN: 0253-505X; 1869-1099
• DOI: 10.1007/s13131-014-0528-0

The East China Sea is a productive marginal sea with a wide continental shelf and plays an important role in absorbing atmospheric carbon dioxide and transferring terrigenous organic matter to the open ocean. To investigate the roles of heterotrophic bacteria in the biogeochemical dynamics in the East China Sea, bacterial biomasses （BB） and productions （BP） were measured in four cruises. The spatial distributions of the BB and the BP were highly season-dependent. Affected by the Changjiang River discharge, the BB and the BP were high in shelf waters （bottom depth not deeper than 50 m） and generally decreased offshore in August 2009. In December 2009 to lanuary 2010, and November to December 2010, the BB and the BP were high in waters with medium bottom depth. The onshore-offshore decreasing trends of the BB and the BP also existed in May-June 2011, when the BB was significantly higher than in other cruises in shelf break waters （bottom depth deeper than 50 m but not deeper than 200 m）. The results of generalized additive models （GAM） suggest that the BB increased with the temperature at a range of 8-20~C, increased with the chlorophyll concentration at a range of 0.02-3.00 mg/m3 and then declining, and decreased with the salinity from 28 to 35. The relationship between the temperature and the log-transformed bacterial specific growth rate （SGR） was linear. The estimated temperature coefficient （Q10） of the SGR was similar with that of the phytoplankton growth. The SGR also increased with the chlorophyll concentration. The ratio of the bacterial to phytoplankton production ranged from less than 0.01 to 0.40, being significantly higher in November December 2010 than in May-June 2011. Calculated from the bacterial production and growth efficiency, the bacterial respiration consumed, on average, 59%, 72% and 23% of the primary production in August 2009, November-December 2010, and May-/une 2011, respectively.