Carbon biomass,production rates and export flux of copepods fecal pellets in the Changjiang(Yangtze) River estuary  

作　　者：GUO Shujin SUN Xiaoxia 郭术津;孙晓霞(Jiaozhou Bay Marine Ecosystem Research Station, Chinese Academy of Sciences, Qingdao 266071, China;Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China;University of Chinese Academy of Sciences, Beijing 100049, China)

机构地区：[1]Jiaozhou Bay Marine Ecosystem Research Station,Chinese Academy of Sciences,Qingdao 266071,China [2]Laboratory for Marine Ecology and Environmental Science,Qingdao National Laboratory for Marine Seienee and Technology Qingdao 266071,China [3]Univetsity Of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Journal of Oceanology and Limnology》2018年第4期1244-1254,共11页海洋湖沼学报（英文）

基　　金：Supported by the Innovation Plan of Science and Technology for Ao Shan(No.2016ASKJ02);the National Basic Research Program of China(973 Program)(No.2014CB441504);the “Strategic Priority Research Program-Western Pacific Ocean System” of Chinese Academy of Sciences(No.XDA11030204);the National Natural Science Foundation of China(No.31700425)

摘　　要：Copepod fecal pellets are ubiquitous throughout the oceans. Their production and export can represent a highly efficient pathway of carbon export. However, the role these fecal pellets play in carbon export in the Changjiang(Yangtze) River estuary is not well known. Two cruises were carried out in the Changjiang estuary in the spring and summer of 2013, during which time carbon biomass, production, and export of copepod fecal pellets were studied. Spring and summer fecal pellet carbon biomass ranged 0.30–1.01 mg C/m^3(mean=0.56±0.20 mg C/m^3) and 0.31–1.18 mg C/m^3(mean=0.64±0.24 mg C/m^3), respectively, significantly lower than phytoplankton. At most stations, fecal pellet carbon biomass was higher in surface or subsurface layers than deeper layers. Production rates ranged 0.65–1.49 pellets/(ind.?h)(mean=1.02±0.27 pellets/(ind.?h)) in spring and 0.62–1.34 pellets/(ind.?h)(mean=0.98±0.22 pellets/(ind.?h)) in summer, within the range reported in previous studies. Higher production rates of fecal pellets occurred at stations with higher chlorophyll a concentrations, and production rates of copepods of size 500–1 000 μm greater than copepods >1 000 μm during both cruises. The potential export flux of fecal pellets was slightly higher in summer(mean=68.95±14.37 mg C/(m^2 ?d)) than spring(mean=52.08±11.33 mg C/(m^2 ?d)) owing to higher summer copepod abundances. To our knowledge, this study is the first of its kind in the Changjiang estuary, and it confirms the significant role of copepod fecal pellets in local carbon export.Copepod fecal pellets are ubiquitous throughout the oceans. Their production and export can represent a highly efficient pathway of carbon export. However, the role these fecal pellets play in carbon export in the Changjiang（Yangtze） River estuary is not well known. Two cruises were carried out in the Changjiang estuary in the spring and summer of 2013, during which time carbon biomass, production, and export of copepod fecal pellets were studied. Spring and summer fecal pellet carbon biomass ranged 0.30–1.01 mg C/m^3（mean=0.56±0.20 mg C/m^3） and 0.31–1.18 mg C/m^3（mean=0.64±0.24 mg C/m^3）, respectively, significantly lower than phytoplankton. At most stations, fecal pellet carbon biomass was higher in surface or subsurface layers than deeper layers. Production rates ranged 0.65–1.49 pellets/（ind.？h）（mean=1.02±0.27 pellets/（ind.？h）） in spring and 0.62–1.34 pellets/（ind.？h）（mean=0.98±0.22 pellets/（ind.？h）） in summer, within the range reported in previous studies. Higher production rates of fecal pellets occurred at stations with higher chlorophyll a concentrations, and production rates of copepods of size 500–1 000 μm greater than copepods 〉1 000 μm during both cruises. The potential export flux of fecal pellets was slightly higher in summer（mean=68.95±14.37 mg C/（m^2 ·d）） than spring（mean=52.08±11.33 mg C/（m^2 ·d）） owing to higher summer copepod abundances. To our knowledge, this study is the first of its kind in the Changjiang estuary, and it confirms the significant role of copepod fecal pellets in local carbon export.

关 键 词：fecal pellets copepods production rates carbon export Changjiang （Yangtze） River estuary 

分 类 号：P7[天文地球—海洋科学] X171[环境科学与工程—环境科学]