ABSORPTION SPECTRUM OF PARTICULATE MATTER IN LOW-OXYGEN AREA OFF THE QINHUANGDAO
More and more attention has been paid on the oxygen depletion in the Bohai Sea in recent years.However,the mechanism of deoxygenation has not been well known.We investigated the characterization of the absorption spectra of suspended particles in seawater off Qinhuangdao,Hebei,China.Furthermore,and evaluated the sources and features of organic matter responsible for deoxygenation in bottom water in summer based on the relationships of particulate absorption spectra with the size-based components of chlorophyll a(chi a)and with environment factors.Results show that nano-phytoplankton contributed approximately 80％of total chl a.The absorption spectra of pigment[aph(λ)]reflected the major feature of total particulate absorption spectra[ap(λ)]in surface water,while that of detritus[ad(λ)]was dominant in middle and bottom layers.ap(440)and ad(440)increased from surfac to bottom waters.The size of phytoplankton controlled the absorption efficiency of pigment,i.e.,aph*(440).Therefore,aph(440)could be calculated using multiple regression based on Chl a concentrations of three phytoplankton size classes.The characters of ad(λ)were also influenced by the phytoplankton community and the relative abundance of organic detritus.This study revealed that nano-sized organic particles produced during primary production were the main substrates of deoxygenation in summer in Bohai Sea.
particlesabsorption spectrachlorophyll aoffshore of Qinhuangdao
万方数据
维普
