Environmental impacts of typhoon KAEMI on coastal phytoplankton assemblage in the South China Sea,with special reference to the effects of solar UV radiation
会议名称：《中国海洋湖沼学会藻类学分会第七届会员大会暨第十四次学术讨论会》
会议日期：2007年
关 键 词：typhoon phytoplankton community structure UVR sensitivity South China Sea
摘 要：Typhoons or tropical cyclones usually cause drastic environmental changes in coastal ***,little has been documented on their influences on coastal primary *** Jul-18 to Aug-7 2006,we investigated the photosynthetic carbon fixation,chlorophyll a concentration and species composition of surface phytoplankton assemblage in the coastal waters of the South China Sea prior- and post- the typhoon KAEMI(landing on July 25 at Jinjiang,Fujian province, 122 km away from the experimental site).Chlorophyll a concentration started to decrease from 12.3μg L30 h before to 1.6μg L40 h after its landing,which then increased gradually to 7.9μg Lin a *** to the typhoon’s arrival, microphytoplankton(20μm)accounted for about 50% of the total chl a in the surface seawater,being mainly dominated by diatoms;howcvcr,in the post-typhoon period piconanoplankton(20μm)became the dominating group again in 2 weeks aRcr the typhoon,accounting for about 60% of the total chl α,with the diatoms being the dominant group *** photosynthetic carbon fixation rate under PAR were 18.3μg C(μg chl a)h30 h prior to the typhoon,which reached 22.4μg C(μg chl a)hin 6 days after the typhoon’s *** passage of typhoon led to enhanced apparent photosynthetic efficiency at low light and decreased light-saturating *** UV radiation significantly inhibited the photosynthetic carbon fixation by about 17% and 28% before and after the typhoon,respectively, reflecting that a higher sensitivity of the phytoplankton assemblages to UVR after the typhoon.