The Influence Of Ocean Acidification On Microzooplankton Grazing In Different Sea Water

The herbivorous activities of microzooplankton under the acidification condition were estimated by dilution technique from May 2014 to November 2014 in four typical stations B02,B03,SEATS and J4.Station B02 is a cruise home-port in Tianjin coastal;station B03 is nearing a drainage river in a scenic spot in Tianjin coastal;SEATS and J4 are in the northern South China Sea,and SEATS is farther away from continent.In this study,the analysis in microzooplankton community and phytoplankton community used Utermohl method;and three treatment were set:760 ppm group?higher pCO₂?,390 ppm group?reality oceanpCO₂ now?and blank control group?no bubble?.Every stations' phytoplankton community were comprised of Bacillariophyta and Pyrroptata;besides Bacillariophyta and Pyrroptata,Cyanophyta was founded in station B03 and station J4,and Chrysophyta was observed at SEATS.There were 29 phytoplankton species found at the station B02,the cell abundance of phytoplankton was 414.120 cells/L.There were 31 phytoplankton species found at the station B03,the cell and abundance of phytoplankton was 36668.571 cells/L.There were 71 phytoplankton species found at SEATS,the cell abundance of phytoplankton was 329.659 cells/L.There were 73 phytoplankton species found at the station J4,the cell abundance of phytoplankton was 648.293 cells/L.Every stations' microzooplankton community were comprised of oligotrichs,tintinnid and nauplii;besides those,copepodite and radiolarian were founded in SEATS and J4.There were 9 microzooplankton species found at the station B02,abundance of microzooplankton was 136.574 ind./L.There were 24 microzooplankton species found at the station B03,abundance of microzooplankton was 25253.333 ind./L.There were 44 microzooplankton species found at SEATS,abundance of microzooplankton was 127.159 ind./L.There were 39 microzooplankton species found at the station J4,abundance of microzooplankton was 54.959 ind./L.During the station B03 experiment,the high nutritive likely caused of the bloom of phytoplankton and microzooplankton in B03.After acidification,the microzooplankton and phytoplankton community were changed,however the regularity were not very clear.After dilution,the abundance of Nitzschia sp.and Thalassiosira sp.and tintinnid were the highest.Dilution experiment suggested that the intrinsic growth rate of phytoplankton were different in all four stations;and the 760 ppm grazing rate of microzooplankton in station B02,station B03 and station J4 were lower than 390 ppm.