The Study Of Micro-zooplankton Grazing In Tianjin Coast

To analysis under the condition of hydrological and biological community,the phytoplankton's growth rate and micro-zooplankton feeding rate of phytoplankton,a monthly experiment carried out with hydrological environment,the community structure of phytoplankton and zooplankton and dilution experiment at three fixed positions of Tianjin coast.In the same period,we sampled offshore for the same experiment in February,May,August and November.According to the contrast result of Tianjin coast and offshore zooplankton feeding,the influence of coastal ecological on zooplankton feeding was analysised.In Tianjin coastal,totally 99 species of phytoplankton were found,which belonged in 49 generas of 5 phylas,and there were 53 species of diatom in 26 generas,accounted for 53.5%of all the species;27 species of dinoflagellate in 10 generas,accounted for 27.3%of all the species;16 species of cholrophyta in 10 generas,accounted for 16.2%of all the species;2 species of cyanophyta in 2 generas,accounted for 2%;1 species of cryptophyra in 1 generas,accounted for 1%.In Tianjin coastal's three stations,the lowest phytoplankton cells appeared in May.The highest phytoplankton cells of station B01 and B03 appeared in September and the highest phytoplankton cells of station B02 appeared in August.The dominant species were not the same of all stations.In station BO 1,the dominant species were all diatom;in station B02,dominant species were given priority to with diatom,dinoflagellates accounts for a small;in station B03,dominant species were cyanophyta and cholrophyta.In station B01,13 species of titinnids in 10 generas and 12 species of aloricate ciliates in 9 generas were identified;in station B02,19 species of titinnids in 7 generas and 14 species of aloricate ciliates in 7 generas were identified;in station B03,8 species of titinnids in 3 generas and 14 species of aloricate ciliates in 5 generas were identified.Copepod larva and copepod nauplii were found in all stations.The lowest and highest number of planktonic ciliate individuals appeared in September and March in station B01 and B02 respectively.The lowest number of planktonic ciliate individuals appeared in June and the highest number appeared in December.The dominant species in three stations were exactly the same,just the dominance were different.In the offshore survey,118 species of phytoplankton were found,which belonged in 46 generas of 3 phylas.The species number of summer was the highest,followed by spring and autumn,winter was the least.Diatom and dinoflagellate dominated the composition of species.Phytoplankton cell abundance in spring ranged from 0.50×10⁴ to 2.00×10⁴ cells/L,maximum cell abundance appeared in station A2 which station was near to the shore.Phytoplankton cell abundance in summer ranged from 1.20×10⁴ to 25.00×10⁴ cells/L,maximum cell abundance appeared in station E1.The phytoplankton cell abundance in autumn ranged from 0.18×10⁴ to 5.20×10⁴ cells/L,the maximum cell abundance appeared in station El and each station's cell abundance were similar.The phytoplankton cell abundance in winter ranged from 0.22×10⁴ to 8.80×10⁴ cells/L,and the cell abundance appeared in station El.69 species of 23 generas planktonic ciliate were found in the four seasons offshore,which included titinnids 29 species of 10 generas and aloricate ciliates 40 species of 13 generas.The dominant species of planktonic ciliate were same mostly but slightly different.Tintinnopsis beroidea and Strombidium sp.were the dominant species in Bohai Sea.The result of feeding in coast was that the growthing of total phytoplankton in station B01 ranged between 0.12-3.00 d^-1 and the size-fractionated growthing rate ranged between 0.39-2.55 d^-1?pico-?,0.06-2.13 d^-1?nano-?and 0.24-2.83 d^-1?micro-?.The grazing rate of total micro-zooplankton ranged between 0.19^-1.44 d^-1,and the size-fractionted grazing rate ranged between 0.39^-1.73 d^-1?pico-?,0.12^-1.27 d^-1?nano-?and 0.33^-1.92 d^-1?micro-?.The pressure on potential primary productivity of micro-zooplankton grazing on phytoplankton ranged from 26.79%to 276.02%.The growthing of total phytoplankton in station B02 ranged between 0.17-3.83 d"1 and the size-fractionated growthing rate ranged between 0.12-2.13 d^-1?pico-?,0.25-2.25 d^-1?nano-?and 0.32-3.25 d^-1?micro-?.The grazing rate of total micro-zooplankton ranged between 0.20-2.14 d^-1,and the size-fractionted grazing rate ranged between 0.36^-1.84 d^-1?pico-?,0.18^-1.00 d^-1?nano-?and 0.13^-1.33 d^-1?micro-?.The pressure on potential primary productivity of micro-zooplankton grazing on phytoplankton ranged from 25.07%to 249.05%.The growthing of total phytoplankton in station B03 ranged between 0.29-4.03 d^-1 and the size-fractionated growthing rate ranged between 0.12^-1.45 d^-1?pico-?,0.23^-1.48 d^-1?nano-?and 0.38-2.51 d^-1?micro-?.The grazing rate of total micro-zooplankton ranged between 0.27^-1.78 d^-1,and the size-fractionted grazing rate ranged between 0.35^-1.14 d^-1?pico-?,0.28^-1.09 d^-1?nano-?and 0.23^-1.37 d^-1?micro-?.The pressure on potential primary productivity of micro-zooplankton grazing on phytoplankton ranged from 40.36%to 130.55%.The result of feeding offshore was that the growthing of total phytoplankton in station D1 ranged between 0.21-3.89 d^-1 and the size-fractionated growthing rate ranged between 0.12-3.39 d^-1?pico-?,0.24-4.10 d^-1?nano-?and 0.36-3.51 d^-1?micro-?.The grazing rate of total micro-zooplankton ranged between 0.33-3.51 d^-1,and the size-fractionted grazing rate ranged between 0.67^-1.10 d^-1?pico-?,0.27^-1.48 d^-1?nano-?and 0.43-2.20 d^-1?micro-?.The pressure on potential primary productivity of micro-zooplankton grazing on phytoplankton ranged from 79.81%to 276.26%.The growthing of total phytoplankton in station E2 ranged between 0.23^-1.51 d^-1 and the size-fractionated growthing rate ranged between 0.18-2.33 d^-1?pico-?,0.55-3.30 d^-1?nano-?and 0.27-3.34 d^-1?micro-?.The grazing rate of total micro-zooplankton ranged between 0.19-3.25 d^-1,and the size-firactionted grazing rate ranged between 0.22^-1.41 d^-1?pico-?,0.32^-1.39 d^-1?nano-?and 0.25^-1.89 d^-1?micro-?.The pressure on potential primary productivity of micro-zooplankton grazing on phytoplankton ranged from 56.53%to 140.07%.The growthing of total phytoplankton in station D3 ranged between 0.56-2.98 d^-1 and the size-fractionated growthing rate ranged between 0.83^-1.95 d^-1?pico-?,0.51-2.84 d^-1?nano-?and 1.25-3.69 d^-1?micro-?.The grazing rate of total micro-zooplankton ranged between 0.18-2.18 d^-1,and the size-fractionted grazing rate ranged between 0.42^-1.69 d^-1?pico-?,0.29-2.05 d^-1?nano-?and 0.45-2.44 d"1?micro-?.The pressure on potential primary productivity of micro-zooplankton grazing on phytoplankton ranged from 32.74%to 120.18%.The trend of growth rate and grazing rate generally showed summer>spring>autumn>winter.To compare the pressure on potential primary productivity of micro-zooplankton grazing on phytoplankton with the world's average value 59.9%,we know that the control of micro-zooplankton grazing on phytoplankton at high levels.