Estimating Calanus sinicus grazing on phytoplankton and microzooplankton

A study on grazing speed of mesozooplankton on phytoplankton and microzooplankton was carried out with in situ feeding experiment, the Frost's method, and the Landry dilution experiment in 6 stations in area of frequent red tide occurrence in the East China Sea, from April 27 to June 5, 2005. Changes in community structure of phytoplankton and microzooplankton, grazing speed, food composition of Calanus sinicus, and mesozooplankton and microzooplankton grazing pressures on phytoplankton were studied. In the survey area, the specific growth rate of phytoplankton species ranged from 0.09 -5.70 at (2.01 c 1.33 ) d super(-1) in average; and that of microzooplankton ranged from 0-3.89 in average of (0.46 c 0.79) d super(-1). The species specific grazing rate of C. sinicus on phytoplankton varied from 0.01 - 8.43 in average of (2.72 c 2.14) d super(-1) in speed of 0.05-838.23 averaged at (52.72 c 154.21 ) cells ind. super(-1)d super(-1). C. sinicus took mostly some harmful algal blooms species, such as Karenia miki