TY - JOUR
T1 - Microzooplankton grazing and selective feeding during bloom periods in the Tolo Harbour area as revealed by HPLC pigment analysis
AU - Liu, Xiangjiang
AU - Tang, Chi Hung
AU - Wong, Chong Kim
N1 - Funding Information:
The work was funded by the Hong Kong RGC Research Grant-Direct Allocation to C.K. Wong (Project Number CUHK476909 ). The authors would like to thank K.C. Cheung and Y.H. Yung for their technical assistance in the field and lab.
PY - 2014/7
Y1 - 2014/7
N2 - Dilution experiments were conducted to investigate microzooplankton grazing impact on phytoplankton of different taxonomic groups and size fractions (<5, 5-20, 20-200μm) during spring and summer bloom periods at two different sites (inner Tolo Harbour and Tolo Channel) in the Tolo Harbour area, the northeastern coastal area of Hong Kong. Experiments combined with HPLC pigment analysis in three phytoplankton size fractions measured pigment and size specific phytoplankton growth rates and microzooplankton grazing rates. Pigment-specific phytoplankton growth rates ranged between 0.08 and 3.53d-1, while specific grazing rates of microzooplankton ranged between 0.07 and 2.82d-1. Highest specific rates of phytoplankton growth and microzooplankton grazing were both measured in fucoxanthin in 5-20μm size fraction in inner Tolo Harbour in summer, which coincided with the occurrence of diatom bloom. Results showed significant correlations between phytoplankton growth and microzooplankton grazing rates. Microzooplankton placed high grazing pressure on phytoplankton community. High microzooplankton grazing impact on alloxanthin (2.63-5.13) suggested strong selection toward cryptophytes. Our results provided no evidence for size selective grazing on phytoplankton by microzooplankton.
AB - Dilution experiments were conducted to investigate microzooplankton grazing impact on phytoplankton of different taxonomic groups and size fractions (<5, 5-20, 20-200μm) during spring and summer bloom periods at two different sites (inner Tolo Harbour and Tolo Channel) in the Tolo Harbour area, the northeastern coastal area of Hong Kong. Experiments combined with HPLC pigment analysis in three phytoplankton size fractions measured pigment and size specific phytoplankton growth rates and microzooplankton grazing rates. Pigment-specific phytoplankton growth rates ranged between 0.08 and 3.53d-1, while specific grazing rates of microzooplankton ranged between 0.07 and 2.82d-1. Highest specific rates of phytoplankton growth and microzooplankton grazing were both measured in fucoxanthin in 5-20μm size fraction in inner Tolo Harbour in summer, which coincided with the occurrence of diatom bloom. Results showed significant correlations between phytoplankton growth and microzooplankton grazing rates. Microzooplankton placed high grazing pressure on phytoplankton community. High microzooplankton grazing impact on alloxanthin (2.63-5.13) suggested strong selection toward cryptophytes. Our results provided no evidence for size selective grazing on phytoplankton by microzooplankton.
KW - HPLC
KW - Microzooplankton Grazing
KW - Selective Feeding
KW - Tolo Harbour
UR - http://www.scopus.com/inward/record.url?scp=84897890648&partnerID=8YFLogxK
U2 - 10.1016/j.seares.2014.02.017
DO - 10.1016/j.seares.2014.02.017
M3 - Article
AN - SCOPUS:84897890648
SN - 1385-1101
VL - 90
SP - 83
EP - 94
JO - Journal of Sea Research
JF - Journal of Sea Research
ER -