[Ecological characteristics of zooplankton in frequent HAB areas of the East China Sea in spring].
A comprehensive oceanographic survey was made in the East China Sea (122 degrees-123 degrees 30'E, 29 degrees-32 degrees N) during April to May, 2002, and the zooplankton samples were collected by zooplankton net (mesh size 0.567 mm). Analyses on the ecological characteristics of zooplankton such as its quantity, community characteristics, species composition and dominant species showed that 128 species of diet zooplankton were identified (16 pelagic larvae and fish juveniles were not involved). Among them, copepods occupied dominant position, including 40 species, composing 31.25% of diet zooplankton. The community was divided into 3 ecological types, in which, eurythermy and euryhalinity occupied dominant position. Key species, Calanus sinicus, was the first dominant species (142.10 ind.m-3, composing 68.09% of diet zooplankton abundance). The average biomass of zooplankton was 243.80 mg.m-3 (55.53-773.92 mg.m-3), and the highest density (> 500 mg.m-3) was found in the estuary area of the Yangtze River (30 degrees 45'-31 degrees 15'N, 122 degrees 45'-123 degrees 15'E). The average biomass of diet zooplankton was 195.96 mg.m-3 (55.53-496.09 mg.m-3). It was also showed that the biomass value of the estuary area of the Yangtze River (the north of 30 degrees 30'N) was higher than that of the southwest of Zhoushan waters, and that of the offshore of the estuary area of the Yangtze River (122 degrees 45'E) was higher than that of coastal waters. The mean value of diversity index (H') was 2.12 (1.09-3.73), and the stations having low H' (< 2) occupied 37.03%. The index of diversity, evenness and richness in the estuary area of the Yangtze River were low, but dominance was high. These results showed that the community structure of zooplankton in studied areas was not stable. Regression analysis results showed that main factors in relation to the characteristic distribution of zooplankton were temperature, diatom abundance, and dinoflagellate abundance.
Xu
Zhaoli
Z
East China Sea Fisheries Research Institute, Chinese Academy of Fishery Science, Shanghai 200090, China.
Hong
Bo
B
Zhu
Mingyuan
M
Chen
Yaqu
Y
D000818:Animals; D018533:Biomass; D002681:China; D017377:Diatoms; D004141:Dinoflagellida; D017753:Ecosystem; D057097:Harmful Algal Bloom; D009792:Oceans and Seas; D045483:Rivers; D054712:Salinity; D012621:Seasons; D012623:Seawater; D013696:Temperature; D015048:Zooplankton / Q000145:classification