Ecological characteritics of zooplankton in the northern waters of Nan’ao Island
Lianggen Wang1,2, Feiyan Du1,2 and Pimao Chen1
1
South China Sea Fisheries Research Institute, Chinese Academy of Fishery Science, Guangzhou, PR China. E-mail:
feiyanegg@163.com
2
Key laboratory of Fishery Ecology and Environment, Guangdong Province. Guangzhou, PR China
Four oceanographic surveys of zooplankton were conducted in the northern waters of Nan’ao
Island, in April, August, November 2011 and February 2012. The species composition,
ecological groups, abundance, biomass, dominant species and diversity index of the zooplankton
in the zone were investigated using the survey data, and the impact factors of the zooplankton
distribution were discussed. A total of 158 zooplankton species were identified, including 46
species in spring, 104 species in summer, 96 species in autumn and 44 species in winter. The
fauna of zooplankton belonged to Indo-West-Pacific-tropic-fringe Region with three main
ecological groups, such as warm water neritic species, warm water oceanic species, and warm
water euryhaline species. The abundance of the zooplankton was 292.31 ind m-3 in summer,
143.25 ind m-3 in winter, 116.65 ind m-3 in autumn and 26.48 ind m-3 in spring. The zooplankton
biomass was 140.15 mg m-3 in summer，126.75 mg m-3 in autumn，89.84 mg m-3 in winter，
and 37.96 mg m-3 in spring. Most of the dominant species were neritic species, and Centropages
tenuiremis was only one of the annual dominant species. The species diversity of zooplankton
was the highest in summer and the lowest in winter. The zooplankton ecological characters,
which were closely related to the seasonal variation of water masses, especially the runoffs, had
the typical subtropical estuary ecological characteristics in the zone.