Study On The Zooplankton Community In Rushan Bay And Adjacent Sea Area

Zooplankton community was surveyed in the Rushan Bay and adjacent sea area onMay2011and October2011.There were22stations, consisted of14outside the bay and8inside the bay. And the station C3near the mouth was chosen as the time-seriessampling station to study the diel vertical migration. The species, structure, thespace-time distribution, seasonal variation and the dominant species of zooplanktoncommunity were explored. By the results, the efficiency of two plankton nets was tested.The environmental factors of water were to identify the correlation with the indices ofzooplankton community. At the same time, the vertical migration characters ofzooplankton and the dominant species were tested. All studies of the zooplankton werehoped to contribute to protect the marine ecology and environment and give advices tothe sustainable utilization of the ocean resources. The results were followed:(1)A total of69taxa were identified.52taxa were collected in spring, among themthere were of44species in the net of typeâ… and the number was42in the net of typeâ…¡.While in autumn,48taxa were identified, the numbers of the two nets were44and45.In all, the composition of zooplankton was quite different between spring and autumn.And the species distributions of each station were not uniformity. The species numbers ofthe stations in spring evidently higher than which in autumn.(2)In spring, the average zooplankton abundance was22724.72ind/m~3, the result inthe typeâ… net was4496.8ind/m~3, which reached20378.67ind/m~3in the typeâ…¡net. Inautumn, zooplankton abundance was14338.89ind/m~3, the result of the typeâ… net and thetypeâ…¡net were114.54ind/m~3and14209.07ind/m~3. The average Shannon-Weiner indexin the study was2.306. The index inside the bay performed a much higher level in spring,while in autumn the higher one was in the adjacent sea area. In both seasons, zooplanktoncommunities were quite different. The biomass and abundance were raised and thediversity dropped inside the bay while in the adjacent area the biomass and abundancewere dropped and the diversity rose up. (3)In spring the dominant species were Noctilucidae scientillans, Calanus sinicus,Paracalanus parvus, Acartia clasi, A. bifilosa and Sagitta crassa, which were N.scientillans, P. parvus, A. bifilosa and Oithona similis.The abundance of most speciesshowed evident correlation with the pollutions, while only temperature were correlationwith the abundance of N. scientillans and S. crassa in spring.(4) After tested the correlation between zooplankton and environmental factors, itshowed that the temperature and salinity were the only normal environmental factorswhich had great influence on zooplankton community, while the Nitrogen andPhosphorus organic compounds, petroleum hydrocarbon and heave metal also madegreat impact on the zooplankton in the study.(5)The diel vertical migration of zooplankton was visible and exhibited as a seasonalvariation. The research of dominant species showed that the moving modes based on thespecies themselves.