黄海与渤海交界区附近表层沉积物中的底栖有孔虫分布与环境因素制约

DISTRIBUTION OF BENTHIC FORAMINIFERA IN SURFACE SEDIMENTS IN THE JUNCTION OF BOHAI SEA AND YELLOW SEA AND ENVIRONMENTAL CONSTRAINTS

对取自黄海西北部以及渤海东部研究区内的144个表层沉积物样品中的底栖有孔虫群落进行了分析,结果表明这一区域底栖有孔虫以适应低温、低盐环境的冷水种和广温、广盐种为主。利用Q型因子分析提取了5个有孔虫组合:Protelphidium turberculatum(d'Orbigny)为主的组合1主要体现了温度和底质粒度的控制作用;Buccella frigida(Cushman)-Buccella tunicata(Ho,Hu et Wang)-Elphidium advenum(Cushman)为主的组合2最主要的影响因素是低温水团;Cribrononion subincertum(Asano)-Cribrononion porisuturalis(Zheng)-Elphidium advenum(Cushman)为主的组合3体现了水深和盐度的控制作用;Eggerella advena(Cushman)-Proteonina atlantica(Cushman)-Haplophragmoides canariensis(d'Orbigny)为主的组合4受控于底质沉积物粒度变化;Elphidium advenum(Cushman)-Ammonia becarii(Linné)-Ammonia compressiuscula(Brady)为主的组合5受到温度、盐度以及底质沉积物粒度的综合影响。总之,研究区内底栖有孔虫的水深分带性特征不明显,而温度、盐度和底质沉积物粒度对其分布具有显著的控制作用。

144 surficial samples acquired from the northwestern Yellow Sea and the eastern Bohai Sea in 2008 and 2009 were selected to study the distribution pattern of benthic foraminifera and its relationships with modern marine environment. The benthic foraminiferal fauna are mainly composed of the species with high tolerances to low temperature and low salinity. Moreover, 78 species/genera with relatively higher abundance were chosen to carry out a Q-mode factor analysis, and 5 varimax factors corresponding to 5 foraminiferal assemblages were obtained. Correlations between the assemblages and environmental parameters suggest that. 1. Protelphidium turberculatum （d＇Orbigny） assemblage be constrained by the water temperature and the grain size of sediment; 2. Buccella frigida （Cushman） Buccella tunicata （Ho, Hu et Wang）-Elphidium advenum （Cushman） assemblage be constrained by the cold water masses; 3. Cribro- nonion subincertum （Asano） Cribrononion porisuturalis （Zheng） Elphidium advenum （Cushman） assem blage be constrained by water depth and salinity; 4. Eggerella advena （Cushman）-Proteonina atlantica （Cushman）-Haplophragmoides canariensis （d＇Orbigny） assemblage be constrained by the grain size of sediment ; 5. Elphidium advenum （Cushman）-Ammonia becarii （Linne） -Ammonia compressiuscula （Bra- dy） assemblage be constrained by temperature, salinity and grain size of sediment. In general, water depth shows no distinct influence on the distribution pattern of foraminifera. However, the topography of the sea floor has great influences on the distribution of benthic foraminifera.