Benthic foraminifera asemblages and isotopic composition of surface sediment samples off Morocco

The influence of different primary productivity regimes on live (Rose Bengal stained) and dead benthic foraminiferal distribution, as well as on the stable carbon isotopic composition of foraminiferal tests, was investigated in sediment surface samples (0-1 cm) from the upwelling region off Morocco between Cape Ghir (31°N) and Cape Yubi (27°N). A combination of factor analysis, detrended correspondence analysis (DCA) and canonical correspondence analysis (CCA) was applied to the benthic foraminiferal data sets. Five major assemblages for both the live and dead fauna were revealed by factor analysis. In the cape regions organic matter fluxes are enhanced by high chlorophyll-a concentrations in the overlying surface waters. Here, benthic foraminiferal faunas are characterized by identical live and dead assemblages, high standing stocks, and low species delta13C values, indicating constant year-round high productivity. […]

本研究探讨了不同初级生产力模式对活（玫瑰红染色）及死底栖有孔虫分布的影响，以及对有孔虫壳体稳定碳同位素组成的贡献，研究对象为摩洛哥沿岸（自Ghir角（31°N）至Yubi角（27°N））上升流区域内的沉积表层样品（0-1厘米）。本研究对底栖有孔虫数据集进行了因素分析、去趋势对应分析（DCA）和经典对应分析（CCA）的综合应用。因素分析揭示了活体和死体生物群落的五大主要组合。在Ghir和Yubi角区域，表层水体中高叶绿素a浓度增强了有机物质通量。在此，底栖有孔虫生物群以活体与死体组合相同、高生物量储备和低物种δ13C值为特征，表明全年生产力保持恒定的高水平。