Foraminifer faunas in the Tagus Prodelta

Pluri-annual proxy records of marine sediment cores from the Tagus Prodelta off Lisbon, Portugal, have been generated to gain insight into the climatic and hydrographic changes in the area during the twentieth century. The study includes benthic and planktonic foraminiferal faunas and the stable isotopic composition of one benthic (Uvigerina celtica) and two planktonic (Globigerina bulloides and Globorotalia inflata) foraminiferal species. Sea bottom and surface water temperatures were estimated based on the d18O values of these species and compared with instrumental data. The foraminiferal fauna and the isotope-based temperature record indicate increasing temperatures throughout the last century. The immigration of a new species, Saidovina karreriana, to the area around 100 years ago indicates changes in the trophic conditions and water mass properties, which are probably at least partly due to anthropogenic pollution.针对葡萄牙里斯本外塔古斯河前三角洲的海洋沉积物岩芯，本研究构建了多年尺度的气候替代指标序列，以期深入解析该区域20世纪的气候与水文变化。本研究涵盖了底栖与浮游有孔虫的类群组成，以及1种底栖有孔虫（Uvigerina celtica）和2种浮游有孔虫（Globigerina bulloides、Globorotalia inflata）的稳定同位素组成。研究基于上述有孔虫物种的δ¹⁸O值重建了海底与表层海水温度，并与器测数据进行了对比。有孔虫类群组成与同位素重建的温度记录均显示，过去一个世纪以来该区域温度呈持续上升趋势。约100年前，新物种Saidovina karreriana迁入该区域，这一现象指示该区域的营养状况与水团属性发生了改变，而这类改变至少有一部分可能源于人为污染。