The increase in anthropogenic induced warming over the last two centuries is impacting marine environment. Planktic foraminifera are a globally distributed calcifying marine zooplankton responding sensitively to changes in sea surface temperatures and interacting with the food web structure. Here, we study two high resolution multicore records from two western Mediterranean Sea regions (Alboran and Balearic basins), areas highly affected by both natural climate change and anthropogenic warming. Cores cover the time interval from the Medieval Climate Anomaly to present. Reconstructed sea surface temperatures are in good agreement with other results, tracing temperature changes through the Common Era (CE) and show a clear warming emergence at about 1850 CE. Both cores show opposite abundance fluctuations of planktic foraminiferal species (Globigerina bulloides, Globorotalia inflata and Globorotalia truncatulinoides), a common group of marine calcifying zooplankton. The relative abundance changes of Globorotalia truncatulinoides plus Globorotalia inflata describe the intensity of deep winter mixing in the Balearic basin. In the Alboran Sea, Globigerina bulloides and Globorotalia inflata instead respond to local upwelling dynamics. In the pre-industrial era, changes in planktic foraminiferal productivity and species composition can be explained mainly by the natural variability of the North Atlantic Oscillation, and, to a lesser extent, by the Atlantic Multidecadal Oscillation. In the industrial era, starting from about 1800 CE, this variability is affected by anthropogenic surface warming, leading to enhanced vertical stratification of the upper water column, and resulting in a decrease of surface productivity at both sites. We found that natural planktic foraminiferal population dynamics in the western Mediterranean is already altered by enhanced anthropogenic impact in the industrial era, suggesting that in this region natural cycles are being overprinted by human influences.

在过去的两个世纪里，人为引起的变暖正在影响海洋环境。浮游有孔虫是一种全球分布的钙化海洋浮游动物，对海面温度的变化做出敏感反应并与食物网结构相互作用。在这里，我们研究了地中海西部两个地区（阿尔博兰和巴利阿里盆地）的两个高分辨率多核记录，这些地区受自然气候变化和人为变暖的影响很大。核心涵盖了从中世纪气候异常到现在的时间间隔。重建的海面温度与其他结果非常吻合，追踪了整个共同时代 (CE) 的温度变化，并在大约 1850 年 CE 显示出明显的变暖出现。两个核心都显示出浮游有孔虫物种的相反丰度波动（Globigerina bulloides、Globorotalia inflata和Globorotalia truncatulinoides），是一类常见的海洋钙化浮游动物。Globorotalia truncatulinoides和Globorotalia inflata的相对丰度变化描述了巴利阿里盆地冬季深层混合的强度。在奥尔博兰海，Globigerina bulloides和Globorotalia inflata而是响应当地的上升流动态。在前工业化时代，浮游有孔虫生产力和物种组成的变化主要可以用北大西洋涛动的自然变化来解释，在较小程度上可以用大西洋多年代际涛动来解释。在工业时代，大约从公元 1800 年开始，这种变异性受到人为地表变暖的影响，导致上水柱的垂直分层增强，导致两个地点的地表生产力下降。我们发现，地中海西部的天然浮游有孔虫种群动态已经因工业时代人为影响的增强而改变，这表明该地区的自然周期正被人类影响所覆盖。