The upper Thanetian–lowermost Ypresian succession in Tunisia is part of an extensive high-productivity upwelling regime in the southern Tethyan margin. As in several modern coastal upwelling systems, the upwelling strengthening regionally accentuated sustained acidification conditions, which prevailed in the Roman Bridge area (Central Tunisia). The poor-carbonate sedimentation, associated with the bad preservation state of calcifiers, points to the expansion of carbonate undersaturation in the water column and deep-sea sediments. The upwelling of deep CO₃²⁻ and dissolved oxygen-depleted water significantly put calcifiers under chemically stressed habitats. Foraminiferal dwarfism, decrease in abundance and diversity, and especially occurrence of abundant dissolved and fragmented shells could account for the severe carbonate-corrosive waters. The spoiled primary morphological characteristics of benthic foraminifera emphasize the alkalinity increase in the deep marine waters. The well-preserved organic matter in the Roman Bridge sediments suggested a relatively minor role of remineralization in CaCO₃-unsaturated waters. The expansion of carbonate-depleted water in the Roman Bridge area was principally driven by upwelled deep depleted-carbonate waters. These findings highlight the challenge to predict the response of the marine ecosystem to rising ocean acidification in upwelling strengthening regions in the future.

突尼斯的上塔尼提亚-最下端的伊普雷西亚序列是特提斯南部边缘广泛的高产上升流体系的一部分。与几个现代沿海上升流系统一样，上升流加强区域性加剧了持续的酸化条件，这在罗马桥地区（突尼斯中部）普遍存在。碳酸盐沉积不良与钙化物保存状态差有关，表明水体和深海沉积物中碳酸盐欠饱和程度的扩大。深部CO ₃ ^{2−的上涌}溶解氧耗尽的水显着使钙化剂处于化学压力的栖息地。有孔虫侏儒症、丰度和多样性减少，特别是大量溶解和破碎的贝壳的出现，可能是严重碳酸盐腐蚀水域的原因。底栖有孔虫被破坏的主要形态特征强调了深海水域的碱度增加。Roman Bridge 沉积物中保存完好的有机质表明 CaCO _{3中的再矿化作用相对较小}- 不饱和水。罗马桥地区碳酸盐枯竭水的扩张主要是由上涌的深层枯竭碳酸盐水驱动的。这些发现突出了预测海洋生态系统对未来上升流加强区域海洋酸化上升的反应的挑战。