Benthic Foraminifera-Based Biomonitoring of Aquatic Environmental Pollution: A Review of Egypt’s Nile Delta Lagoons and Mediterranean Coast

Benthic foraminifera have emerged as reliable bioindicators for assessing organic contamination, industrial pollution and environmental stresses in Egypt’s aquatic systems. This review brings insights from 20 studies carried out in key regions such as the Nile Delta lagoons and the Mediterranean coast. Species like Ammonia tepida consistently appear as dominant in environments affected by hypoxia, organic loading, heavy metal, and salinity fluctuations. Assemblage data reveal not only reduced diversity but also notable morphological abnormalities, particularly in response to heavy metals. Beyond recent surface sediments, sediment core analyses point to a long-term ecological decline, marked by a rise in opportunistic forms and the disappearance of more sensitive taxa over time. The Foraminiferal Abnormality Index (FAI) and diversity indices have proven valuable for gauging ecosystem health; however, their application is often hindered by inconsistencies in sampling methods and analytical protocols. A clear contrast emerges when comparing relatively stable environments where assemblages appear healthier, with more degraded systems where low species richness, high test deformities, and the dominance of stress-tolerant taxa reflect significant environmental pressure. This synthesis highlights the need for standardized methodologies tailored to Egypt’s unique environmental settings. Integrating benthic foraminiferal data with molecular, geochemical, and sedimentological approaches could significantly enhance our understanding of ecosystem conditions. Despite being underutilized, benthic foraminifera offer robust potential as part of a comprehensive environmental monitoring strategy, one that could play a vital role in shaping more sustainable management practices for Egypt.