University Of Tehran Press Pollution 2383-451X 11 2 2025 02 01 Water Quality Assessment for the Southern Al-Hawizeh Marsh Using Diatom Indicators 454 463 99863 10.22059/poll.2024.380917.2510 EN Safa Hussein Saki Department of Ecology, College of Science, University of Basrah, Iraq Maitham Abdullah Al-Shaheen Department of Ecology, College of Science, University of Basrah, Iraq 0000-0003-1535-5333 Journal Article 2024 08 15 The current study was conducted to assess water quality in the southern Al-Hawizeh Marsh using epiphytic diatoms. Two types of plants were used, Phragmites australis and Tamarix aucheriana. Four study sites were selected at the southern Al-Hawizeh Marsh, plant samples were collected quarterly, double months for each season, starting from October 2020 to July 2021. Two of diatom indicators were applied, Trophic Diatom Index (TDI) and Specific Pollution Sensitivity Index (SPI). The results of TDI showed that the waters of the Southern Al-Hawizeh Marsh were generally at a mesotrophic level; the temporal results recorded the lowest values during the winter season at the oligotrophic level and the highest values of the index were recorded in the summer with a rich nutritional level (eutrophic). As for the results of the spatial index of TDI, the lowest values of the index were recorded in Well 11 as oligo-mesotrophic, while the highest rate was recorded at the Al-Keser site at the level of eutrophic. However, the SPI analysis results showed that the marsh's waters, in general, have moderate organic pollution or significant eutrophication. Autumn season has the highest index rates ranging from moderate to light pollution, while the spatial SPI index in the sites showed that the lowest rates of index were recorded by the Al-Sabelah site, and the highest rates of index were recorded by the site Well 11, both of them with a moderate to eutrophic of pollution. https://jpoll.ut.ac.ir/article_99863_0e1dea5b42e9414ca892af745ac65667.pdf