Spatial distribution and population density of submerged aquatic vegetation in Shatt Al-Arab River

Submerged aquatic vegetation (SAV) is an integral component of aquatic ecosystems and provides essential habitats and ecosystem services. This study investigated the distribution and abundance of SAV in the Shatt Al-Arab River, located in Southern Iraq, and examined its relationship with changing environmental factors. Monthly surveys were conducted at three stations from October 2015 to September 2016 to assess the percentage cover of vegetation, biomass, and the physicochemical properties of water and sediment. Three SAV species belonging to the Potamogetonaceae family have been recorded. Canonical correspondence analysis showed a negative relationship between Potamogeton perfoliatus and depth/reactive phosphorus. The abundance of plants in this area was significantly lower than that reported in previous studies. Species richness and abundance were analyzed at all stations during the same period using biodiversity indices. The analysis revealed differences in species richness between the stations. This decline in abundance was likely due to increased salinity, nutrients, and anthropogenic pressures. This study demonstrates the impact of environmental changes on ecologically important SAV and emphasizes the necessity of implementing conservation and management strategies.