Assessment of Trophic status for Shatt Al-Arab River using trophic state index (TSI)

Abstract

Shatt Al-Arab River receives considerable loads of nutrients, and other compounds, result-ing from anthropogenic activities within its catchment. The main aims of this first line research in trophic state index in Shatt Al-Arab River were to evaluate spatial and seasonal trends in waer nutrients and also to compare data with trophic state index (TSI), identifying and assessing the impact of the loads to the environment. Ten stations were sampled within northern parts of Shatt Al-Arab River. Field measurements (water temperature, pH, Dissolved Oxygen and secchi disc transparency) and laboratory water analysis (total phosphorus and chlorophyll-a) were carried on the sampling stations monthly. The results explained that the secchi disc transparency was negative correlated with chlorophyll-a , although there were ex-ceptions in some individual stations. The analysis of the data suggested that the relationship between transparency and total phosphorus was negative and slightly curvilinear. Positive correlation was found between Chl-a and total phosphorus. Trophic state index calculations (44.3) indicated mesotrophic conditions of Shatt Al-Arab River. The relationship of TSI with the diversity of different aquatic organisms is more beneficial to study in the future programs in this study area