Spatiotemporal Fluctuations in Phytoplankton Communities and Their Potential Indications for the Pollution Status of the Irrigation and Drainage Water in the Middle Nile Delta Area, Egypt

Abstract

Water pollution monitoring programs should include phytoplankton analysis to get a deep understanding of the degree of pollution and eutrophication of aquatic ecosystems. In this chapter, spatial and temporal variations of the phytoplankton composition in the Middle Nile Delta surface water were investigated. Water was sampled from two main irrigation canals (Qudaba and Mit-yazed canal) and two main drains (Janag drain and El-Gharbia main drain). A total number of 250 species and varieties belonging to 100 genera and 7 algal divisions were recorded. Bacillariophyta, Chlorophyta, Cyanophyta, and Euglenophyta were the most important and effective algal divisions in the surface water of the Nile Delta. The phytoplankton communities of the irrigation canals had a quite similar composition and so the communities of drains except in the estuary of El-Gharbia main drain. Significant differences were found between drain’s phytoplankton communities and that of irrigation canals. In general, the temperature and nutrient availability during summer seemed to give higher productivity in both irrigation and drainage water. There was evidence for heavy organic pollution through the presence of pollution-tolerant algal taxa; also there were many species that were tolerant to eutrophication. In this work, besides the observation of phytoplankton communities’ fluctuations, a phytoplankton checklist was established for irrigation and drainage water of the Middle Nile Delta so that it can be used as environmental bioindicators and other probable applications. Palmer index was used to evaluate the organic contamination in the studied water bodies. Organic pollution in summer was higher than that of winter. In general, pollution increased along the water pathways from southern to northern direction.