Eutrophication of the Nile: Comparative nutrient data of the Damietta Branch, Egypt, from 1978 and 2003

Abstract

The Nile is the major life artery for life in the arid north-east quarter of the African continent. This is especially true for Egypt, where the highest human population density exists on the river's banks and its delta. As a result, the Nile in Egypt is one ofthe most controlled rivers in the world. The Nile flows from south to north where it eventually empties its water into the Mediterranean Sea. At its delta, beginning just south of Cairo, it bifurcates into 2 branches; the Damietta Branch to the east and the Rosetta Branch to the west. Despite the importance of the Nile in Egypt, few studies have been performed on its water quality, especially in the delta region. Studying the water quality and biological diversity o f the de l ta waters should provide useful information on the many human impacts upstream. Such studies are especially important after the reduction of the Nile water flow into the Mediterranean after 1970 as a result ofthe completion ofthe Aswan High Dam (NIXON 2003). Until now, the Nile Delta received little attention in limnological research. Zooplankton of the Damietta Branch was considered by HELAL (1981, 2006), and phytoplankton was investigated by BAKA (1980) and DEYAB (1987). In addition to plankton, these studies addressed some aspects o f water quality. A published portion of the present study, with a focus on zooplankton, revealed a decline in zooplankton species diversity in 2003 compared to earlier data from 1978 (HELAL 2006). Studies on heavy metals focused only on the brackish segments of the Damietta Estuary (IBRAHIM et al. 1999) and the Rosetta Estuary (SAAD & HASSAN 2002) In this paper, I document some important forms of water pollution: (a) eutrophication as a result ofhigh nutrients concentration (nitrate and phosphate), and (b) pollution by heavy metals (lead and mercury). I compared data from 2 separate studies 24 years apart. Both studies covered the same section of the Damietta Branch. The first study was performed during 1978-1979 (BAKA 1980, HELAL 1981 ), and the more recent study was done during 2002-2003.