Pollution influence on bacterial abundance and chlorophyll-<i>a</i> concentration: case study at Idku Lagoon, Egypt

Abstract

SUMMARY: Idku lagoon is one of the northern delta lakes, connected with the Mediterranean Sea through Boughaz El Maadyah. It is subjected to industrial, domestic and agricultural pollution. Depending on collected data of water samples during one year of research, the lagoon was separated into different water masses by using the discriminant function analysis (DFA). Estimation of some biological (total and saprophytic bacteria, faecal bacteria and chlorophyll-a) and chemical variables (chlorosity, organic matter, dissolved oxygen and dissolved inorganic nutrients) lead to differentiate Idku lagoon waters into four sites: Drain (I), Lake Proper (II), Bay (III) and Boughaz (IV). The highly effective parameters for the predicted sites were chlorosity, organic matter and faecal bacteria (E. coli). Factor analysis was applied for each site to find out the correlating variables (biological and chemical) that seemed to control each independent site. At Drain site (I) pollution by agricultural sewage (through Idku Drain) supported bacterial as well as algal growth, while at Lake Proper site (II) bacteria seemed to obtain their nutrient supply from algal origin after their death and lysis. Site II was characterized by its absolute highest chlorophyll-a content. Factor models for sites II and III indicated a positive and mutual relationship between bacterial microbiota and chlorophyll-a. The strong correlation that appeared between all biota from factor model for site III, at the absolutely high chlorosity values (compared to the other sites), could be due to the development of salt tolerant strains and species. Factor model for site IV revealed a strong positive correlation between bacterial microbiota and nutrients (derived from industrial pollution at Boughaz El Maadyah), but negatively correlated to chlorophyll-a. Thus it seemed that bacteria obtained their nutrient supply mostly from sewage.

Assessment of a Non-Optical Water Quality Property Using Space-based Imagery in Egyptian Coastal Lake

“…Accordingly, the lake receives wastewaters with different pollution degree from fish farming therapeutic drugs, nutrient flux from agricultural drainage network (e.g. Edku, El-Boussili, Khairy and Bearsik drains), in addition to effluents from municipal WasteWater Treatment Plants (WWTPs) and industrial facilities (Siam and Ghobrial, 2000). The lake is connected to the Mediterranean Sea with single opening "Boghaz Al-Maadia", which allows temporal tidal inflows and localized saline water interaction.…”

Impact of environmental parameters on fish condition and quality in Lake Edku,Egypt

“…Many studies were conducted on the hydrology, chemical and biological characteristics of Lake Edku (Soliman 1983;Gharib and Soliman, 1998;Siam and Ghobrial, 2000;Okbah and El-Gohary, 2002;Shakweer, 2006;Badr & Hussein, 2010). However these studies did not investigate whether prevailing conditions (e.g.…”

Conceptual Merge of Ecohydrologic Watershed and Sponge City Techniques for Managed Sustainability and Strengthened Adaptive Capacity of Nile Delta Coastal Lakes, Egypt

“…oils and textiles), Wastewater Treatment Plants (WWTPs), water reuse units, as well as aquacultural activities all end up into the lake's water. Disposed wastewaters are reported to have a high level of polluting impact especially nutrients; fertilizers and pesticides, and pathogens (Siam and Ghobrial, 2000) Lake Edku is considered a shallow eutrophic lake that rarely exceeding 1.5 m in depth, with similarity to a wetland system. The dominant aquatic plants in the lake are emergent reed Phragmites australis.…”

“…At present, coastal lakes experience deteriorating biochemical state and disturbed flow dynamics within. As degrading system state would compromise the beneficial uses, a number of studies were triggered for assessment and restoration attempts (Siam and Ghobrial, 2000;Saad, 2003 Rostom et al, 2017). It has been estimated that 80% of coastal pollution comes from land-based sources (UNESCO-IHP, 2012).…”