Mahmoud A. Halablab, Nabila E. Abdelmeguid, Hanafi M. Holail and Maysa F. Choukeir
College of Science & Information Systems, Rafik Hariri University, P.O. Box: 10, Damour, Chouf 2010, Lebanon
Water resource shortage is a major problem that is plaguing the world. Water demand and availability is affected by a number of factors namely geographies, population demographics, climatic conditions, socio-economic development, technological developments, environmental conservation and water pricing.
The modernization and maintenance of society has increased the demand for water. A number of water augmentation projects have been implemented to help facilitate water entrapment. Consequently, the industrialization of society and unsustainable practices has also been the source of pollution of many of our water resources. It must be noted that all water resources contain a variety of natural contaminants, which stem from erosion, leaching and weathering processes. Most water bodies have the ability to self-purify whereby they are capable of assimilating a certain amount of these contaminants without any detrimental effects. This is, however, dependent on environmental conditions, pollutant load and water retention times. If these natural contaminants are coupled with artificial pollutants, which are a result of human activities, the pollution load becomes too much for the water body to handle. The most significant form of artificial pollution is the return flows of wastewater, sewage and industrial effluents into our aquatic environment.
A major fresh water source in Lebanon is the Litani River, which drains over fifth of Lebanon’s total area. Exceeding 170 km and an estimated average annual discharge rate of over 750 million cubic meters, it originates from a spring in the fertile Bekaa Valley, and flows south then west until reaching the Mediterranean Sea 7 km north of Tyre.
The Litani River suffers from potential water pollution problems due to the uncontrolled solid and liquid domestic and industrial waste disposal practices, agrochemical usage and lack of sustainable wastewater treatment system.
As most contaminants ultimately end up in water, the aquatic environment is of highest interest in environmental monitoring. When fish are exposed to elevated levels of metals in aquatic ecosystems, they tend to accumulate these metals up directly from their environment through the food web. It is assumed that most metals are taken up in the ionic form. Transport of metals in the fish occurs through the blood where ions are usually bound to proteins. The metals are thus brought into contact with the organs and tissues of the fish and consequently accumulated, to a different extent, in different organs/tissues. It is of considerable interest that all the metals taken up are not accumulated because fish have the ability to regulate their body metal concentration to a certain extent.
The Litani River water is collected in a man-made lake (Karoon Lake) which serves as a major hydroelectric source, irrigation of a significant fertile land area and acts as a major medium for fish industry. The latter industry is the main source of living for many families in the area. Most of the towns and villages along the Litani River banks discard untreated domestic and industrial waste into the river. Therefore, most of the polluted effluent ends up in the Karoon Lake where fish can assimilate some of these pollutants. Needless to say the use of the contaminated river water for irrigation of vegetables consumed raw (such as parsley, lettuce, etc.) grown along the river flow.
Microbiological and chemical pollution of water have detrimental effect on food industry including fisheries. It was, therefore, interesting to evaluate the environmental impact on fish industry in the Karoon Lake. Samples of common fish (Cyprinus carpio) were collected and the microbiological and chemical effect on this species was evaluated. Physicochemical assessment of the surface water was carried out. This included measurement of pH, hardness, BOD, DO, nitrate, nitrite, phosphate, and ammonia and identification of heavy metals (Fe, Cu, Mg, Cr, Zn, Al, Cl) and determination of their levels in water samples. Histology of key organs in the fish samples was also investigated. The key organs dissected included liver, kidneys and testes. The microbiological and histological studies of these organs will be discussed in details. Recommendations and proposals to save fish industry in this area will also be highlighted.