Assessment of recent rehabilitation projects’ impact on water quality improvement in Lake Burullus, Egypt

Abstract

Lake Burullus, the second largest coastal lake and wetland in Egypt, is suffering environmentally and economically under the tremendous pressure of rapid urbanization and increase of agriculture, aquaculture and industrial activities for more than 4 decades. This caused significant reduction of the lake’s area and sever degradation of its ecological system, including the decrease in fishing yield, which consequently led to serious socio-economic challenges for the local fisheries communities as well as affecting the national fish production of Egypt. Recently, the Egyptian Government has made great efforts for the rehabilitation and restoration of the northern lakes and wetlands in attempt to improve their environmental conditions and restore their economic value. Among these efforts is Burullus Lake Rehabilitation Project, which has started in 2018 covering the inlet and the eastern part of the lake and aims to improve the water quality and fish production in the lake mainly by enhancing water exchange between the lake and the sea through dredging and side protection works. The current study provides an update of the water quality conditions over Burullus lake by carrying out a wide water sampling program that covers the entire perimeter of the lake with an emphasis on the most problematic areas. The main water quality parameters were measured and analyzed spatially in order to provide a quantitative assessment of the efficiency of the implemented rehabilitation and restoration works and provide recommendation for further improvement works. The results show that there was a significant improvement of investigated water quality parameters over the lake inlet and the eastern part where the dredging works were carried out while less improvement was found over the western part. This indicates that water exchange with the sea and the circulation pattern in the lake have the most significant influence on the lake’s water quality, which should be considered in future rehabilitation projects.