The coastal environment has changed in the past 25 years relation to the industrial and human settlement around the Tuzla Lake, Istanbul, Turkey. At first, the inlet of the Tuzla Lagoon Lake was filled and isolated from the sea, and changed to a fresh water lake. This was followed by chanelling of dirty creeks and a tunnel construction 8 m below the sea level just behind the lake. These engineering constructions resulted in a 3 m fall of ground water level in 4 years around the lake and, as a result a drought occurred in June, 2001. During this period, salty water encroachment and groundwater saltation occurred and farmlands faced significant irrigation problems. After the drought, two connection pipe lines were constructed between the sea and the lake. However, these pipes were filled by sea originated material, mostly shells, within a year and water exchange between the lake and the sea became impossible. As a result, environmental equilibrium has been disturbed and farming habits have changed.
The investigations on the lake mud after the drought reveal that sedimentation rate has been about 1cm/year for past 25 years. A bed rich in shrimp skeletons observed within the lake mud indicates significant pollutant introduction into the lake from industrial or agricultural activities.