Lake Işıklı, Denizli, Turkey

Environment

Environment

Human settlements

Human settlements

Surrounding area

Işıklı Lake is a lake of tectonic origin located in the upper basin of the Büyük Menderes River. Işıklı Lake is an important wetland that feeds the Büyük Menderes River together with Gökgöl, which is its connection. The average altitude of Işık Lake is 818 meters. The surface area of the lake, whose deepest place is 7 meters, is 73 km². However, depending on the rain and temperature conditions, changes occur in the lake nutrition in Işıklı Lake, which causes differences in the lake level from year to year. Işıklı Akgöz resources contribute 23% to the nutrition of Işıklı Lake.

There are various opinions for the formation of the lake. One of these; According to Saraçoğlu (1990), the Kufi Stream is in the Çivril Plain. It formed a set by accumulating the alluvium it carried in the place where it was opened, thus, Işıklı Lake was formed with the accumulation of water behind the embankment. Being a reed-swamp to a large extent, Işıklı Lake has become a dam lake with various arrangements between 1949 and 1963.

According to the AMSAR Agreement, there are 123 bird species belonging to 34 families in Işıklı Lake and Gökgöl, which are in the A group wetland category, and in Akdağ Nature Park located in the eastern part of this area. Of these, 107 species are covered by Bern contracts, 3 species are covered by IUCN and 58 species are covered by the Red Data Book (RDB).

The lake flora also provides income to the local people economically. Wicker that grows in shallow areas by the lake various hand weavings are made from plant. Reed harvesting in the lake is another economic activity.

Underwater landscape

Işıklı Lake has intensive vegetation. While there are terrestrial and amphibian reed types in the coastal areas, Potamogeton and water lily species are found in the inner parts. Apart from its flora, it has a rocky ground. Due to the trees in certain places, broken branches are also encountered under water. There is a mixture of silica and gravel sand. Anatolichthys (Aphanius) maeandricus, the host of this biotope, lives in the shallow, swamp and vegetation regions of Lake Işıklı. There are dense filamentous algae in these areas. Aphanius meandricus also acquires regions on these algae and realizes its breeding.

Fishes:

• Anatolichthys maeandricus
• Gobio meandricus
• Cobitis fahirae
• Oncorhynchus mykiss
• Squalius cephalus 
• Esox lucius
• Chondrostoma maeandrese
• Barbus pectoralis 
• Nemachelius angorae
• Pseudophoxinus maeandricus
• Cobitis taenia
• Tinca tinca
• Carassius gibelio
• Gambusia holbrooki   

Plants:

• Ranunculus saniculifolius
• Ceratophyllum demersum
• Butomus umbellatos
• Polygonum amphibium
• Potamogeton perfoliatus
• Nymphaea alba
• Nuphar lutea
• Trapa natans
• Lemna minor
• Phragmites australis
• Myriophyllum spicatum
• Vallisneria sp.
• Elodea sp.

Threats to ecology

There is a large amount of plant infestation in the shallow areas due to the level decreases in Işıklı Lake. In the land use maps created by the controlled classification made on the satellite images of 1987-2013, it is seen that there is a large increase in aquatic plants in Lake Işıklı from year to year. The increase in aquatic plants and the decrease in the water surface in Işıklı Lake are remarkable.

As a matter of fact, aquatic plants covered an area of 43 km² in 1987 and 78 km² in 2013. While the water surface was 60 km² in 1987, it decreased to 28 km² in 2013. This decrease in the water surface is the result of water withdrawal from the lake within the scope of the Baklan-Çivril Irrigation Project, which was activated in 1992.

The lake flora also provides income to the local people economically. Various hand weavings are made from the wicker plant grown in shallow areas by the lake. Reed harvesting in the lake is another economic activity. However, the lack of controlled reed harvesting harms the feeding and sheltering areas of the bird species living in and around the lake. Bird species that cannot find feeding and sheltering opportunities leave the area.

Another reason can be explained as the material carried by various streams and rivers, especially Kufi Stream and Akçay, feeding the Lake Işıklı, filling the lake. In order to prevent this, in 2015, 2 reverse weirs were built by DSI on Kufi Stream and Akçay with 60 intensive weirs. It is aimed to control the sediment coming to the lake with these weirs. Thus, it is tried to prevent the Işık Lake from filling with materials.

If ecological threats are to be considered on the basis of pollution. The pollution load carried by Dinarsuyu from Dinar damages Lake Işıklı. Apart from this, the people of the region also have an effect on the increase of pollution. Waste garbage was found at some places.

Tinca tinca, Carassius gibelio and Gambusia holbrooki, which were added to Lake Işıklı, are invasive. The Anatolichthys (Aphanius) maeandricus toothcarp was added to IUCN Red List because of it is in danger of generation. These invasive fish species have a major role in reducing the numbers of Anatolichthys (Aphanius) maeandricus toothcarp.

Riparian zone

Trees near the aquatic habitat

Few -

Bibliography

• → IŞIKLI GÖLÜ VE IŞIKLI ÇAYI’NDA (ÇİVRİL-DENİZLİ) DETERJAN, FOSFAT VE BOR KİRLİLİĞİNİN ARAŞTIRILMASI by Murat ÇAKIR, Orkide MİNARECİ
  

Sitography

Comment by the expert