Professor Kocabaş, of Tunceli University, went on to say that there are five types of indigenous trout found in Turkey.

 

The Black Sea trout, despite living in the Black Sea, migrates inland via rivers in the autumn to lay its eggs, then returns to the sea. However, the young trout hatchlings from those eggs spend up to one year in the fresh water of the rivers, before also swimming out to sea.

 

Kocabaş went on to say that the other types of trout found in Turkey are the brook trout, the Anatolian trout, the Abant Lake trout and the Aras trout, which originates from the Caspian Sea and is found in eastern Anatolia. He went on to state that “The Anatolian trout, the Black Sea trout and the brook trout can all be found living in the Uzungöl EPA”.

 

He explained that rainbow trout were introduced to Turkey from America in the 1950s, when trout farms were first set up in Abant and Yedigöller lakes, from where the practise of farming trout then spread across the whole of Turkey. In the fish farm rainbow trout reach a weight of 200 – 300 grams in 6 – 7 months, and in one year can weigh over a kilogram, whereas in the wild this fish would only weigh 350 – 400 grams after one year. Kocabaş went on to point out that the wild brook trout gets to a maximum length of 15-16cm and a weight of 70 – 80 gram in one year.

 

Kocabaş went on to cite the example of the French brook trout which is also bred in fish farms and said “We don’t know exactly how this fish initally came to Turkey, but presume its eggs were brought here specifically to be used in fish farming. Whilst rainbow trout cannot breed with wild trout, some of these French brook trout have escaped from fish farms and bred with wild trout, thus creating a new cross breed and leading to a form of genetic pollution.”

 

''FARMED TROUT ARE CONSUMING WILD TROUT EGGS AND YOUNG''

Kocabaş points out that amongst the live organisms which trout eat, as well as fly and insect larva, butterflies and micro-organisms that live in water, they also feed on the young and eggs of other species of fish. He goes on to say that wild trout and farmed trout eat the same diet of live organisms but, amongst the farmed trout, the rainbow trout eats far more than any other type. According to Kocabaş:

 

''When rainbow trout escape from farm ponds and start to share the same environment as wild trout, the whole picture changes. Compared to other types of trout, the rainbow trout are greedier, have bigger appetites and a greater need for food. In order to support their rapid growth rate in a wild situation, in which they are sharing food sources with wild trout, they eventually begin to eat the young and the eggs of the wild trout.

 

At the same time pollution is affecting the lakes in which wild trout live. An example of this is Uzungöl lake, where there has been so much building, to the point where waste from houses is polluting the fresh water sources that feed the lake. This in turn limits the areas in which wild trout can survive. As well as the effects of pollution, the viability of wild trout eggs has fallen, which means fewer baby trout are hatched. Thus farmed trout are taking over from wild trout.''

 

''RAINBOW TROUT MUST BE REMOVED FROM THE AREA''

Kocabaş explained that rainbow trout have now adapted to the Uzungöl EPA and are actively breeding there: “You can easily catch rainbow trout or the French brook trout outside the fish farms. I myself caught a rainbow trout weighing over a kilo in one of the rivers feeding Uzungöl, about 1700-2000 metres above the level of the lake. This is clear proof that they are breeding in the region.”

 

Kocabaş went on to state that rainbow trout breeding in the area is yet another threat to the types of wild trout found there:

 

''The number of wild trout found in the Uzungöl EPA is decreasing due to a combination of pollution, over-fishing and the presence of escapees from fish farms. This situation must be addressed. People living in the region must be taught the difference between wild trout and introduced exotic species, such as the rainbow trout and French brook trout. To ensure the continued presence of natural forms of wild trout, there must be strict controls placed on fishing. And at the same time the rainbow trout must be removed from the area. Fish farms need to be protected from the influx of waste water; and farmed fish, or their eggs, must not be allowed to escape into the natural environment.