| Popis: |
DeliceRiver is the one of our long stream is decharging to Kızılırmak River. It hasbeen appeared with the small tributaries from the South-east of Yozgat province.the improtant tributaries of Delice River are Kanak, Karasu, Koyunluyusufözü, Killiközü,Budaközü and etc. In particular, with the merging of Kanak and Karasu Streamsin the district of Sefaatli, it takes the name of Delice River.DeliceRiver shows flow characteristics between Çankırı, Yozgat, Kırşehir andKırıkkale provinces. Its surface area is approximately 78.189 km², its annualwater volume is 6 billion m³, and its average flow rate is 30,352 m3/sec.Inthis study, 22 stations were determined on the Delice River and its tributariesvia Field observation. Seasonally, fish samples were taken from these stationsbetween March 2019 and February 2020. For the fish catching back typeelectrofisher device and various meshes were used.Itis identified that 2 invasive species belonging to 2 families which are Poeciliidaeand Cyprinidae. Gambusia holbrooki isused in mosquito control. It is considered like the rapidly spreading andinvasive species in Turkey's inland waters.G. holbrooki individuals had been caught in only one station with a lowpopulation in next to Kızılırmak and Delice River joint point. G. holbrooki entered the Delice Riverlately and there is no information about routes of the entry. Although, Thereis only one record from Kızılırmak River, not any record from Delice River. Itis very important to be the first record from Delice River. It is thought thatit has not spread over a wide area in the Delice River yet, but it may havenegative effects on other species due to the species' invasiveness and rapidspread.Pseudorasbora parvaindividuals, had been caught in 5 stations which were far form each other withlow population. It has been observed that it can be found in areas withdifferent physicochemical parameters indicates its high environmental toleranceand adaptability. It has been understood that P. parva individuals generally live in the same habitats withCyprinidae species. It has been observed that the individuals have not yetspread in the majority of the stations in the Delice River and their populationdensity is very low compared to other species. In addition, P. parva records has been reported byresearchers from Kızılırmak River and Gelingüllü Dam Lake.Itis thought that invasive species do not pose a significant threat in DeliceRiver yet, but when compared with the other water systems, they will causehabitat shrinkage for other species if they spread in this water system.However, in fact it has been prooved that Delice River has good conditions tothese invasive individuals for growing new populations. In the near future, itcan be tought that they can easily spread in Delice River and its tributaries. |
