Fish are the most numerous, but at the same time the least researched group of vertebrates. Due to their connection with aquatic ecosystems, freshwater fish are exposed to immense human pressure, which manifests itself through pollution of watercourses, habitat degradation, fishing and invasive species. The diversity of Croatian ichthyofauna ranks it at the very top of Europe, and ecological, climatic and geomorphological conditions as well as a large number of available and different habitats are responsible for the richness of species.
“Invasive ichthyofauna of the Čikola River” is a research and educational project of the BIUS Fish Section that focuses on mapping invasive species in the Čikola through four field trips during the year.
The rivers of the Adriatic basin are short and isolated and very often flow through deep canyons forming cascades and lakes. When they pass through the karst fields, the banks are shallower, and the bottom of the bed is overgrown with vegetation. During the summer, they can completely or partially dry up. It is precisely these specific ecological conditions that make the rivers of the Adriatic basin, and thus the Čikola River, extremely ichthyologically rich habitats that abound with endemic species. Čikola is one of the main tributaries of the Krka River and is the habitat of three endemic species of freshwater fish: bream (Aulopyge huegelii), Turkish chub (Telestes turskyi) and Dalmatian pijurica (Phoxinellus dalmaticus).
Freshwater fish are exposed to great human pressure, but one of the biggest threats to the endemics of the Adriatic basin is precisely invasive species. Therefore, the goal of this project is to investigate in more detail the distribution of invasive fish species in the Čikola River and to provide a better and more recent view of the state of endangered and critically endangered endemic fish species with the collected data.
Among the invasive species, gambusia, carp and potentially black catfish are found in Čikola.
All 3 endemic species and all the invasive ones we expected in Čikola were confirmed, except for the black catfish.
The project was financed by:
Donators:
