As part of the "Improve River LIFE" project, we conducted monitoring of invasive fish species on the Vrljika and Jadro rivers. Despite challenging weather conditions, our expert team successfully tackled field tasks, allowing us to gain a detailed understanding of the presence and distribution of invasive species in these watercourses.
Identified invasive species, such as rainbow trout on the Jadro river and pike on the Vrljika river, have a significant negative impact on native fish populations, especially on the softmouth trout, which was subjected to competition and predation. However, besides these invasive species, we also observed the presence of other non-native species such as carp (Cyprinus carpio), pumpkinseed (Lepomis gibbosus), perch (Perca fluviatilis) and Prussian carp (Carassius gibelio), which can also have undesired consequences on the softmouth trout.
The implementation of monitoring was crucial for the development of effective protection and management strategies, aimed at reducing the negative impact of all invasive and alien fish species and preserving the balance and biodiversity of our rivers.
Following thorough monitoring, our next phase involves continuous removal of invasive and alien fish species on a monthly basis, which will further contribute to the preservation of natural habitats and native fish populations on the Vrljika and Jadro rivers.