Research Information System
the 16th International Congress on the Zoogeography and Ecology of Greece and Adjacent Regions (ICZEGAR) , Athens, Greece, 3 - 07 July 2025, vol.1, no.1, pp.63, (Summary Text)
The construction of all types of hydraulic barrier on rivers has various ecological impacts, including habitat fragmentation, changes in water quality and a decline in the biodiversity of aquatic communities. Fishes migrating to reproduce are among the most affected by these barriers and different fish passage models have been developed to mitigate this ecological problem. Designed to support the migration of strong swimmers such as salmon and trout, Larinier fish passage (LFP) is typically applied to hydraulic barriers with high vertical drops and base slopes of more than 12%. This study marks the first time that the LFP has been used in a culvert structure with a low base height (approximately 90 cm) and a 4% slope. This innovative approach was developed under natural conditions on the Kurtköy Stream, which flows into Sapanca Lake. Fish migration activity was monitored monthly over two periods: February–December 2023 (without fish passage) and January–December 2024 (with fish passage). During the first period (2023), only Squalius pursakensis and Phoxinus strandjae were found upstream of the culvert, whereas ten different fish species were recorded downstream. In the second period, individuals of seven different species (Alburnus istanbulensis, Gambusia holbrooki, Petroleuciscus borysthenicus, P. strandjae, Rhodeus amarus, S. pursakensis and Vimba vimba) were observed above the LFP. Considering that many species of varying sizes used this fish pass this study proposes the LFP— operated under natural conditions at a low slope using an innovative approach—as a fast and practical solution for maintaining ecological continuity in culvert structures with low gradients.
Keywords: Fish migration, hydraulic barrier, ecological connectivity, small-bodied fish, Sapanca Lake, Kurtköy Stream.