Fish migration and fish ramp assessment at a gauging station on a Mediterranean river (Catalonia, NE Iberian Peninsula)

Abstract

Fish migration and fish ramp assessment at a gauging station on a Mediterranean river (Catalonia, NE Iberian Peninsula)In May and October 2013, an in situ assessment of the fish ramp at the gauging station on the Fluvià River at Olot was performed, using different techniques to estimate the fish ramp's effectiveness. This fish ramp is one of the first in Catalonia (NE Iberian Peninsula) that follows international guidelines for fish passes and especially for fish ramps. The fish ramp allowed passage of all native cyprinid species from this river. The crossing rates were higher in May (average of 7.9 ind./day for Barbus meridionalis and 3.8 ind./day for Squalius laietanus), a month associated with their spawning period, than in October (average of 4.6 ind./day for B. meridionalis and 1.0 ind./day for S. laietanus). Pending complementary year-round samplings for several annual periods, the results show that the spawning period seems to be the primary driver of upstream fish migration, which is also influenced by a decrease in river flow just after a peak flow, a minimum water temperature value and less bright lunar phases.

The role of connectivity in conservation planning for species with obligatory interactions: Prospects for future climate scenarios

“…The ability of fish to overcome obstacles is highly dependent on their traits and life histories (Hermoso & Filipe, 2021; Table S5). Most Iberian freshwater fish species present a migratory behaviour (i.e., potamodromous or diadromous), and thus are prone to move great distances (Ordeix & Casals, 2024). As such, migratory fish species will most likely be primarily responsible for moving mussels to newly suitable habitats across the river network when compared to the few Iberian fish hosts that do not show a migratory behavior (Table S5).…”

Why and when do freshwater fish migrate? Observations of migration patterns of the native fishes from the Iberian Peninsula (SW Europe)

“…The biggest catches of glass eel (A. anguilla) in the estuarine fisheries in Catalonia occur mostly during the new moon, also positively influenced by wind, big river flows and mild temperatures (Gómez et al, 2012). In the Fluvià River (NE Catalonia), during the breeding season, statistically significant differences between full moon and new moon crossing rates upstream of Western Mediterranean barbel (B. meridionalis) and Catalan chub (S. laietanus) were also observed (Ordeix, 2017).…”

“…In NE Catalonia (Ordeix et al, 2011), in the Llobregat river basin, Iberian redfin barbel (B. haasi) move upstream when water temperature rises up 7-10 ºC. In the Ter and Fluvià river basins (Ordeix et al, 2011, Ordeix, 2017, Western Mediterranean barbel (B. meridionalis) and Catalan chub (Squalius laietanus), when water temperature rises above 10 and 13 ºC, respectively, but high passage rates are associated with warmer water: 14-18 ºC. Sea lamprey (P. marinus) migrate in northern Portugal (Santos et al, 2004) at temperatures above 11 ºC, showing pronounced activity at 12-16 ºC.…”