Migration patterns of a potamodromous piscivore, asp (Leuciscus aspius), in a river–lake system

Abstract

Potamodromous fishes require safe migration routes between spawning, feeding and wintering habitats to complete their life cycle. As knowledge on asp migrations is restricted, this work investigated the movements of adult asp tagged with acoustic transmitters for 3 years in the large Peipsi-Emajõgi-Võrtsjärv lake-river system, Estonia, which is free of migration barriers. Asp showed complex migration patterns, moving between and within different waterbodies (lakes, river, tributaries) in all seasons, but with a tendency to repeat habitat use patterns between years. Lakes were mainly used for feeding during spring and summer (after spawning 65% of the fish migrated to Lake Peipsi), and more so by large fish. The majority (80-96%) of the fish spent the winter in the rivers, mostly close to their subsequent spawning area. Spawning areas were in swift-flowing waters in tributaries and the main river. The results indicate that asp may benefit from an extensive and diverse complex of habitats, and any migration barrier during any season may restrict the natural habitat use by asp. Maintenance and restoration of habitat heterogeneity and connectivity is critical to protect behaviourally diverse fish populations and increase resilience in rivers negatively impacted by various human activities.

Effects of physical parameters on fish migration between a reservoir and its tributaries

“…The relationship between water level changes and L. aspius migration from the reservoir into the tributary did not show any linear change over time, as the species migrated only in response to a significant increase in the water level. Leuciscus aspius are benthopelagic, rheophilic, potamodromous predators 50 , 54 , 72 known to migrate upstream from reservoirs and utilize tributary resources for prolonged periods, possibly suppressing native species 29 , 52 , 79 . Colonizing L. aspius , e.g., in France 80 and Spain 53 , has great invasive potential due to its migratory behaviour 29 , 50 , 79 supported by predation 72 .…”

“…Leuciscus aspius are benthopelagic, rheophilic, potamodromous predators 50 , 54 , 72 known to migrate upstream from reservoirs and utilize tributary resources for prolonged periods, possibly suppressing native species 29 , 52 , 79 . Colonizing L. aspius , e.g., in France 80 and Spain 53 , has great invasive potential due to its migratory behaviour 29 , 50 , 79 supported by predation 72 . The upstream movement of L. aspius is driven mainly by spawning migration with a lithophilic preference for gravel substratum 34 , 72 and by migration to feeding grounds in rivers since the species predominantly prefers lotic environments 35 .…”

A Comment on: Migrating silver eels return from the sea to the river of origin after a false start (2021) by Tambets M et al .

“…[5,6]), and such has been the practice of Tambets et al . [1] also in their previous studies on other species [7,8]. However, Tambets et al .…”

“…Such has been the common practice in silver eel studies (e.g. [5,6]), and such has been the practice of Tambets et al [1] also in their previous studies on other species [7,8]. However, Tambets et al [1] did not follow such practice, because they translocated their study specimens downriver ca 250 km from the capture location and released them ca 200 m from a hydropower plant intake canal, to study silver eel migration to the sea.…”

Use of a flow deflector to protect rheophilic fish spawning grounds during hydropeaking

“…We focused on the spawning grounds of a rheophilic cyprinid species, the asp, Leuciscus aspius . The asp is a large predator that migrates to fluvial river sections in early spring to spawn (Kärgenberg et al, 2020; Šmejkal et al, 2017; Vašek et al, 2018). It lays its adhesive eggs on a stony and gravelly substrate at flow velocities usually between 20 and 50 cm × s −1 .…”