Table 1. Fish species included in the analyses and their occurrence frequency.

Species code	Species name	Occurrence frequency
Abrarama	Abramis brama	0.385
Albuatus	Alburnoides bipunctatus	0.076
Alburnus	Alburnus alburnus	0.278
Anguilla	Anguilla anguilla	0.658
Aspipius	Aspius aspius	0.120
Barbrbus	Barbus barbus	0.279
Barbtula	Barbatula barbatula	0.482
Blicrkna	Blicca bjoerkna	0.283
Caraelio	Carassius gibelio	0.189
Carasius	Carassius carassius	0.274
Chonasus	Chondrostoma nasus	0.098
Cobienia	Cobitis taenia	0.183
Cottobio	Cottus gobio	0.420
Cyprrpio	Cyprinus carpio	0.406
Esoxcius	Esox lucius	0.523
Gastatus	Gasterosteus aculeatus	0.523
Gobiobio	Gobio gobio	0.616
Gymnrnus	Gymnocephalus cernuua	0.244
Lampilis	Lampetra fluviatilis	0.085
Lampneri	Lampetra planeri	0.337
Leucatus	Leucaspius delineatus	0.206
Leucidus	Leuciscus idus	0.181
Leucscus	Leuciscus leuciscus	0.384
Lotalota	Lota lota	0.165
Misgilis	Misgurnus fossilis	0.145
Percilis	Perca fluviatilis	0.576
Phoxinus	Phoxinus phoxinus	0.248
Pungtius	Pungitius pungitius	0.253
Rhodarus	Rhodeus amarus	0.159
Rutiilus	Rutilus rutilus	0.648
Salmutta	Salmo trutta	0.597
Salvalis	Salvelinus fontinalis	0.104
Sanderca	Sander lucioperca	0.248
Scarlmus	Scardinius erythrophthalmus	0.334
Siluanis	Silurus glanis	0.124
Squaalus	Squalius cephalus	0.447
Thymllus	Thymallus thymallus	0.319
Tincinca	Tinca tinca	0.481