The classification of European rivers comes from the fish fauna found in them. Changes in taxonomic composition relate to physical and chemical changes that occur longitudinally.
This zone has a characteristic steep gradient, fast flowing water and cool temperature. The fast flow rate causes turbulence which keeps the water well oxygenated. Fish species found in this zone usually lay adhesive eggs that can stick to the substrate, this is to help prevent eggs being carried down stream by the water flow.
Similar in physical characteristics to the Trout zone, although the temperature is usually slightly higher. Fish species in this zone also lay adhesive eggs.
Characteristic fish species include all of the above species, with the addition of;
This zone is essentially lowland, but retains some characteristics of upland rivers. It has a gentle gradient with a moderate water flow and temperature. It also has a good oxygen content and a mixed substrate of silt and gravel in which plants can take root. Most of the fish species found in this zone lay their eggs in the vegetation on the river bed, this provides them with good protection and allows the eggs a good supply of oxygen given off from photosynthesis in the plants.
Characteristic fish species include all of the species from the previous zones with addition of;
The true lowland zone, has a very gentle gradient and slow flowing water, there is usually good oxygen content but the temperature is much more variable than in the other zones. This zone has a silty substrate and is often turbid. Fish species found in this zone lay adhesive eggs in the weeds. Most upland fish species can not survive in this zone.
Characteristic fish species include only a few species from the Barbel zone (Roach, Rudd, Perch and Pike), with the addition of:
Aarts, B. G. W. and Nienhuis, P. H. (2003) ‘Fish zonations and guilds as the basis for assessment of ecological integrity of large rivers’, Hydrobiologia, 500, pp. 157–178. doi: 10.1023/A:1024638726162.
January 01, 1970
european, river, zonation, this, article, does, cite, sources, please, help, improve, this, article, adding, citations, reliable, sources, unsourced, material, challenged, removed, find, sources, news, newspapers, books, scholar, jstor, december, 2009, learn, . This article does not cite any sources Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources European river zonation news newspapers books scholar JSTOR December 2009 Learn how and when to remove this message The classification of European rivers comes from the fish fauna found in them Changes in taxonomic composition relate to physical and chemical changes that occur longitudinally Contents 1 Zonation from headwater to estuary 1 1 Trout zone 1 2 Grayling zone 1 3 Barbel zone 1 4 Bream zone 2 References 3 Further readingZonation from headwater to estuary editTrout zone edit This zone has a characteristic steep gradient fast flowing water and cool temperature The fast flow rate causes turbulence which keeps the water well oxygenated Fish species found in this zone usually lay adhesive eggs that can stick to the substrate this is to help prevent eggs being carried down stream by the water flow Characteristic fish species are Brown trout Salmo trutta Atlantic salmon Salmo salar Bullhead Cottus gobio Loach Barbatula barbatula Grayling zone edit Similar in physical characteristics to the Trout zone although the temperature is usually slightly higher Fish species in this zone also lay adhesive eggs Characteristic fish species include all of the above species with the addition of Grayling Thymallus thymallus Minnow Phoxinus phoxinus Chub Leuciscus cephalus Dace Leuciscus leuciscus Barbel zone edit This zone is essentially lowland but retains some characteristics of upland rivers It has a gentle gradient with a moderate water flow and temperature It also has a good oxygen content and a mixed substrate of silt and gravel in which plants can take root Most of the fish species found in this zone lay their eggs in the vegetation on the river bed this provides them with good protection and allows the eggs a good supply of oxygen given off from photosynthesis in the plants Characteristic fish species include all of the species from the previous zones with addition of Barbel Barbus barbus Roach Rutilus rutilus Rudd Scardinius erythrophthalmus Perch Perca fluviatilis Pike Esox lucius Eel Anguilla anguilla Bream zone edit The true lowland zone has a very gentle gradient and slow flowing water there is usually good oxygen content but the temperature is much more variable than in the other zones This zone has a silty substrate and is often turbid Fish species found in this zone lay adhesive eggs in the weeds Most upland fish species can not survive in this zone Characteristic fish species include only a few species from the Barbel zone Roach Rudd Perch and Pike with the addition of Bream Abramis brama Tench Tinca tinca Carp Cyprinus carpio References editFurther reading editAarts B G W and Nienhuis P H 2003 Fish zonations and guilds as the basis for assessment of ecological integrity of large rivers Hydrobiologia 500 pp 157 178 doi 10 1023 A 1024638726162 Retrieved from https en wikipedia org w index php title European river zonation amp oldid 1192890942, wikipedia, wiki, book, books, library,
