A Comprehensive Assessment of Stream Fragmentation in Great Britain
Overview
Authors
Affiliations
Artificial barriers are one of the main threats to river ecosystems, resulting in habitat fragmentation and loss of connectivity. Yet, the abundance and distribution of most artificial barriers, excluding high-head dams, is poorly documented. We provide a comprehensive assessment of the distribution and typology of artificial barriers in Great Britain, and estimate for the first time the extent of river fragmentation. To this end, barrier data were compiled from existing databases and were ground-truthed by field surveys in England, Scotland and Wales to derive a correction factor for barrier density across Great Britain. Field surveys indicate that existing barrier databases underestimate barrier density by 68%, particularly in the case of low-head structures (<1 m) which are often missing from current records. Field-corrected barrier density estimates ranged from 0.48 barriers/km in Scotland to 0.63 barriers/km in Wales, and 0.75 barriers/km in England. Corresponding estimates of stream fragmentation by weirs and dams only, measured as mean barrier-free length, were 12.30 km in Scotland, 6.68 km in Wales and 5.29 km in England, suggesting the extent of river modification differs between regions. Our study indicates that 97% of the river network in Great Britain is fragmented and <1% of the catchments are free of artificial barriers.
An annotated satellite imagery dataset for automated river barrier object detection.
Wu J, Li W, Du H, Wan Y, Yang S, Xiao Y Sci Data. 2025; 12(1):237.
PMID: 39929845 PMC: 11811227. DOI: 10.1038/s41597-025-04590-z.
Blonska D, Tarkan A, Britton J Sci Rep. 2024; 14(1):23015.
PMID: 39362953 PMC: 11452197. DOI: 10.1038/s41598-024-73965-w.
Genetic consequences of improved river connectivity in brown trout ( L.).
Moccetti P, Dodd J, Joyce D, Nunn A, Gillespie B, Bolland J Evol Appl. 2024; 17(4):e13660.
PMID: 38617825 PMC: 11009428. DOI: 10.1111/eva.13660.
Over 200,000 kilometers of free-flowing river habitat in Europe is altered due to impoundments.
Parasiewicz P, Belka K, Lapinska M, Lawniczak K, Prus P, Adamczyk M Nat Commun. 2023; 14(1):6289.
PMID: 37813852 PMC: 10562483. DOI: 10.1038/s41467-023-40922-6.
Fish response to the presence of hydrokinetic turbines as a sustainable energy solution.
Muller S, Muhawenimana V, Sonnino-Sorisio G, Wilson C, Cable J, Ouro P Sci Rep. 2023; 13(1):7459.
PMID: 37156821 PMC: 10167261. DOI: 10.1038/s41598-023-33000-w.