We use cookies to ensure that we give you the best experience on our website. By continuing to browse this repository, you give consent for essential cookies to be used. You can read more about our Privacy and Cookie Policy.

Durham Research Online
You are in:

A comprehensive assessment of stream fragmentation in Great Britain.

Jones, Joshua and Börger, Luca and Tummers, Jeroen and Jones, Peter and Lucas, Martyn and Kerr, Jim and Kemp, Paul and Bizzi, Simone and Consuegra, Sofia and Marcello, Lucio and Vowles, Andrew and Belletti, Barbara and Verspoor, Eric and de Bund, and Gough, Peter and de Leaniz, Carlos Garcia (2019) 'A comprehensive assessment of stream fragmentation in Great Britain.', Science of the total environment., 673 . pp. 756-762.


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.

Item Type:Article
Full text:(AM) Accepted Manuscript
Available under License - Creative Commons Attribution Non-commercial No Derivatives.
Download PDF
Publisher Web site:
Publisher statement:© 2019 This manuscript version is made available under the CC-BY-NC-ND 4.0 license
Date accepted:09 April 2019
Date deposited:11 April 2019
Date of first online publication:10 April 2019
Date first made open access:10 April 2020

Save or Share this output

Look up in GoogleScholar