Many species of migratory fish are seriously endangered or threatened in Ireland.  They face a wide range of pressures, from river pollution to climate change, but their survival is particularly jeopardised by the numerous man-made river barriers that block their passage to breeding grounds, including weirs, fords, sluice gates, dams, ramps and culverts. 

Recognising this, IFI established the National Barriers Programme (NBP) with funding from the Department of Housing, Local Government and Heritage (DHLGH).  The aim of this initiative was to assess all potential barriers to fish passage at a national level, for the first time, and gather data to inform future mitigation schemes.  

A clear, nationwide picture of river barriers 
Through the use of ArcGIS, IFI has created Ireland’s first ever national, geospatial record of potential and actual river barriers.  It has also built a fast and effective way for IFI and its partners to assess these potential barriers in the field and find the locations where there are real and significant obstacles to fish migration. 

Scientific evidence for prioritising barrier mitigation 
With its automated, data-driven process for scoring barriers, IFI can now focus its attention on removing or easing barriers in precisely those locations where it can have the most positive impact on fish migration.  “We can now be sure that we are putting funding in the areas where we can make the biggest difference, based on the best science that we have available at the time,” says Brian Coghlan, Research Officer for the National Barriers Programme at IFI. 

Improved public understanding of the impacts of barriers 
The stories told using ArcGIS StoryMap are helping to improve public understanding of the importance of removing and easing river barriers.  “Often communities are very attached to structures like weirs and don’t realise the ecological damage they are doing,” explains Ciara O’Leary, Senior Research Officer for the National Barriers Programme at IFI.  “ArcGIS StoryMaps helps us to explain the challenges for migrating fish species and get the public onboard.” 

Effective empowerment of stakeholders 
By making its river barrier data easily accessible via data.gov.ie and the Esri Living Atlas, IFI is empowering river trusts, government departments and community groups to come up with their own plans of action.  They can easily find barriers in their local areas and formulate informed bids for funding from the new National Barriers Mitigation Programme.  “Once people understand the impacts of river barriers, they can do something about it,” O’Leary observes.

Efficient operation of a national programme
The extensive use of ArcGIS in almost all aspects of the National Barriers Programme is enabling IFI to deliver the initiative efficiently.  The dashboards simplify reporting; the mobile apps save time in the field; and the web apps facilitate the response  to Freedom of Information or ‘Access to Information on the Environment’ requests.  Looking ahead, Mannix says: “This project is gold standard, so we now hope to replicate our GIS-led approach in more future projects.”