Owenriff Fish Stock Survey and Rehabilitation Plan published by Inland Fisheries Ireland

Introduction of pike likely the main factor causing the decline of brown trout and salmon in the Owenriff catchment


Tuesday, 20th February, 2018: Inland Fisheries Ireland has today announced the publication of its Owenriff Fish Stock Survey 2017 and also its Owenriff Fish Population Rehabilitation Plan 2018 in which declining fish stocks have been identified and a project outlined to promote the recovery of the brown trout and salmon populations in both lakes and rivers and to prevent further decline in the catchment.

Critically, the Fish Stock Survey - which was conducted in the summer of 2017 and forms the basis for the Rehabilitation Plan – deduces that the introduction of pike into the catchment has been the significant factor in the declining fish stocks.

It states: ‘As there are little or no major anthropogenic pressures in the catchment to cause the decline in fish stocks, it is reasonable to infer that the introduction of pike and their subsequent range expansion in the Owenriff catchment (with impacts of competition for food and space and predation on resident and migratory fish) is the main factor causing the decline of brown trout and salmon in the Owenriff catchment. Research from Europe and North America supports this finding.’

(‘Anthropogenic pressures’ include human-induced factors such as urban growth, deleterious discharges, farming activities and introduction of alien species.)

Although pike were captured for the first time by Inland Fisheries Ireland (IFI) staff in 2009 in two lakes in the catchment (Loughs Bofin and Agraffard) and efforts were made by IFI staff to remove the pike from the system, they did not show up in two catchment-wide surveys in 1997 and 2007 and were only officially recorded in a survey for the first time in 2015.

However, this new report states: ‘Results from the 2017 survey suggest that pike are present all over the Owenriff catchment, in areas where they can freely gain access and in some areas where they cannot naturally gain access.’




Welcoming the publication of the two reports, Minister Sean Kyne TD said: “We have acted swiftly since the interim results of this survey became known. In late January, I announced that Inland Fisheries Ireland is to commence fish stock management operations on the Owenriff catchment to protect and restore trout stocks which have been impacted by recent introductions of pike to the catchment. The consequences of not taking wider remedial action on the basis of these survey results would lead to further decline in ecological biodiversity in the catchment, so I very much welcome the publication by IFI of the Owenriff Fish Population Rehabilitation Plan 2018.”

He continued: “The purpose of the plan is to develop a fisheries rehabilitation project that can be undertaken on the catchment to promote the recovery of the brown trout (both resident and migratory Corrib) and salmon populations in both lakes and rivers. It will take time and will be costly, but we are already underway with this very constructive and positive roadmap.”

With stock management actions having already commenced, the success of the broader rehabilitation project will depend on applying the correct tools to rehabilitate the brown trout and salmon populations in the Owenriff catchment. These include: fisheries enhancement works in selected sub-catchments to favour brown trout and salmon; genetic restoration; removing the problem (pike control); reducing anthropogenic impacts in the catchment; public awareness (especially in relation to the impacts of the introductions of species not indigenous to an area); interagency coordination; climate change mitigation; and any other necessary measures.

The Owenriff catchment is located on the north-western end of the Lough Corrib catchment and the main Owenriff River drains into Lough Corrib Upper downstream of Oughterard, Co. Galway. The Lough Corrib catchment, itself, is the largest and most important wild salmonid catchment in Ireland and Lough Corrib is considered the premier wild brown trout fishery in Ireland.

Please click here for the full pdf Owenriff Fish Stock Survey 2017 (5.09 MB) and the pdf Owenriff Fish Population Rehabilitation Plan (7.24 MB) .



For media information:

Paul O’Mahony

Communications Manager

E: This email address is being protected from spambots. You need JavaScript enabled to view it.

T: 353 (0) 1 8842675


Notes to Editors:


Main objectives of the rehabilitation plan:

The principal objectives of the plan are to:

  •  Protect biodiversity
  •  Rebuild the brown trout and salmon population
  •  Prevent further decline of fish stocks in the Owenriff catchment.
  •  Improve habitat for all life stages of brown trout and salmon
  •  Improve survival rates of brown trout and salmon by reducing/mitigating against the impact of the introduced pike (see separate stock management plan for the Owenriff (IFI, 2018b))
  •  Improve the opportunity for adult fish to reach their spawning habitats (by understanding predator prey interactions at various bottlenecks in the catchment).


Estimated Costs of the Owenriff Rehabilitation Plan:

Implementation of a rehabilitation plan for the fish stocks in the Owenriff catchment would be costly and would include numerous remedial measures and involve various stakeholders, but should be designed specifically for this catchment.

Total approximate costs for year 1 of the project, including capital items: €470,398. This figure excludes fisheries enhancement works as detailed plans are required prior to costing. Estimated costs reduce to approximately €217,500 (year 2), €211,000 (year 3), €102,500 (year 4) and €92,000 (year 5).

The costs include a project manager to oversee the project (both the tools and effectiveness monitoring) and two temporary staff for a minimum of 3 years, to assist with implementation of rehabilitation tools and effectiveness monitoring.




About Minister Kyne

Minister Kyne is the Minister of State at the Department of Communications Climate Action and Environment with policy responsibility for the Inland Fisheries Sector.


About Inland Fisheries Ireland:

Inland Fisheries Ireland is a statutory body operating under the aegis of the Department of Communications, Climate Action and Environment (DCCAE) and was established under the Fisheries Act on 1st July 2010. Its principal function is the protection and conservation of the inland fisheries resource. Inland Fisheries Ireland promotes, supports, facilitates and advises the Minister on the conservation, protection, management, development and improvement of inland fisheries, including sea angling. Inland Fisheries Ireland also develops policy and national strategies relating to inland fisheries and sea angling and advises the Minister on same.