Inland Fisheries Ireland Tackling Issues With Barriers to & Impacts on Fish Populations

The fragmentation of rivers is one of the biggest global risks to fish populations. Why? Because it disrupts fish migration upstream and downstream, it blocks movement within the channel and alters the flow of sediment within the body of water.

A healthy river is one long connected ecosystem. Fragmentation breaks up the continual flow of a river from source to sea. Irish rivers can be heavily broken up by barriers, some of these barriers being natural, however most of them are man-made structures such as: weirs, dams, sluices, culverts, bridges and other artificial structures.

During the industrial revolution as far back as the 1830s, Ireland saw the collapse of specific salmonid stocks directly correlated to the introduction of dams and weirs to a river.

Along with the introduction of these instream structures, the 19th century was a period of rapid construction in terms of transportation such as roads, railways, bridges and other structures, much of which did not take into account facilitation of fish passage.

Today, our catchments are directly reflective of these works and historic pressures that continue to further impact our fisheries resource.

Attendees at the recent public meeting

Annacotty weir, located on the River Mulkear, Co. Limerick, is within the Lower River Shannon Special Area of Conservation (SAC) and has been identified as a significant barrier to the free passage of fish. Atlantic salmon, sea lamprey, river lamprey, eels and trout migrate upstream and downstream of the weir and it poses a barrier to the movement of these important species.

In 2022, Inland Fisheries Ireland secured funding of €99,481 within the ‘Salmon and Sea Trout Rehabilitation, Conservation and Protection Fund’ and this money will be used to support the assessment and planning phase of this project.

Further assessment is needed as the Annacotty weir is located within a Special Area of Conservation (SAC) therefore the impact of any proposed works on the habitats and qualifying interests of the SAC must be fully assessed.

Initial studies will also identify any additional ecological, engineering, or archaeological constraints that may impact the final choice of fish passage improvement option.

An Interagency Group for the Annacotty Fish Passage Project has been set-up which includes representatives from Inland Fisheries Ireland, the Department of the Environment, Climate and Communications, the Department of Housing, Local Government and Heritage, Limerick City and County Council, the Office of Public Works (OPW), the National Parks and Wildlife Service (NPWS), the Local Authority Waters Programme (LAWPRO) and the ESB.

In August 2022, Inland Fisheries Ireland held a well-attended public information meeting in Limerick to make more people aware of the Annacotty Fish Passage Project and to highlight potential solutions to the problems that the weir is causing to Ireland’s fish populations. Attendees included members of the public, representatives from community groups, local angling clubs, Annacotty residents, government departments, state agencies and environmental organisations.

More information about the Annacotty Fish Passage Project is available at www.fisheriesireland.ie/annacotty

The works on Annacotty Weir are part of a pilot project to assist with the design and implementation of a national barriers restoration programme currently being progressed by the Department of Housing, Local Government and Heritage in collaboration with a range of State Bodies.