Dáil Éireann Debate, Wednesday - 7 February 2024
290. Deputy Mairéad Farrell asked the Minister for Housing, Local Government and Heritage if a series of matters in relation to the detrimental impact that invasive pike have on the freshwater pearl mussel's reproductive cycle by extirpating native juvenile salmonid populations (details supplied) will be examined and rectified; and if he will make a statement on the matter. [5782/24]
View answerInland Fisheries Ireland (IFI) is the agency under the aegis of the Minister for Environment, Climate and Communications with responsibility for fish species listed the Habitats Directive in Ireland, including Salmon (Salmo salar) and other species. The IFI have categorised pike as a non-native species influencing ecology in Ireland.
The National Parks and Wildlife Service (NPWS) of my Department commissioned a survey on the host fish of the freshwater pearl mussel in 2017. The authors remarked that while IFI had reported a decline in stock of juvenile trout and salmon that coincided with the introduction and spread of pike throughout the river and Iakes (IFI, 2018a), however there appear to be sufficient densities of salmon fry (0+) for glochidial encystment at the two sites sampled in the Owenriff (Johnston and Moorkens, 2018). Both sites sampled were in close proximity to abundant mussels beds which have been shown to be brooding successfully (Moorkens, 2017). Water quality and hydrological issues are a more direct pressure on salmonids and freshwater pearl mussel in this catchment, based on the most recent assessments.
In relation to the captive breeding trial, mussels from the Owenriff catchment were used, as access to the Newport river was not possible during summer 2023 due to high rainfall and associated river water levels. This prevented the collection of mussels from the Newport river to facilitate the development of the captive breeding methodology.
IFI (2018a). Fish Stock Survey of Selected Lakes and River Sites in the Owenriff Catchment 2017. IFI/2018/1-4396. National Research Survey Programme, Inland Fisheries Ireland, 3044 Lake Drive, Citywest Business Campus, Dublin 24.
Johnston, P.M. and Moorkens, E.A. (2018) Electrofishing survey to identify fish hosts for the freshwater pearl mussel Margaritifera margaritifera in 12 populations in the Republic of Ireland. 2017 Survey. Unpublished Report to the National Parks and Wildlife Service, DCHG, Dublin
Moorkens, E.A. (2017). Survey and Condition Assessment of the population of the freshwater mussel Margaritifera margaritifera in the Owenriff River, County Galway. Unpublished Report to the National Parks and Wildlife Service, DCHG, Dublin.
