By IFI Staff In Fisheries Research 479 downloads
A genetic study of the mixed trout populations of the Lough Mask catchment
Technical Report for Inland Fisheries Ireland
In 2010, a collaborative project between IFI and Lough Mask angling clubs received the final report from the UCD School of Biology & Environmental Science on the genetic structuring of the adult trout stock in the Lough Mask catchment. The project aimed to investigate the genetic diversity of trout populations in eight streams and rivers flowing into Lough Mask catchment and their contribution to the lake’s adult stock; the study also investigated the trout population of the Aille River, an isolated stream in the west of the catchment. The report’s findings indicate the following conclusions:
- All the genetic diversity found in the lake is accounted for by the trout populations of Lough Mask’s inflowing streams.
- The Aille trout probably represent a genetically impoverished relict population that has diverged due to strong random genetic drift.
- Lough Mask’s adult trout stock appears to be dominated by fish recruited from the lake’s western inflowing streams, with a smaller contribution from the Robe.
- The trout population in the Cong Canal is a divergent genetic cluster that constitutes the gene pool of the ferox phenotype.
- The ferox trout identified in the Mask end of the Cong Canal are genetically similar to the ferox genotype of Lough Corrib.
- There is evidence of gene flow due to multigenerational straying of spawning fish between stream subpopulations, especially between the lake’s western streams.