Llyn Padarn, has a delicate ecosystem home to a select few native fish species. However, recent years have witnessed the arrival of European perch, a non-native species, potentially disrupting the lake's natural balance. Anecdotal evidence from Anglers suggests that the perch population may be flourishing at Llyn Padarn. As a result concerns have arisen that these predatory perch could pose a threat to the native salmonids, like the rare Arctic charr.

Research suggests that the perch population could have an effect on the survival of Arctic charr fry and compete for vital resources, exacerbating their decline (Morrissey-McCaffrey et al., 2019; Connor et al., 2019). Despite the coexistence of perch and salmonids in other British lakes over centuries, the sudden introduction of perch in Llyn Padarn warrants careful attention, especially considering the critical status of Arctic charr and salmon in Wales. There are, however, numerous lakes in the British Isles where perch and salmonids coexist, but coexistence may have developed over many centuries or millennia and there are no studies assessing the impact of a recent perch arrival on salmonids. 

In response Prosiect Torgoch is planning to establish an annual citizen-led snorkel survey to monitor the trends in the non-native perch population at Llyn Padarn. These surveys will aim to gather data to inform future management strategies and safeguard the lake's biodiversity.

The surveys will be conducted in July, targeting the shallow sections of the lake where perch are known to inhabit. Volunteers, equipped with the necessary gear and training, will undertake snorkel surveys along designated sections of the lake. Through systematic observation, volunteers will document perch numbers. 

Biosecurity measures will be implemented to prevent the spread of invasive species, ensuring the integrity of the lake ecosystem.

Are you local to Llyn Padarn? Then get in touch if you are interested in taking part in this citizen science project. Updates on volunteer training sessions and survey dates will be coming soon. 

These surveys are part of Prosiect Torgoch which is funded by the National Heritage Lottery Fund. 

Email poppy@northwalesriverstrust.org for more information

References

Connor, L. et al. (2019) ‘Potential climate change impacts on Arctic char Salvelinus alpinus L. in Ireland’, Fisheries Management and Ecology, 26(6), pp. 527–539.

Morrissey-McCaffrey, E. et al. (2019) ‘Non-native species and lake warming negatively affect Arctic char Salvelinus alpinus abundance; deep thermal refugia facilitate co-existence’, Journal of Fish Biology, 94(1), pp. 5–16. 

Smith, A., (2022). The population dynamics and conservation of Arctic charr, Salvelinus Alpinus; lessons from Llyn Padarn, North Wales. Bangor University (United Kingdom).

Wheeler, A. (1977). The origin and distribution of the freshwater fishes of the British Isles. Journal of biogeography, 1-24.