Population trends of Arctic charr (Salvelinus alpinus) in the UK: assessing the evidence for a widespread decline in response to climate change
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The UK lies towards the southernmost distribution limit of the circumpolar Arctic charr (Salvelinus alpinus), and native populations of high national conservation value occur in all four component countries. However, given the temperature requirements of this species and the already relatively mild UK climate, there is strong reason to expect a significant negative impact of climate change on local populations. Data were assembled from repeated Arctic charr population assessments using combinations of hydroacoustics, gill netting, entrapment records and fisheries catches at five Scottish populations, five English populations and one Welsh population. These data were then used to test the hypotheses that there has been a widespread decline of Arctic charr in the UK and that it can be attributed at least in part to climate change. Ten of the 11 studied populations exhibited significant 1990-onwards declines in abundance, while only the most northerly population showed a significant increase. Overall, there was a significant positive relationship between the observed population decline ranking and a vulnerability to climate change ranking based on water body latitude, altitude and mean depth. These observations support the hypothesis that this species has suffered a recent and widespread decline in the UK, and although additional factors are undoubtedly also involved in some specific cases, climate change is a significant factor.
KeywordsLong-term monitoring Hydroacoustics Gill netting Fishery catch-per-unit-effort Entrapment Conservation
We would like to record our thanks to the Arctic charr anglers of Coniston Water and Windermere for making their catch records available to us and to Graeme McKee of the Environment Agency for operating the log book scheme on Windermere. We also appreciate the granting of sampling permissions by numerous land and fishing rights owners. This work was funded by the Centre for Ecology & Hydrology, Environment Agency, Environment Agency Wales, Scottish Natural Heritage and United Utilities.
- Adams, C. E., 1995. The Arctic Charr Salvelinus alpinus population of Loch Girlsta, Shetland. Unpublished Report, Scottish Natural Heritage, Edinburgh, UK.Google Scholar
- Barbour, S. E. & S. M. Einarsson, 1987. Ageing and growth of charr, Salvelinus alpinus (L.), from three habitat types in Scotland. Aquaculture and Fisheries Management 18: 63–72.Google Scholar
- Clabburn, P. & R. Davies, 2008. Summary of the results of a hydroacoustic survey of Llyn Padarn during August 2007. Unpublished Report, Report Ref. FAT/TR/08/01, Environment Agency Wales, Cardiff, UK.Google Scholar
- Hateley, J., 2008. Fisheries hydroacoustic survey of Ennerdale Water 15th October 2008. Unpublished Report, Environment Agency, Warrington, UK.Google Scholar
- Jones, I. D., I. J. Winfield & F. Carse, 2008. Assessment of long-term changes in habitat availability for Arctic charr (Salvelinus alpinus) in a temperate lake using oxygen profiles and hydroacoustic surveys. Freshwater Biology 53: 393–402.Google Scholar
- Maitland, P. S., R. B. Greer, R. N. Campbell & G. F. Friend, 1984. The status and biology of Arctic Charr, Salvelinus alpinus (L.), in Scotland. In Johnson, L. & B. Burns (eds), Biology of the Arctic Charr: Proceedings of the Third International Charr Symposium. University of Manitoba Press, Winnipeg: 193–215.Google Scholar
- Winfield, I. J., J. M. Fletcher & P. R. Cubby, 1998. The impact on the whitefish (Coregonus lavaretus (L.)) of reservoir operations at Haweswater, UK. Archiv fur Hydrobiologie, Official Journal of the International Association for Theoretical and Applied Limnology, Special Issues: Ergebnisse der Limnologie 50: 185–195.Google Scholar
- Winfield, I. J., J. M. Fletcher, J. B. James & B. D. Bayliss, 2006. Fisheries on the edge in Cumbria, UK: where salmonids, cyprinids and climate change collide. Proceedings of the Institute of Fisheries Management Annual Conference 2005. Institute of Fisheries Management, Nottingham: 125–136.Google Scholar
- Winfield, I. J., J. M. Fletcher & J. B. James, 2007. Modelling the impacts of water level fluctuations and predation by cormorants (Phalacrocorax carbo) on the population dynamics of whitefish (Coregonus lavaretus) in Haweswater, UK. Advances in Limnology 60: 277–284.Google Scholar
- Winfield, I. J., J. M. Fletcher & J. B. James, 2008. The Arctic charr (Salvelinus alpinus) populations of Windermere, UK: population trends associated with eutrophication, climate change and increased abundance of roach (Rutilus rutilus). Environmental Biology of Fishes 83: 25–35.CrossRefGoogle Scholar