Spatiotemporal genetic structure of anadromous Arctic char (Salvelinus alpinus) populations in a region experiencing pronounced climate change
We examined spatio-temporal genetic variation at 53 single nucleotide polymorphisms in anadromous Arctic char populations from Western Greenland, a region experiencing pronounced climate change. The study was based on contemporary and historical samples, the latter represented by DNA extracted from otoliths and scales from the 1950s–1960s. We investigated whether genetic population structure was temporarily stable or unstable, the latter due to relatively small spawning and nursery areas combined with a harsh Arctic environment. Furthermore, in order to evaluate the potential for adaptive responses and local adaptation we estimated effective population size (Ne) and migration rate (m). Temporal stability of genetic population structure was suggested, based on a hierarchical analysis of genetic differentiation showing much higher differentiation among samples from different populations (FCT = 0.091) than among temporal samples from the same populations (FSC = 0.01). This was further supported by a neighbor-joining tree and assignment of individuals that showed high contingency between historical and contemporary samples. Estimates of Ne were high (> 500) in three out of four populations, with a lower estimate in one population potentially reflecting fishing pressure or suboptimal environmental conditions. Estimates of m were in most cases low, ≤ 0.01. Ne and m estimates suggest a potential for adaptive responses and local adaptation. However, long generation time may also cause adaptive responses by microevolution to be unable to track climate change, especially considering the low migration rates that reduce potential evolutionary rescue by gene flow from populations better adapted to the altered environments.
KeywordsGreenland Historical samples Effective population size Genetic differentiation Climate change Single nucleotide polymorphism
We thank Rasmus Hedeholm, Lars Heilman, Anne-Laure Ferchaud, Marti Pujolar, Louis Bernatchez, Dylan Fraser and Shenglin Liu for assistance with collecting contemporary samples and a number of anonymous persons for collecting and storing otolith and scale samples during the 1950s and 1960s. We are grateful to Annie Brandstrup for laboratory assistance and we acknowledge The Danish Council for Independent Research, Natural Science for funding (Grant No. 1323-00158A to MMH).
- Anon (2005) Ecosystems and human well-being: synthesis. Washington DC. Retrieved from http://www.millenniumassessment.org/documents/document.356.aspx.pdf. Accessed 13 Jan 2018
- Cappelen J, Vinther BM (2014) SW Greenland temperature data 1784–2013. In: Technical Report from the Danish Meteorological Institute 14-06, Copenhagen, Denmark. Retrieved from https://www.dmi.dk/fileadmin/user_upload/Rapporter/TR/2014/tr14-06.pdf
- Franklin IR (1980) Evolutionary change in small populations. In: Soulé ME, Wilcox BA (eds) Conservation biology: an evolutionary-ecological perspective. Sinnauer, Sunderland, pp 135–150Google Scholar
- Jeppesen E, Lauridsen TL, Christoffersen KS, Landkildehus F, Geertz-Hansen P, Amsinck SL, Sondergaard M, Davidson TA, Riget F (2017) The structuring role of fish in Greenland lakes: an overview based on contemporary and paleoecological studies of 87 lakes from the low and the high Arctic. Hydrobiologia 800:99–113CrossRefGoogle Scholar
- Moore JS, Harris LN, Le Luyer J, Sutherland BJG, Rougemont Q, Tallman RF, Fisk AT, Bernatchez L (2017) Genomics and telemetry suggest a role for migration harshness in determining overwintering habitat choice, but not gene flow, in anadromous Arctic Char. Mol Ecol 26:6784–6800CrossRefPubMedGoogle Scholar
- Stendel M,., Christensen J, Hesselbjerg., Aðalgeirsdóttir G-n, Kliem N, Drews M (2007) Regional climate change for Greenland and surrounding seas. Part I: atmosphere and land surface. Danish Climate Centre Report 07-02Google Scholar
- Thackeray SJ, Henrys PA, Hemming D, Bell JR, Botham MS, Burthe S, Helaouet P, Johns DG, Jones ID, Leech DI, Mackay EB, Massimino D, Atkinson S, Bacon PJ, Brereton TM, Carvalho L, Clutton-Brock TH, Duck C, Edwards M, Elliott JM, Hall SJG, Harrington R, Pearce-Higgins JW, Hoye TT, Kruuk LEB, Pemberton JM, Sparks TH, Thompson PM, White I, Winfield IJ, Wanless S (2016) Phenological sensitivity to climate across taxa and trophic levels. Nature 535:241–294CrossRefPubMedGoogle Scholar
- Therkildsen NO, Hemmer-Hansen J, Hedeholm RB, Wisz MS, Pampoulie C, Meldrup D, Bonanomi S, Retzel A, Olsen SM, Nielsen EE (2013) Spatiotemporal SNP analysis reveals pronounced biocomplexity at the northern range margin of Atlantic cod Gadus morhua. Evol Appl 6:690–705CrossRefPubMedPubMedCentralGoogle Scholar