2012). Previous genetic comparisons involving several
marine species have shown that most Baltic populations contain lower levels of variation than conspecific Atlantic ones (reviewed in Laikre et al. 2005a; selleck kinase inhibitor Johannesson and André 2006; Johannesson et al. 2011). In addition, several species show large genetic differences at the entrance of the Baltic Sea (Johannesson and André 2006). Further, a genetic barrier near to the Islands of Åland has been identified DNA-PK inhibitor in both herring (Clupea harengus; Jørgensen et al. 2005) and perch (Perca fluviatilis; Olsson et al. 2011), separating northern populations from southern ones. An important question is whether this and other barriers are consistent across taxa. Testing the hypothesis of shared overall genetic structures is of high relevance to management. The present study is based on population genetic data from seven species of key socio-economic and/or ecological importance sampled from each of seven geographic regions throughout the Baltic Sea. The key question is whether
genetic divergence patterns of these different species are similar over the Baltic Sea. Despite the adaptive relevance of such ecological variables as temperature and salinity, our data sets are not designed to address levels or types of selection affecting specific loci, noting the ambiguity of interpreting such effects on outlier loci even from extensive genomic scans (Bierne et al. p38 MAPK cancer 2011, 2013). Rather, we assume an overall signal of neutrality as a first approximation of reality (Ihssen et al. 1981) as balanced by divergent, convergent, and nonselective forces. O-methylated flavonoid This interpretation has been widely validated for diverse organisms and is particularly applicable to initial comparisons among heterogeneous data sets such as those used in this study (Utter and Seeb 2010). Each species diverges uniquely from the null hypothesis of panmixia,
reflecting factors including barriers to effective migration, isolation by distance, and repeated colonizations. Genetic data of Baltic species Genetic data were compiled or generated for each of the following seven species selected for this study: (1) Atlantic herring (C. harengus), one of the most economically important species fished in the Baltic Sea, (2) Northern pike (Esox lucius), and (3) European whitefish (Coregonus lavaretus), two ecologically important predators and popular targets for commercial and recreational fishing, (4) three-spined stickleback (Gasterosteus aculeatus), and (5) nine-spined stickleback (Pungitius pungitius), abundant mesopredators; and two important habitat forming species, (6) the blue mussel (Mytilus trossulus) including collections from populations putatively hybridized with M. edulis at the Baltic/Atlantic interface (Väinölä and Strelkov 2011; Zbawicka et al.