Environmental Correlates of Population Differentiation in Atlantic Herring

Abstract

The marine environment is characterized by few physical barriers, and pelagic fishes commonly show high migratory potential and low, albeit in some cases statistically significant, levels of genetic divergence in neutral genetic marker analyses. However, it is not clear whether low levels of differentiation reflect spatially separated populations experiencing gene flow or shallow population histories coupled with limited random genetic drift in large, demographically isolated populations undergoing independent evolutionary processes. Using information for nine microsatellite loci in a total of 1951 fish, we analyzed genetic differentiation among Atlantic herring from eleven spawning locations distributed along a longitudinal gradient from the North Sea to the Western Baltic. Overall genetic differentiation was low (theta = 0.008) but statistically significant. The area is characterized by a dramatic shift in hydrography from the highly saline and temperature stable North Sea to the brackish Baltic Sea, where temperatures show high annual variation. We used two different methods, a novel computational geometric approach and partial Mantel correlation analysis coupled with detailed environmental information from spawning locations to show that patterns of reproductive isolation covaried with salinity differences among spawning locations, independent of their geographical distance. We show that reproductive isolation can be maintained in marine fish populations exhibiting substantial mixing during larval and adult life stages. Analyses incorporating genetic, spatial, and environmental parameters indicated that isolating mechanisms are associated with the specific salinity conditions on spawning locations.

Multi-marker estimate of genetic connectivity of sole (Solea solea) in the North-East Atlantic Ocean

“…This was in contrast to the previous population genetic study of sole by Rolland et al (2007), which used only three nuclear EPIC markers. Our results are concordant with observations for several other marine Wsh species in the region, such as for turbot (Nielsen et al 2004), herring (André et al 2011;Bekkevold et al 2005), plaice (Hoarau et al 2002), hake (Lundy et al 1999), cod (Nielsen et al 2003) and sand goby (Larmuseau et al 2010a). The signiWcant diVerentiation between the North Sea and the Baltic transition zone is mainly attributed to geographic isolation, a bottleneck, selection on adaptive traits in Baltic populations or a combination thereof (Johannesson and André 2006;Larmuseau et al 2010b).…”

Population genetic structure of chub mackerel Scomber japonicus in the Northwestern Pacific inferred from microsatellite analysis

“…Nevertheless, numerically small but significant genetic differentiation has been detected in many marine pelagic fishes despite high dispersal capabilities and large effective population sizes [5,6,9,63]. In this study, multiple analyses showed that a weak but significant genetic structure existed in chub mackerel populations.…”

“…The biological peculiarities of these fishes combined with the apparent lack of physical barriers in the marine realm, are thought to facilitate extensive gene flow and low genetic differentiation among populations [1][2][3][4]. However, this long heldview was challenged by recent studies that cryptic population structuring has been increasingly detected in highly abundant and widely distributed migratory marine fishes [5][6][7][8][9]. The complicated interaction between marine environment and biological characteristics of marine fishes could sufficiently account for the differentiation processing.…”

Genetic divergence and connectivity among river and reef spawning groups of walleye (Sander vitreus vitreus) in Lake Erie

“…As in walleye, natal site fidelity appears to maintain reproductive isolation in a number of species, including rainbow smelt (Osmerus mordax; Bernatchez 1997), Atlantic herring (Clupea harengus; Bekkevold et al 2005;Jorgensen et al 2005), walleye pollock (Theragra chalcogramma; O' Reilly et al 2004), and mackerels (Scomber spp. ; Zardoya et al 2004).…”