External authors:

• Livia Peluso ( Universidad Austral de Chile )
• Juan Faundez ( Pontificia Universidad Catolica de Chile , Instituto de Fomento Pesquero (Valparaiso) )
• Sergio A. Navarrete ( Pontificia Universidad Catolica de Chile , Universidad de Concepcion , Millenium Nucleus Ecol & Conservat Temperate Mesop )
• Bernardo R. Broitman ( Pontificia Universidad Catolica de Chile , Universidad Adolfo Ibanez , Millennium Nucleus UPWELL )
• Pablo Saenz-Agudelo ( Universidad Austral de Chile , Millenium Nucleus Ecol & Conservat Temperate Mesop )

Abstract:

The seascape comprises multiple environmental variables that interact with species biology to determine patterns of spatial genetic variation. The environment imposes spatially variable selective forces together with homogenizing and diverging drivers that facilitate or restrict dispersal, which is a complex, time-dependent process. Understanding how the seascape influences spatial patterns of genetic variation remains elusive, particularly in coastal upwelling systems. Here, we combine genome-wide SNP data, Lagrangian larval dispersal simulated over a hydrodynamic model, and ocean environmental information to quantify the relative contribution of ocean circulation and environmental heterogeneity as drivers of the spatial genetic structure of two congeneric intertidal limpets, Scurria scurra and S. araucana, along the central coast of Chile. We find that a genetic break observed in both limpet species coincides with a break in connectivity shown by the Lagrangian dispersal, suggesting that mean ocean circulation is an important seascape feature, in particular for S. scurra. For S. araucana, environmental variation appears as a better predictor of genetic structure than ocean circulation. Overall, our study shows broad patterns of seascape forcing on genetic diversity and contributes to our understanding of the complex ecological and evolutionary interactions along coastal upwelling systems.