Post-Disturbance Genetic Changes: The Impact of the 2010 Mega-Earthquake and Tsunami on Chilean Sandy Beach Fauna

Abstract

AbstractEarthquake/tsunamis can have profound impacts on species and their genetic patterns. It is expected that the magnitude of this impact might depend on the species and the time since the disturbance occurs, nevertheless these assumptions remain mostly unexplored. Here we studied the genetic responses of the crustacean speciesEmerita analoga,Excirolana hirsuticauda, andOrchestoidea tuberculatato the 27F mega-earthquake/tsunami that occurred in Chile in February 2010. mtDNA sequence analyses revealed a lower haplotype diversity forE. analogaandE. hirsuticaudain impacted areas one month after the 27F, and the opposite for O.tuberculata. Three years after the 27F we observed a recovery in the genetic diversity ofE. analogaandE. hirsuticaudaand decrease in the genetic diversity inO. tuberculatain 2/3 of sampled areas.Emerita analogadisplayed decrease of genetic differentiation and increase in gene flow explained by long-range population expansion. The other two species revealed slight increase in the number of genetic groups, little change in gene flow and no signal of population expansion associated to adult survival, rapid colonization, and capacity to burrow in the sand. Our results reveal that species response to a same disturbance event could be extremely diverse and depending on life-history traits and the magnitude of the effect.