Genomic resilience to sequential environmental perturbations in two sympatric costal fish species

Natural disasters impose acute environmental stressors that can drastically reshape marine populations. Abrupt changes in habitat, resulting from hypoxia due to upwelling and seismic-induced tsunamis, are known chronic events, but their effects on marine taxa are poorly studied. This study investigates the genomic and mitochondrial responses of two coastal fish species, Aphos porosus and Normanichthys crockeri, to two sequential disturbances: a hypoxic upwelling event in 2008 and a seismic-induced tsunami in 2010 in Coliumo Bay, Chile. Whole-genome and mitochondrial DNA analyses may reveal strong genetic differentiation and reduced genetic diversity in N. crockeri, indicating a demographic bottleneck and adaptive shifts. While A. porosus could exhibited genomic resilience, likely due to parental care and sex-biased dispersal, with moderate mitochondrial divergence and increased matrilineal diversity post-disturbance. Functional annotations highlighted possible signatures of stress response, metabolic adaptation, and mitochondrial plasticity. These findings may underscore the complex interplay of ecological traits, environmental stressors, and genetic mechanisms driving population resilience and structuring in marine systems.