DOI: https://doi.org/10.36347/sajb.2026.v14i07.003

Pages: 505-513

Climate change is fundamentally altering the thermal, chemical, and hydrological regimes of aquatic ecosystems worldwide, imposing unprecedented physiological stress on wild fish populations. While genetic adaptation through natural selection operates over many generations, epigenetic mechanisms heritable changes in gene expression that do not involve alterations to the DNA sequence itself offer a more rapid and potentially reversible pathway for phenotypic plasticity and transgenerational acclimation. This review synthesizes emerging evidence for climate-induced epigenetic reprogramming in wild and laboratory-held teleost fishes, with an emphasis on DNA methylation, histone post-translational modifications, and non-coding RNA regulation. We examine case studies across commercially important and ecologically keystone species, from Atlantic salmon (Salmo salar) and Atlantic cod (Gadus morhua) to killifish (Fundulus heteroclitus) and threespine stickleback (Gasterosteus aculeatus). Evidence suggests that thermal stress, ocean acidification, hypoxia, and salinity fluctuation each leave distinct epigenetic signatures, some of which are transmitted to F1 and F2 offspring via germline inheritance. We further explore how these mechanisms interact with standing genetic variation to shape population-level resilience. Finally, we discuss the implications of epigenetic variation for fisheries management, including brood stock selection, habitat prioritization, and the development of epigenomic biomarkers for stock health assessment. We argue that integrating epigenomics into fisheries science is no longer aspirational but operationally necessary given the pace of contemporary climate change.