Multigenerational effects of selected environmental contaminants in fishes: A comprehensive review

The pervasive presence of environmental contaminants in aquatic ecosystems has raised significant concerns regarding their long-term impacts on aquatic organisms, particularly fishes. While ecotoxicological studies have traditionally focused on single-generation or single-life-stage exposures, such approaches may underestimate or overestimate population-level consequences. This review critically evaluates the current state of knowledge on the multigenerational effects of both traditional and emerging contaminants in fishes. The study includes five major contaminant groups: pesticides, pharmaceuticals and personal care products (PPCPs), metals and metalloids, microplastics and plasticizers, and per- and polyfluoroalkyl substances (PFASs). Most multigenerational studies have been conducted on freshwater species, including Danio rerio, Oryzias latipes, Oryzias melastigma, Oncorhynchus mykiss, Menidia beryllina, Nothobranchius furzeri, Pimephales promelas, and Paramisgurnus dabryanus, highlighting a substantial research gap in marine fish species. Findings consistently reveal that multigenerational exposure to these contaminants can lead to developmental, behavioural, reproductive, and neurodevelopmental impairments, which may reduce reproductive success, population growth, and overall fitness. Moreover, emerging evidence points to epigenetic modifications, such as DNA methylation and histone alterations, as potential mechanisms underlying these multigenerational effects. Notably, our review identifies considerable variability across studies, with some contaminants exhibiting pronounced multigenerational toxicity, while others show limited or inconsistent outcomes. Given the increasing global concern over aquatic pollution and its far-reaching effects on biodiversity, food security, and public health, this review underscores the urgent need to integrate multigenerational endpoints into ecological risk assessments.