A Review on Emerging Trends and Future Perspectives in Aquatic Toxicology: From Conventional Ecotoxicology to Predictive and Integrated Risk Assessment

Aquatic toxicology is rapidly evolving from conventional single-contaminant toxicity testing toward an integrated discipline capable of addressing complex chemical mixtures, emerging contaminants, climate-related stressors, and ecosystem-level responses. Aquatic ecosystems are increasingly exposed to pharmaceuticals, pesticides, endocrine-disrupting chemicals, per- and polyfluoroalkyl substances (PFAS), microplastics, nanoplastics, nanoparticles, industrial chemicals, antibiotics and transformation products. At the same time, climate change, eutrophication, habitat alteration and changing hydrological conditions can modify contaminant fate, bioavailability and toxicity. Recent advances in high-resolution mass spectrometry, non-target chemical analysis, multi-omics, environmental DNA (eDNA), adverse outcome pathways (AOPs), exposomics, biosensors and artificial intelligence are transforming aquatic toxicology. Emerging research increasingly emphasizes environmentally realistic concentrations, chronic exposure, mixture toxicity, trophic transfer and interactions between chemical and non-chemical stressors. Multi-omics approaches can connect molecular initiating events with physiological and ecological outcomes, while machine learning can assist contaminant identification, toxicity prediction and risk assessment. Micro- and nanoplastics are particularly important because they can act as both toxicants and vectors for other contaminants. Future aquatic toxicology should integrate field observations, laboratory experimentation, computational modelling and real-time environmental monitoring. Standardization, validation, transparency and environmentally relevant experimental designs will be essential for translating technological advances into effective ecological risk assessment and management.