Researchers Bridge the Toxicological Gap Between Zebrafish and Wild Ecosystems

Zebrafish have become one of toxicology's most powerful tools for studying emerging contaminants, from PFAS and microplastics to pharmaceuticals and nanomaterials. But translating what happens in a laboratory zebrafish into meaningful predictions for wild species remains a major challenge, according to a new perspective published in New Contaminants.

The article, authored by Raymond W.M. Kwong of York University, examines how zebrafish can help scientists uncover the biological mechanisms behind contaminant toxicity while highlighting factors that can limit their ecological relevance.

Zebrafish give us extraordinary tools to understand how contaminants affect biological systems, but the goal is not simply to understand zebrafish. We need to translate those mechanistic insights into predictions that can protect more sensitive species and real ecosystems."

Raymond W.M. Kwong, York University

Zebrafish offer several advantages, including rapid development, genetic tractability and compatibility with advanced tools such as omics, functional imaging, electrophysiology and gene editing. These approaches can reveal how contaminants disrupt genes, cells, organs and behavior.

However, genetic strain, age, sex, exposure route and physiological differences can strongly influence toxicological outcomes. Laboratory conditions also differ substantially from natural environments, where organisms face mixtures of chemicals alongside changing temperature, oxygen, pH and salinity.

To address this gap, Kwong proposes Zebrafish Predictive Assessment for Translational Health, or Z-PATH, a four-tiered framework that combines methodological standardization, mechanistic characterization, environmental calibration and cross-species extrapolation.

The strategy aims to connect molecular effects with whole-organism performance and ultimately population-level consequences. It also encourages targeted use of animal experiments alongside computational modelling.

The perspective argues that future environmental risk assessment should move beyond simply detecting toxic effects and focus on determining when laboratory findings can reliably predict harm in the real world.

The study was supported by the Canada Research Chairs Program.