Mechanistic research in aquatic toxicology: perspectives and future directions

On the 30th anniversary of the journal, I provide a perspective on some of the questions and opportunities for new understanding that will interest aquatic toxicologists during the next 30 years. I focus on mechanisms of toxicity involving transcription factors, signalling pathways, and gene networks involved in toxic and adaptive responses in aquatic animals. Prominent questions address the value of a toxicity pathways approach in aquatic systems, issues involving extrapolation among species, identification of susceptibility genes and useful biomarkers of adverse effect, new emerging contaminants, the importance of epigenetic mechanisms, effects of multiple stressors, evolutionary toxicology, and the relative roles of technical and conceptual limitations to our understanding of chemical effects on aquatic systems.