ABSTRACT
Adverse outcome pathways (AOPs) organize scientific information concerning the linkage between biological perturbations measured at low levels of biological organization (e.g., molecular, biochemical, cellular) and adverse effects of concern for risk assessment, regulatory decision-making, and/or resource management. AOP development is (1) stressor agnostic, (2) modular in structure, (3) pragmatically simple, but (4) capable of representing biological complexity as networks, and (5) continuously evolving as scientific knowledge expands. The foundation of AOP development is the assembly and evaluation weight of evidence that establishes causal relationships between measurable key events that serve as markers in the progression of toxicity from the initial perturbation of a biological target to an adverse outcome of concern. As of fall 2021, there were 33 fish-relevant AOPs out of over 360 described in an open-access AOP-Wiki. There are many opportunities for experts in fish toxicology, physiology, aquaculture, and other related fields to expand this complement of AOPs. Concerted efforts in fish AOP development support expanded use of data from new approach methodologies for chemical safety assessment in aquatic toxicology and ecological risk assessment.
