Commentary: Integrating non-targeted and targeted chemical screening in Great Lakes fish monitoring programs

The Great Lakes are a vital resource for drinking water and recreation and provide a major fishery for millions of people. As part of the Great Lakes Water Quality Agreement, the US and Canadian governments have been charged with the protection of this system. Persistent, bioaccumulative, and toxic (PBTs) contaminants were found to be affecting the lake water quality as early as the late 1960s, and various programs sponsored by the US and Canada have been created to monitor PBTs such as polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs). These programs have refined measurement techniques to quantify trace level contaminants using a targeted analytical approach. However, new PBTs are being detected in the environment, and the traditional targeted methodology is inadequate for understanding the complex chemical mixture affecting Great Lakes wildlife. Fortunately, new analytical technologies are emerging that allow for comprehensive screening of PBTs beyond targeted methods. The current commentary presents an outline of a new framework for contemporary monitoring programs. The goal is to facilitate the compilation of legacy, emerging PBT, and archive PBT signatures by utilizing the basic practices of traditional targeted analysis. This example focuses on fish monitoring programs, and how they are ideally suited for legacy monitoring as well as data-driven discovery of new chemicals of concern.