With support from the Walton Family Foundation, ACS and the Instituto Milenio en Socio-Ecología Costera are working to improve the sustainability of fisheries in the Humboldt current marine ecosystem. With a diverse team of natural and social scientists based in Peru and Chile, we are taking a systems thinking approach for several fisheries: southern Hake, south Pacific hake, octopus, brachyuran crabs, and jumbo squid. Overfishing is rarely caused by a single action of a single actor. Rather, it typically results from multiple behaviors by multiple actors across a supply chain. Thus, it can be challenging to identify leverage points with the greatest potential to positively impact fishing sustainability. Doing so requires to systematically consider the proximate threats (and underlying drivers) to a fishery, the actors involved, and the behaviors performed by those actors. Because interventions necessarily attempt to trigger change somewhere within a fishery supply chain, identifying the threats, actors, and leverage points for potential changes across the entire landscape of a fishery is an important step to designing solutions to improve fisheries sustainability. We are using established methodologies focused on systems thinking to identify the landscape of threats, actors, and leverage points for Humboldt fisheries in Chile and Peru. Grounded in research in these two countries, the work will leverage existing data (i.e., secondary research) and collect primary data via surveys, interviews, and expert workshops.