In the most recent U.S. Dietary Guidelines, the USDA Advisory Committee recommended for the first time the inclusion of sustainability considerations (DGA Committee, 2015). Since the U.S. Dietary Guidelines provide standards for nutrition and targets for federal and state food programs, explicitly incorporating sustainability would advance considerably discussions of food system sustainability (Merrigan et al., 2015). However, despite broad public support, sustainability 80 concerns were ultimately jettisoned from the 2015–2020 Guidelines (Secretary Vilsack and Burwell, 2015; US Department of Health and Human Services and US Department of Agriculture, 2015; Wood-Wright, 2016). Though much of the concern around incorporating sustainability has focused on animal agriculture, the sectors most heavily impacted by sustainability policies are arguably fisheries and aquaculture. Fish have been promoted as a sustainability strategy, providing nutritious alternatives to resource intensive livestock and poultry, and a concern, given the decline of many global fish stocks (Worm et al., 2006; Health Council of the Netherlands, 2011; FAO, 2014). Yet, we regularly overlook the origins and implications of this decline due to fragmented notions of our food resources. Resources that originate in our oceans, rivers, and lakes are almost entirely omitted in our conceptions of a sustainable food system. To understand the trade-offs from food production and consumption to sustainability, we must extend our understanding of food resources to conceive of fishery, agricultural, and livestock systems as integrally linked. Our failure to do so thus far has led to a disjointed understanding of our food system, contributed to inequalities in food access, and exacerbated overexploitation and environmental degradation. We argue here that fishery resources are of particular concern for sustainability yet often omitted in conceptions of our food system, and that such disjointed notions of food resources limit our ability to foster sustainable diets (Farmery et al., 2017).