Different human expectations and environmental ethics are key factors preventing the creation of marine reserve networks. People are skeptical about the benefits of no-take marine reserves because they have adjusted to scarcity and have low expectations about the productive capability of marine ecosystems. Pauly (1995) described this as a shifting baseline in which each generation sets its expectations based on its direct experiences and discounts experiences of previous generations. I show evidence of a declining Caribbean baseline based on Nassau grouper landings from Cuba and the U.S., and review common and often conflicting types of conservation ethics existing in North America. No-take marine reserves can help reestablish human expectations about resource productivity by restoring past conditions in places. Leopold’s biotic ethic provides a framework for achieving sustainable resource use based on laws of ecology and human self-interest. Because changing expectations usually requires direct local experience, education, and changes in conservation ethics, implementing successful marine reserve networks will probably be a slow, incremental process. Establishing no-take reserves can help restore human expectations and provide a common basis for conservation by providing a window to the past and a vision for the future.