Marine-protected areas (MPAs) are among the most frequently used tools in marine conservation. Influential scientists, donors, and conservation organizations are calling for ambitious global expansions of MPAs. Yet, little is known about how they benefit or cost users from perspectives outside of traditional economics. Advocates often describe the potential benefits of MPAs as relating to increased catches from spillover of adult and larval fish, but the empirical evidence for this is limited and does not capture broader issues related to livelihoods, health, and empowerment. Incorporating these broader perspectives into discussions on the costs and benefits of marine conservation is particularly important in the context of coral reef ecosystems, which sustain the livelihoods of millions of people in developing countries. Novel research on the frontiers of marine conservation, human health, and human ecology shows how MPAs can benefit and cost communities in unexpected ways and how this information can be used to help target conservation strategies to reduce impacts and build from opportunities. This panel of leading experts will present the latest findings in this emerging research frontier to define both solutions and key challenges. They will use a series of comparative studies from around the world to highlight how institutional conditions, social context, and implementation process can create winners and losers in marine conservation.