Beaches and dunes of the open coast form one of the globe’s longest ecological interfaces, linking the oceans with the land. These systems are of great importance to society as prime sites for housing and recreation, buffers against storms, and providers of fisheries and mineral resources. By contrast, their unique ecological attributes and biodiversity are much less recognized. In this chapter, we provide a synthesis of the key ecological features and functions of beaches and dunes, outline the main elements of their faunal biodiversity, examine human threats and their biological consequences, and sketch some salient issues in management to achieve conservation of these unique ecosystems. It is apparent that the range of ecosystem goods and services is broad, but nutrient cycling, water filtration, and the provision of habitat and prey for a diverse range of animals are often the key ecological traits. Contrary to common perceptions, beaches and dunes contain a diverse and unique set of species, many of which are found nowhere else. In addition to the complement of highly adapted invertebrates, many wildlife species (e.g. birds, turtles, fishes) are dependent on beaches and dunes for nesting and feeding, and they use these habitats extensively. Human pressures on sandy shorelines and their biodiversity are numerous. Coastal squeeze is, however, the most pervasive, trapping beaches and their biota between the pressures of development from the terrestrial side and the consequences of climate change from the marine side. Beaches are also naturally malleable habitats whose interlinkages, including the exchange of organisms, with the abutting dunes and surf zones are essential to their functioning. Unfortunately, human actions intended to arrest the dynamics of beach habitats, such as seawalls and dune stabilizations, run counter to these natural dynamics and generally produce negative environmental outcomes. These present a set of formidable management challenges when the primary goal is to conserve intact ecosystems and biodiversity, calling for more systematic approaches in conservation design and implementation for beach and dune ecosystems.