Marine mammals and turtles have frequently been overlooked in the field of zooarchaeology. This, despite the fact that these animals have played vital roles in past subsistence economies all over the world and across time. Human impact on these animals has been significant, having led to multiple populations of species declining--in some cases, even resulting in extirpation or extinction events. Long-term perspectives are needed in order to inform marine management; in this, zooarchaeology can play a valuable role. This third meeting of the Marine Mammal Working Group (MMWG) organized by the University of Groningen, the Netherlands, will provide a platform for innovative research into marine mammals, but will also integrate research on marine turtles, a keystone set of species that are increasingly the focus of highly innovative zooarchaeological work.