Over the last decade, there has been an alarming deterioration in the conservation status of a large number of marine mammals (whales, dolphins, seals) around the world. Bycatch - the incidental capture of these species in fishing gear - is the most significant threat to these animals. In 2006, the Yangtse River Dolphin was declated functionally extinct, and the Vaquita, endemic to the Gulf of California, is likely next. Scientists have been aware of this situation for decades, but why are marine mammals still slowly disappearing? Who's next? What can be done to address the problem?