The conservation status of the toothed whales has worsened dramatically since 2001. Since then, more species have been listed in the IUCN Red List as Vulnerable and Nearly Threatended, while the Baiji river dolphin, which used to live in the Yangtze River, is now probably extinct. One major threat to toothed whales world wide is entanglement in fishing gear.
The Convention on Migratory Species (CMS) currently includes three species of chondrichthyan fishes on its Appendices, in recognition of their unfavourable conservation status and need for concerted international conservation measures. The primary purpose of this study was to prepare a database of migratory chondrichthyan fishes (the sharks, skates, rays and chimaeras) and to use it to identify potential species that would benefit from a CMS listing.