 The dolphins are also thought to have been harpooned off South Africa, but the numbers are not considered large.The dusky dolphin is listed on Appendix II of the Convention on the Conservation of Migratory Species of Wild Animals (CMS) as it has an unfavourable conservation status or would benefit significantly from international co-operation organised by tailored agreements.The effect of mussel farming on dusky dolphins has been studied in Admiralty Bay, New Zealand.