Māui Dolphin of Aotearoa New Zealand

Abstract

The Māui dolphin (Cephalorhynchus hectori maui) is an endemic subspecies of Hector's dolphin (C. h. hectori) found in the coastal waters off the west coast, North Island of Aotearoa New Zealand. They are thought to have been isolated from populations of Hector's dolphins around the South Island for about 15,000years. The two subspecies differ in morphology and show diagnostic differences in mitochondrial DNA. Māui dolphins are listed as “Critically Endangered” on the IUCN Red List and “Nationally Critical” in the New Zealand Threat Classification System; the most recent abundance estimate is 54 (95% CL 48, 66) dolphins, aged 1 year or older, for the period 2020–21. In 2008, a Marine Mammal Sanctuary was established to protect Māui dolphins from fisheries bycatch, thought to be responsible for a decline in abundance over the last several decades, and coastal waters were designated an IUCN Important Marine Mammal Area in 2020. Modifications to the sanctuary have been made since 2008 to increase protection from fisheries interactions but the threat of disease, in particular toxoplasmosis and brucellosis, are an increasing concern.