DOC says the dolphin was found by a member of the public last week and DOC also received a number of reports from other people in the area.
DOC’s Senior Ranger, Biodiversity Richard Kinsey, says the mature adult female dolphin was in good condition and has no obvious marks that might indicate why it died.
“The dolphin is being sent to Wildbase Pathology at Massey University Palmerston North, for a necropsy to try to determine the cause of death.
“This may be difficult because the animal has been frozen, which can obscure signs of cause of death but tests for toxoplasmosis should still be possible.
While other dolphins such as bottlenose dolphins are frequently seen in the fiord, the presence of a Hector’s dolphin in Milford Sound is highly unusual,” Richard Kinsey says.
“The last time a Hector’s dolphin was reported dead in Fiordland was in 2013. A population of the dolphins live on the West Coast, but don’t often come as far south as Fiordland.”
It was a busy week for Hector’s sightings. Earlier in the week marine mammal experts were excited at a report of a live Hector’s dolphin seen near Coromandel, also outside their normal range.
A Hector’s dolphin calf was also found washed up in Oamaru earlier in the week but was washed back out to sea before DOC could respond.
Members of the public are encouraged to report Hector’s dolphin incidents and sightings via the 24-hour DOC hotline, 0800 DOC HOT (0800 362 468).
Hector’s dolphins are among the world’s smallest marine dolphins, growing to around 1.5m in length. They are found only in the inshore waters of Aotearoa/New Zealand. Their population numbers around 15,000 and they are classified as Nationally Vulnerable under New Zealand’s threat classification system.