Two more dead Hector’s dolphins have been located on South Island beaches.
One was discovered just south of Greymouth on Monday 11 April, and a second at Tiwai on Saturday 16 April.
Department of Conservation (DOC) Marine Species Manager, Katie Clemens-Seely says the adult dolphin found at Greymouth was very decomposed with only the spine and tail remaining when it was discovered. It would be impossible to say what caused its death, she said.
The Tiwai dolphin also appeared to be an adult and has been collected by DOC staff to send to Massey University for examination.
“Sadly, this makes 14 Hector’s dolphins found dead around the South Island since early November 2021,” Ms Clemens-Seely says.
“At this stage we don’t know why we’ve had this many Hector’s dolphins wash up over the past four months. We’re waiting for the remaining necropsy results to understand more about possible causes of death.”
Eight of the recent deaths were calves. A very decomposed and scavenged Māui dolphin was also found at Muriwai, west of Auckland, on Christmas Day.
Twelve of the dolphins have been sent to Massey University. When deceased dolphins are reported and retrieved quickly, they can be chilled and sent to the pathologist, DOC advised.
“They are gradually being examined by the pathologist. We’ve received results from necropsies on four calves, but a definite diagnosis wasn’t possible due to decomposition,” said Ms Clemens-Seely.
“Maternal separation, potentially during storm conditions, has been cited as the possible cause of death of those four calves.”
Results have also been received for an adult female found near Hokitika on 28 November 2021. Age-related disease has been cited as the probable cause of death of that animal. The other dolphins collected since November are still under investigation. Results will be shared on the DOC website when available.
“The information from the necropsies will help us build our understanding of Hector’s and Māui dolphins and help with future planning for marine protection and management.”
The public is urged to report dolphin deaths to DOC via 0800 DOC HOT. It is also important for the public to report live sightings via the DOC webpage, or the hotline.