A dead adult Hector’s dolphin has been discovered at Te Waewae Bay in Southland – the 15th to be found since November.
Department of Conservation Aquatic Director, Elizabeth Heeg said the adult female dolphin was found by a member of the public on 7 May. DOC staff were able to retrieve the body and have sent it to Massey University for examination.
“Sadly, this is the 15th Hector’s dolphin found dead around the South Island since early November 2021,” said Ms Heeg.
“At this stage we don’t know why we’ve had this many Hector’s dolphins wash up over the past six months. We’re waiting for the remaining necropsy results to understand more about possible causes of death.”
DOC confirmed that eight of the recent dolphin deaths were calves. A very decomposed and scavenged Māui dolphin was also found at Muriwai, west of Auckland, on Christmas Day but was not collected, it said.
Thirteen of the dolphins found since November last year have been sent to Massey University.
“They are gradually being examined by the pathologist. So far, we’ve had results back from necropsies on eight of the dolphins,” Ms Heeg said.
She said none of the dead dolphins showed any evidence of being caught in fishing nets. The causes of death results received to date have indicated a mix of natural causes – maternal separation (calves), disease and predation.
“There are approximately 15,700 Hector’s dolphins around the South Island. The death of any dolphin is always unfortunate, but not entirely unexpected, and isn’t likely to have an impact on the population as a whole.”
“Clusters of death raise questions about whether they might be connected and a sign of something else going on in the dolphins’ environment. Equally it could just be a coincidence, and a year in which the number of deaths is at the high end of ‘normal’ mortality for the population.”
She thanked the member of the public who reported the dead dolphin.
“When people are quick to alert us to discoveries of dead dolphins, it increases the volume and value of the information we can obtain.”
“We urge anyone finding a dead Hector’s or Māui dolphin to report it to DOC via 0800 DOC HOT. It is also important for the public to report live sightings via the DOC webpage, or the hotline.”
DOC manages a Hector’s and Māui dolphin sightings database, and incident database, both of which help inform management actions to protect the dolphins. Results are shared on the DOC website when available.
