Warning: Graphic photo
An orca has been found dead off a remote island north-west of Auckland.
A fisherman initially alerted authorities of a live stranding on Friday evening off Manakapua Island, also known as the Big Sand Island, near Kaipara.
Because there was limited light by then, authorities were not able to head out until the next morning.
However, it is understood by Saturday morning, the mammal could not be found.
Marine biologist Dr Karen Stockin, of Massey University, was among the university team later called in to take a sample from the dead mammal - after it was found lifeless on Saturday evening.
"As apex species, orca are great sentinel species and close proxies for human health," she said.
Professor Stockin's five-year fellowship with the Royal Society for New Zealand is examining contaminant levels in New Zealand marines, she said.
"Animal, environment and human health are all connected.
"If nothing else, the current Covid pandemic reminds us all of how animal health and welfare concerns can lead to public health concerns."
Stockin said their team, as well as members of the Department of Conservation, worked together with the local iwi to ensure the mammal was treated with care.
The iwi had given its blessing for the university team to take samples from the carcass; with a request that the mammal be kept intact as much as possible.
It was later buried on the island.