The Department of Conservation last week appealed for special consideration for a female bottlenose dolphin in the Bay of Islands that was carrying a dead calf.
The calf, believed to have been stillborn, was first seen on January 29, the female displaying strong maternal bond behaviour, as was typical with marine mammals, including carrying the calf on her back and vocalising.
"The mother is grieving, and needs space and time to do this," Senior DOC ranger biodiversity Dr Catherine Peters said.
"The Bay of Islands is a busy place in summer, with a lot of activity in and around the water. This female needs everyone on the water to give her the extra space and respect she needs whilst she copes with her loss."
The rest of the pod had separated from the female at times, leaving her vulnerable. She had dropped the calf frequently as she tried to swim, then circled back to retrieve it.
Efforts to contact Dr Peters yesterday, to establish when the dolphin was last seen, were unsuccessful.
Meanwhile summer was the time when most dolphins gave birth, Dr Peters added, and if mothers were subjected to ongoing disturbance they were prevented from doing what was necessary to care for themselves and their calves.
Boaties were urged to keep watch for dolphins, especially around Tapeka Point; to approach them carefully, from the side and slightly to the rear; to slow to 'no wake' speed within 300 metres; not to approach a group of dolphins if three or more boats were already within 300 metres of them; to manoeuvre your boat carefully, not obstructing their path, cutting through a pod or separating mothers from calves.
To observe dolphins, boaties should switch off their motor and give the animals plenty of space, allowing them to continue with important activities such as catching fish and nursing.
If they are not interested they should be left alone.
Mothers and calves should be given extra space, and all Bay of Islands dolphins should be left undisturbed by boats between 11.30am and 1.30pm.