Warnings after orca calf death in Hauraki Gulf
Warnings for boaties to use more care follow the death of an orca calf to probable boat strike.
Its grieving mother was harassed, orca expert Dr Ingrid Visser says.
A female orca with a dead calf was spotted off Tiritiri Matangi Island nearly a fortnight ago.
The 2-month-old had been killed by "blunt force trauma" consistent with being struck by a boat.
The mother had then been carrying it for at least three days, Visser says.
Out on the water observing, Visser was appalled at the behaviour of some people in boats around the pair.
"Some boaties were respectful but others were more worried about getting their photos than caring about the grieving process that the mother was going through," she says.
"I spent 22 hours with her and watched this process, including trying to stop some boaties approaching too fast. At one stage there were three boats approaching too fast, from three different directions, and I was unable to stop two of them.
"In the end the mother was driven off."
Concerned the calf's body might be vandalised, Visser took it ashore and after a blessing from a kaumatua it was buried.
Beach goers at Manly were angry and upset with the behaviour of boaties after dolphins in the bay were harassed on October 4.
One boat pulling a wake boarder followed and circled the animals, Matthew Cattin of Stanmore Bay says.
But it was the behaviour of the driver of a small, white inflatable boat that caused the most concern.
It was chasing and circling the animals for 30 minutes, Cattin says.
Whale and Dolphin Watch Whangaparaoa Facebook group members called the Department of Conservation at Warkworth.
With no boat available in the vicinity, the North Shore Coastguard were called out, but the dolphins and the boats had gone by the time they arrived.
There were reports of dolphins and orca being harassed off Leigh Harbour and Omaha Bay last week too.
Warkworth ranger Charlie Barnett says he is concerned at what appears to be a deterioration of behaviour by boaties around orca, dolphins and whales in the Hauraki Gulf.
Fishers are also causing concern by plowing into "boil ups" then throwing over their lines. "Boil ups" occur when big predators like dolphins drive a school of fish to the surface where they are also attacked from above by gannets and shearwaters.
Not only do fishers run the risk of hitting the dolphins or whales that get involved, the noise of the motor disperses the fish and interferes with the animals' feeding.
Boats should travel at less than 10 knots within 300 metres of any marine mammal, approaching them from behind and to the side, not crossing in front or through the group. No more than three boats are allowed at any one time within 300m. This also includes standup paddle boards.
Keep at least 50m from whales and orca and 200m from a mother and calf.
Swimming with seals and dolphins is allowed, providing there's no young, but not in the case of orca or whales.
Anyone striking a dolphin, whale or seal with a boat must report it within 48 hours to the DOC HOTLINE, 0800 362 468. If you see other people or boats harassing marine mammals, report it to the hotline as it is an offence to disturb, harass, injure or kill a marine mammal.
Any offence carries a maximum penalty of two years imprisonment or $250,000 fine.