The Department of Conservation is appealing for help identifying boaties seen harassing a pod of orca in a Northland bay and at one point driving at speed over the top of one of the mammals.
The incident came to light when drone footage was shared in a Facebook group Teal Bay/Ngawai Bay.
The three-minute video — which shows four orca, including a calf, cruising around a rocky shore in Helena Bay, north of Whangārei — is spectacular but it also captures boatie behaviour that has alarmed marine mammal experts.
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The footage, which was first shared on January 4, starts with the orca passing a paddleboarder as they cruise around rocks at Ngawai Bay.
The orca then approach a small fishing boat and a red dinghy with five people on board, swimming around and under the vessels.
The clip then shows the orca cruising past Helena Bay Lodge with the paddleboarder following at a distance when the red dinghy re-appears and approaches the pod at speed.
The dinghy passes over the top of an orca, still at speed, while a white inflatable boat joins the chase.
The two boats then drop their speed but continue following the orca at close quarters. The clip ends as the orca leave the bay, still followed by the inflatable.
DoC Bay of Islands marine ranger Cat Peters said the two vessels were criss-crossing over the top of the orca and driving directly in their path, cutting off their direction of travel.
Driving over the top of marine mammals ''absolutely'' risked propeller strike, particularly in shallow water.
Harassment could also interrupt behaviour critical for survival, such as feeding or resting, and drive orca out of the area.
The boaties' behaviour was a clear breach of the New Zealand Marine Mammal Regulations which barred people from disturbing or harassing marine mammals.
The rules also stated that boats needed to keep at least 50m from whales or orca and drop to no-wake speed within 300m.
She urged anyone who knew who the boaties were to call the 24-hour hotline 0800 DOC HOT.
Peters said she had no problem with the paddleboarder, who had allowed the orca to pass him then approached slowly from behind.
There was also no problem with boaties being approached by orca, as happens at the start of the clip, because that was the animals' choice.
The 50m-rule applied to people approaching orca, Peters said.
''It's only a problem when you remove the animals' choice.''
Breaching marine mammal rules could lead to a fine or in extreme cases even imprisonment, she said.
The pod seen at Ngawai Bay could be the same one filmed from shore on New Year's Day at Whangārei Heads by fisherman Jack Vallings, as reported in last Saturday's Advocate.
Too much interaction with boats is thought to be one of the factors behind a plunging bottlenose dolphin population in the Bay of the Islands, leading to cuts in the number of dolphin-spotting tours and a ban on swimming with bottlenose dolphins in the Bay.
NZ Marine Mammal Regulations
• Don't travel faster than idle or no-wake speed within 300m of marine mammals.
• No more than three vessels within 300m.
• Don't block their path. Approach from a parallel position or behind.
• Don't swim with dolphin pods when juveniles are present.
• Stay 50m away from any whale or orca.
• Stay 200m away from any baleen or sperm whale with a calf.
• Don't swim with whales or orca.
DoC also requires drone users to have a permit to fly within 600m altitude or 150m horizontally of marine mammals.
• Call 0800 DOC HOT if you see someone harassing marine mammals.