Boat trips offering passengers a chance to swim with dolphins in the Bay of Islands have been axed amid fears for the future of the local dolphin population.
The number of bottlenose dolphins in the Bay has plummeted from 270 in 1999 to a current estimate of 31, a decrease of almost 90 per cent.
The new rules for commercial operators also limit dolphin watching tours to afternoons only and cut the interaction time from 30 minutes per cruise to 20.
In 2016 a Massey University report found the Bay's bottlenose dolphins were ''being loved into extinction'' because the marine mammals were interacting with humans so much they had little time left for feeding, nursing their young or sleeping.
The study also found three-quarters of dolphin calves died before adulthood, the highest mortality rate observed anywhere in the world.
Since then numbers have continued to dive, from 96 in 2015 to 31 this year.
While no one would discuss their concerns about the new rules on the record, some in the industry worry that fewer licensed operators on the water will mean fewer people keeping an eye on how private boaties behave around dolphins.
They also worry about the impact on the Bay's tourism industry because anyone determined to swim with dolphins can go to Kaikoura or Akaroa instead.
Department of Conservation marine mammal ranger Cat Peters said, however, the new rules were specific to bottlenose dolphins with no reduction in the total number of marine mammal trips permitted.
Tour operators could, for example, still do two trips a day to look for common dolphins, which swam in larger pods further out to sea.
The Bay of Islands still had a unique product as the only place in New Zealand where people could watch bottlenose dolphins. Other ventures around the country focused on common or dusky dolphins.
Peters, the author of the 2016 study, did not agree that a reduction in licensed dolphin-spotting trips would mean less oversight of recreational boaties.
She would patrol the Bay all summer and planned to match or surpass last summer when she spoke to 3500 boats in one month.
Just three businesses — Fullers GreatSights, Explore and Carino Sailing and Dolphin Adventures — are licensed by DOC to take dolphin tours.
Fullers GreatSights chief executive Charles Parker said the company was following the new rules but did not want to comment while they were still under discussion with DOC,
while Explore managing director William Goodfellow said the company was "working closely with DOC to make sure we are doing all we can to protect the bottlenose population."
Vanessa MacKay, of Carino Sailing, said the new rules would make it hard from a commercial point of view but her business would adapt.
The family-owned business had voluntarily given up swimming with dolphins in May due to behavioural changes it was causing, and tried to educate customers about the need to look after the mammals.
During the past 25 years she had seen the number of private boats and unlicensed operators increase 10-fold.
''For us it's about the dolphins. If they need us to back away we will.''
Another change is in the areas where commercial operators are prohibited (see fact box on this page). Peters said the new sanctuary areas had been chosen because they were the areas of greatest overlap between boats and dolphins, and the places dolphins actually liked to go.
''If nothing else the new rules will give the dolphins a chance to be dolphins. It will reduce the amount of time they spend with boats, which is a major issue. We're just loving them too much — we have to love them from a distance and protect them that way.''
Another benefit of the changes was that DOC was sitting down with the operators and talking about what was best for the dolphins, which hadn't necessarily been the case in the past, Peters said.
While the new rules applied only to commercial operators DOC was investigating ways private boats could be regulated in future, for example through a marine mammal Sanctuary. However, a lot more work was needed before that would become an option. The new rules
New rules for commercial dolphin tours include:
■ No swimming with dolphins.
■ Dolphin watching trips in the afternoons only.
■ Interaction limited to 20 minutes per trip.
■ No-go areas from Tapeka Pt to Mosquito Pt, including Russell's Long Beach; and the passage between Motuarohia (Roberton) and Moturua Islands.
The old rules allowed swimming with dolphins as long as no calves were present, set an interaction-free dolphin lunch break from 11.30am-1pm, and banned commercial operations in Te Puna Inlet, Waikare Inlet, Kerikeri Inlet, Deep Water Cove and off Waewaetorea Island.
Guidelines for boaties
The rules for private boaties have not changed. They include:
■ Maximum three vessels within 300m of a pod at any time.
■ Stay below wake speed within 300m.
■ Approach dolphins slowly from behind or the side.
■ Never drive through, cut off or circle a pod.
■ No swimming when calves or juveniles are present.
■ Give dolphins a lunch break from 11.30am-1pm.
See www.doc.govt.nz/boi-marine-mammals for the complete guidelines.