The Department of Conservation (DoC) has issued a dire warning about the plight of bottlenose dolphins in the Bay of Islands.
Their population has dropped a whopping 91 percent over 20 years.
Now there are calls to give them better protection, in the hope it'll save them from leaving the bays for good.
The Bay of Islands is often marketed as a playground for bottlenose dolphins - but the experts say that's no longer the case.
"What we've seen over the years is the dolphins have changed how they feel about the Bay of Islands," says DoC senior marine ranger Cat Peters.
The area should be a haven - food is plentiful and sheltered bays provide safety for the dolphin's young.
But humans like this part of the country too and a rise in boating is putting these mammals at risk.
"We've seen them stopping feeding and resting and instead socialising with boats, or jumping on the front of the boat and that's a really worrying sign for us in terms of population," Peters says.
Five years ago, bottlenose dolphins would have been flourishing in these waters but days when you don't spot a single one are becoming more and more common.
In fact researchers have been painstakingly documenting the demise of bottlenose for 20 years.
More than 270 were living around the islands in 1999 but by 2015 the population had plummeted to 96. And now in 2020 just 26 bottlenose dolphins have been recorded - a decline of 91 percent.
"The Bay of Islands locally has dramatically dropped in terms of number which is still quite a big worry because it's a very unique habitat for these animals, there's not really another Bay of Islands anywhere around the coast," TriOceans field director Thibaud Guerin says.
DoC along with local iwi are vowing to turn the sad statistic around.
One proposal is to turn parts of the Bay of Islands into a marine mammal sanctuary putting laws in place designed to protect sea life from harm.
"We're identifying them as special and the area as special and we'd make sure they've got a bit more space. Things like areas where they can just be dolphins," Peters says.
Over summer researchers and rangers ramp up patrols on the water and have seen firsthand what bottlenose dolphins are up against.
"People who mostly don't really know the rules, who try to donut around at high speeds to push the dolphins into that behaviour which from our data has been shown to be quite disruptive to them," Guerin says.
"It's devastating. Nobody wants to see something in their lifetime, that they've studied and cared for in that time, disappear on their watch," Peters says.
Which is why these experts are doing everything they can to bring the bottlenose back.
