Relief as risky idea dropped

The adopted or possibly hybrid dolphin calf Pee-wee with its mother, a bottlenose dolphin named Kiwi. Photo / Lawrence Hamilton

Plans to take a biopsy from a Bay of Islands dolphin calf that shot to worldwide fame this year would have put the animal at unnecessary risk, a marine mammal campaigner says.

In August staff on a dolphin cruise boat reported that Pee-wee, a common dolphin calf, had been adopted by a bottlenose dolphin named Kiwi. Cross-species adoption is rare so the discovery sparked worldwide excitement among researchers and media. The adoptive mum had lost her own calf when she was stranded on mudflats in Kerikeri Inlet five years earlier.

However, plans by researchers contracted to the Department of Conservation to biopsy the calf - which involves using a dart to remove a small sample of skin and blubber - divided the marine mammal community.

Researchers said they needed the genetic information to determine whether Pee-wee really was adopted or was a hybrid of the two species.

The information could help understand why young dolphins in the Bay of Islands had such a high mortality rate.

Others, however, said biopsies were risky for dolphin calves and they had proved fatal in the past.

It is understood the contractor to have carried out the biopsy withdrew on September 18 and DoC has no plans to hire someone else.

News that the plan had been abandoned was welcomed by marine mammal campaigners such as Whale and Dolphin Conservation's Gemma McGrath, who said she was "hugely relieved".

The blubber layer of a common dolphin calf was much thinner than that of other larger cetaceans, she said. "There's a lot of risk in taking a biopsy from smaller species. There's no need to risk invasive research when there are other ways to get the same information."

Researchers could find out about Pee-wee's genetics by analysing skin sloughs and faecal matter. Ongoing photo identification would provide information about future mother-calf associations. It was important to understand what was causing the Bay's high calf mortality rate, "But what's the point in risking the death of a calf when that's the very thing they're trying to prevent in the first place?"

Ms McGrath said DoC should have consulted a wider range of marine scientists and all iwi, "not just a select few", before attempting a biopsy.

DoC did not wish to comment for this story.