Research co-author and University of Otago Tawaki Project co-leader Dr Thomas Mattern said the genetic isolation and loss of diversity of erect-crested and Eastern rockhopper penguins highlighted how urgent it was to understand and address the causes of their ongoing population decline.
He said there were two distinct populations of erect-crested penguins — one on the Bounty Islands and one on the Antipodes, just 200km apart.
"The erect-crested penguin is a really weird species because they are doing fine on the Bounties, but they're in steep decline on the Antipodes.
"So we've got them on two subantarctic islands and it's like Schrodinger's cat — they're dead and alive at the same time.
"There's very little genetic exchange, which means that the Bounty birds stay on the Bounties and the Antipodes stay on the Antipodes."
He said there was major concern about genetic inbreeding of the erect-crested and rockhopper penguins on the Antipodes.
"The population is that small that there are siblings that are pairing up and that is usually the downfall of a population."
However, he said the solution was not as simple as introducing the Antipodes populations to the Bounties populations on a romantic blind date aboard a cruise ship somewhere between the two islands.
"What is the solution? I wish I could give you a definite answer to that.
"The problem is, particularly with erect-crested penguins, we only started to study them three years ago.
"We have literally no idea about their biology, their ecology. We know next to nothing about this species.
"It's only just coming to your attention now that, hey, this population might be gone in the next 20-30 years."
Dr Mattern said the group now had funding which would allow them to investigate the penguins on the subantarctic islands in much more detail.
He said it was no use trying to manipulate the populations without changing the circumstances in which those species existed.
"There's something very wrong with the marine environment around the Antipodes.
"Potentially it has something to do with climate change, but I wouldn't rule out other factors that we haven't identified yet.
"So unless those circumstances change, there's no point in trying to bolster up the population on the Antipodes.
"It would be like patching up a soldier in the war and then sending them back into the trenches again. The war has to stop first, so to speak."
From the little information they had gleaned so far, the Bounty Islands was the place to be for erect-crested and rockhopper penguins, he said.
"That's our back-up population there.
"Yet, the Bounties is the one archipelago that is exposed to industrial fisheries and with proposed changes to the fishing legislation, there's a good chance that this might increase.
"That might ruin the last stronghold we have for that species.
"Right now, we are identifying the problem.
"The next step will be to understand the mechanics behind the problem, and then we can try to think about fixing it.
"We need to tailor conservation strategies to the unique realities of each species and island group."
