NEARLY half the breeding population of endangered yellow-eyed penguins (hoiho) on Codfish Island (Whenua Hou), near Stewart Island, have disappeared this year.
Only 14 yellow-eyed penguin nests were found during Department of Conservation (DoC) nest counts this year, down from 24 the previous year.
Forest & Bird chief executive Kevin Hague said he believed the penguins had most likely drowned in commercial fishing set nets.
Set netting is a common practice in New Zealand waters, with the nets running like a fence along the ocean floor, suspended between lines anchored at one end and bouyed at the other.
Forest & Bird was now calling on the fishing industry to agree to an immediate set of actions to eliminate the risks from set netting in the penguins’ feeding areas, he said.
Yellow-eyed penguins often swim along the sea floor and are the world’s most endangered penguin species.
Their breeding numbers off the South Island coast have been falling year on year since 2005.
Mr Hague said unlike previous years when disease and high temperatures had caused most penguin deaths on land, this year the birds had been disappearing at sea.
At current rates of decline hoiho would soon be lost from mainland New Zealand, he said.
“As a first step, MPI [the Ministry for Primary Industries] needs to get more of their observers on to set net vessels and prioritise putting cameras on set netting boats.”
A spokesman for MPI said the ministry had been increasing observation levels off the southern South Island area from 15% in 2015-16 to 25% in 2016-17.
In 2016-17, there were no observed penguin set net captures, but one set net capture of a yellow-eyed penguin had been reported by an unobserved fisherman off the east coast of the South Island, he said.
Fisheries Inshore New Zealand (FINZ) chief executive Dr Jeremy Helson said the industry was concerned Forest & Bird’s claims were simplistic and based on a selective use of information.
“While a reduction from 24 to 14 [yellow-eyed penguin nests] on Codfish Island is concerning, it needs to be seen in the context of the entire yellow-eyed penguin population, which is estimated to be around 1700 pairs.”
Dr Helson said while fishing did pose some risk to yellow-eyed penguins, the industry took a range of precautions to limit accidental captures and was happy to discuss what measures could be implemented to assist further.
He did not believe the claim set nets were solely responsible was evidence-based.
“It is well-documented yellow-eyed penguins face several threats, including predation by sea lions, great white sharks and leopard seals.”
The penguins could also fall victim to avian diptheria, heat stress and dog attacks, he said.
DoC threatened species ambassador Nicola Toki said as well as the disappearance of almost half the yellow-eyed penguins on Codfish Island, data showed they had also declined elsewhere this year.
“While nest numbers are similar to last year from Dunedin northwards, there are declines further south. The estimate for the total southern east coast based on current counts is around 250 nests, down from 261 a year ago. This number is of concern, given historically there were between 400-600 breeding pairs and the current number is the lowest for 27 years.”
Nest counts of yellow-eyed penguins on Codfish Island had been steadily declining, with a sharp decrease in the number of nests over the past couple of years, she said.
As Codfish Island was a predator-free island with limited human access, land-based influences were unlikely to be the cause, she said.
“We ask people to help us to protect these vulnerable birds this summer by giving them plenty of space and quiet, respecting barriers and encouraging the same behaviour from others” Ms Toki said.
If people came across yellow-eyed penguins and were concerned about their condition, they should call DoC’s Hotline on 0800 DOC HOT (0800 362 468), Ms Toki said.