The future of the world’s rarest penguin hangs in the balance. Numbers of the precious seabird have slumped recently due to the loss of almost half of all breeding adults on some islands. Over the past 30 years, the number of yellow-eyed penguins, also known as hoiho, has dropped to the lowest on record, as conservationists fear that commercial fishing may be taking its toll.
The news comes after researchers surveyed the south New Zealand island of Whenua Hou, or Codfish Island. They found that despite being a wildlife sanctuary, half of the entire island's breeding population has vanished. Because the birds seemingly disappeared at sea, it is thought that the animals are being caught as bycatch in local fisheries and fishermen are not reporting the numbers caught.
The hoiho used to live along much of the southern island's coastline, but despite approaching 7,000 birds in 2000, this number has crashed to an estimated 1,600 to 1,800 penguins. “This bird is so special that it appears on New Zealand’s five dollar note,” said Forest & Bird chief executive Kevin Hague. “The critical information about the Whenua Hou catastrophe should not have been held back from the public.”
While Whenua Hou is not the only nesting site for the birds, the colony there is a good indicator of the threats faced by the species. The small island has had its population of invasive predators like rats and stoats removed, meaning that in theory there should be no terrestrial threats left. This suggests that whatever is causing the decline is out at sea, potentially affecting other penguin populations.
“Unlike previous years where disease and high temperatures caused deaths on land, this year birds have disappeared at sea,” continued Hague. “There is an active set net fishery within the penguins’ Whenua Hou foraging ground, and the indications are that nearly half the Whenua Hou hoiho population has been drowned in one or more of these nets.”
Because the birds are often feeding in the same waters that ships fish in, they are at particular risk of being caught by accident. But despite this risk – and the bird’s endangered status – only 3 percent of boats have independent observers on board to check the bycatch. Earlier this year, Forest & Bird showed that almost all recorded penguin deaths came from this 3 percent of boats, suggesting that other unobserved fishing vessels simply aren’t recording the deaths themselves.
There are now serious concerns that we are running out of time to save the hoiho, unless action is taken by the government and conservation plans drawn up immediately.