Four years ago, sea lion researcher and Wellington vet Andy Maloney visited Enderby Island on one of his regular research trips to the subantarctic.
At one of the island's two New Zealand or Hooker's sea lion sites, he counted 400 female Hooker's sea lions.
This year, just 85 females were there.
The decline was alarming, and he held grave fears for the future of the species.
Early last year, the species was listed as critically endangered.
Many of the creatures live on Enderby Island, alongside albatrosses, yellow-eyed penguins, skuas and other bird species.
They are visited only a few times a year, by sea lion research parties, the odd cruise ship visitor (the Department of Conservation issues 1100 visitor permits to Enderby each year), and the occasional Doc worker or MetService staff members who drops in to maintain a weather station on the island.
Behind them, in an area known as penguin alley, a procession of timid yellow-eyed penguins stops, wary as our large group passes through their patch.
They stop and watch as we pass through to a short boardwalk that will take us away, through a belt of southern rata, which forms a compact low canopy around the edge of this largely flat island.
The boardwalk weaves across the middle of the hummocky moors covering much of the 710ha island, where southern royal albatrosses nest and mate, among brightly flowering gentians only found on this island, past pink and yellow megaherbs and shrubs.
As on Campbell Island, domestic animals and pests have been eradicated from Enderby and the plant and birdlife is flourishing.
The problem now in this conservationists' idyll lies with the water, where the sea lions get their food.
Mr Maloney sees the effects of the problem during his work as part of a Doc research team looking at the size of sea lion populations, estimated survival and reproductive rates, foraging, growth and population health status.
A team of researchers visits each year for six weeks, and annual surveys take place on the Auckland Islands.
Aside from epidemics, there were many reasons female sea lions died, Mr Maloney said.
Among the causes of death was getting caught or injured in squid fishing nets.
Researchers knew that Enderby Island's female sea lions foraged in squid feeding areas, some up to 100km away, far outside the Auckland Islands' marine mammal sanctuary, where fishing is prohibited within 12 nautical miles of the islands.
The Ministry of Fisheries sets a maximum limit on sea lion deaths every season; if this limit is exceeded the southern squid fishery is closed for the season. However, the limit is based on theoretics and there is no reliable way of knowing what the real sea lion take is.
Without an observer on every fishing boat, the reality of a sea lion take will never be known.
Some squid boats have sea lion exclusion devices on their squid nets, but there is no data on how many sea lions escape the nets. It is also unknown how many sea lions are injured in the devices and later die.
Doc is involved with other stakeholders on research into the effectiveness of these devices.
What was known, Mr Maloney said, was that the sea lion population was in dramatic decline, and the Government must do more to protect the species.
Ruling out squid fishing in areas where sea lions foraged and making use of a jigger (which basically hooked squid on a bait line, thus eliminating the risk of catching a sea lion) compulsory in squid fisheries were two things that might stop the decline of the sea lion.
"If we continue fishing like this eventually we will wipe out all the megaforms of this island.
"Do we really want that?
"Is it so important that we continue catching squid?"
Conservation Minister Kate Wilkinson visited Enderby Island with the New Zealand navy early last month and met researchers working there.
She said she often received official briefings about issues such as the sea lions' decline, but trips like this opened her eyes to the reality.
If there was a decline in New Zealand's endemic species, that was a concern, she said.
However, it was a difficult issue, she said, because there was no absolute data on what had actually happened to the sea lions that had not returned to Enderby and none on how many sea lions were actually killed by the fisheries.
It might be suggested that the number of sea lions taken could contribute to population decline, but the difficulty was the impact of fisheries-related mortality on the New Zealand sea lion population was, as yet, unknown.
She discussed sea lion kills with the minister of fisheries every year, but limits were based on likelihoods rather than facts.
The jigger issue was one for her colleague, but she would continue to "advocate hard" for changes needed to stem the decline of the sea lion.
Last month, the annual by-catch kill quota for the New Zealand sea lion was about to be reviewed, as it is at the beginning of each southern squid fishing season.
Earlier this year conservation group Forest and Bird said it wanted to see the by-catch reduced to zero, especially since the mammal is officially recognised as being critically endangered.
But Ministry of Fisheries chief executive Wayne McNee said the southern squid fishery was worth $80 million a year in export earnings and reducing the quota to no accidental catches of sea lions was impractical.
