There are growing concerns for penguins in the Hauraki Gulf after ten chicks were found starving and dozens dead on Waiheke Island in the past fortnight.
It has conservationists worried about a repeat of the mass die-off of kororā in the summer of 2017 to 2018.
The deaths are thought to be due to over-fishing and rising sea temperatures, which drive the fish the birds feed on into deeper water where they can not catch them.
Two chicks, Waddles and Aroha, were found at just two weeks old emaciated and starving on Waiheke Island.
Members of the public took them to Native Bird Rescue where they are now receiving critical care along with five other kororā.
Native Bird Rescue founder Karen Saunders is worried this could be the start of another mass die-off.
"It's like taking us back to 2017 to 2018 season as it started like this, all the chicks were dying.
"They were all coming out of their nests and that year we had thousands and thousands of kororā from Waiheke up the northeastern coastline of New Zealand.
"We would have people calling with like 10 or 20 dead on the beach each day."
That was thought to be a one in 10 or even 20-year event but it now seemed to be the new normal.
Saunders said overfishing in the Hauraki Gulf was a huge factor.
"On a normal weekend here, we'll have 5000 recreational boats in the Hauraki Gulf ... bottom trawling is still happening in the Hauraki Gulf and then you've got the commercial fishing as well. so it's a really massive take."
Climate change is also at play with warmer sea temperatures driving fish into deeper water - much further for penguins to dive for food.
About 150 penguins have been admitted to Native Bird Rescue over the seven years the charity has been operating.
Another chick nicknamed Gus was found recently by Zoe Wenn and her partner on Palm Beach.
"My partner, all of a sudden leaped up and ran towards the breakers and scooped something up which I thought was a piece of driftwood, which turned out to be a little baby penguin; he just scooped him up just before he got dumped hard by a wave."
Only two weeks old, Gus weighed just a third of what a chick his age should; he was severely dehydrated and also hypothermic because his down feathers were not waterproof yet.
Wenn said it was a huge wake-up call.
"We've all been told that the Hauraki Gulf actually needs a rest and it's just really obvious when you're getting sea life washing up starving."
Now Gus is receiving intensive care along with the other penguins Pebbles, Lucky, Pengy, Bob, Aroha and Waddles at Native Bird Rescue.
Another, however, had to be euthanised as it had been bitten by a dog.
Rehabilitation starts with hydrating the penguins and then feeding them something similar to what they would get from their mothers - fish smoothies.
"At the stage, we have to make two 1.5 litre anchovy smoothies a day and you have to put that through a very fine sieve.
"So it takes probably over an hour to make each one and then we have to feed them five times a day with a three-hour gap in between each feed."
They guzzle down the smoothie through a syringe with a tube that goes down to their stomach.
While it is an arduous task, the team of volunteers is always gratified to see the penguins become healthy again.
Once the penguins have enough strength they move from critical care to a rehabilitation habitat where they do physiotherapy and swimming to prepare them for life in the wild.
It is hoped the penguins in care at Native Bird Rescue on Waiheke can be released in March when there will be enough anchovies to eat in the Hauraki Gulf.
Saunders admits it can be hard saying goodbye.
"We never want to imprint on them or form too deep a bond but to do the work we do, we have to have a deep kindness inside and a deep caring so you do get attached to them."
If things in the Hauraki Gulf carry on as they are, kororā face an uncertain future.
"We might have an extinction of kororā, there's been a few numbers thrown around by a few experts, but it's not looking too good."
If members of the public find a kororā on the beach that looks abandoned they should contact Native Bird Rescue on Waiheke Island, Bird Rescue Aotearoa in Green Bay or the Department of Conservation.