A woman who has spent her life fishing the Kaipara Harbour is seriously worried about an illness impacting snapper, which has left them so unwell they are described as “zombie fish”.

Dargaville recreational fisherman Sam Erickson first noticed the sick fish about a month ago while fishing near Ruawai in Northland.

He coined the term “zombie fish” because he said they looked like the walking dead, with sunken eyes that were bloodshot and milky, and appearing to be missing flesh and their normal mucus layer.

Zombie fish is an appropriate term according to Port Albert resident Steph Treadwell, who caught two of the sick fish on Saturday in the Ōruawharo River, west of Auckland’s Wellsford.

“They are looking like zombies – the bigger one its eyes were sunken away. It’s almost like the flesh was falling off along the spine and it looked like the skin was shrinking away somehow.”

Treadwell is a fourth-generation Albertlander and has been fishing the Kaipara Harbour all her life, including helping her father commercially fish.

While snapper numbers have fallen and risen again, she said this year is the first time she has ever seen them unwell.

Treadwell said she and husband Rex have caught several sick snapper near Port Albert over the last two months.

But on Saturday, two of the nine snapper they caught were “like zombies”, with sunken faces and milky, bloodshot eyes.

“It’s got me really concerned that out of nine fish, two were sick. It appears that everyone that I talk to are finding fish that are like this and it is escalating.”

The Ōruawharo River is in the western part of the Kaipara Harbour and is about 40km away from Ruawai as the crow flies, suggesting the disease is more widespread through the harbour.

After reading the Northern Advocate’s zombie snapper story, Treadwell knew to report the catch to the Ministry for Primary Industries, which arranged for samples to be sent to it at its animal health laboratory for testing.

Steph Treadwell normally catches fat and healthy snapper on Kaipara Harbour, like the one pictured, but she is concerned two out of the nine snapper she caught last Saturday were sick like zombies.

An earlier sample has also been sent to the lab, with the ministry testing to rule out exotic or emerging diseases and gain an understanding of the cause of the symptoms.

On Friday, the ministry did not have an update on results.

Scientist Dr Kate Hutson, the aquatic animal health team leader at the Cawthron Institute, previously said the symptoms described are common fish disease symptoms,

Fish disease is usually caused by a complex combination of factors, including the fish, its environment, pollutants and any pathogens present. Disease management usually requires collaboration on and off the water, Hutson said.

The Ministry for Primary Industries is urging anyone who is concerned about the state of fish caught to report it as soon as possible to Fisheries New Zealand on 0800809966.

Denise Piper is a news reporter for the Northern Advocate, focusing on health and business. She has more than 20 years in journalism and is passionate about covering stories that make a difference.