Reports of fish with milky white flesh
In 2022, the Ministry for Primary Industries (MPI) received reports of some snapper and trevally being caught that had flesh that looked "milky white" or "mushy". This is being referred to as "milky white flesh syndrome". While the syndrome has been seen and reported in previous years, it appears to be more common this season (2022-23).
We know the syndrome has been affecting snapper in the Hauraki Gulf and East Northland areas. There have also been some reports of the syndrome appearing in other finfish species, such as trevally.
Tests found no biosecurity or food safety concerns
Testing of snapper with this syndrome has found no reason for any biosecurity or food safety concerns. The main finding from the affected fish was evidence of nutritional deficiencies. This can happen after fish spawn.
A summary of the testing report will be published in the June 2023 edition of Biosecurity New Zealand's quarterly magazine, Surveillance.
Help us determine the spread of milky white flesh syndrome
As a precaution, Biosecurity New Zealand is interested in reports of:
- affected snapper from outside the east of Auckland and Northland areas
- in finfish other than snapper.
If you find any suspected cases, freephone our pest and disease hotline on 0800 80 99 66.
If you have any fish to submit, keep them chilled (refrigerated) but not frozen, and send in the whole fish (not just the fillets). Samples are best when they can be analysed within 24 hours.
What we are doing about the syndrome
Fisheries New Zealand has commissioned NIWA to undertake research alongside a regular catch sampling programme for commercially caught snapper off the north-east of the North Island (SNA 1). This is to help understand any seasonal patterns and areas where the syndrome is most prevalent.
Filleting tables (professional filleting stations for charter and recreational fishers) in the Hauraki Gulf are also being monitored.
This research will continue through until September 2023.
Pictures of fish affected by milky white flesh syndrome





Who to contact
If you have questions about the syndrome, email info@mpi.govt.nz