Mushy Fish Project

Imagine tucking into a freshly caught Yellowtail Kingfish (Seriola lalandi) (highly prized for sashimi and sushi) or a Mahi Mahi/Dolphin fish (Coryphaena hippurus) only for it to crumble and has the texture of wet newspaper.

Caught in waters along the New South Wales coast, these fish can be infected with a suspected parasite (a microscopic Cnidarian - think corals and jellyfish!). This group of parasites are known to cause flesh altering conditions among other fish species worldwide, and in some cases can even result in food-borne illnesses. The prevalence of infections is on the rise under climate change.

The first documented case of infected Kingfish in Australia was in 1982 off the coast of Brisbane, through the work of Bob Lester. Since then, species distributions are expanding, resulting in range-shifts and the issue is now found throughout NSW waters. Infected fish are indistinguishable from those not harbouring the parasite when live or dispatched. Cooking, smoking, or preparing as ceviche is the only method to confirm parasite presence as tissue disintegrates resulting in “mushy flesh”, rendering the fish unpalatable. This results in a lower market value for commercial fishers, wasted effort for recreational anglers, an unpalatable dinner for consumers, and a wasted product. Mahi Mahi present a little differently to infected Kingfish and suffer from post-mortem myoliquification, or essentially, can turn to jelly in the esky. Additionally, many anglers throughout NSW waters have also reported other species of fish with similar issues.

When you catch a mushy fish, jump onto this story map and click on the embedded survey, (or follow the survey link or QR code below). No download or login required.

 Survey link 

This data will help us better understand the spread of this issue along our coast (you don’t need to be in NSW, we welcome fishers from all over Australia and our friends in NZ).

We are seeking anglers (First Nations cultural fishers, commercial or recreational fishers) to log their mushy fish.

Your help is needed to improve our understanding of the spread of the mushy fish issue in Australia. The last documented evidence was recorded in 1982! It is important to collect on-going information so we know if the parasite is spreading, how far it has travelled and whether commercial and recreational anglers elsewhere will soon be facing a similar issue. By knowing the location of current infections, we can also target our sampling efforts to understand the ecology of the parasite.