Across five days in December 2023, IFS staff undertook a fisheries survey in the Arthur River, located on the NW coast of Tasmania. This survey was to assess the population of the protected native estuary perch (Percalates colonorum), which is only found in this river.

Estuary perch are a slow growing species which can live for up to 41 years. They are widespread through southeastern Australia, ranging from the Richmond River in New South Wales, through to the Murray River in South Australia. Although they were originally established in both the Ansons and Arthur rivers in Tasmania, there has been no evidence of the Ansons River population since the 1980s.

The last survey undertaken in the Arthur River was in 2014, where the results suggested the population of estuary perch is low, and dominated by three older age classes, which at the time were approximately 12, 13, and 14 years old.

Over the course of the survey in December 2023, 378 estuary perch were caught, with the majority tagged and released. The largest fish caught was a mature female of 470 mm, weighing 1,820 g, while the smallest fish was a mature running ripe male of 199 mm and 150 g in weight. Twelve tagged estuary perch from the 2014 survey were recaptured, while three tagged fish from the current survey were also caught.

A small number of fish were aged via otolith analysis, which showed that there were dominant young age classes in the population, five and eight years old, in addition to an older age class that was 23 years old (i.e. the 14 year old cohort detected during the last survey). 

Ongoing monitoring of the estuary perch population is currently being undertaken. Please remember that due to their protected status, any estuary perch caught should be released immediately. Penalties apply for taking protected fish.

To assist with this research and contribute to the sustainable management of this species, please report any tagged estuary perch if caught as bycatch while fishing for other species. Take note of the tag number before release, and report it to 1300 INFISH or email infish@ifs.tas.gov.au. 

A detailed report of the full survey is currently being prepared.