Estuary perch (Percalates colonorum) are a long-lived and slow-growing native species which are distributed throughout southeastern Australian estuaries. In Tasmania, only one known population remains which is located in the Arthur River, on the remote northwest coast.

During December 2023, the Inland Fisheries Service (IFS) conducted an estuary perch population survey on the Arthur River where 378 estuary perch were captured, with 191 tagged and released, and 31 fish retained for age and gonad analysis. Three strong age classes were detected (five, eight and twenty-three years old), however numerous weak and missing cohorts were apparent. This study also confirms this population has a delayed spawning season in comparison to mainland populations.

The work indicated that the population is still reproductively active and stable; however, due to their restricted distribution, variable recruitment, slow growth, and small population, further conservation efforts are required.

The results from this survey have now been combined with the findings of estuary perch research undertaken in 2014-2015 by former Institute for Marine and Antarctic Studies (IMAS) Honours student, Bryan Van Wyk.

The results have also been published in “Fishes”, an international, peer-reviewed, scientific, open access journal, and will be part of a Special Issue “The Roles of Fishery Biology and Fish Population Dynamics in Fisheries Management”. The paper is authored by Jonah Yick (Senior Fisheries Management Officer), former IMAS fisheries biologist Dr. James Haddy, and former Honours student Bryan Van Wyk.

The IFS has also been in recent discussions with IMAS regarding a potential research project to explore the feasibility of rearing Tasmanian estuary perch in a hatchery environment for stock enhancement purposes and for potentially establishing insurance populations in suitable habitats across Tasmania.  Funding options for this research are currently being explored.

Ongoing monitoring of the estuary perch population in the Arthur River is also 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. 

To read the IFS report and the published journal article, see the links below:

Arthur_River_Estuary_Perch_Population_Assessment_-_FINAL__.pdf

The Tasmanian Estuary Perch Population—A Threatened Species?