Budget expenditure: $494,794.00
Project Status:
Principal Investigator: Meaghan Duncan
Organisation: NSW Department Of Primary Industries
Project start/end date: 3 Nov 2019 - 29 Sep 2024
Stock Assessment
Population Dynamics
Fishing Gear
Fisheries Management
Electronic Monitoring
Murray Cods


The effective management of fisheries resources implicitly requires accurate abundance estimates. But, even after more than a century of effort, this prerequisite need remains one of the greatest challenges facing fisheries scientists. Traditional methods of estimating abundance include parametric and empirical approaches that often rely on extensive time-series of size-at-age data (e.g. from otoliths). Acquiring these data can be expensive and therefore restricted to species that are most economically important or of conservation concern. Due to the cost of independent sampling, indicators of abundance usually involve fishery-dependent data, which have numerous biases that can affect accurately quantifying population trends.

The clear need for accurate and rapid stock assessments is increasingly apparent in the current climate of competing commercial, recreational and conservation interests. Specifically, marine protected areas have been implemented across all NSW coastal bioregions and are a source of political and public contention as a result of perceived inequalities in access to (and allocation of) fisheries resources, particularly among species shared by commercial and recreational fishers. Also, recent fish kills in NSW due to hypoxic water have sparked debate over the cause of poor water quality and longer-term effects on freshwater habitats. Rapidly quantifying existing and/or changing stock abundances of key species will be essential to inform recovery actions, and advise on the sustainable exploitation of commercial and recreational species. Sampling eDNA could meet these needs by directly facilitating cost-effective biomass and/or relative abundance estimates for population assessments in NSW where fishery-dependent data are scarce or unavailable.


1. Assess the species-specific precision and importance of key influencing abiotic and biotic factors for determining abundances of mulloway and Murry cod using eDNA under controlled conditions.
2. Compare the utility of eDNA against directed fishery-dependant methods for assessing relative abundances of mulloway and Murray cod across appropriate spatio-temporal scales in the wild.
3. Based on results of phase 2, determine what additional factors affect concentration of eDNA such as depth of eDNA water sampling.
4. Assess if eDNA of other selected species collected from samples obtained during 2 above, correspond to routinely collected catch-and-effort data in NSW.

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