qld.gov.au
Department of Primary Industries

Species

Fish stock status

Although a species may be classified as sustainable under the Status of Australian Fish Stocks (SAFS) framework, this does not mean that the stock is meeting Queensland targets under the harvest strategy.

Stock20232020201820162014
Eastern Australia Sustainable Sustainable Sustainable Sustainable Sustainable

Stock assessment

The 2026 stock assessment used current biological and commercial catch data to:

  • determine the sustainability of the sea mullet stock in Queensland and New South Wales
  • inform management decisions in line with the harvest strategy.

This assessment estimated that the sea mullet stock was between 25% and 76% of unfished levels, and most likely at around 39%.

Difference between current and previous assessments

The 2026 assessment:

  • analysed data through to December 2024
  • included more up-to-date data on catches
  • included more biological data
  • presented an ensemble result based on a range of plausible scenarios
  • used Stock Synthesis, a modelling framework that was developed by the National Oceanic and Atmospheric Administration (United States).

The 2022 assessment:

  • analysed data through to December 2020
  • included more up-to-date data on catches
  • used new biological data such as fish length and age
  • used Stock Synthesis, a modelling framework that was developed by the National Oceanic and Atmospheric Administration (United States).

The 2018 stock assessment:

  • only analysed data through to December 2016
  • used a stock assessment model that was custom built by DPI.

Biomass estimates and key management actions

Line graph shows the trend of sea mullet spawning biomass relative to unfished from 1899 to 2025 along with key management changes. It shows an initial decline in the early 1900s during the start of the fishery to just below 40% in the 1920s. From 1922, spawning biomass gently increased, reaching a peak in the 1970s of around 51%. From 1980, a decline is shown with some fluctuation, ending with a spawning biomass ratio of 39% in the beginning of 2025.
Chart of Queensland stock assessment biomass estimates and key management actions for sea mullet stock.

Queensland and New South Wales estimated retained catch from 1899 to 2024

Line graph shows sea mullet commercial catch from 1899-2024 for NSW and Queensland ocean beach and estuarine fishing sectors. For NSW estuarine, catch peaked at around 3,700 tonnes in 1915 declining to around 1,138 tonnes in 2024. For NSW ocean beach, catch was around 500 tonnes until the 1980s, increasing to a peak of around 3,400 tonnes in 1994 and then declining to 1,123 tonnes in 2024. For Qld estuarine, catch peaked at around 1,750 tonnes in 1953 declining to around 488 tonnes in 2024. For Qld ocean beach, catch was around 250 tonnes until 1980, then increased to a peak of around 1,500 tonnes in 1988 and then declining to 272 tonnes in 2024.
Estimated retained catch of sea mullet stock from from 1899 to 2024.

Monitoring

Map showing areas in Queensland where the sea mullet stock is monitored.
Monitoring areas.

The biological monitoring program collects data on length, sex and age of fish caught by commercial fishers:

  • in estuaries year-round using mesh and tunnel nets (non-ocean beach sector)
  • along ocean beaches from April to August on their annual spawning migration using seine/haul nets (ocean beach sector).

In Queensland most fish are harvested from waters south of Baffle Creek.

Sampling began in 1999 and is ongoing.

Annual harvest

The annual harvest of sea mullet in Queensland has been consistent over a long period of time.

Harvest from the ocean beach and non-ocean beach sectors fluctuate annually, but on average each sector contributes 50%.

Age

Most fish harvested commercially are between 3 and 5 years old, but fish as old as 16 have been sampled.

Sea mullet grow at different rates due to several factors including their habitat, food availability and sex. On average, a sea mullet is 3 years old by the time it reaches the minimum legal length of 30 cm total length.

The age structure of the commercial catch assists in determining the status of fish stocks. If age structure is consistent over a long period, and old fish are being caught regularly, this indicates that fishing pressure is not excessive.

Results from the monitoring of sea mullet show that age structure in southern Queensland has been consistent for several years, and old fish are present in the population.

Ecological risk assessment

Assessed in the east coast inshore fishery.

Management

East coast inshore fishery:

Last updated: 23 Oct 2026