Stout Whiting Sillago robusta

Darren Roya and Amy Smootheyb

Stout Whiting

Table 1: Stock status determination for Stout Whiting


Queensland, New South Wales


Eastern Australian

Stock status




Standardised catch rate, catch-at-age frequencies

FTF = Finfish Trawl Fishery (Queensland); OTF= Ocean Trawl Fishery (New South Wales)

Stock Structure

The geographic distribution of the east-coast Stout Whiting biological stock is restricted to southern Queensland and northern New South Wales. Genetic analysis of Stout Whiting catches from southern Queensland locations indicates that substocks are unlikely to exist1. Hence, status for this species is reported at the level of the biological stock.

Stock Status

Eastern Australian biological stock

On average, 80 per cent of the annual commercial catch of Stout Whiting is taken in Queensland, and 20 per cent is taken in New South Wales. The status of the Stout Whiting biological stock in Queensland waters is therefore adopted as representative of the whole biological stock in any given year2.

In Queensland, the current annual total allowable catch (TAC) for Stout Whiting is 1360 tonnes (t). The annual TAC is reassessed before the start of each fishing year using a decision-support model developed in 20023. Every 5 years, a full stock assessment of the fishery is completed. In 2014, the Queensland Department of Agriculture, Fisheries and Forestry completed a quantitative stock assessment for the Finfish Trawl Fishery (unpublished data from the Department of Agriculture, Fisheries and Forestry, Queensland), incorporating new data on changes to the fishery area, fishing gear and otolith weight. The assessment included New South Wales catch data on Stout Whiting, and Queensland otter trawl fishery bycatch estimates. The 2014 assessment recommended reducing the TAC (which represents the maximum sustainable yield [MSY] of the fishery) from 1500 t to 1360 t, despite the current harvest being much lower than these limits.

The 2014 assessment estimated that the 2013 standardised catch rate (1.016) was about equal to the long-term average standardised catch rate (1) and 18 per cent higher than in 2012. Estimated total mortality (1.043) was above the reference point (0.855) for the recommended target catch. There have been no declining trends in catch per unit effort over time. Fish length frequencies were similar across years, and age structures were dominated by 1–3-year-old fish (longevity is 8 years). The assessment model estimated sustainable (greater than 1) stock status ratios in 2013 for exploitable biomass (B 2013/BMSY = 1.07, where B = biomass) and for spawning egg production (E2013/EMSY = 1.19, where E = effort). The above evidence indicates that the biomass of this stock is unlikely to be recruitment overfished.

The 2013 total commercial catch of 704 t was approximately 52 per cent of the Queensland annually adjusted TAC (equal to MSY). Long-term size-at-catch and age-at-catch frequency data from commercial landings indicate that the biological stock size structure is relatively stable2. This evidence indicates that the current level of fishing mortality is unlikely to cause the biological stock to become recruitment overfished.

On the basis of the evidence provided above, the biological stock is classified as a sustainable stock.

Table 2: Stout Whiting biology3

Longevity and maximum size

8 years; 230 mm FL

Maturity (50%)

2–3 years; 140–180 mm FL

FL = fork length

Figure 1: Distribution of reported commercial catch of Stout Whiting in Australian waters, 2013 (calendar year)

Figure 1: Distribution of reported commercial catch of Stout Whiting in Australian waters, 2013 (calendar year)

Note: The reporting period is fishing season (1 April – 31 December) for Queensland data, and calendar year for New South Wales data.

Table 3: Main features and statistics for Stout Whiting fisheries in Australia, 2013 (calendar year)



New South Walesb

Fishing methods


Otter trawl



Rod and line


Rod and line

Management methods


Limited entry

Vessel restrictions

Catch limits

Gear restrictions

Spatial closures

Temporal closures


Bag limits

Spatial closures


Bag limits

Spatial closures

Section 37(1)(c1), Aboriginal cultural fishing authority

Active vessels


2 in FTF

48 in OTF



704 t in FTF

148 t in OTF










FTF = Finfish Trawl Fishery; OTF = Ocean Trawl Fishery

a Queensland reporting period is fishing season (1 April – 31 December).

New South Wales reporting period is calendar year.

In Queensland, under the Fisheries Act 1994 (Qld), Indigenous fishers in Queensland are able to use prescribed traditional and noncommercial fishing apparatus in waters open to fishing. Size and possession limits, and seasonal closures do not apply to Indigenous fishers. Further exemptions to fishery regulations may be applied for through permits.

The Aboriginal Fishing Interim Compliance Policy allows an Indigenous fisher in New South Wales to take in excess of a recreational bag limit in certain circumstances—for example, if they are doing so to provide fish to other community members who cannot harvest themselves.

The Aboriginal cultural fishing authority is the authority that Indigenous persons can apply to to take catches outside the recreational limits under the New South Wales Fisheries Management Act 1994, section 37(1)(c1) (Aboriginal cultural fishing authority).

Unknown quantity taken as bycatch in the East Coast Otter Trawl Fishery (Queensland).

Figure 2: Commercial catch of Stout Whiting in Australian waters, 1997 to 2013 (calendar years)
Figure 2: Commercial catch of Stout Whiting in Australian waters, 1997 to 2013 (calendar years)

Note: The reporting period is fishing season (1 April – 31 December) for Queensland data, and calendar year for New South Wales data.

Effects of fishing on the marine environment
  • The seabed where the fishery occurs lacks major reef structures4. Anecdotal information from research trawls and commercial fishers indicates that the seabed in the fishery area is predominantly bare sand5. Consequently, the impact of trawling on benthic habitats in the fishery area is likely to be relatively low5.
  • The fishery has potential for interactions with sea turtles, but these occur infrequently6. Compulsory use of turtle excluder devices (TEDs) in otter trawls minimises the impact of interactions with turtles. TEDs are not required in Danish-seine nets; however, the nature of this type of fishing means that nets are hauled at a much slower speed and pose minimal risks to turtles, which are able to outswim the nets.
  • Although Danish-seine is legislated as an acceptable method for targeting Stout Whiting in Queensland and New South Wales, it is only used by one vessel, which fishes in both Queensland and New South Wales. Compared with trawling, Danish-seining harvests Stout Whiting more efficiently, has less physical contact with the seabed, and more effectively reduces some forms of bycatch, including prawns, bugs, squid, sea snakes and pipefish6. However, since Danish-seine nets are not required to have TEDs installed, the bycatch of small sharks and rays can be high when using this type of gear6.
  • Sustainability of Stout Whiting taken as bycatch in the East Coast Otter Trawl Fishery (Queensland) has been assessed. At predicted future levels of effort, there is no more than an intermediate risk that discarding will result in an unacceptable decline in Stout Whiting biological stock abundance (unpublished data from the Department of Agriculture, Fisheries and Forestry, Queensland).

Environmental effects on Stout Whiting
  • Because Stout Whiting is a shallow-water oceanic species, it is unlikely that land-based events would significantly affect the biological stock. Marine environmental pressures that may affect the biological stock have not been identified.

a Department of Agriculture, Fisheries and Forestry, Queensland
b Department of Primary Industries, New South Wales