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Mulloway is a widely distributed species in Australian waters. Stock status is sustainable in WA and SA, recovering in NSW and undefined in QLD.

Mulloway has a wide distribution in Australia, from the Gascoyne region on the west coast of Western Australia, around the southern coasts of the continent, and up to the Wide Bay–Burnett region on the east coast of Queensland [Kailola et al. 1993]. 

Biological stock structure for Mulloway in Australia is uncertain. It has been suggested that a single panmictic population occurs in Australia [Archangi 2008]. However, regional differences in genetics, and otolith morphology and chemistry suggest sub-structuring between populations in New South Wales, South Australia and Western Australia [Ferguson et al. 2011; Barnes et al. 2015; Hughes et al. 2022].

Here, assessment of stock status for Mulloway is presented at the jurisdictional level—Western Australia, Queensland, New South Wales and South Australia.

Western Australia

The majority of Mulloway catches in Western Australia are landed by commercial fishers, making up approximately 70–80% of the total catch over the last ten years. Commercial catches have declined from around 60 t in 2001–02 and have fluctuated between 6 t and 28 t since 2007–08 [Newman et al. 2023]. The recent lower catch levels are associated with reductions in fishing effort by the main demersal fisheries that catch Mulloway; the West Coast Demersal Scalefish (Interim) Managed Fishery (WCDSIMF) and Gascoyne Demersal Scalefish Managed Fishery (GDSMF). Boat-based recreational and charter catches of Mulloway remain low, i.e., less than 10 t per year, with most landed in the West Coast and Gascoyne coast bioregions [Ryan et al. 2022, Newman et al. 2023]. Shore-based recreational catches of Mulloway are unknown.

Annual CPUE of Mulloway derived from commercial line fishing methods has fluctuated below 6 kg per block per day, reflecting the low level of commercial targeting of this species. Estimates of CPUE for the two main fisheries that land Mulloway (WCDSIMF and GDSF) have also been highly variable over the past 15 years, generally mirroring variations in catch of this species and may not provide a reliable index of abundance. Recent management measures taken to substantially reduce line fishing effort and catch in the West Coast and Gascoyne Coast bioregions are expected to further limit fishing pressure on Mulloway.

Analyses of length composition data available from charter logbooks (in years with adequate catches) show that the mean lengths of Mulloway in the West Coast Bioregion were greater than those in Carnarvon/Shark Bay (Gascoyne) [Crisafulli et al. in prep.]. In both regions, the mean lengths of charter-caught Mulloway show an increasing trend in recent years, increasing within the West Coast Bioregion from 672 mm in 2013 to around the estimated size of 50% maturity of females (approximately 900 mm) in 2021. The applicability of length-based models for estimating fishing mortality and relative spawning biomass of Mulloway in Western Australia is currently limited due to uncertainty about available biological information for this species in the Gascoyne [Crisafulli et al. in prep.].

A data-limited Catch-MSY analysis of the Western Australian stock of Mulloway, based on available catch data from 1975 to 2022, predicts a Maximum Sustainable Yield (MSY) of 32 t (95% CLs: 24–42 t). Annual catches of this species have fluctuated within or below this range since 1975, except for the period of peak catches between 1999 and 2002. While uncertain and based on assumptions about the final level of depletion of the stock (0.3–0.8), the analysis indicates that the recent low catches are likely to have reduced the fishing mortality (F) experienced by the stock to well below the predicted level of FMSY (0.12 year^-1). This suggests that the current level of fishing mortality is unlikely to cause the stock to become recruitment impaired. The predicted relative stock biomass (B, i.e., the depletion level) in 2021–22 was 0.65 of the unfished level (95% CLs: 0.38–0.79), i.e., above the threshold level of 0.5 corresponding to BMSY. 

The above evidence indicates that the biomass of this stock is unlikely to be depleted and that recruitment is unlikely to be impaired. Furthermore, the evidence indicates that the current level of fishing mortality is unlikely to cause the stock to become recruitment impaired. 

On the basis of the evidence provided above, Mulloway in Western Australia is classified as a sustainable stock.

Mulloway biology [Farmer 2008; Silberschneider and Gray 2008; Ferguson et al. 2014]

Western Australia – Recreational (Catch totals). Shore based catches are unknown, thus landings are likely to be underestimated.

Western Australia – Indigenous (Management Methods). Subject to the defence that applies under Section 211 of the Native Title Act 1993 (Cth), and the exemption from a requirement to hold a recreational fishing licence, the non-commercial take by Indigenous fishers is covered by the same arrangements as that for recreational fishing.

Queensland – Indigenous (Management Methods). For more information see: https://www.daf.qld.gov.au/business-priorities/fisheries/traditional-fishing

Queensland – Commercial (Catch). Queensland commercial and charter data have been sourced from the commercial fisheries logbook program. Further information available through the QueenslandFisheries Summary Report https://www.daf.qld.gov.au/business-priorities/fisheries/monitoring-research/data/queensland-fisheries-summary-report. 

Queensland – Recreational Fishing (Catch). Data with high uncertainty (Residual Error >50 %) has been excluded and listed as unknown. More information available at: https://www.daf.qld.gov.au/business-priorities/fisheries/monitoring-research/monitoring-reporting/statewide-recreational-fishing-surveys 

New South Wales – Commercial (Management Methods). Fishers using haul nets in the New South Wales commercial Ocean Hauling Fishery are permitted a bycatch allowance of 500 kg of Mulloway per day.

New South Wales – Recreational (Catch). Murphy et al. [2020], includes charter catch. 

New South Wales – Indigenous (Management Methods).  https://www.dpi.nsw.gov.au/fishing/aboriginal-fishing

Commercial catch of Mulloway - note confidential catch not shown

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