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Sandbar Shark occurs primarily off both the east and west coasts of Australia. The eastern Australian stock is sustainable and the Western Australian stock is recovering.

Sandbar Shark (Carcharhinus plumbeus) occurs primarily off both the east and west coasts of Australia, from approximately latitude 17–32°S off the east coast, and latitude 13–36°S off the west coast [McAuley et al. 2007a; Last and Stevens 2009]. The species is also encountered off the northern Australian coast, although in much lower numbers. In addition to genetic analysis that suggests limited gene flow between eastern and western Sandbar Shark stocks [Portnoy et al. 2010], there are limited recorded catches in the Gulf of Carpentaria and southern Australia. Conventional tagging data and recent genomic studies indicate that Sandbar Sharks form a single population within Western Australia (McAuley et al. 2005; Pember et al 2023). Thus, the species is considered to be represented by separate Eastern and Western biological stocks in Australian waters.

Here, assessment of stock status is presented at the biological stock level—Western Australia and Eastern Australia.

Western Australia

In Western Australia, Sandbar Shark is targeted by the West Coast Demersal Gillnet and Demersal Longline Fishery, and is also taken in lesser quantities by the Joint Authority Southern Demersal Gillnet and Demersal Longline Managed Fishery [McAuley et al. 2015]. Sandbar Shark was also previously targeted by the Western Australian North Coast Shark Fishery [McAuley and Rowland 2012]. The Western Australia stock assessment uses current and historical data from all of these fisheries. Minor catches historically reported from the Offshore Net and Line Fishery (Northern Territory) are assumed to be from the Western Australia biological stock, as are recently quantified catches from the Memorandum of Understanding (MoU) Box Shark Fishery [Marshall et al. 2016, Braccini et al. 2021].

The status of this stock was initially assessed using demographic modelling techniques and fishing mortality rates estimated from tagging studies between 2001 and 2004 [McAuley et al. 2005; McAuley et al. 2007b]. This assessment  indicated that combined levels of fishing mortality in Western Australian targeted shark fisheries, non-target commercial fisheries and the recreational fishing sector became increasingly unsustainable between 2001 and 2004 (when reported catches peaked at 918 t) and had probably exceeded sustainable levels since 1997–98. These conclusions were supported by fishery-independent survey data that indicated declining breeding stock abundance between 2002 and 2005 [McAuley et al. 2005; McAuley and Rowland 2012].

Since 2010, Sandbar Shark catches have remained well below the levels expected to allow a gradual recovery of the breeding stock [McAuley et al. 2015]. The expected reductions in recruitment from historical excessive exploitation of the breeding stock are likely to have been ameliorated by this significant reduction in targeted fishing effort. Therefore, the more recent levels of fishing were considered suitably precautionary to ensure the recovery of this biological stock [McAuley et al. 2015].

In 2018, a stock assessment was conducted based on a risk-based weight of evidence approach using all available lines of evidence, including simulated biomass trajectories derived from a combination of demographic modelling and catch-only modelling [Braccini et al. 2018]. This assessment estimated a “Medium” current sustainability risk from fishing for the Sandbar Shark stock [Braccini et al. 2018].

Updated stock assessments using a range of catch-only methods, a state-space biomass dynamics model (JABBA, Winker et al. 2018), integrated age-structured models (Stock Synthesis, Methot and Wetzel, 2013), and time series of reconstructed catches, catch rates, abundance and length composition are underway (Braccini et al. unpublished). Preliminary findings, based on catch only methods and the biomass dynamics model, indicate that for the last 10 years total catches have been below those required to achieve MSY and that the recent biomass trajectory has considerably increased. In addition, fishery independent surveys of the adult component of the stock in northern western Australia show a strong increasing trend since 2008.

The above evidence indicates that the biomass of this stock is likely to be depleted and that recruitment is likely to be impaired. However, for the period 2015 to 2022 these indicators suggest a recovering stock. The above evidence indicates that the current level of fishing mortality should allow the stock to recover from its recruitment impaired state.

On the basis of the evidence provided above, the Western Australia biological stock is classified as a recovering stock.

Sandbar Shark biology [McAuley et al. 2006; McAuley et al. 2007a; Geraghty et al. 2013 ]

Distribution of reported commercial catch of Sandbar Shark

Western Australia – Recreational (Management methods) A recreational fishing from boat licence is required for recreational fishing from a powered vessel in Western Australia.

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

Queensland – Indigenous (management methods) for more information see https://www.daf.qld.gov.au/business-priorities/fisheries/traditional-fishing

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

Recreational and Indigenous (catch) Given the offshore distribution of Sandbar Shark, near-shore catches are likely to be negligible.

Commercial catch of Sandbar Shark - note confidential catch not shown

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