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Common Blacktip Shark (2023)

Carcharhinus limbatus

  • Michael Usher (Department of Industry, Tourism and Trade, Northern Territory)
  • Matias Braccini (Department of Primary Industries and Regional Development, Western Australia)
  • Victor Peddemors (New South Wales Department of Primary Industries)
  • Ian Jacobsen (Department of Agriculture and Fisheries, Queensland)

Date Published: June 2023

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Summary

Common Blacktip Sharks are found worldwide in tropical and warm temperate waters. Three biological stocks—East Coast, Gulf of Carpentaria and North and West Coast—have been identified for Australia. The East Coast and North and West Coast stocks are sustainable, while the Gulf of Carpentaria stock is undefined. Previous editions of the SAFS reports have combined Australian Blacktip Shark, Common Blacktip Shark and Spot-Tail Shark, but all three are now reported at the species level.

Photo: Department of Industry, Tourism and Trade, Northern Territory

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Stock Status Overview

Stock status determination
Jurisdiction Stock Stock status Indicators
New South Wales, Queensland East Coast Sustainable

Catch, MSY, Biomass

Northern Territory, Western Australia North Western Australia Sustainable

Biomass, fishing mortality, catch, catch rate

Northern Territory, Queensland Gulf of Carpentaria Undefined

Catch

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Stock Structure

Common Blacktip Shark have a circumglobal distribution in tropical and warm temperate waters. In Australian waters, genetic studies have identified three biological stocks of Common Blacktip Shark; a western stock extending from the western Northern Territory into northern Western Australia, a Gulf of Carpentaria (GoC) stock and an east coast stock in Queensland and New South Wales [Ovenden et al. 2007]. The stock boundary between the North and West Coast, and Gulf of Carpentaria biological stocks is uncertain. 

Common Blacktip Shark are similar in appearance to the Australian Blacktip Shark (C. tilstoni). Previously taxonomical differentiation of these species was only possible by genetic analyses, precaudal vertebral counts or, in certain size classes, differences in size of maturity [Harry 2011]. A new identification technique, utilising body measurements and pelvic fin colouration, has been developed and may assist in distinguishing between these two species. However, accurate field identification remains difficult and is not practical during commercial fishing operations [Johnson et al. 2017]. Hybridisation between the species has also been recorded and, while a new investigation is helping to understand the prevalence and dynamics of this phenomenon [Queensland Department of Agriculture and Fisheries 2021], the current knowledge regarding its implications for fisheries assessment and management is limited [Harry et al. 2012; Johnson et al. 2017; Morgan et al. 2011]. Consequently, Common Blacktip and Australian Blacktip sharks are often reported as a species complex in commercial logbooks.  For the purpose of these assessments a portion of the combined Blacktip Shark catch for each jurisdiction has been attributed to Common Blacktip Shark using relative abundance ratios determined from on board observer programs and published research [Johnson et al. 2017; Ovenden 2007].

Here, assessment of stock status for Common Blacktip Shark is presented at the biological stock level—North and West Coast, Gulf of Carpentaria, and East Coast.

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Stock Status

East Coast

In Queensland, the last stock assessment for the Common Blacktip Shark was completed in 2015 and was based on data up to and including 2013 [Leigh 2015]. This assessment produced Maximum Sustainable Yield (MSY) estimates for the Common Blacktip Shark on the Queensland east coast ranging from 237 t to 907 t. The lower bound of the MSY estimate range is highly conservative and was included in the assessment in response to concerns surrounding the quantity and quality of the available data on shark harvests [Leigh 2015].

Harvest for the Common Blacktip Shark peaked between 2003–04 and 2007–08 with an average annual harvest of 111 t. In 2021–22, the annual commercial harvest was 24 t, which was below the 10-year average of 35 t and well below the most conservative MSY estimate of 237 t [Leigh 2015]. This reflects a sustained long-term drop in harvest for the Common Blacktip Shark. 

Observed declines in the annual harvest are attributed to poor market demand, declining effort and management reforms targeted at the commercial net fishery rather than declining biomass. The most significant reforms were implemented in 2009 and included the introduction of a combined 600 t Total Allowable Commercial Catch (TACC) limit for retained sharks and rays. In 2021, this limit was reduced to 400 t (not including Hammerhead Sharks) as part of a broader reform program for the East Coast Inshore Fishery (ECIF). These reforms included a transition in the ECIF to regional management, and a fishery-specific harvest strategy. The harvest strategy includes reference points, trigger limits and other measures to guide the long-term management of sharks harvested on the Queensland east coast [Queensland Department of Agriculture and Fisheries 2020]. 

Outside of the commercial fishing sector, the catch of Common Blacktip Sharks in Queensland waters is low to negligible. The Queensland Shark Control Program typically reports the capture of less than five individuals per year [Queensland Government 2023]. No recreational data is available for this species [Teixeira et al. 2021]. However, recreational harvest is limited by a one shark in possession limit and a maximum legal size limit of 1.5 m total length. Commercial catch records for the New South Wales Ocean Trap and Line Fishery indicate that the annual reported commercial catch of Blacktip Sharks (comprising mostly Common Blacktip Shark) from New South Wales waters ranged from 13–66 t during the 10 year period spanning financial years from 1998–99 to 2007–08 [Macbeth et al. 2009]. However, significant use of catch reporting categories 'Unspecified Sharks' (5–204 t) and 'Unspecified Whaler Sharks' (7–26 t) during that period suggest that these historical quantities are most probably underestimates. Since management intervention in this fishery in 2009, the tonnage of Blacktip Sharks caught has dropped substantially and the reliability of species-specific catch reporting has improved considerably [Macbeth et al. 2018]. A total of 24.1 t of Blacktip Sharks (comprising mostly C. limbatus) was landed in New South Wales during the 2022 fiscal year The catch of Blacktip Sharks in the New South Wales Shark Meshing Program is negligible, at less than 1 t per year [Dalton et al. 2023]. Collectively, these figures indicate that the overall catch of this species in New South Wales waters is minimal in terms of impacting the East Coast stock. 

The most recent assessment, using data up to 2019, was undertaken for the East Coast biological stock of Common Blacktip Shark utilising a catch Maximum Sustainable Yield (catch-MSY) model. The assessment estimated that the harvest rate for Common Blacktip Shark was below that required to reach MSY and that the biomass in 2019 was 68% of the unfished biomass [Usher et al. 2020a]. Overall, the information provided above indicates that the biomass of the stock is not considered to be depleted and that recruitment is unlikely to be impaired. Furthermore, the current level of fishing mortality is unlikely to cause the stock to become recruitment impaired. 

On the basis of the evidence provided above, the East Coast biological stock of Common Blacktip Shark is classified as a sustainable stock

Gulf of Carpentaria

The Gulf of Carpentaria biological stock straddles two jurisdictions: The Northern Territory, east of the Wessel Islands-Queensland border and Queensland, west of Torres Straight Islands to the Northern Territory border. In this stock, most Common Blacktip Sharks are reported by Queensland Fisheries (Queensland 18 t; Northern Territory 1.3 t). However, there are limitations associated with the species identifications which impact the quantity and reliability of available catch data [Leigh 2015]. As a result of these deficiencies, Maximum Sustainable Yield (MSY) could not be estimated for the species in the Gulf of Carpentaria [Leigh 2015] and estimates of harvest in Queensland are currently Null as catch is attributed to C. tilstoni following Leigh [2015] and Ovenden et al [2007]. 

On the basis of the evidence provided above, the Gulf of Carpentaria biological stock of Common Blacktip Shark is classified as an undefined stock.

North Western Australia

The North Western Australia biological stock straddles two jurisdictions: The Northern Territory, west of the Wessel Islands–Western Australian border; and Western Australia.

Changing operational practices in the NT Offshore Net and Line Fishery have greatly reduced the take of Common Blacktip Shark in the Northern Territory. There has been little to no shark-targeted fishing occurring in the Northern Territory since 2012. This is attributed to declining shark fin prices and increasing value of Grey Mackerel (Scomberomorus semifasciatus), which is currently the main target species of this fishery. In this circumstance, the declining catches are likely to have allowed the abundance of the population of Common Blacktip Shark to increase.

Although there is uncertainty regarding species composition and the magnitude of historical catches of Blacktip Sharks from Western Australia, harvests of Common Blacktip Shark in this jurisdiction have been negligible since April 2009 [Molony et al. 2013; Braccini et al. 2021]. These negligible harvests are expected to allow for increasing biomass levels. In addition, recreational catches are negligible [Ryan et al. 2019].

The most recent stock assessment, using data up to 2021, was undertaken for the North Western Australia biological stock of Common Blacktip Shark utilising a catch-MSY model (developed by Martell and Froese [2013] and modified by Haddon et al. [2018]). The results indicate that the inferred biomass exceeds the target reference point, with the 95% confidence intervals positioned above the target. This indicates that the stock is unlikely to be depleted and that recruitment is unlikely to be impaired. The assessment also estimated that recent harvests are below that required to achieve maximum sustainable yield [Northern Territory Government, unpublished]. The biomass of the stock is not considered to be depleted and the current level of fishing mortality is unlikely to cause the stock to become recruitment impaired.

On the basis of the evidence provided above, the North Western Australia biological stock of Common Blacktip Shark is classified as a sustainable stock.

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Biology

Blacktip Sharks biology [Harry 2011; Harry et al. 2019; Last and Stevens 2009]

Biology
Species Longevity / Maximum Size Maturity (50 per cent)
Common Blacktip Shark

Maximum age unknown, 2,500 mm TL 

Males 1,800 mm, females unknown

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Distributions

Distribution of reported commercial catch of Common Blacktip Shark

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Tables

Fishing methods
Western Australia Northern Territory Queensland New South Wales
Commercial
Gillnet
Unspecified
Line
Net
Hook and Line
Demersal Longline
Mesh Net
Otter Trawl
Various
Recreational
Handline
Hook and Line
Indigenous
Spearfishing
Hook and Line
Various
Charter
Hook and Line
Management methods
Method Western Australia Northern Territory Queensland New South Wales
Charter
Bag limits
Bag/possession limits
Gear restrictions
Licence
Licence (boat-based sector)
Possession limit
Processing restrictions
Seasonal or spatial closures
Size limits
Spatial closures
Commercial
Bag/possession limits
Catch limits
Effort limits
Effort limits (individual transferable effort)
Gear restrictions
Harvest Strategy
Limited entry
Processing restrictions
Quota
Seasonal or spatial closures
Size limits
Spatial closures
Total allowable catch
Vessel restrictions
Indigenous
Customary fishing management arrangements
No limits on customary catch
Recreational
Bag and boat limits
Bag limits
Bag/possession limits
Gear restrictions
Licence (boat-based sector)
Possession limit
Processing restrictions
Seasonal or spatial closures
Size limits
Spatial closures
Catch
Western Australia Northern Territory Queensland New South Wales
Commercial 48.85t 24.23t 23.84t
Charter Unknown Unknown Unknown Unknown
Indigenous Unknown Unknown Unknown unknown
Recreational No Common Blacktip Shark caught from boats [Ryan et al. 2019], shore-based catches are undetermined Unknown Unknown unknown

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

Queensland – Indigenous (management methods). For more informationsee 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. Due to low confidence in species-specific reporting caused by challenges in distinguishing between C. limbatus and C. tilstoni, catch for this species has been derived by combining harvest across the multiple blacktip shark reporting categories and applying a latitudinal split following Leigh [2015] and Ovenden et al. [2007]. Further information available through the Queensland Fisheries 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  

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

Queensland – Commercial (Management Methods). Harvest strategies are available at: https://www.daf.qld.gov.au/business-priorities/fisheries/sustainable/harvest-strategy  

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

Northern Territory - Indigenous (management methods). The Fisheries Act 1988 (NT), specifies that: “Unless expressly provided otherwise, nothing in this Act derogates or limits the right of Aboriginal people who have traditionally used the resources of an area of land or water in a traditional manner to continue to use those resources in that area in that manner.”

Northern Territory — Charter (Management methods) In the Northern Territory, charter operators are regulated through the same management methods as the recreational sector but are subject to additional limits on license and passenger numbers.

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Catch Chart

Commercial catch of Common Blacktip Shark - note confidential catch not shown

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References

  1. Braccini, M, Kangas, M, Jaiteh, V and Newman, S 2021, Quantifying the unreported and unaccounted domestic and foreign commercial catch of sharks and rays in Western Australia. Ambio 50: 1337-1350
  2. Dalton, S, Peddemors, V and Doak, C 2023, Shark Mehsing (Bather Protection) Program 2022/23 Annual Performance Report. NSW Department of Primary Industries. 45 pp.
  3. Department of Agriculture and Fisheries, Queensland 2021, Monitoring of Queensland’s shark catch for the net fisheries: summary report. Project Report. State of Queensland, Brisbane.
  4. Haddon M, Punt A and Burch P 2018, simpleSA: A package containing functions to facilitate relatively simple stock assessments. R package version 0.1.18.
  5. Harry, AV 2011, Life histories of commercially important tropical sharks from the Great Barrier Reef World Heritage Area, PhD thesis, James Cook University, Townsville
  6. Harry, AV, Butcher, PA, Macbeth, WG, Morgan, JAT, Taylor, SM and Geraghty, PT 2019, Life history of the Common Blacktip Shark, Carcharhinus limbatus, from central eastern Australia and comparative demography of a cryptic shark complex. Marine and Freshwater Research, 70, 6, 834-848
  7. Harry, AV, Morgan, JAT, Ovenden, JR, Tobin, A, Welch, DJ and Simpfendorfer, C 2012, Comparison of the reproductive ecology of two sympatric Blacktip Sharks (Carcharhinus limbatus and Carcharhinus tilstoni) off north-eastern Australia with species identification inferred from vertebral counts. Journal of Fish Biology, 81: 1225–1233.
  8. Johnson, GJ, Buckworth, RC, Lee, H, Morgan, JAT, Ovenden, JR and McMahon, CR 2017, A novel field method to distinguish between cryptic carcharhinid sharks, Australian blacktip shark Carcharhinus tilstoni and common blacktip shark C. limbatus, despite the presence of hybrids. Journal of Fish Biology, 90, 1, 39-60.
  9. Last, PR and Stevens, JD 2009, Sharks and rays of Australia, CSIRO Publishing, Collingwood.
  10. Leigh GM 2015, Stock assessment of whaler and hammerhead sharks (Carcharhinidae and Sphyrinidae) in Queensland, Agri-Science Queensland, Department of Agriculture and Fisheries, Brisbane.
  11. Macbeth, WG, Butcher, PA, Collins, D, McGrath, SP, Provost, SC, Bowling, AC, Geraghty, PT and Peddemors, VM 2018, Improving reliability of species identification and logbook catch reporting by commercial fishers in an Australian demersal shark longline fishery. Fisheries Management and Ecology, 25: 186-202.
  12. Macbeth, WG, Geraghty, PT, Peddemors, VM, and Gray, CA 2009, Observer-based study of targeted commercial fishing for large shark species in waters of New South Wales, Industry and Investment New South Wales. Fisheries Final Report Series 82.
  13. Martell, S, and Froese, R 2013, A simple method for estimating MSY from catch and resilience. Fish and Fisheries 14:504–514.
  14. Molony, B, McAuley, R and Rowland, F 2013, Northern shark fisheries status report: Statistics only, in WJ Fletcher and K Santoro (eds), Status Reports of the Fisheries and Aquatic Resources of Western Australia 2012/13: The State of the Fisheries, Western Australian Department of Fisheries, Perth, 216–217.
  15. Morgan, JA, Harry, AV, Welch, DJ, Street, R, White, J, Geraghty, PT, Macbeth, WG, Tobin, A, Simpfendorfer, CA and Ovenden, JR 2011, Detection of interspecies hybridisation in Chondrichthyes: hybrids and hybrid offspring between Australian (Carcharhinus tilstoni) and common (C. limbatus) Blacktip Shark found in an Australian fishery. Conservation Genetics, 13: 455–463.
  16. Ovenden, JR, Street, R, Broderick, D, Kashiwagi, T and Salini, J 2007, Genetic population structure of Black-tip Sharks (Carcharhinus tilstoni and C. sorrah) in northern Australia, in J Salini, R McAuley, S Blaber, RC Buckworth, J Chidlow, N Gribble, JR Ovenden, S Peverell, R Pillans, JD Stevens, I Stobutzki, C Tarca and TI Walker (eds), Northern Australian sharks and rays: the sustainability of target and bycatch species, phase 2, Fisheries Research and Development Corporation, Cleveland, Queensland.
  17. Queensland Fisheries Harvest Strategies. Available at: https://www.daf.qld.gov.au/business-priorities/fisheries/sustainable/harvest-strategy (Accessed 18 October 2023).
  18. Queensland Government, 2023, Shark Control Program: Shark Catch Statistics by Year. Available at: https://www.data.qld.gov.au/dataset/shark-control-program-shark-catch-statistics (Accessed: 2 August 2023).
  19. Ryan, KL, Hall, NG, Lai, EK, Smallwood, CB, Tate, A, Taylor, SM, Wise, BS 2019, Statewide survey of boat-based recreational fishing in Western Australia 2017/18. Fisheries Research Report No. 297. Department of Primary Industries and Regional Development, Government of Western Australia, Perth.
  20. Stock Status Summary - 2022 Common Blacktip Shark (Carcharhinus limbatus) North and West Coast stock Catch-MSY. Unpublished Fishery Report
  21. Teixeira, D, Janes, R, and Webley, J 2021, 2019–20 Statewide Recreational Fishing Survey Key Results. Project Report. State of Queensland, Brisbane.
  22. Usher, M, Saunders, T and Roelofs, A 2020a, Stock Status Summary - 2020 Common Blacktip Shark (Carcharhinus limbatus) East Coast stock Catch-MSY. Unpublished Fishery Report

Downloadable reports

Click the links below to view reports from other years for this fish.