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Silverlip Pearl Oyster (2020)

Pinctada maxima

  • Anthony Hart (Department of Primary Industries and Regional Development, Western Australia)
  • Thor Saunders (Department of Industry, Tourism and Trade)
  • Anthony Roelofs (Department of Agriculture and Fisheries, Queensland)

You are currently viewing a report filtered by jurisdiction. View the full report.

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Summary

The Silverlip Pearl Oyster is the largest species in the pearl oyster family. It also produces the largest pearls. Australia has three stocks of Silverlip Pearl Oyster, all of which are sustainable. 

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Stock Status Overview

Stock status determination
Jurisdiction Stock Stock status Indicators
Queensland Queensland Sustainable

Catch, effort

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Stock Structure

Pinctada maxima or the Silverlip Pearl Oyster is the largest species in the pearl oyster family [Shirai 1994], and produces the largest pearls. It is distributed within the central Indo-Pacific region, bounded by the Bay of Bengal to the west, Solomon Islands to the east, Taiwan to the north, and Northern Australia to the south [Southgate et al. 2008], at depths from the shallow sub-tidal to more than 50 m. Within Australia, the population genetic distribution has been investigated in Western Australia and Northern Territory [Benzie et al. 2006]. The biological stock structure is uncertain; however, Western Australian stocks are generally considered to be one stock (with the possible exception of a localised population in Exmouth Gulf), separate from stocks in the Northern Territory. The biological stock structure for Queensland is unknown.

Here, assessment of stock status is presented at the jurisdictional level—Western Australia, Northern Territory and Queensland.

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Stock Status

Queensland

The East Coast Pearl Fishery (Queensland) is a small-scale, wild-harvest fishery that enables the collection of broodstock for the pearl aquaculture industry. The general demand for wild-harvested pearl oysters is very low as the aquaculture industry produces the majority of its broodstock needs from its own hatcheries. Catches have been low in recent years, rarely exceeding 500 shells per year and 50 days of effort [QFISH 2020]. There has been a long history of low catches and effort and no collection of Silverlip Pearl Oyster occurred between 2013 and 2017. Annual catches since 2017 have averaged 115 kg per year, suggesting that the biomass of this stock is unlikely to be depleted and that recruitment is unlikely to be impaired. Similarly, the harvest rate in 2019 was zero as there was no catch of this species indicating 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, Silverlip Pearl Oyster in Queensland is classified as a sustainable stock.

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Biology

Silverlip Pearl Oyster biology [Hart and Joll 2006]

Biology
Species Longevity / Maximum Size Maturity (50 per cent)
Silverlip Pearl Oyster 30 years, 250 mm DVM  Males: 2–3 years, 110 mm DVM Females: 7–8 years, 175 mm DVM
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Distributions

Distribution of reported commercial catch of Silverlip Pearl Oyster
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Tables

Fishing methods
Queensland
Commercial
Diving
Recreational
Diving
Indigenous
Various
Management methods
Method Queensland
Commercial
Gear restrictions
Limited entry
Size limit
Spatial closures
Recreational
Gear restrictions
Limited entry
Size limit
Spatial closures
Catch
Queensland
Commercial 94.00kg
Indigenous Unknown
Recreational Unknown

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

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Catch Chart

Commercial catch of Silverlip Pearl Oyster - note confidential catch not shown
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References

  1. Benzie, JAH and Smith-Keune, C 2006, Microsatellite variation in Australian and Indonesian pearl oyster Pinctada maxima populations. Marine Ecology Progress Series. 314: 197–211.
  2. DoF 2016, Western Australian Silver-Lipped Pearl Oyster (Pinctada maxima) Resource Harvest Strategy 2016–2021, v1. Fisheries Management Paper No. 276.
  3. Haddon M., A Punt and P. Burch (2018). simpleSA: A package containing functions to facilitate relatively simple stock assessments. R package version 0.1.18.
  4. Hart AM, Thomson AW and Murphy D 2011, Environmental influences on stock abundance and fishing power in the silver-lipped pearl oyster fishery. ICES Journal of Marine Science, 68(3): 444–53.
  5. Hart, AM and Joll, L 2006, Growth, mortality, recruitment, and sex ratio in wild stocks of the silver-lipped pearl oyster Pinctada maxima (Jameson) (Mollusca: Pteriidae) in Western Australia. Journal of Shellfish Research, 25 (1): 201–210.
  6. Knuckey IA 1995, The Northern Territory Pearl Oyster Fishery. FRDC final report 1991/14. 47 pp.
  7. Martell, S. and R. Froese (2013). A simple method for estimating MSY from catch and resilience. Fish and Fisheries 14: 504-514.
  8. QFish, Department of Agriculture and Fisheries, www.qfish.gov.au
  9. Saunders T. 2020, Northern Territory Silverlip Pearl Oyster Stock Status Summary - 2020. Unpublished Fishery report.
  10. Shirai, S 1994, Pearls and pearl oysters of the world. Marine Planning Co. Japan. 95 pp. (in Japanese and English).
  11. Southgate PC, Strack E, Hart AM, Wada KT, Monteforte M, Carino M, Langy S, Lo C, Acosta-Salmon H and Wang A 2008, Chapter 9: Exploitation and Culture of Major Commercial Species. pp. 303–56. In: The Pearl Oyster, Eds Southgate PC and Lucas J, Elsevier London.

Downloadable reports

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