*

Black Jewfish

Protonibea diacanthus

  • Thor Saunders (Department of Primary Industry and Resources, Northern Territory)
  • Anthony Roelofs (Department of Agriculture and Fisheries, Queensland)
  • Stephen Newman (Department of Fisheries, Western Australia)

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

Toggle content

Stock Status Overview

Stock status determination
Jurisdiction Stock Fisheries Stock status Indicators
Northern Territory Northern Territory BF, CLF, DF, FTO, ONLF, TRF Overfished Biomass, egg production
BF
Barramundi Fishery (NT)
CLF
Coastal Line Fishery (NT)
DF
Demersal Fishery (NT)
FTO
Fishery Tour Operator (NT)
ONLF
Offshore Net and Line Fishery (NT)
TRF
Timor Reef Fishery (NT)
Toggle content

Stock Structure

Black Jewfish is a widespread Indo-Pacific species found from the Pilbara and Kimberley regions in Western Australia, across Northern Australia, to the east coast of Queensland. The stock structure for this species has been investigated in the north western part of its range from the western Gulf of Carpentaria to its southern extent along the west Australian coastline1. The results indicated that separate stocks exist at the scale of 10s of km1.

However, given the recent nature of these findings, here assessment of stock status is presented at the jurisdictional level—Western Australia, Northern Territory; and at the management unit level—Gulf of Carpentaria (Queensland) and Queensland east coast.

Toggle content

Stock Status

Northern Territory

The most recent assessment3 estimates that the biomass and egg production was 28 per cent of unfished levels (1973). The model used was an update of the 2011 Stock Reduction Analysis model4 including data up until 2014. The outputs indicated that there was a high probability (98 per cent) that Black Jewfish stocks have been overfished and that overfishing is still occurring (80 per cent). Given the recent new information on the stock structure of this species, it is likely that the assessment incorporates several populations. As the model is driven by the populations that receive the highest harvest rates in the Northern Territory the assigned status can be assumed to be representative of the highest level of exploitation that occurs on any population. The immediate area of concern is in waters around Darwin where most of the fishing pressure occurs3. The fisheries accessing these exploited stocks are those that operate inshore including the Coastal Line Fishery, Barramundi Fishery, fishing tour operators and recreational fishers. Black Jewfish have also been shown to be highly susceptible to barotrauma when caught in waters deeper than ten metres5,6. Management in the form of catch limits and area closures have been put in place to reduce harvest rates by the necessary 20 per cent to allow for the biomass of Black Jewfish stocks to recover4. The stock is considered to be recruitment overfished. This reduction in fishing pressure is expected to allow the stock to recover from its recruitment overfished state; however measurable improvements in biomass are yet to be detected.

On the basis of the evidence provided above, Black Jewfish in the Northern Territory is classified as an overfished stock.

Toggle content

Biology

Black Jewfish biology6,8

Biology
Species Longevity / Maximum Size Maturity (50 per cent)
Black Jewfish 15 years; 1 500 mm TL, 30 kg Northern Territory: 890 mm TL (2 years)
Toggle content

Distributions

Distribution of reported commercial catch of Black Jewfish

Toggle content

Tables

Fishing methods
Northern Territory
Commercial
Line
Gillnet
Otter Trawl
Unspecified
Pots and Traps
Recreational
Spearfishing
Hand Line, Hand Reel or Powered Reels
Indigenous
Hand Line, Hand Reel or Powered Reels
Management methods
Method Northern Territory
Commercial
Catch limits
Gear restrictions
Limited entry
Spatial closures
Vessel restrictions
Recreational
Gear restrictions
Limited entry
Passenger restrictions
Possession limit
Spatial closures
Active vessels
Northern Territory
14 in BF, 9 in CLF, 9 in DF, 10 in ONLF, 8 in TRF
BF
Barramundi Fishery (NT)
CLF
Coastal Line Fishery (NT)
DF
Demersal Fishery (NT)
ONLF
Offshore Net and Line Fishery (NT)
TRF
Timor Reef Fishery (NT)
Catch
Northern Territory
Commercial 3.11t in BF, 173.18t in CLF, 11.25t in DF, 28.12t in FTO, 77.00kg in ONLF, 579.00kg in TRF
Indigenous Unknown
Recreational 28 t in FTO, 75 t (in 2010)
BF
Barramundi Fishery (NT)
CLF
Coastal Line Fishery (NT)
DF
Demersal Fishery (NT)
FTO
Fishery Tour Operator (NT)
ONLF
Offshore Net and Line Fishery (NT)
TRF
Timor Reef Fishery (NT)

a Queensland – Indigenous In Queensland, under the Fisheries Act 1994 (Qld), Indigenous fishers are able to use prescribed traditional and non-commercial 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.
b Western Australia – Recreational (catch) Boat-based recreational catch from 1 May 2013–30 April 2014.

Toggle content

Catch Chart

Commercial catch of Black Jewfish

Toggle content

Effects of fishing on the marine environment

  • Black Jewfish are mainly targeted by fishers in all sectors using handlines and rods. Beyond the removal of target and a small proportion of bycatch species, there is little evidence to suggest that this gear significantly impacts on benthic or pelagic ecological communities.
  • In Queensland, coastal river and estuary set gillnets have been shown to have minimal impact on the environment and are quite selective in their harvest10. Bycatch is generally low when compared to the harvest of the target species.
  • Commercial trawl gear used in waters across northern Australia has the potential to impact on the benthic habitat. However, finfish trawl nets have been designed to fish above the seabed, reducing interaction with benthic habitats11. Additionally, the trawl fishery across northern Australian waters comprises a very small fleet and only fishes approximately seven per cent of the available area11.
Toggle content

Environmental effects on Black Jewfish

  • The impact of environmental factors on Black Jewfish is largely unknown. However, juveniles mainly inhabit coastal estuaries and bays, making these phases of their lifecycle sensitive to ocean current strength and direction, rainfall and river flow and water temperature, salinity and acidity3.
Toggle content

References

  1. 1 Saunders, TM, Welch, D, Barton, D, Crook, D, Dudgeon, C, Hearnden, M, Maher, S, Ovenden, J, Taillebois, L, Taylor J 2016, Optimising the management of tropical coastal reef fish through the development of Indigenous capability. FRDC final report 2013/017.
  2. 2 Brown, JI, Newman, SJ, Mitsopoulos, G, Skepper, C, Thomson, A and Wallis, D 2015, North Coast Nearshore and Estuarine Fishery Status Report. pp. 182-188. In: Fletcher, W.J. and Santoro, K. (eds.). Status Reports of the Fisheries and Aquatic Resources of Western Australia 2014/15: The State of the Fisheries. Department of Fisheries, Western Australia, Perth, Australia. 353p.
  3. 3 Northern Territory Government 2016, Fishery Status Reports 2015, Northern Territory Government Department of Primary Industry and Resources, Fishery report 115.
  4. 4 Grubert, MA, Saunders, TM, Martin, JM, Lee, HS and Walters, CJ 2013, Stock Assessments of Selected Northern Territory Fishes, Fishery report no. 110, Northern Territory Fisheries.
  5. 5 Phelan, M 2008, Assessment of the implications of target fishing on Black Jewfish (Protonibea diacanthus) aggregations in the Northern Territory, Fisheries Research and Development Corporation project 2004/004, fishery report 91, Northern Territory Fisheries.
  6. 6 Welch, DJ, Robins, J, Saunders, T, Courtney, T, Harry, A, Lawson, E, Moore, BR, Tobin, A, Turnbull, C, Vance, D and Williams, AJ 2014, Implications of climate change impacts on fisheries resources of northern Australia. Part 2: Species profiles, final report to the Fisheries Research and Development Corporation, project 2010/565, James Cook University, Townsville.
  7. 7 Roelofs, AJ 2003, Ecological Assessment of the Gulf of Carpentaria Inshore Finfish Fishery - A report to Environment Australia on the sustainable management of a multi-species tropical gillnet fishery, Department of Primary Industries and Fisheries, Brisbane.
  8. 8 Phelan, MJ 2002, Fishery biology and management of the Black Jewfish Protonibea squamosa (Sciaenidiae) aggregations near Injinoo community, Far Northern Cape York. Stage 1: Initial characterisation of the aggregations and associated fishery, Fisheries Research and Development Corporation project 98/135, Department of Primary Industries, Queensland and Balkanu Cape York Development Corporation, Cairns.
  9. 9 Webley, J, McInnes, K, Teixeira, D, Lawson, A, and Quinn, R 2015, Statewide Recreational Fishing Survey 2013-14, Queensland Department of Agriculture and Fisheries, Brisbane.
  10. 10 Halliday, IA, Ley, JA, Tobin, A, Garrett, R, Gribble, NA, and Mayer, DG 2001, The effects of net fishing: addressing biodiversity and bycatch issues in Queensland inshore waters, Fishieries Research and Development Corporation project 97/206, Department of Primary Industries, Queensland.
  11. 11 Mounsey, RP and Ramm, DC 1991, Evaluation of a new design of semi-demersal trawl, Northern Territory Department of Primary Industry and Fisheries, Darwin.

Archived reports

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