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Black Jewfish (2018)

Protonibea diacanthus

  • Shane Penny (Department of Primary Industry and Resources, Northern Territory)
  • Robyn Lovett (Department of Agriculture and Fisheries, Queensland)
  • Fabian Trinnie (Department of Primary Industries and Regional Development, Western Australia)
  • Stephen Newman (Department of Primary Industries and Regional Development, Western Australia)

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

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Summary

Black Jewfish is a sustainable species in WA and recovering from overfishing in the NT. Stocks in QLD are undefined, with limited information available.

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Stock Status Overview

Stock status determination
Jurisdiction Stock Fisheries Stock status Indicators
Northern Territory Northern Territory BF, CLF, DF, ONLF, TRF Recovering Biomass, egg production
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)
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Stock Structure

Black Jewfish is a widespread Indo-Pacific species found from Exmouth Gulf in Western Australia, north and east 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 coastline [Saunders et al. 2016]. The results indicated that separate stocks exist at the scale of tens of kilometres [Saunders et al. 2016]. However, it is extremely difficult to collect relevant biological and catch and effort information to assess each of these individual fine-scale biological stocks, although this fine-scale stock structure is an explicit consideration for fishery managers. Due to the logistic and operational constraints of the relevant monitoring, assessment and management agencies, assessment is only feasible at the jurisdictional level. This assumes that the assessment of stock status within a jurisdictional assessment unit is relevant to all biological stocks within that assessment unit.

Here assessment of stock status is presented at the jurisdictional level—Western Australia, Northern Territory; and at the management unit level—Gulf of Carpentaria and Queensland East Coast (Queensland).

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Stock Status

Northern Territory

Black Jewfish are harvested by commercial and recreational sectors across most of the Northern Territory, with the majority of catch occurring within the Greater Darwin Region (i.e. within a radius of approximately 150 km of this population centre). Within this region, Black Jewfish is a targeted species of the Coastal Line Fishery, contributing 68 per cent of the total harvest; the recreational fishing sector, contributing 21 per cent; Fishing Tour Operators, contributing 5 per cent; no estimates of the Indigenous harvest of Black Jewfish is available for the Northern Territory. For the purposes of this assessment only commercial logbooks and recreational data from the Greater Darwin Region have been used.

A 2014 stock assessment using a Stock Reduction Analysis [Grubert et al. 2013] indicated that Black Jewfish were overfished and that overfishing was occurring. The most recent assessment [NTG 2018, unpublished] updates the previous assessment incorporating data up to and including 2017. The results of the model indicate that, despite high recent exploitation levels, the Greater Darwin Region stocks were not overfished in 2017 and there was a 24 per cent probability that the stock is overfished and 5 per cent probability that current harvest rates are causing overfishing. Biomass and egg production were estimated to be at 50 per cent and 47 per cent respectively of the unfished biomass. Given the recent information on the stock structure of this species [Saunders et al. 2016], 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 these heavily-fished areas, with other less accessible areas being more lightly-fished. The recovery of this species is primarily driven by successive years of above average recruitment (indicated by the reduction in average length of monitored catches and an increase in the number of fish caught) as well as the management measures (catch limits and area closures) introduced in 2015 aimed to reduce the harvest of the species by 20 per cent in exploited areas [NTG 2017]. There is a high likelihood that the illegal harvest of this species, which historically has been non-existent, will increase the risk of this species being overfished in the future as the price of swim bladders exceeds $750 per kg. The swim bladders are considered a delicacy and an aphrodisiac in some Asian countries. The current level of fishing mortality should allow further recovery, though the development of any illegal fishing mortality and its potential impact will need to be assessed.

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

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Biology

Black Jewfish biology [Phelan 2002, Welch et al. 2014]

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

Distribution of reported commercial catch of Black Jewfish
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Tables

Fishing methods
Northern Territory
Commercial
Hook and Line
Gillnet
Pelagic Gillnet
Otter Trawl
Fish Trap
Recreational
Spearfishing
Unspecified
Handline
Charter
Handline
Indigenous
Handline
Management methods
Method Northern Territory
Charter
Limited entry
Passenger restrictions
Commercial
Catch limits
Gear restrictions
Limited entry
Spatial closures
Vessel restrictions
Indigenous
Laws of general application
Recreational
Gear restrictions
Possession limit
Spatial closures
Active vessels
Northern Territory
14 in BF, 14 in CLF, 8 in DF, 7 in ONLF, 5 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 6.67t in BF, 168.83t in CLF, 21.33t in DF, 296.00kg in ONLF, 11.34t 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)

Western Australia – Recreational (Catch) Boat-based recreational catch if from 1 September 2015–31 August 2016. These data are derived from those reported in Ryan et al. 2017.

Western Australia – Recreational (management methods) A Recreational Fishing from Boat Licence is required for the use of a powered boat to fish or to transport catch or fishing gear to or from a land-based fishing location.

Western Australia – Indigenous 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.

Western AustraliaActive Vessels Data is confidential as there were fewer than three vessels operating in the Pilbara Fish Trawl Interim Managed Fishery.

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.

Northern Territory – Indigenous The Fisheries Act 1988 (NT), specifies that “…without derogating from any other law in force in the Territory, nothing in a provision of this Act or an instrument of a judicial or administrative character made under it limits the right of Aboriginals who have traditionally used the resources of an area of land or water in a traditional manner from continuing to use those resources in that area in that manner”.

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Catch Chart

Commercial catch of Black Jewfish - note confidential catch not shown
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References

  1. 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.
  2. Newman, SJ, Brown, JI, Fairclough, DV, Wise, BS, Bellchambers, LM, Molony, BW, Lenanton, RCJ, Jackson, G, Smith, KA, Gaughan, DJ, Fletcher, WJ, McAuley, RB and Wakefield, CB 2018, A risk assessment and prioritisation approach to the selection of indicator species for the assessment of multi-species, multi-gear, multi-sector fishery resources. Marine Policy, 88: 11–22.
  3. Newman, SJ, Mitsopoulos, G, Skepper, C and Smith, E 2018, North Coast Nearshore and Estuarine Resource Status Report 2017. pp. 123-126. In: Gaughan, D.J. and Santoro, K. (eds.). Status Reports of the Fisheries and Aquatic Resources of Western Australia 2016/17: The State of the Fisheries. Department of Primary Industries and Regional Development, Western Australia, Perth, Australia. 237p.
  4. Northern Territory Government 2017, Status of key Northern Territory Fish Stocks Report 2015, Northern Territory Government Department of Primary Industry and Resources, Fishery Report 118.
  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. 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.
  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. Ryan, KL, Hall, NG, Lai, EK, Smallwood, CB, Taylor, SM, Wise, BS 2017, Statewide survey of boat-based recreational fishing in Western Australia 2015/16. Fisheries research Report No. 287. Department of Primary Industries and Regional Development, Government of Western Australia, Perth. 
  9. Saunders, TM, Welch, D, Barton, D, Crook, D, Dudgeon, C, Hearnden, M, Maher, S, Ovenden, J, Taillebois, L and Taylor J 2016, Optimising the management of tropical coastal reef fish through the development of Indigenous capability. FRDC final report 2013/017.
  10. Taillebois, L, Barton, DP, Crook, DA, Saunders, T, Taylor, J, Hearnden, M, Saunders, RJ, Newman, SJ, Travers, MJ, Welch, DJ, Greig, A, Dudgeon, C, Maher, S and Ovenden, JR 2017, Strong population structure deduced from genetics, otolith chemistry and parasite abundances explains vulnerability to localized fishery collapse in a large Sciaenid fish, Protonibea diacanthus, Evolutionary Applications, vol. 10, no. 10, pp. 978–993.
  11. 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.
  12. 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.