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Dusky Flathead (2018)

Platycephalus fuscus

  • Jason McGilvray (Department of Agriculture and Fisheries, Queensland)
  • Matt Broadhurst (Department of Primary Industries, New South Wales)
  • Paul Hamer (Victorian Fisheries Authority)

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

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Summary

Dusky Flathead is an inshore and estuary fish found in QLD, NSW and VIC, and stocks in all states are sustainable.

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Stock Status Overview

Stock status determination
Jurisdiction Stock Fisheries Stock status Indicators
New South Wales New South Wales EGF Sustainable Commercial catch and CPUE, length frequency
EGF
Estuary General Fishery (NSW)
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Stock Structure

The biological stock structure of Dusky Flathead populations is unknown.

In the absence of information on biological stock boundaries, here assessment of stock status is presented at the jurisdictional level—Queensland, New South Wales and Victoria.

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Stock Status

New South Wales

In New South Wales during the past decade, commercial catches of Dusky Flathead have fluctuated at between 116 t and 178 t per year, and with more than 95 per cent of the total catch is caught using mesh nets. During the past five years, catches were initially consistent at 125 t, but peaked at 160 t in 2016, and declined to 116 t in 2017. The latter reduction was associated with substantially reduced effort, and the nominal catch rate by mesh netters has slightly increased during the past five years [Department of Primary Industries 2018]. Further, the size compositions of Dusky Flathead measured from commercial catches in 2017 were similar to annual estimates during the preceding decade, suggesting broad temporal consistency in the size composition of the stock [Department of Primary Industries 2018]. The total recreational harvest was estimated at 505 t in 2000–01 [Henry and Lyle 2003], and then substantially less at 288 t in 2013–14 [West et al. 2015], but with some reduction in effort and high uncertainty owing to different sampling methods. In addition to these retained catches, large numbers (up to 55 per cent of the total catches) of Dusky Flathead were released at each period (minimum legal size is 360 mm TL, and fishers are allowed only one individual > 700 mm TL within a total daily bag limit of 10 fish). The above evidence indicates that the biomass of this stock is unlikely to be depleted and that recruitment is unlikely to be impaired.

There are no current estimates of fishing or natural mortality for Dusky Flathead in New South Wales, but it is well established that the species has very high short-term survival after being released by anglers [91 per cent; Butcher et al. 2008]. While their survival after discarding by mesh netters is much less [23 per cent; Broadhurst et al. 2009], in the last decade, mandated changes to mesh-net configurations, including increases in mesh size [Broadhurst et al. 2003, 2009; Gray et al. 2005] have improved selectivity, and therefore reduced discard mortality. Escape mortalities remain unknown, but these are presumed to be minimal [Uhlmann and Broadhurst 2015]. Consequently, fishing mortality on undersize Dusky Flathead (360 mm TL) in New South Wales is likely to be quite low. The above evidence indicates that the currently level of fishing mortality is unlikely to cause the stock to become recruitment impaired.

On the basis of the evidence provided above, Dusky Flathead in New South Wales is classified as a sustainable stock.

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Biology

Dusky Flathead biology [Gray and Barnes 2008, Hicks et al. 2015, Kailola et al. 1993]

Biology
Species Longevity / Maximum Size Maturity (50 per cent)
Dusky Flathead Females ≥ 16 years, 1 200 mm TL Males ≥ 11 years, 620 mm TL Females 570 mm TL Males 320 mm TL
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Distributions

Distribution of reported commercial catch of Dusky Flathead

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Tables

Fishing methods
New South Wales
Commercial
Mesh Net
Unspecified
Indigenous
Spearfishing
Hook and Line
Recreational
Spearfishing
Hook and Line
Charter
Hook and Line
Management methods
Method New South Wales
Charter
Fishing gear and method restrictions
In possession limits
Licence
Size limit
Spatial closures
Commercial
Gear restrictions
Limited entry
Size limit
Spatial closures
Temporal closures
Indigenous
Bag limits
Native Title
Section 37 (1d)(3)(9), Aboriginal cultural fishing authority
Recreational
Bag and possession limits
Bag limits
Fishing gear and method restrictions
Licence
Size limit
Spatial closures
Active vessels
New South Wales
258 in EGF
EGF
Estuary General Fishery (NSW)
Catch
New South Wales
Commercial 131.68t in EGF
Indigenous Unknown
Recreational 288 t (2013–14)
EGF
Estuary General Fishery (NSW)

Queensland – Indigenous (Management Methods). 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 bag limits and seasonal closures do not apply to Indigenous fishers. Further exemptions to fishery regulations can be obtained through permits.

New South Wales – Indigenous (Management Methods) (a) The Aboriginal Cultural Fishing Interim Access Arrangement allows an Indigenous fisher in New South Wales to take in excess of a recreational bag limit in certain circumstances—for example, if they are doing so to provide fish to other community members who cannot harvest themselves.; (b) The Aboriginal cultural fishing authority is the authority that Indigenous persons can apply to take catches outside the recreational limits under the Fisheries Management Act 1994 (NSW), Section 37 (1d)(3)(9), Aboriginal cultural fishing authority; and (c) In cases where the Native Title Act 1993 (Cth) applies fishing activity can be undertaken by the person holding native title in line with S.211 of that Act, which provides for fishing activities for the purpose of satisfying their personal, domestic or non-commercial communal needs. In managing the resource where native title has been formally recognised, the native title holders are engaged with to ensure their native title rights are respected and inform management of the State's fisheries resources.

Victoria – Indigenous (Management Methods) In Victoria, regulations for managing recreational fishing may not apply to fishing activities by Indigenous people. Victorian traditional owners may have rights under the Commonwealth's Native Title Act 1993 to hunt, fish, gather and conduct other cultural activities for their personal, domestic or non-commercial communal needs without the need to obtain a licence. Traditional Owners that have agreements under the Traditional Owner Settlement Act 2010 (Vic) may also be authorised to fish without the requirement to hold a recreational fishing licence. Outside of these arrangements, Indigenous Victorians can apply for permits under the Fisheries Act 1995 (Vic) that authorise fishing for specific Indigenous cultural ceremonies or events (for example, different catch and size limits or equipment). There were no Indigenous permits granted in 2017 and hence no Indigenous catch recorded.

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Catch Chart

Commercial catch of Dusky Flathead - note confidential catch not shown

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References

  1. Broadhurst, MK, Gray, CA, Young, DJ, and Johnson, DD 2003, Relative efficiency and size selectivity of bottom-set gill-nets for dusky flathead, Platycephalus fuscus and other species in New South Wales, Australia, Fishery and Marine Research, 50: 289–302.
  2. Broadhurst, MK, Millar, RB, and Brand, CP 2009, Mitigating discard mortality from dusky flathead Platycephalus fuscus gillnets, Diseases of Aquatic Organisms, 85: 157–166.
  3. Butcher, PA, Broadhurst, MK and Cairns, SC 2008, Mortality and physical damage of angled and released dusky flathead Platycephalus fuscus, Diseases of Aquatic Organisms, 81: 127–134.
  4. Conron S., Giri K, Hamer P and Hall K 2016, Gippsland Lakes Fishery Assessment 2016. Fisheries Victoria Science Report Series No. 14
  5. Department of Agriculture and Fisheries 2018, Queensland Stock Status Assessment Workshop Proceedings 2018. Species Summaries. 19–20 June 2018, Brisbane.
  6. Department of Primary Industries 2018, NSW DPI Commercial catch records, New South Wales Department of Primary Industries, Sydney. 
  7. Gray, CA and Barnes, LM 2008, Reproduction and growth of dusky flathead in NSW estuaries, Fisheries final report series no. 101, NSW Department of Primary Industries, Cronulla.
  8. Gray, CA, Broadhurst, MK, Johnson, DD and Young, DJ 2005, Influences of hanging ratio, fishing height, twine diameter and material of bottom-set gillnets on catches of dusky flathead Platycephalus fuscus and non-target species in New South Wales, Australia, Fisheries Science, 71: 1217–1228.
  9. Henry, GW and Lyle JM, 2003, The National Recreational and Indigenous Fishing Survey. Tasmanian Aquaculture and Fisheries Institute, Hobart. FRDC 99/158
  10. Hicks T, Kopf RK, Humphries P 2015, Fecundity and egg quality of dusky flathead (Platycephalus fuscus) in East Gippsland, Victoria. Institute for Land Water and Society, Charles Sturt University. Report number 94. Prepared for the Recreational Fishing Grants Program, Fisheries Victoria. The State of Victoria Department of Economic Development, Jobs, Transport and Resources. Pp. 1–34. ISBN 978-1-86-467279-4.
  11. Ingram, BA, Hall, K, and Conron, S 2016, Recreational fishery assessment 2016 – small eastern estuaries. Recreational Fishing Grants Program Research Report, Victorian Government, Department of Economic Development, Jobs, Transport and Resources.
  12. Kailola, PJ, Williams, MJ, Stewart, PC, Reichelt, RE, McNee, A and Grieve, C 1993, Australian Fisheries Resources, Bureau of Rural Resources and the Fisheries Research and Development Corporation, Canberra, Australia.
  13. Kemp, J, Bruce, T, Conron, S, Bridge, N, MacDonald, M and Brown, L 2013, Gippsland Lakes (non‐bream) fishery assessment 2011, Fisheries Victoria assessment report series no. 67, Fisheries Victoria, Victoria.
  14. Moreton Bay Seafood Industry Association 2012, Moreton Bay tunnel net fishery code of best practice.
  15. Pollock, BR 2015, The annual spawning aggregation of Dusky Flathead Platycephalus fuscus at Jumpinpin, Queensland. Proceedings of the Royal Society of Queensland.
  16. Then, AY, Hoenig, NJ, Hall, NG, Hewitt, DA 2014, Evaluating the predictive performance of empirical estimators of natural mortality rate using information on over 200 fish species. ICES Journal of Marine Science.
  17. Uhlmann, SS and Broadhurst, MK 2015, Mitigating unaccounted fishing mortality in gillnets and traps. Fish and Fisheries, 16: 183−229.
  18. Webley, J, McInnes, K, Tiexiera, D, Lawson, A and Quinn R 2015, Statewide Recreational Fishing Survey 2013–14, Department of Agriculture and Fisheries, Queensland.
  19. West, LD, Stark, KE, Murphy, JJ, Lyle JM and Doyle, FA 2015, Survey of recreational fishing in New South Wales and the ACT, 2013/14. Fisheries Final Report Series.