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Red Emperor (2023)

Lutjanus sebae

  • Stephen Newman (Department of Primary Industries and Regional Development, Western Australia)
  • Michael Usher (Department of Industry, Tourism and Trade, Northern Territory)
  • Fabian Trinnie (Department of Primary Industries and Regional Development, Western Australia)
  • Corey Wakefield (Department of Primary Industries and Regional Development, Western Australia)
  • Amos Mapleston (Department of Agriculture and Fisheries, Queensland)

Date Published: June 2023

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Summary

Red Emperor occur throughout the Western Pacific and Indian Oceans [Allen 1985]. The species' Australian distribution encompasses the entire northern coastline, from Cape Naturaliste in WA, around to the east coast, occasionally extending as far south as Sydney. All stocks of Red Emperor in Australia are considered sustainable.

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Stock Status Overview

Stock status determination
Jurisdiction Stock Stock status Indicators
Northern Territory Gulf of Carpentaria Sustainable

Biomass, catch

Northern Territory Arafura Sea Sustainable

Biomass, catch

Northern Territory Joseph Bonaparte Gulf Sustainable

Biomass, catch

Northern Territory Timor Sea Sustainable

Biomass, catch, fishing mortality

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Stock Structure

Red Emperor is widely distributed throughout the Western Pacific and Indian Oceans, ranging from western and eastern Australia to southern Japan, and westward to east Africa and the southern Red Sea (Allen 1985). Within Australia, Red Emperor range from Cape Naturaliste (33°30’ S) in Western Australia, north and east across northern Australia and down the east coast to Sydney in New South Wales. Red Emperor in Western Australia is exploited primarily in the North Coast Bioregion [Newman et al. 2020]. Smaller catches are taken in the Northern Territory and Queensland. Red Emperor is one of the indicator species used to assess the status of the demersal resources in the North Coast Bioregion [Newman et al. 2018].

van Herwerden et al. [2009] examined the genetic connectivity of Red Emperor using mitochondrial DNA from samples collected at two locations in Western Australia (Browse Island, Kimberley region; Montebello Islands, Pilbara region) and two locations on the east coast (High Peak Island and Catfish Shoal, East Coast Queensland). The mitochondrial DNA data for Red Emperor did not differ genetically either within or between coasts at the locations examined, suggesting a panmictic population structure with high levels of gene flow among populations. This study indicates that eastern and western Australian populations of Red Emperor form a single inter-breeding genetic stock [van Herwerden et al. 2009] or one biological stock. The results of van Herwerden et al. [2009] confirm those derived by Johnson et al. [1993] using allozymes for Red Emperor in Western Australian waters. Johnson et al. [1993] examined allozyme samples of Red Emperor from the Lacepede Islands, Bedout island, Lowendal Islands, Ningaloo and Shark Bay. This study reported extensive connectivity and gene flow among populations throughout the sampled range of 1,400 km in Western Australia.

Stephenson et al. [2001] examined stable isotopes in sagittal otolith carbonates of Red Emperor from four locations; Shark Bay (Gascoyne), Ningaloo (Gascoyne), Pilbara and Broome (Kimberley). Significant differences in stable isotope ratios provided evidence that there was limited mixing of adult Red Emperor between three broad zones; Shark Bay (Gascoyne), Pilbara, and Broome (Kimberley), a distance of approximately 1,400 km [Stephenson et al. 2001]. Therefore, these broad locations could be managed separately for the purposes of fishery management, if management arrangements were established to harmonise with the spatial patterns of exploitation. Stephenson et al. [2001] reported partial mixing of Red Emperor from Pilbara west and east sites. The overlap in the multivariate analyses of otolith stable isotope signatures between some sites potentially reflects dispersal by a proportion of juvenile or adult fish. This suggests that, in Western Australia, Red Emperor can be managed as a number of separate management units. Additionally, Saunders et al. [2018] used otolith microchemistry and parasitology to identify separate biological Red Emperor stocks in the Joseph Bonaparte Gulf, Timor Sea, Arafura Sea and Gulf of Carpentaria.

Here, assessment of stock status is presented at the management unit level — Gascoyne, Pilbara and Kimberley (Western Australia) and East coast (Queensland); and at the biological stock level for the Joseph Bonaparte Gulf, Timor Sea, Arafura Sea and Gulf of Carpentaria.

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Stock Status

Arafura Sea

Red Emperor were initially harvested by the foreign trawl fleet operating in this region in the 1970s and 1980s with a peak catch of 69 tonnes (t) recorded in 1989. In 1991 this fleet left Northern Territory (NT) waters and only small catches were recorded by trap and line gear in the Demersal Fishery (DF). From 1995 a single trawl vessel in the fishery resulted in a slight increase in catch which was further increased when three additional trawlers commenced fishing in 2012. Catch in the last 10 years (2012–13 to 2021–22) has ranged from 19 to 46 t, at an annual average of 32 t.  

A fishery independent survey was undertaken in 2021 to estimate the relative biomass of key species in the Timor Reef Fishery (TRF) and DF, including Red Emperor. As a result of this work the biomass of Red Emperor in the NT was estimated to be 2,670 t, with a coefficient of variation of 0.17. Within this, the biomass of Red Emperor in the Arafura Sea stock was estimated to be 1,102 t [Knuckey and Koopman 2022]. The commercial harvest in this stock has averaged 32 t in the last 10 years, which is 2.9% of the estimated biomass. It is important to note that the survey was designed to obtain a time-series of consistent and robust relative abundance indices that and due to uncertainties around assumptions of catchability, herding and escapement, this one-off estimate of absolute abundance should be used with caution [Knuckey and Koopman 2022]. Regardless, this estimate of biomass can assist in understanding the impact fishing has on this stock, with the low level of catch indicating the stock is unlikely to be depleted and the resultant low level of fishing mortality is unlikely to result in the stock becoming recruitment impaired.

On the basis of the evidence provided above, Red Emperor in the Arafura Sea biological stock is classified as a sustainable stock.

Gulf of Carpentaria

Red Emperor in this stock has historically been taken by demersal fish trawl in the Gulf of Carpentaria Developmental Fin Fish Trawl Fishery (GOCDFFTF) and Northern Territory Demersal Fishery (DF). This stock was also exposed to historical fishing from foreign fleets during the 1950s to the 1980s [O’Neill et al. 2011]. 

There are limited estimates of recreational or Indigenous harvest of Red Emperor in the Gulf of Carpentaria, but it is expected to be minor given the offshore nature of the fishery. Recreational catch of Red Emperor in the Northern Territory was estimated to be < 0.5 t in 2018–19 [West et al. 2022]. There has been a small amount of charter catch in Queensland, with catches increasing and averaging 5t from 2006–07 to 2010–11. Catches declined and no charter catch has been reported since 2017–18. The Northern Territory charter catch in the Gulf of Carpentaria has average less than 100 fish per year for the last ten years.

Commercial catches peaked during the 1970s at approximately 30 t and are only slightly higher than the 2008 peak (23 t). The GOCDFFTF is responsible for the majority of the post-2000 Gulf of Carpentaria Red Emperor harvest. However, harvest rates in this fishery declined markedly over the post-2012 period and no Red Emperor was reported from the fishery from 2016–17 to 2019–20. Commercial fishing in the GOCDFFTF resumed from 2020-21 with the fishery registering annual harvests of < 4 t. These catch totals are well below the 21 t Red Emperor TACC set for the fishery. Northern Territory commercial catch of Red Emperor in the Gulf of Carpentaria has ranged from < 0.5 to 7.6 t, at an annual average of 2.9 t, for the last 10 years (2012–13 to 2021–22).

Red Emperor harvests in the GOCDFFTF is managed under a combined 450 t Total Allowable Commercial Catch (TACC). This limit was introduced in 2015 and represented a considerable reduction from the previous combined 1,250 t TACC [O’Neil et al. 2011; Leigh and O’Niell 2016]. For reference and context, fishery independent surveys provided a relative biomass estimate for Red Emperor in the GOCDFFTF [Knuckey et al. 2022]. 

A fishery independent survey was undertaken in 2021 to estimate the relative biomass of key species in the TRF and DF, including Red Emperor. As a result of this work the biomass of Red Emperor in the NT was estimated to be 2,670 t, with a coefficient of variation of 0.17. Within this, the biomass of Red Emperor in the Northern Territory portion of the Gulf of Carpentaria stock was estimated to be 1,127 t [Knuckey and Koopman 2022]. NT commercial harvest in this stock has averaged < 3 t in the last 10 years, which is less than 0.3% of the estimated relative biomass. It is important to note that the survey was designed to obtain a time-series of consistent and robust relative abundance indices that and due to uncertainties around assumptions of catchability, herding and escapement, this one-off estimate of absolute abundance should be used with caution [Knuckey and Koopman 2022]. Regardless, the low level of catch indicates the stock is unlikely to be depleted and the level of fishing mortality is unlikely to result in the stock becoming recruitment impaired.

On the basis of the evidence provided above, Red Emperor in the Gulf of Carpentaria biological stock is classified as a sustainable stock.

Joseph Bonaparte Gulf

Harvest from this stock was first reported in 1985, and the average catch from trap and line vessels in the Demersal Fishery (DF) to 2011 was very small (average < 1 t) compared to the adjacent Timor Sea stock. From 2012 a trawler entered the fishery and catches increased to a peak of 16 t in 2018–19. Commercial catch in 2021–22 was 4.3 t and recreational catch in this stock is limited, estimated at 1,452 fish (± 974) in 2017 [Errity et al. 2022]. A fishery independent survey was undertaken in 2021 to estimate the relative biomass of key species in the TRF and DF, including Red Emperor. As a result of this work the biomass of Red Emperor in the NT was estimated to be 2,670 t, with a coefficient of variation of 0.17. Within this, the biomass of Red Emperor in the Joseph Bonaparte Gulf stock was estimated to be 208 t [Knuckey and Koopman 2022]. The commercial harvest in this stock has averaged 9.9 t in the last 10 years (2012–13 to 2021–22), which is 4.8% of the estimated biomass. It is important to note that the survey was designed to obtain a time-series of consistent and robust relative abundance indices that and due to uncertainties around assumptions of catchability, herding and escapement, this one-off estimate of absolute abundance should be used with caution [Knuckey and Koopman 2022]. Regardless, the low level of catch indicates the stock is unlikely to be depleted and the level of fishing mortality is unlikely to result in the stock becoming recruitment impaired.

Based on the evidence above, the Joseph Bonaparte biological stock is classified as a sustainable stock.

Timor Sea

Red Emperor harvest in this stock began in 1988, and quickly peaked at just over 100 t in 1991 as the TRF quickly developed. Targeting shifted to the more abundant Goldband Snapper, and only small annual catches (average < 10t) were reported from 1994 to 1999. Thereafter, the trap effort in the TRF and DF increased substantially and catches of Red Emperor have ranged between 19 and 46 t in the last 10 years (2012–13 to 2021–22).

A fishery independent survey was undertaken in 2021 to estimate relative biomass of key species in the TRF and DF including Red Emperor. As a result of this work, the biomass of Red Emperor in the NT was estimated to be 2,670 t, with a coefficient of variation of 0.17. Within this, the biomass of Red Emperor in the Timor Sea stock was estimated to be 247 t [Knuckey and Koopman 2022]. The commercial harvest in this stock has averaged 33 t in the last 10 years, which is 13% of the estimated relative biomass. It is important to note that the survey was designed to obtain a time-series of consistent and robust relative abundance indices that and due to uncertainties around assumptions of catchability, herding and escapement, this one-off estimate of absolute abundance should be used with caution [Knuckey and Koopman 2022].  

The stock was assessed in 2019 using catch data from all commercial fisheries applied to a modified catch-MSY model (developed by Martell and Froese [2013] and modified by Haddon et al. [2018]). The results inferred that biomass was in excess of the target reference point, with the mean estimated biomass exceeding the target and 95% confidence intervals positioned above the limit reference point [Saunders 2020]. This indicates that the biomass of this stock is unlikely to be depleted and that recruitment is unlikely to be impaired. Similarly, the fishing mortality rate in 2019 was 0.07, which was well below the limit reference point 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, Red Emperor in the Timor Sea biological stock is classified as a sustainable stock.

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Biology

Red Emperor biology [McPherson et al. 1992; McPherson and Squire 1992; Newman et al. 2000, 2001; Newman and Dunk 2002; Newman et al. 2010; O'Neill et al. 2011; Sumpter et al. 2022]

Biology
Species Longevity / Maximum Size Maturity (50 per cent)
Red Emperor

WA: 40–45 years, 800 mm FL (860 mm TL). East coast Queensland: 43 years, at least 100 mm TL

WA: 4–6 years, 430–460 mm FL (460–490 mm TL). East Coast Queensland: 5 years, 542 mm FL for females

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Distributions

Distribution of reported commercial catch of Red Emperor.

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Tables

Fishing methods
Northern Territory
Commercial
Unspecified
Fish Trap
Bottom Trawls
Handline
Charter
Hook and Line
Indigenous
Hook and Line
Recreational
Hook and Line
Management methods
Method Northern Territory
Charter
Gear restrictions
Limited entry
Possession limit
Spatial closures
Vessel limits
Commercial
Gear restrictions
Spatial closures
Total allowable catch
Indigenous
No limits on customary catch
Recreational
Gear restrictions
Possession limit
Spatial closures
Catch
Northern Territory
Commercial 80.18t
Charter 0.6 t
Indigenous Unknown
Recreational 4,555 fish ± 974 se (2018–19)

Western Australia. Active Vessels data are confidential as there were fewer than three vessels in the Pilbara Fish Trawl Interim Managed Fishery, the Pilbara Trap Managed Fishery and the West Coast Demersal Gillnet and Demersal Longline (Interim) Managed Fishery.

Western Australia – Commercial (Management Methods). Red Emperor forms part of the combined Total Allowable Commercial Catch for other mixed demersal species in the Gascoyne Demersal Scalefish Managed Fishery.

Western Australia – Recreational (Catch). Boat-based recreational catch is from 1 September 2020–31 August 2021. These data are derived from those reported in Ryan et al. 2022.

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 (Management Methods). Subject to application of 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.

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 (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.”

Queensland – Commercial (Catch). Queensland commercial and charter data have been sourced from the commercial fisheries logbook program.  Further information is 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 based at the whole of Queensland level and derived from statewide recreational fishing surveys. Estimates have been converted to weight (tonnes) using best known conversion multipliers. Conversion factors may display regional or temporal variability. 

Queensland – Indigenous (Management Methods). For more information see: https://www.daf.qld.gov.au/business-priorities/fisheries/traditional-fishing.

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

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Catch Chart

Commercial catch of Red Emperor - note confidential catch not shown

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References

  1. Campbell, AB, Fox, AR, Hillcoat, KB and Sumpter, L 2021, Stock assessment of Queensland east coast saddletail snapper (Lutjanus malabaricus), Australia, Tech. Rep. Brisbane, Australia: Department of Agricultures and Fisheries
  2. DPIRD 2017, North Coast demersal scalefish resource harvest strategy 2017–2021. Version 1.0. Fisheries Management Paper No. 285. Department of Primary Industries and Regional Development, Government of Western Australia, Perth, Australia. 35p.
  3. Errity, C, Penny, SS and Steffe, A 2022, A Survey of Recreational Fishing in the Greater Darwin area 2017, Northern Territory Government, Australia. Fishery Report No 125
  4. Fox, AR, Campbell, AB, Sumpter, LI and Hillcoat, KB 2021, Stock assessment of Queensland east coast crimson snapper (Lutjanus erythropterus), Australia. Tech. Rep. Brisbane, Department of Agriculture and Fisheries.
  5. Gaughan, DJ and Santoro, K (eds.) 2020, Status Reports of the Fisheries and Aquatic Resources of Western Australia 2018/19: The State of the Fisheries. Department of Primary Industries and Regional Development, Western Australia, Perth, Australia. 291p.
  6. 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.
  7. Johnson, MS, Hebbert, DR and Moran, MJ 1993, Genetic analysis of populations of north-western Australian fish species. Australian Journal of Marine and Freshwater Research, 44: 673–685.
  8. Knuckey, I, Koopman, M and Hudson, R 2022, Survey of tropical snapper in Queensland Gulf of Carpentaria Developmental Fin Fish Trawl Fishery
  9. Leigh, GM and O'Neill, MF 2016, Gulf of Carpentaria Finfish Trawl Fishery: Maximum Sustainable Yield, Agi–Science Queensland, Department of Agriculture and Fisheries, Queensland.
  10. Martell, S and Froese, R 2013, A simple method for estimating MSY from catch and resilience. Fish and Fisheries 14:504–514.
  11. McPherson, GR and Squire, L 1992, Age and growth of three dominant Lutjanus species of the Great Barrier Reef Inter-Reef Fishery, Asian Fisheries Science, 5, 25–36.
  12. McPherson, GR, Squire, L and O'Brien, J 1992, Reproduction of three dominant Lutjanus species of the Great Barrier Reef Inter-Reef Fishery, Asian Fisheries Science, 5, 15–24.
  13. Newman, SJ and Dunk, IJ 2002, Growth, age validation, mortality, and other population characteristics of the red emperor snapper, Lutjanus sebae (Cuvier, 1828), off the Kimberley coast of North–Western Australia, Estuarine, Coastal and Shelf Science,55 (1): 67–80.
  14. 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.
  15. Newman, SJ, Cappo, M and Williams, DMcB 2000, Age, growth, mortality rates and corresponding yield estimates using otoliths of the tropical red snappers, Lutjanus erythropterus, L. malabaricus and L. sebae, from the central Great Barrier Reef. Fisheries Research 48 (1): 1–,14.
  16. Newman, SJ, Moran, MJ and Lenanton, RCJ 2001, Stock assessment of the outer–shelf species in the Kimberley region of tropical Western Australia, final report to the Fisheries Research and Development Corporation, project 97/136.
  17. Newman, SJ, Skepper, CL and Wakefield, CB 2010, Age estimation and otolith characteristics of an unusually old, red emperor snapper (Lutjanus sebae) captured off the Kimberley coast of north–western Australia, Journal of Applied Ichthyology, 26 (1): 120–122.
  18. O’Neill, MF, Leigh, GM, Martin, JM, Newman, SJ, Chambers, M, Dichmont, CM and Buckworth, RC 2011, Sustaining productivity of tropical red snappers using new monitoring and reference points, Final Report to the Fisheries Research and Development Corporation, Project 2009/037. 104p.
  19. Queensland Department of Agriculture and Fisheries, 2020, Reef line fishery harvest strategy: 2020–2025, Brisbane, Queensland.
  20. Ramm, DC 1994, Assessment of the status, composition and market potential of the demersal trawl fish resources in northern Australian waters, Final report the Fisheries Research and Development Corporation on project number 90/15.
  21. Ryan, KL, Lai, EKM and Smallwood, CB 2022, Boat-based recreational fishing in Western Australia 2020/21, Fisheries Research Report No. 327 Department of Primary Industries and Regional Development, Western Australia. 221pp.
  22. Sainsbury, KJ, Campbell, R, Brewer, DT, Harris, AN, McLoughlin, K, Ramm, DC, Staples, DJ, Xiao, Y and Knuckey, I 1991, Northern Fisheries Research Committee Trawl Fisheries Assessment Working Group.
  23. Saunders, T 2020, Arafura Sea Red Emperor Stock Status Summary - 2020. Unpublished Fishery Report.
  24. Stephenson, PC, Edmonds, JS, Moran, MJ and Caputi, N 2001, Analysis of stable isotopes to investigate stock structure of red emperor and Rankin cod in northern Western Australia, Journal of Fish Biology, 58: 126–144.
  25. Sumpter, LI, Fox, AR and Hillcoat, KB 2022, Stock assessment of Queensland east coast red emperor (Lutjanus sebae), Australia, with data to June 2021, Australia. Tech. Rep. Brisbane, Department of Agriculture and Fisheries.
  26. Teixeira, D, Janes, R and Webley, J 2021, 2019–20 Statewide Recreational Fishing Survey Key Results, Project Report. State of Queensland, Brisbane.
  27. van Herwerden, L, Aspden, WJ, Newman, SJ, Pegg, GG, Briskey, L and Sinclair, W 2009, A comparison of the population genetics of Lethrinus miniatus and Lutjanus sebae from the east and west coasts of Australia: evidence for panmixia and isolation, Fisheries Research, 100 (2): 148–155.
  28. Wakefield, C, Trinnie, F, Skepper, C, Boddington, Newman, SJ and Steele, A 2023, North Coast Demersal Resource Status Report 2022. pp. 167-176. In: Gaughan, D.J. and Santoro, K. (eds.). 2023. Status Reports of the Fisheries and Aquatic Resources of Western Australia 2021/22: The State of the Fisheries. Department of Primary Industries and Regional Development, Western Australia, Perth, Australia.
  29. 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.

Downloadable reports

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