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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. Red Emperor is assessed as sustainable in the Gascoyne, Pilbara, and Kimberley management units. The Timor Sea, Arafura Sea, and Gulf of Carpentaria biological stocks are also sustainable, while the Joseph Bonaparte Gulf biological stock and East Coast Queensland management unit are classified as undefined.

Red Emperor are 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 is exploited primarily in the North Coast Bioregion of Western Australia [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.

East Coast Queensland

There has been no stock assessment to determine biomass, and there is no estimate of MSY, for the East Coast Queensland management unit. Recreational catches of Red Emperor were around 73 per cent (95 t) of the total landings for the species based on the 2019–20 recreational catch numbers [Teixeira et al. 2021] and commercial landings in 2018–19. Recreational harvest estimates decreased from 2000–01 (235 t) to 2013–14 (85 t), however the estimate increased slightly in 2019–20 (95 t). It is not known if the overall decline in recreational catch and harvest is related to lower biomass or decreased effort (or both).  

In 2004–05 the reported commercial harvest declined from between 100–200 t per year to less than 61 t per year. The decrease coincided with expansion of no-take marine reserves within the Great Barrier Reef Marine Park and the introduction of a quota management system for coral reef finfish species. Both management interventions likely reduced commercial targeting of Red Emperor. Over the last decade, annual commercial catches have generally declined from 61 t (2009–10) to 35 t (2018–19). Red Emperor is a secondary target and by-product species in the Reef Line Fishery (RLF). While commercial harvest is constrained by a multi-species total allowable commercial catch (TACC) and a minimum legal size, species-specific harvest control rules and catch reference points introduced in early 2020 for secondary target species including Red Emperor through the RLF Harvest Strategy [QDAF 2020] provide additional control of fishing pressure. Harvest of Red Emperor that exceeds the catch reference points and control rules will trigger a stock assessment and the implementation of an interim species specific TACC. Recreational harvest is also controlled through the minimum legal size and a possession limit. The Indigenous catch is unknown but is expected to be minor. A portion of the biomass is afforded some protection from fishing by zoning in the Great Barrier Reef Marine Park although this has not been quantified. There is insufficient information available on the current biomass to confidently classify the status of this stock.

On the basis of the evidence provided above, the East Coast Queensland management unit is classified as an undefined stock.

Gulf of Carpentaria

Red Emperor in this stock has historically been taken by demersal fish trawl (Gulf of Carpentaria Developmental Fin Fish Trawl Fishery (GOCDFFTF) and Northern Territory Demersal Fishery (DF)).There is no reliable estimate 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. This stock was also exposed to historical fishing from foreign fleets during the 1950s to the 1980s [O’Neill et al. 2011]. These catches peaked during the 1970s at approximately 30 t and were only slightly higher than the recent peak catch of 23 t in 2008. Commercial catches were initially dominated by the GOCDFFTF however these have declined markedly since 2012 as a result of transfer of effort to Northern Territory stocks outside the Gulf of Carpentaria. In 2019, the commercial catch increased to 9 t due to the DF substantially increasing its fishing effort in this stock area targeting Saddletail and Crimson Snappers (Lutjanus malabaricus and Lutjanus erythropterus).

A preliminary assessment 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]), estimated that the 2019 biomass of Red Emperor was 59 per cent of unfished levels [Saunders and Roelofs 2020] suggesting that the biomass of this stock is unlikely to be depleted and that recruitment is unlikely to be impaired. Similarly, the fishing mortality 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 Gulf of Carpentaria biological stock is classified as a sustainable stock.

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, DAF unpublished data 2018]

Distribution of reported commercial catch of Red Emperor.

Western Australia Active Vessels data is 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 2017–31 August 2018. These data are derived from those reported in Ryan et al. 2019.

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 “…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”.

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

Commercial catch of Red Emperor - note confidential catch not shown

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