Redthroat Emperor (2023)
Lethrinus miniatus
Date Published: June 2023
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Summary
Redthroat Emperor is fished in WA and the east coast of QLD. The stock in both states is classified as sustainable.
Stock Status Overview
Jurisdiction | Stock | Stock status | Indicators |
---|---|---|---|
Queensland | East Coast Queensland | Sustainable | Catch, effort, standardised catch rate, stock assessment (integrated age and length structured model) |
Stock Structure
While records of occurrence are known from the Torres Strait, Gulf of Carpentaria and the Northern Territory [Atlas of living Australia], the distribution of Redthroat Emperor in Australia appears to be discontinuous [Van Herwerden et al. 2009], ranging from south of Perth to the Montebello Islands on the west coast, and between approximately 17.5º S (Innisfail) to at least 31°S (Lord Howe Island) on the Australian east coast. Genetic analysis using mitochondrial genome hypervariable region 1, indicates that the biological stocks from Western Australia are different compared to eastern Australian populations [Van Herwerden et al. 2009]. Here, assessment of stock status is presented at the biological stock level—Western Australia and East Coast Queensland.
Stock Status
East Coast Queensland
The stock assessment of East Coast Queensland Redthroat Emperor was updated in 2020. This assessment was based on data till 2019 and estimated the spawning biomass to be 72% of unfished levels [Northrop and Campbell 2020]. The maximum sustainable yield (MSY) was estimated to be 897 t per year. After significant management changes in 2004 including increased minimum landing size, revised marine park zoning, introduction of a commercial catch quota and reduced recreational in-possession limits, the annual commercial catch has seen a stable reduction. From 2017–18 to 2021–22, the Queensland commercial harvest averaged 137 t per year with 114 t landed in 2021–22. The most recent recreational fishing survey in 2019–20 estimated the charter sector landed 62.8 t while the remainder of the recreational sector harvested an estimated 50.3 t [DAF 2022; Teixeira et al. 2021] which is a reduction from previously reported for these sectors. This reduction is likely attributed to COVID-19 restrictions, particularly on the operations of the charter fishing sector. The combined total Queensland harvest across all sectors for 2019–20 is an estimated 253 t, well below the estimated MSY. The above evidence indicates that the biomass of the stock is unlikely to be depleted and that recruitment is unlikely to be impaired.
Management reforms from 2004 appear to have reduced fishing mortality to above target levels [Northrop and Campbell 2020]. Given the Queensland long term target of 60% unfished biomass is lower than the current estimated spawning biomass, the stock should be able to sustain higher fishing mortality than presently occurs and remain above the long-term target biomass. In addition, zoning in the Great Barrier Reef Marine Park provides additional protection to the biomass of this stock. The evidence indicates 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, the East Coast Queensland biological stock is classified as a sustainable stock.
Biology
Redthroat Emperor biology [Williams 2003; Williams et al. 2003; Van Herwerden et al. 2009]
Species | Longevity / Maximum Size | Maturity (50 per cent) |
---|---|---|
Redthroat Emperor | 20 years, 650 mm TL |
Protogynous-variant sequential hermaphrodite with large overlap in size and ages Females mature: 1.2 years, 310 mm TL (east coast) |
Tables
Queensland | |
---|---|
Commercial | |
Line | |
Charter | |
Spearfishing | |
Hook and Line | |
Indigenous | |
Spearfishing | |
Hook and Line | |
Recreational | |
Spearfishing | |
Hook and Line |
Method | Queensland |
---|---|
Charter | |
Bag/possession limits | |
Gear restrictions | |
Marine park closures | |
Processing restrictions | |
Seasonal or spatial closures | |
Size limits | |
Commercial | |
Gear restrictions | |
Harvest Strategy | |
Individual transferable quota | |
Limited entry | |
Marine park closures | |
Processing restrictions | |
Seasonal or spatial closures | |
Size limits | |
Total allowable catch | |
Vessel restrictions | |
Recreational | |
Bag/possession limits | |
Gear restrictions | |
Marine park closures | |
Processing restrictions | |
Seasonal or spatial closures | |
Size limits |
Queensland | |
---|---|
Commercial | 113.94t |
Charter | 63 t (2019–20) |
Indigenous | Unknown |
Recreational | 50 t (2019–20) |
Western Australia – Commercial/Charter. Catches reported by calendar year.
Western Australia – Recreational. Boat-based catch from 1 September 2020 to 31 August 2021.
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.
Queensland – Indigenous (Management Methods). For more information see: https://www.daf.qld.gov.au/business-priorities/fisheries/traditional-fishing
References
- Crisafulli BM, Hesp SA, Denham A, Fairclough DV, Fisher EA, Wakefield CB, Newman SJ and Lewis, P (in review), Exploring the reliability of data-limited, length-based assessments using recreational charter fishing information, Fisheries Research Report No. 331, DPIRD WA.
- DPIRD 2021, West Coast Demersal Scalefish Resource Harvest Strategy 2021-2025, Fisheries Management Paper No. 305, Department of Primary Industries and Regional Development, Western Australia.
- Fairclough, DV, Hall, NG and Potter, IC 2023, Length and age compositions, hermaphroditic traits and reproductive characteristics vary among five congeneric species of labrid in a large embayment, Estuarine, Coastal and Shelf Science, 291: 108429.
- Fairclough, DV, Molony, BW, Crisafulli, BM, Keay, IS, Hesp, SA and Marriott, RJ 2014, Status of demersal finfish stocks on the west coast of Australia, Fisheries Research Report No. 253, Department of Fisheries, Western Australia.
- Fisher, E 2013, Tools for assessing data-limited fisheries and communicating stock status information, PhD thesis, Murdoch University, Perth.
- 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.
- Northrop, A and Campbell, A B 2020, Stock assessment of the Queensland east coast redthroat emperor (Lethrinus miniatus), Technical Report, State of Queensland, Brisbane.
- 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.
- Statewide recreational fishing surveys. Recreational fishing catch estimates dashboard. Accessed September 2023.
- Teixeira, D, Janes, R, and Webley, J 2021, 2019–20 Statewide Recreational Fishing Survey Key Results. Project Report. State of Queensland, Brisbane.
- 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: 148–155.
- Williams, AJ 2003, Spatial patterns in population biology of a large coral reef fish: what role can movement play? James Cook University, Townsville.
- Williams, AJ, Davies, CR, Mapstone, BD and Russ, GR 2003, Scales of spatial variation in demography of a large coral-reef fish: an exception to the typical model? Fishery Bulletin, 101: 673–683.