*

Blue-eye Trevalla is a sustainable species around the Australian coastline. It is mainly targeted by commercial fishers, but catch is highly variable.

Three lines of evidence, based on phenotypic variation in age and growth, otolith chemistry and potential larval dispersal, suggest spatial patterns that may delineate natural subpopulations of Blue-eye Trevalla [Williams et al. 2017]. This research identified four geographically distinct subpopulations around the Australian coast: ‘West’—comprising continental slope fishing grounds off Western Australia, South Australia and western Victoria to western Tasmania; ‘South’—continental slope grounds around Tasmania and north eastwards to eastern Bass Strait; ‘East’—fishing grounds on the NSW continental slope and Tasmanian seamounts; and ‘Offshore’—fishing grounds on the Lord Howe Rise [Williams et al. 2017]. 

Here, stock status is presented at the management unit level—Eastern Australia and Western Australia. 

Western Australia

Stock assessment for Blue-eye Trevalla in Western Australia is based on an assessment of fishing mortality derived from a catch-curve analysis of representative samples of the age structure in the state-managed demersal fisheries (West Coast Demersal Scalefish Interim Managed Fishery, Joint Authority Southern Demersal Gillnet and Demersal Longline Managed Fishery and Wet Line Fishery (South Coast, Western Australia)). These assessments use reference levels (target, threshold and limit) based on ratios of natural mortality for each species [DPIRD 2017]. The assessments indicated that the estimated fishing mortality rate on Blue-eye Trevalla in this biological stock was stable at close to the threshold level in 2011 and 2014 [Wakefield unpub.]. This assessment of Blue-eye Trevalla is also supported by the results of a data-limited Catch-MSY assessment, where recent catches are compared to median model estimates for maximum sustainable yield (MSY). 

The total catch of Blue-eye Trevalla in WA has been variable over the last 10 years (2013–2022) ranging from 1.8–13.5 t, with a mean annual catch of 7.8 t. This is slightly lower than the average catches across the previous 10 years of 10.3 t. Recreational and charter catch are relatively low compared to the commercial catch and have averaged 25% of the total catch over the last ten years. Analyses using a Catch-MSY model applied to data on annual catches for this species demonstrated that the annual catches since 2008 have remained below or within the 95% CI of the median model estimate for MSY. The predicted values for biomass since 2012 have remained above B_MSY, and fishing mortality has remained below F_MSY. However, it is important to recognise that Catch-MSY is a data-limited technique with strong assumptions, dependent on user inputs. For this assessment, these included specified ranges for initial depletion (0.4–0.8), based on the relative high catch at the beginning of the time series, final depletion (0.15–0.7), based on recent catches relative to maximum recorded annual catch and as catches are limited to localised areas in WA and the species is not exploited continually across the entire distribution, and low resilience (r=0.1–0.6, consistent with species longevity, of approximately 65 years). The above evidence indicates that current fishing pressure is not having an unacceptable impact on the age structure of the population and that the biomass of this stock is unlikely to be depleted and that recruitment is unlikely to be impaired. Furthermore, current fishing mortality is unlikely to result in the stock becoming recruitment impaired.

On the basis of the evidence provided above, the Western Australia management unit is classified as a sustainable stock.

Blue-eye Trevalla biology [Baelde 1995; Stobutzki et al. 2009]

Distribution of reported commercial catch of Blue-eye Trevalla

Commonwealth – Commercial (Management Methods/Catch). Data provided for the Commonwealth align with the Commonwealth Southern and Eastern Scalefish and Shark Fishery for the 2021–22 financial year.

Commonwealth – Recreational. The Australian government does not manage recreational fishing in Commonwealth waters. Recreational fishing in Commonwealth waters is managed by the state or territory immediately adjacent to those waters, under its management regulations.

Commonwealth – Indigenous. The Australian government does not manage non-commercial Indigenous fishing in Commonwealth waters, with the exception of Torres Strait. In general, non-commercial Indigenous fishing in Commonwealth waters is managed by the state or territory immediately adjacent to those waters.

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 License 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.

New South Wales – Commercial. Dropline cannot be automated in New South Wales.

New South Wales – Recreational (Catch). Murphy et al. [2022].

New South Wales – Indigenous (Management Methods). https://www.dpi.nsw.gov.au/fishing/aboriginal-fishing. 

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

Queensland – Recreational Fishing. Data with high uncertainty (Residual Error > 50 %) have been excluded and listed as unknown. More information available at: https://www.daf.qld.gov.au/business-priorities/fisheries/monitoring-research/monitoring-reporting/statewide-recreational-fishing-surveys

Queensland – Commercial. Queensland Commercial and charter data have been sourced from the commercial fisheries logbook program. Further information available through the Queensland Fisheries Summary Report https://www.daf.qld.gov.au/business-priorities/fisheries/monitoring-research/data/queensland-fisheries-summary-report

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

Tasmania – Recreational (Management Methods). In Tasmania, a recreational licence is required for fishers using dropline or longline gear, along with nets, such as gillnet or beach seine. 

Tasmania – Charter (Management Methods). In New South Wales there are four charter boat endorsement categories (Estuarine Fishing; Nearshore Bottom Fishing and Sportfishing; Gamefishing; and Deep Sea Bottom Fishing). The different categories have limitations on the species of fish they can access. 

Tasmania - Indigenous (Management Methods). In Tasmania, Indigenous persons engaged in traditional fishing activities in marine waters are exempt from holding recreational fishing licences but must comply with all other fisheries rules as if they were licensed. For details, see the policy document 'Recognition of Aboriginal Fishing Activities” (https://fishing.tas.gov.au/Documents/Policy%20for%20Aboriginal%20tags%20and%20alloting%20an%20UIC.pdf).

Commercial catch of Blue-eye Trevalla - note confidential catch not shown

1. AFMA 2018a, Species summaries for the Southern and Eastern Scalefish and Shark Fishery: for stock assessments completed in 2018 in preparation for the 2019–20 fishing seasons, Australian Fisheries Management Authority, Canberra.
2. AFMA 2018b, Total allowable catch recommendations for Southern and Eastern Scalefish and Shark Fishery 2019–20 fishing year, Australian Fisheries Management Authority, Canberra.
3. AFMA 2021a, Harvest strategy framework for the Southern and Eastern Scalefish and Shark Fishery: amended (2021), Australian Fisheries Management Authority, Canberra.
4. AFMA 2021b, Southern and Eastern Scalefish and Shark Fishery South East Resource Assessment Group (SERAG) meeting 1, minutes, 28–29 September 2021, Australian Fisheries Management Authority, Canberra.
5. AFMA 2021c, Southern and Eastern Scalefish and Shark Fishery South East Resource Assessment Group (SERAG) meeting 3, minutes, 29 November—1 December 2021, Australian Fisheries Management Authority, Canberra.
6. Althaus, F, Thomson, R and Sutton, C 2021, Southern and Eastern Scalefish and Shark Fishery catches and discards for TAC purposes using data until 2020, CSIRO Oceans and Atmosphere, Hobart.
7. Baelde, P 1995, Blue-eye trevalla 1994, compiled by Pascale Baelde for the South East Fishery Assessment Group, Australian Fisheries Management Authority, Canberra.
8. 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, 35 pp.
9. Emery, T, Wright, D, Davis, K, Keller, K, Woodhams, J and Curtotti, R 2022, Commonwealth Trawl and Scalefish Hook sectors, in Patterson, H, Bromhead, D, Galeano, D, Larcombe, J, Timmiss, T, Woodhams, J and Curtotti, R (eds), Fishery status reports 2022, Australian Bureau of Agricultural and Resource Economics and Sciences, Canberra.
10. Haddon, M and Sporcic, M 2018a, Draft Tier 5 Blue-Eye Trevalla Eastern Seamount Assessment: Catch-MSY Analysis, CSIRO Oceans and Atmosphere, Hobart.
11. Haddon, M and Sporcic, M 2018b, Draft Tier 5 Blue-Eye Trevalla Eastern Seamount Assessment: Age-Structured Stock Reduction Analysis, CSIRO Oceans and Atmosphere, Hobart.
12. Henry, GW and Lyle, JM 2003, The national recreational and Indigenous fishing survey, Fisheries Research and Development Corporation, Canberra.
13. Hughes, JM, Murphy, JJ, Ochwada-Doyle, FA and Taylor, MD 2023, NSW Charter Fishery Monitoring 2019/20, NSW DPI— Fisheries Final Report Series No. 162.
14. Kailola, PJ, Williams, MJ, Stewart, PC, Reichelt, RE, McNee, A and Grieve, C 1993, Australian fisheries resources, Bureau of resource sciences, department of primary industries and energy, Fisheries Research and Development Corporation, Canberra, Australia.
15. Murphy, JJ, Ochwada-Doyle, FA, West, LD, Stark, KE and Hughes, JM, Taylor, MD 2022, Survey of recreational fishing in NSW, 2019/20, NSW DPI—Fisheries Final Report Series No. 161.
16. 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, 221 pp.
17. Smoothey, AF 2023, NSW Stock Status Summary 2022/23—Blue-eye Trevalla (Hyperoglyphe antarctica), NSW, Department of Primary Industries, Fisheries, 15 pp.
18. Sporcic, M 2020, Draft tier 4 assessments for selected SESSF species (data to 2019), CSIRO Oceans and Atmosphere, Hobart.
19. Sporcic, M 2021, Tier 4 assessment for blue-eye trevalla (Hyperoglyphe antarctica) slope (data to 2020), CSIRO Oceans and Atmosphere, Hobart.
20. Stobutzki, I, Patterson, H, Ward, P, Sampaklis, A, Sahlqvist, P, Moore, A and Viera, S 2009, Commonwealth Trawl and Scalefish Hook Sectors, in Wilson, D, Curtotti, R and Begg, G (eds), Fishery status reports 2009: status of fish stocks and fisheries managed by the Australian Government, Australian Bureau of Agricultural and Resource Economics—Bureau of Rural Sciences, Canberra.
21. Teixeira, D, Janes, R and Webley, J 2021, 2019–20 Statewide Recreational Fishing Survey Key Results. Project Report. State of Queensland, Brisbane.
22. Thomson, M and Haddon, M 2021, Tier 5 analyses for seamount blue-eye trevalla in 2021, CSIRO Oceans and Atmosphere, Hobart.
23. 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.
24. West, LD, Stark, KE, Murphy, JJ, Lyle, JM and Ochwada-Doyle, FA 2015, Survey of recreational fishing in New South Wales and the ACT, 2013/14. Fisheries Final Report Series No. 149, NSW Department of Primary Industries, Wollongong.
25. Williams, A, Hamer, P, Haddon, M, Robertson, S, Althaus, F, Green, M and Kool, J 2017, Determining Blue-eye Trevalla stock structure and improving methods for stock assessment, FRDC final report, FRDC project no. 2013/015.