*

King George Whiting is a sustainable species found in WA, VIC and SA waters. It is the premium species in SA and attracts the highest price per unit weight for commercial fishers.

Research on King George Whiting stock structure in southern Australia using genetic and otolith chemistry approaches indicates that separate stocks occur in each state jurisdiction (Western Australia, Victoria and South Australia), but with some genetic mixing between Victorian and South Australian populations [Jenkins et al. 2015]. King George Whiting sampled from northern Tasmania appear genetically different from those in the mainland states, although further sampling is required to confirm whether there are separate genetic stocks in Tasmania [Jenkins et al. 2015].

The South Australian population of King George Whiting is thought to be comprised of three biological stocks—Gulf St. Vincent, Spencer Gulf and the West Coast - Eyre Peninsula. This delineation has been determined based on understanding of the life history, including movement patterns of adult fish, knowledge of the location of spawning grounds and nursery areas [Fowler et al. 2000a, Fowler et al. 2002], and understanding of larval advection pathways and distances based on early life history and hydrodynamic modelling [Fowler et al. 2000b]. Recently, this stock structure has been called into question based on results from a detailed study of the early life history that included consideration of the larval movement processes. This involved studies that considered the microstructure and chemistry of otoliths from larvae and post-settlement juveniles [Rogers et al. 2019a, Rogers et al. 2019b], as well as biophysical oceanographic modelling [Rogers et al. 2020]. The complex findings from this study indicated that there was potential for movement of larvae between the putative stocks.  Nevertheless, given the lack of empirical evidence about the extent of such movement, it is considered preferable here to retain the original model of stock structure until further information becomes available. The Gulf St. Vincent biological stock occurs throughout Gulf St. Vincent, Investigator Strait and around Kangaroo Island. The Spencer Gulf biological stock occurs throughout the waters of Spencer Gulf and adjacent coastal waters from western Kangaroo Island to the Eyre Peninsula. The West Coast - Eyre Peninsula biological stock extends throughout all the bays and offshore areas of the west coast of Eyre Peninsula.

Further subdivision in biological stock structure is uncertain for Western Australian and Victorian populations. In Western Australia, King George Whiting occurs in the West Coast Bioregion (WCB) and South Coast Bioregion (SCB). Juveniles occur in inshore waters of both bioregions, but adults appear to be restricted to offshore waters of the WCB [Hyndes et al. 1998, Sulin 2012, Brown et al. 2013]. On this basis there is assumed to be a single biological stock in Western Australia, with the spawning component of the stock residing in the WCB. Similarly, there is assumed to be a single biological stock in Victorian waters, with juveniles occurring mostly in bays and estuaries and adults in coastal waters [Jenkins et al. 2015].

Here, assessment of stock status is presented at the jurisdictional level—Western Australia and Victoria; and at the biological stock level—Spencer Gulf, Gulf St. Vincent and West Coast - Eyre Peninsula (South Australia).

Western Australia

The current assessment of King George Whiting is primarily based on estimates of biomass and fishing mortality from a data-limited Catch-MSY assessment model, compared periodically to reference levels relating to estimates of Maximum Sustainable Yield (MSY). The estimated biomass expected to achieve MSY (B_MSY) is considered as the threshold reference level for the stock, and 50 per cent B_MSY is set as the limit reference level. The target level is considered as any stock levels above B_MSY.

Annual catches of King George Whiting taken in Western Australia showed large fluctuations between approximately 35 and 150 t between 1976 and 2000. Since 2000, catches do not show the large fluctuations and remained around 20 to 40 t. The estimated fishing mortality experienced by the stock in 2019 was low at 0.06 .year-1, with narrow 95 per cent Confidence Limits (CLs) ranging from 0.04 to 0.08 .year-1. As the current value of this performance indicator is below the level of F_MSY (the maximum rate of fishing mortality that will result in in a population size of B_MSY) (0.3 year[-1]), the stock is unlikely to deplete to a level at which recruitment could be impaired if the current catch level is maintained.

The point estimate for relative stock biomass in 2019 was high at 0.9 of the unfished level (95 per cent CLs = 0.8–0.9). As the current value of this performance indicator is above the threshold, the stock is considered not to be depleted to a level at which recruitment could be impaired.

A previous stock assessment of King George Whiting was completed in 2013 [Fisher et al. 2014] based on age structure data collected in 2010–12 in the WCB. Fishing mortality was estimated to be moderate in inshore waters where juveniles occur, but low in offshore waters where adults occur. The spawning potential ratio (SPR), which is used as a proxy for spawning biomass, was estimated to be around the target level of 40 per cent of the unfished level. Total annual catches (commercial plus recreational) have remained at a similar level since 2010–12, which suggests that the stock level is stable. On this basis, current fishing mortality and SPR are assumed to have remained similar and at the target level.  

The above evidence indicates that the biomass of this stock is unlikely to be depleted and that recruitment is unlikely to be impaired. Furthermore, 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, King George Whiting in Western Australia is classified as a sustainable stock.

King George Whiting biology [Hyndes et al. 1998, Fowler et al. 2000a, Hamer et al. 2004, Sulin 2012]

Western Australia – Recreational (Management methods) In Western Australia a recreational fishing licence is only required for fishing from a boat.

Victoria – Recreational (Management methods) Boat limits do not apply in Victoria. In Victoria a recreational fishing licence is required for all forms or recreational fishing, unless exempt.

Victoria – Indigenous (Management Methods) A person who identifies as Aboriginal or Torres Strait Islander is exempt from the need to obtain a Victorian recreational fishing licence, provided they comply with all other rules that apply to recreational fishers, including rules on equipment, catch limits, size limits and restricted areas. Traditional (non-commercial) fishing activities that are carried out by members of a traditional owner group entity under an agreement pursuant to Victoria’s Traditional Owner Settlement Act 2010 are also exempt from the need to hold a recreational fishing licence, subject to any conditions outlined in the agreement. Native title holders are also exempt from the need to obtain a recreational fishing licence under the provisions of the Commonwealth’s Native Title Act 1993.

South Australia - Recreational (Catch) Giri and Hall [2015].

1. Brown, J, Dowling, C, Hesp, A, Smith, K and Molony, B 2013, Status of nearshore finfish stocks in south-western Western Australia. Part 3: Whiting (Sillaginidae), Fisheries Research Report 248, Department of Fisheries, Western Australia.
2. Conron, S, Green, C, Hamer, P, Giri, K and Hall, K 2016, Corner Inlet-Nooramunga Fishery Assessment 2016, Fisheries Victoria Science Report Series No. 11.
3. Conron, S, Hamer, P, and Jenkins, G 2016, Western Port Fishery Assessment 2015. Recreational Fishing Grants Program Research Report, Fisheries Victoria, Department of Economic Development, Jobs, Transport and Resources.
4. Conron, SA, Bell, JD, Ingram, BA, Gorfine, HK 2020, Review of key Victorian fish stocks — 2019. Victorian Fisheries Authority Science Report Series No. 15, November 2020.
5. Fisher, EA, Hesp, SA, Hall, NG and Sulin, EH 2014, Predicting the impacts of shifting recreational fishing effort towards inshore species, Final report, Fisheries Research and Development Corporation project 2010/001
6. Fowler, AJ, Black, KP, and Jenkins, GP 2000, Determination of spawning areas and larval advection pathways for King George whiting in south-eastern Australia using otolith microstructure and hydrodynamic modelling II. South Australia. Marine Ecology Progress Series, 199: 243–254.
7. Fowler, AJ, Jones, GK, McGarvey, R 2002, Characteristics and consequences of movement patterns of King George whiting (Perciformes: Sillaginodes punctata) in South Australia. Marine and Freshwater Research, 53: 1055–1069.
8. Fowler, AJ, McGarvey, R, Carroll, J and Feenstra, JE 2014, King George Whiting (Sillaginodes punctatus), Fishery Assessment Report to PIRSA Fisheries and Aquaculture, South Australian Research and Development Institute (Aquatic Sciences), Adelaide. F2007/000843-4. SARDI Research Report Series No. 801. 85 pp.
9. Fowler, AJ, McLeay, L, and Short, DA 2000, Spatial variation in size and age structures and reproductive characteristics of the King George whiting (Percoidei: Sillaginidae) in South Australian waters. Marine and Freshwater Research, 51: 11–22.
10. Giri, K, and Hall, K, 2015, South Australian Recreational Fishing Survey. Fisheries Victoria Internal Report Series No. 62.
11. Hamer, P and Giri, K 2016, Port Phillip Bay Commercial Fishery Assessment 2016, Fisheries Victoria Science Report Series No. 9.
12. Hamer, PA and Jenkins, GP 1996, Larval supply and short-term recruitment of a temperate zone demersal fish, the King George whiting, Sillaginodes punctata Cuvier and Valenciennes, to an embayment in south-eastern Australia. Journal of Experimental Biology and Ecology, 208: 197–214.
13. Hamer, PA, Jenkins, GP and Sivakumaran, KP 2004, Identifying the spawning locations of King George whiting in Victoria: a recreational fishing based study, Fisheries Victoria Assessment Report Series No. 21, Marine and Freshwater Resources Institute, Victorian Department of Primary Industries, Queenscliff.
14. Hyndes, GA, Platell, ME, Potter, IC and Lenanton, RCJ 1998, Age composition, growth, reproductive biology and recruitment of King George whiting, Sillaginodes punctata, in south western Australia. Fishery Bulletin U.S., 96: 258–270.
15. Jenkins, GP 2005, The influence of climate on the fishery recruitment of a temperate, seagrass associated fish, the King George whiting, Sillaginodes punctata. Marine Ecology Progress Series, 288: 263–271.
16. Jenkins, GP and May, HMA 1994, Variation in settlement and larval duration of King George whiting, Sillaginodes punctata (Sillaginidae), in Swan Bay, Victoria, Australia. Bulletin of Marine Science 54: 281–296.
17. Jenkins, GP, Black, KP and Hamer, PA 2000, Determination of spawning areas and larval advection pathways for King George whiting in south-eastern Australia using otolith microstructure and hydrodynamic modelling, I. Victoria. Marine Ecology Progress Series 199: 231–242.
18. Jenkins, GP, Hamer, PA, Kent, JA, Kemp, J and Fowler, AJ 2015, Spawning sources, movement patterns, and nursery area replenishment of spawning populations of King George whiting in south-eastern Australia — closing the life history loop, Fisheries Research and Development Corporation Final Report, Deakin, Canberra.
19. Rogers, T, Redondo-Rodriguez, A, Fowler, A, Doubell, M, Drew, M, Steer, M, Matthews, D, James, C, Gillanders, B 2020, Using a biophysical model to investigate connectivity between spawning grounds and nursery areas of King George whiting (Sillaginodes punctatus: Perciformes) in South Australia's gulfs. Fisheries Oceanography.
20. Rogers, TA, Fowler, AJ, Steer, MA, Gillanders, BM 2019, Discriminating natal source populations of a temperate marine fish using larval otolith chemistry. Frontiers in Marine Science 6: 711.
21. Rogers, TA, Fowler, AJ, Steer, MA, Gillanders, BM 2019, Resolving the early life history of King George whiting (Sillaginodes punctatus: Perciformes) using otolith microstructure and trace element chemistry. Marine and Freshwater Research 70: 1659-1674.
22. Ryan, KL, Hall, NG, Lai, EK, Smallwood, CB, Tate, A, Taylor, SM, Wise, BS 2019, Statewide survey of boat-based recreational fishing in Western Australia 2017/18. Fisheries Research Report No. 297. Department of Primary Industries and Regional Development, Government of Western Australia, Perth.
23. Ryan, KL, Morison, AK and Conron, S 2009, Evaluating methods of obtaining total catch estimates for individual Victorian bay and inlet recreational fisheries. Final report, Fisheries Research and Development Corporation, project 2003/047, Marine and Freshwater Resources Institute, Victorian Department of Primary Industries, Queenscliff.
24. Steer, MA, Fowler, AJ, McGarvey, R, Feenstra, J, Smart, J, Rogers, P, Earl, J, Beckmann, C, Drew, M, Matthews, D 2018b, Assessment of the South Australian Fishery in 2017. Fishery Assessment Report to PIRSA Fisheries and Aquaculture. South Australian Research and Development Institute (Aquatic Sciences), Adelaide. SARDI Publication No. F2017/000427-2. SARDI Research Report Series No. 1002. 230 pp.
25. Steer, MA, Fowler, AJ, McGarvey, R, Feenstra, J, Westlake, EL, Matthews, D, Drew, M, Rogers, PJ and Earl, J 2018a, Assessment of the South Australian Marine Scalefish Fishery in 2016, Report to PIRSA Fisheries and Aquaculture. South Australian Research and Development Institute (Aquatic Sciences), Adelaide. SARDI Publication No. F2017/000427-1. SARDI Research Report Series No. 974. 250pp.
26. Steer, MA, Fowler, AJ, Rogers, PJ, Bailleul, J, Earl, J, Matthews, D, Drew, M, and Tsolos, A 2020, Assessment of the South Australian Marine Scalefish Fishery in 2018. Report to PIRSA Fisheries and Aquaculture. South Australian Research and Development Institute (Aquatic Sciences), Adelaide. SARDI Publication No. F2017/000427-3. SARDI Research Report Series No. 1049. 201 pp.
27. Sulin, EH 2012, Comparisons of the size and age compositions and growth of King George whiting (Sillaginodes punctata) in different regions of south-western Australia. M.Sc. thesis, Murdoch University, Western Australia.
28. Victorian Fisheries Authority, 2017, Review of key Victorian fish stocks—2017, Victorian Fisheries Authority Science Report Series No. 1.