*

King George Whiting

Sillaginodes punctatus

  • Paul Hamer (Department of Economic Development, Jobs, Transport and Resources, Victoria)
  • Anthony Fowler (South Australian Research and Development Institute)
  • Kim Smith (Department of Fisheries, Western Australia)
Toggle content

Stock Status Overview

Stock status determination
Jurisdiction Stock Fisheries Stock status Indicators
South Australia Gulf St. Vincent MSF Transitional-depleting Catch, CPUE, age structures, biomass
South Australia Spencer Gulf MSF, NZRLF Transitional-depleting Catch, CPUE, age structures, biomass
Victoria Victoria CIF, GLF, OF, PPBF Sustainable Catch, CPUE, age/length structures, pre-recruit surveys
South Australia West Coast - Eyre Peninsula MSF, NZRLF Sustainable Catch, CPUE, age structures, biomass
Western Australia Western Australia SCEMF, WCEMF, WL (SC) Sustainable Catch, CPUE, recruitment, fishing mortality, per recruit analysis
CIF
Corner Inlet Fishery (VIC)
GLF
Gippsland Lakes Fishery (VIC)
MSF
Marine Scalefish Fishery (SA)
NZRLF
Northern Zone Rock Lobster Fishery (SA)
OF
Ocean Fishery (VIC)
PPBF
Port Phillip Bay Fishery (VIC)
SCEMF
South Coast Estuarine Managed Fishery (WA)
WCEMF
West Coast Estuarine Managed Fishery (WA)
WL (SC)
Open Access in the South Coast (WA)
Toggle content

Stock Structure

Recent research on King George Whiting stock structure in southern Australia using genetic and otolith approaches indicates that separate genetic stocks occur in each state jurisdiction (Western Australia, Victoria and South Australia) but with some genetic mixing between Victorian and South Australian populations1. The research also indicated that whiting sampled from northern Tasmania were genetically distinct from those in the mainland states1.

 

The biological stock structure within Western Australia and Victoria is unclear, but they are considered to be separate, single biological stocks, for management purposes, and separate from the South Australian biological stocks. The South Australian population of King George Whiting comprises three biological stocks2–4. Gulf St. Vincent, Spencer Gulf and the west coast of Eyre Peninsula. This delineation has been determined based on a detailed understanding of the life history, including movement patterns of adult fish, knowledge of the location of spawning grounds and nursery areas2,4 and understanding of larval advection pathways and distances based on early life history and hydrodynamic modelling3.

 

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).

Toggle content

Stock Status

Western Australia

The life cycle of King George Whiting in Western Australia involves both inshore and offshore habitats, juveniles occupy inshore waters in estuaries and protected coastal embayments before migrating to deeper waters as they mature (at around 400 mm; aged 3–4 years), where they remain5,6. The current assessment of stock status uses a weight-of-evidence approach that includes estimates of fishing mortality, per recruit analyses, catch, catch rates, and fishery-independent juvenile recruitment indices7,8. The latest stock assessment of King George Whiting was conducted in 20137.

 

Annual trends in fishery catches in inshore areas appear to correlate with trends in recruitment, with a time lag of 2–3 years. Estimated annual recruitment has been highly variable since recruitment surveys began in 1999, with higher recruitment levels being observed during strong Leeuwin Current (La Niña) years. Catch and catch rates in the main commercial fisheries may not be reliable indices of abundance due to the multispecies nature of these net method fisheries, which makes it difficult to quantify targeted effort and species-specific catch rates. The 2015 catch is, however, similar to the historical range. In the South Coast Estuarine Managed Fishery, the catch (15 tonnes [t]) in 2015 was equal to the long-term (1980–2014) average of 15 t. At current estimated levels of fishing mortality for King George Whiting, based on age data collected from 2010–12, the spawning potential ratio (based on the spawner biomass per recruit) is estimated to be at a sustainable level (42 per cent of the unfished level)8. The above evidence indicates that the biomass of this stock is unlikely to be recruitment overfished.

 

The inshore component of the stock, which is entirely comprised of immature fish, is exposed to relatively high fishing pressure. However, the offshore component (the breeding stock) is offered some protection by its location in deeper waters, where individuals are less easily targeted than the inshore component. The above evidence indicates that current fishing pressure is unlikely to cause the stock to become recruitment overfished.

 

On the basis of the evidence provided above, King George Whiting in Western Australia is classified as a

sustainable stock.

Victoria

Stock status assessment of King George Whiting in Victoria uses a weight-of-evidence approach that considers catch per unit effort (CPUE) from both commercial and recreational sectors, fishery-independent annual surveys of pre-recruit (post-larval) catch rates in Port Phillip Bay, and age and length composition of the catch. Importantly, the indicator data are derived from bay and estuary fisheries that only catch juvenile King George Whiting. When describing the status of the Victorian King George Whiting stock it is important to consider how the life history characteristics influence the above indicators.

 

The dynamics of King George Whiting populations and fisheries in Victorian bays and estuaries are strongly influenced by climatic factors that influence the numbers of larvae transported into the bay and estuary nursery grounds from coastal spawning areas during spring each year9–12. Because most King George Whiting leave these nursery areas permanently by 3–4 years of age (prior to adulthood)13, the fisheries in bays and estuaries are based on only a few age classes/cohorts at any point in time. This means that the Victorian King George Whiting fisheries are highly variable at short time scales. Over the past 60 years King George Whiting fisheries production in Victoria’s bays and estuaries has shown peaks and troughs at approximately 10-year intervals10. It also means that the adult fish, which migrate into deeper waters at maturity (3–4 years), are subject to low fishing mortality.

 

The most recent state-wide King George Whiting stock assessment was conducted in 201014, although more recent general fishery assessments for the Port Phillip Bay15, and Corner Inlet-Nooramunga16 fisheries have included King George Whiting. These assessments indicated for both fisheries that King George Whiting catch rates for the main fishing method (haul seine) have increased dramatically over the past year. This recent increase is consistent with the pre-recruit survey in spring 2013 that showed a major increase in the abundance of post-larval juveniles recruiting in Port Phillip Bay15. These fish have now fully recruited to the bay and estuary fisheries, contributing to increased catches and catch rates. The increase in commercial CPUE in recent years15,16 is consistent with environmental influences driving increased larval supply to bays and estuaries in the spring of 2013. However, the current increase in CPUE will likely be limited to 1–2 years as post-larval recruitment in 2014 and 2015 was poor, and the fish from the 2013 year class will leave the bays and estuaries by 2017–18. Mature fish that escape the inshore fishery and migrate offshore will contribute to an increased adult population for a longer period.

 

Effort for all gear types in Victoria has decreased since 1999 as a result of a reduction in the number of licensed commercial fishers in Victorian waters, and a recent permanent decrease in commercial effort for Port Phillip Bay due to a Government buy-out policy to remove all commercial net fishing from Port Phillip Bay by 2022. From April 2016 onwards, the main Victorian King George Whiting commercial fishery will be the Corner Inlet-Nooramunga Fishery. The above evidence indicates that the biomass of this stock is unlikely to be recruitment overfished and that the current level of fishing mortality is unlikely to cause the biomass to become recruitment overfished.

 

On the basis of the evidence above, King George Whiting in Victoria is classified as a sustainable stock.

Spencer Gulf

In South Australia’s multispecies Marine Scalefish fishery, King George whiting is the premium species attracting the highest price per unit weight for commercial fishers. The most recent assessment was completed in July 20142.

 

This stock extends throughout the northern and southern regions of Spencer Gulf. There have been recent declining trends in both catch and effort for this region, culminating in the lowest recorded values in 20132. Despite the effort decline, CPUE has declined for this region since 2007. As for the Gulf St. Vincent stock, such trends for this high-value species are consistent with a declining biomass. This is reflected in the assessment model outputs, which indicated a slight decline in biomass of 3.3 per cent between 2009 and 2013. Because the estimates of effort and CPUE used in the model do not take into account likely increases in ‘effective’ effort that relate to technological advancements, and because of uncertainty in the time-series of recreational catch and effort, the decline in fishable biomass may have been greater than estimated by the model. Although declining slowly, the stock is not yet considered to be in a recruitment overfished state. However, the above evidence indicates that the current level of fishing pressure is likely to cause the stock to become recruitment overfished.

 

On the basis of the evidence provided above, the Spencer Gulf (South Australia) biological stock is classified as a transitionaldepleting stock.

Gulf St. Vincent

In South Australia’s multispecies Marine Scalefish fishery, King George whiting is the premium species attracting the highest price per unit weight for commercial fishers. The most recent assessment was completed in July 20142.

 

The Gulf St. Vincent biological stock is found throughout the Gulf St. Vincent, Investigator Strait and around Kangaroo Island. Handline effort for this stock has declined since 2009, and handline CPUE has declined since 20072. Both of these declining trends are consistent with a declining level of biomass as, given the value of the species, it is expected that effort would remain high or consistent if biomass was available. The model-estimated biomass for this stock has been relatively flat since 1984, when fishery statistics were first recorded. However, because the estimates of effort and CPUE used in the model do not take into account likely increases in the ‘effective’ effort, relating to technological advancements, and because of uncertainty in the time-series of recreational catch and effort, the decline in fishable biomass may have been greater than estimated by the model. While it is estimated that the biomass of King George Whiting declined between 2009 and 2013, the stock is not yet considered to be in a recruitment overfished state. However, the above evidence indicates that the current level of fishing pressure is likely to cause the stock to become recruitment overfished.

 

On the basis of the evidence provided above, the Gulf St. Vincent (South Australia) biological stock is classified as a transitionaldepleting stock.

West Coast - Eyre Peninsula

In South Australia’s multispecies Marine Scalefish fishery, King George whiting is the premium species attracting the highest price per unit weight for commercial fishers. The most recent assessment was completed in July 20142.

 

This stock extends throughout all the bays and offshore areas of the west coast of Eyre Peninsula. Handline fishing effort for this stock has been relatively stable in recent years. Catch increased gradually by 27 per cent between 2002 and 2013, whilst CPUE increased over the same period by 62 per cent to its highest recorded level2. Output from the stock assessment model showed trends of increasing estimated recruitment rates and levels of biomass between 2004 and 2013. Furthermore, between 1984 and 2013, the exploitation rate fell considerably, as a result of declines in commercial and recreational fishing effort over this period. The above evidence indicates that the biomass of this stock is unlikely to be recruitment overfished and that the current level of fishing mortality is unlikely to cause the biomass to become recruitment overfished.

 

On the basis of the evidence provided above, the West coast Eyre Peninsula (South Australia) biological stock is classified as a sustainable stock.

Toggle content

Biology

Biology
Species Longevity / Maximum Size Maturity (50 per cent)
King George Whiting South Australia: 22 years ; 59 cm TL Western Australia: 14 years; 62 cm TL Victoria – at least 11 years; 60 cm TL South Australia: 3-4 years; 30-35 cm TL Western Australia: 3-4 years, 41 cm TL Victoria - unknown

King George Whiting biology1,3,5,6,13,14

Toggle content

Distributions

Distribution of reported commercial catch of King George Whiting

Toggle content

Tables

Fishing methods
Western Australia Victoria South Australia
Commercial
Various
Line
Mesh Net
Haul Seine
Unspecified - Seine
Unspecified
Hand Line, Hand Reel or Powered Reels
Gillnet
Indigenous
Spearfishing
Hand Line, Hand Reel or Powered Reels
Recreational
Spearfishing
Hand Line, Hand Reel or Powered Reels
Management methods
Method Western Australia Victoria South Australia
Commercial
Gear restrictions
Limited entry
Size limit
Spatial restrictions and closures (nets)
Temporal closures
Vessel restrictions
Indigenous
Bag and boat limits
Size limit
Recreational
Bag and boat limits
Licensing
Size limit
Active vessels
Western Australia Victoria South Australia
27 in SCEMF, 1 in WCDSCMF, 11 in WCEMF, 20 in WL (SC) 18 in CIF, 8 in GLF, 10 in OF, 31 in PPBF 244 in MSF, 11 in NZRLF
CIF
Corner Inlet Fishery (VIC)
GLF
Gippsland Lakes Fishery (VIC)
MSF
Marine Scalefish Fishery (SA)
NZRLF
Northern Zone Rock Lobster Fishery (SA)
OF
Ocean Fishery (VIC)
PPBF
Port Phillip Bay Fishery (VIC)
SCEMF
South Coast Estuarine Managed Fishery (WA)
WCDSCMF
West Coast Deep Sea Crustacean Managed Fishery (WA)
WCEMF
West Coast Estuarine Managed Fishery (WA)
WL (SC)
Open Access in the South Coast (WA)
Catch
Western Australia Victoria South Australia
Commercial 15.31t in SCEMF, 765.00kg in WCEMF, 8.26t in WL (SC) 74.69t in CIF, 1.94t in GLF, 4.86t in OF, 75.18t in PPBF 272.61t in MSF
Indigenous Unknown Unknown Unknown
Recreational 18 t (2013–14) Boat-based only 155 t (2006/07) 367 t (2013/14)
CIF
Corner Inlet Fishery (VIC)
GLF
Gippsland Lakes Fishery (VIC)
MSF
Marine Scalefish Fishery (SA)
OF
Ocean Fishery (VIC)
PPBF
Port Phillip Bay Fishery (VIC)
SCEMF
South Coast Estuarine Managed Fishery (WA)
WCEMF
West Coast Estuarine Managed Fishery (WA)
WL (SC)
Open Access in the South Coast (WA)

Indigenousc,d

 

a Victoria – Recreational (Management methods) Boat limits do not apply in Victoria.

 

b Western Australia – Recreational (Management methods) In Western Australia a recreational fishing licence is only required for fishing from a boat. In Victoria a recreational fishing licence is required for all forms or recreational fishing, unless exempt.

 

c In Victoria, regulations for managing recreational fishing are also applied to fishing activities by Indigenous people. Recognised Traditional Owners (groups that hold native title or have agreements under the Traditional Owner Settlement Act 2010 [Vic]) are exempt (subject to conditions) from the requirement to hold a recreational fishing licence, and can apply for permits under the Fisheries Act 1995 (Vic) that authorise customary fishing (for example, different catch and size limits or equipment). The Indigenous category in Table 3 refers to customary fishing undertaken by recognised Traditional Owners. In 2015, there were no applications for customary fishing permits to access King George Whiting.

 

d Subject to the defence that applies under Section 211 of the Native Title Act 1993 (Cth), and the exemption from a requirement to hold a Victorian recreational fishing licence, the non-commercial take by indigenous fishers is covered by the same arrangements as that for recreational fishing.

Toggle content

Catch Chart

Commercial catch of King George Whiting

Toggle content

Effects of fishing on the marine environment

  • Some bycatch is expected from net or line fishing methods used to target King George Whiting. There has been one major study on the effects of haul seine fishing on seagrass (fine leaf, eel grass, Zostera) habitat20. In that study there was limited evidence of significant damage to seagrass beds by haul net fishing, although the study had some limitations and recommended longer-term replicated studies involving industry, and studies on other seagrass species (broad leaf, Posidonia)20. However, as a result of targeted fishing and the nature of the methods used, the effects of fishing for King George Whiting on the marine environment are considered to be low.
Toggle content

Environmental effects on King George Whiting

  • Historically, catch and catch rates in Victoria have followed an approximate 10-year cyclic pattern. Fluctuations in these biomass indicators are likely to result from environmental conditions affecting spawning success and/or, more likely, recruitment of the post-larval stages to the bay and estuary fishing areas from oceanic spawning areas to the west10,21. A significant relationship has been found between the strength of zonal westerly winds in south-eastern Australia and abundance of post-larvae recruiting into Port Phillip Bay, Victoria, during spring each year10,21. The zonal westerly wind index has shown a long-term downward trend since about 1970, suggesting that the strength of the westerly wind flow over Victoria has decreased over the past 40 years. The decline in zonal westerly winds is consistent with the prediction that westerly winds will weaken in southern Australia under climate change because of a southward migration of the high-latitude westerly wind belt south of Australia22. This may ultimately have a significant impact on the average abundance of larvae that enter Victoria’s bays and inlets.
  • While westerly winds10 and oceanic water temperatures23 during the winter larval dispersal phase play an important role in determining recruitment patterns to the bay and estuary fisheries in Victoria the availability of suitable nursery habitat (primarily seagrass9,12,24) is another critical factor that could influence survival and growth of the young fish, and therefore fisheries productivity in all states. Significant long-term loss of seagrass habitat in bays and estuaries would impact production of this species.
  • Similar to Victoria, annual recruitment by juvenile King George Whiting is highly variable in other states, most likely as a result of various complex interactions with the environment, on both a broad- and local-scale. In Western Australia, relatively strong recruitment occurred in 1999, 2000 and 2008, which coincided with a strong Leeuwin Current in these years. The warm water temperatures associated with this southward flowing current may have led to increased larval growth and survival rates. The positive influence of warmer water temperatures on larval growth rates has also been observed for King George whiting along the Victorian coast25.
Toggle content

References

  1. 1 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.
  2. 2 Fowler, AJ, McGarvey, R, Carroll, J and Feenstra, JE 2014, King George Whiting (Sillaginodes punctatus) Fishery, Fishery Assessment Report to Primary Industries and Regions South Australia, Fisheries and Aquaculture, South Australian Research and Development Institute (Aquatic Sciences), Adelaide. F2007/000843-4. SARDI Research Report Series No. 801. 85pp.
  3. 3 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.
  4. 4 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.
  5. 5 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.
  6. 6 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.
  7. 7 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.
  8. 8 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.
  9. 9 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.
  10. 10 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.
  11. 11 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.
  12. 12 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.
  13. 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. 14 Kemp, J, Ryan, KL, Brown, L, Bruce, TK, MacDonald, M and Conron, S 2012, Victorian King George Whiting Bay and Inlet Stock Assessment 2010, Fisheries Victoria Assessment Report Series No. 65, Victorian Department of Primary Industries, Queenscliff.
  15. 15 Hamer, P and Giri, K 2016, Port Phillip Bay Commercial Fishery Assessment 2016. Fisheries Victoria Science Report Series No. 9.
  16. 16 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.
  17. 17 Ryan, KL, Hall, NG, Lai, EK, Smallwood, CB, Taylor, SM and Wise, BS 2015. State-wide survey of boat-based recreational fishing in Western Australia 2013/14. Fisheries Research Report No. 268, Department of Fisheries, Western Australia. 208pp.
  18. 18 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 Corpopration, project 2003/047, Marine and Freshwater Resources Institute, Victorian Department of Primary Industries, Queenscliff.
  19. 19 Giri, K and Hall, K 2015, South Australian Recreational Fishing Survey. Fisheries Victoria Internal Report Series No. 62.
  20. 20 Otway, NM and Macbeth, WG, 1999, Physical effects of hauling on seagrass beds, final report, Fisheries Research and Development, project 95/149 and 96/286. NSW Fisheries Final Report Series No. 15. 86 pp.
  21. 21 Hamer, P, Jenkins, G and Kemp, J. 2010, Linking key environmental and life history indicators for monitoring and assessment of bay and inlet fisheries in Victoria, Fisheries Victoria Research, Report Series No. 44.
  22. 22 Cai, W, Shi, G, Cowan T, Bi, D and Ribbe, J 2005, The response of the Southern Annular Mode, the East Australian Current, and the southern mid-latitude ocean circulation to global warming, Geophysical Research Letters, 32: L23706.
  23. 23 Jenkins, GP and King, D 2006, Variation in larval growth can predict the recruitment of a temperate, seagrass-associated fish, Oecologia, 147: 641–649.
  24. 24 Jenkins, GP and Wheatley, MJ 1998, The influence of habitat structure on nearshore fish assemblages in a southern Australian embayment: comparison of shallow seagrass, reef-algal and unvegetated sand habitats, with emphasis on their importance to recruitment, Journal of Experimental Marine Biology and Ecology, 221: 147–172.
  25. 25 Jenkins, G.P and King, D 2006, Variation in larval growth can predict the recruitment of a temperate, seagrass‐associated fish. Oecologia, 147: 641‐649.

Archived reports

Click the links below to view reports from other years for this fish.