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West Australian Dhufish

Glaucosoma hebraicum

  • David Fairclough (Department of Fisheries, Western Australia)

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Stock Status Overview

Stock status determination
Jurisdiction Stock Fisheries Stock status Indicators
Western Australia Western Australia GDSMF, JASDGDLMF, WCDGDLIMF, WCDSIMF, WL (SC) Transitional-recovering Catch, fishing mortality
GDSMF
Gascoyne Demersal Scalefish Managed Fishery (WA)
JASDGDLMF
Joint Authority Southern Demersal Gillnet and Demersal Longline Managed Fishery (Zone 1 & Zone 2) (WA)
WCDGDLIMF
West Coast Demersal Gillnet and Demersal Longline (Interim) Managed Fishery (WA)
WCDSIMF
West Coast Demersal Scalefish (Interim) Managed Fishery (WA)
WL (SC)
Open Access in the South Coast (WA)
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Stock Structure

Molecular analyses of microsatellite DNA indicates that West Australian Dhufish comprises a single biological stock in Western Australia, occurring primarily in the West Coast Bioregion between 26°30′S latitude and 115°30′E longitude1,2.

Here, assessment of stock status is presented at the biological stock level—Western Australian.

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Stock Status

Western Australia

Assessments completed in 2007 and 2009 demonstrated that fishing mortality (F) rates for the Western Australian biological stock exceeded the limit reference point of 1.5 times natural mortality (M)3,4. Significant changes to the management of both the commercial and recreational sectors in the West Coast Bioregion (WCB) were introduced between late-2007 and early-2010. These were designed to reduce catches in each sector by at least 50 per cent of 2005–06 levels to achieve a reduction in fishing mortality rates to below the threshold level of F = M and enable recovery of stocks. These 50 per cent catch reduction levels equate to 82 tonnes (t) and 126 t for the commercial and recreational sectors, respectively.

Annual catches of West Australian Dhufish by the West Coast Demersal Scalefish Interim Managed Fishery in the WCB have remained below 50 per cent of 2005–06 catch levels since 2008, when this managed fishery commenced. Total commercial catches have been close to, or below, the benchmark of 82 t since 2009. The same is true for the estimated annual catches of the recreational sector (based on biannual estimates of catch by recreational boat-based fishers5 plus annual charter catch estimates) since the suite of management changes were implemented in early-2010. The most recent assessment in 2014 (based on 2008–09 to 2010–11 data) indicated a decrease in fishing mortality from the previous period (2005–06 to 2007–08)6. However, F remained at or slightly above the limit reference point of 1.5M or 0.165 year-1 and thus still well above the threshold. The above-mentioned trends in catch and fishing mortality indicate that the current level of fishing pressure should allow the stock to recover from its recruitment overfished state.

On the basis of the evidence provided above, the Western Australian biological stock is classified as a transitional–recovering stock.

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Biology

Biology
Species Longevity / Maximum Size Maturity (50 per cent)
West Australian Dhufish ~41 years; ~1 220 mm  TL ~3 years; Females: ~300 mm TL, Males: ~320 mm  TL

West Australian Dhufish biology7,8

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Distributions

Distribution of reported commercial catch of West Australian Dhufish

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Tables

Fishing methods
Western Australia
Commercial
Various
Indigenous
Spearfishing
Hand Line, Hand Reel or Powered Reels
Traditional apparatus
Recreational
Spearfishing
Hand Line, Hand Reel or Powered Reels
Management methods
Method Western Australia
Commercial
Catch limits
Effort limits
Gear restrictions
Limited entry
Size limit
Spatial closures
Vessel restrictions
Indigenous
Bag limits
Boat limits
Gear restrictions
Possession limit
Size limit
Spatial closures
Temporal closures
Recreational
Bag limits
Boat limits
Gear restrictions
Licence
Limited entry
Passenger restrictions
Possession limit
Size limit
Spatial closures
Spatial zoning
Temporal closures
Active vessels
Western Australia
16 in GDSMF, 21 in JASDGDLMF, 5 in WCDGDLIMF, 37 in WCDSCMF, 69 in WL (SC)
GDSMF
Gascoyne Demersal Scalefish Managed Fishery (WA)
JASDGDLMF
Joint Authority Southern Demersal Gillnet and Demersal Longline Managed Fishery (Zone 1 & Zone 2) (WA)
WCDGDLIMF
West Coast Demersal Gillnet and Demersal Longline (Interim) Managed Fishery (WA)
WCDSCMF
West Coast Deep Sea Crustacean Managed Fishery (WA)
WL (SC)
Open Access in the South Coast (WA)
Catch
Western Australia
Commercial 16.30kg in GDSMF, 8.54t in JASDGDLMF, 5.20t in WCDGDLIMF, 35.17t in WCDSIMF, 1.46t in WL (SC)
Indigenous Unknown
Recreational 14 t (2014–15), 84 t (±6 t se; 2013–14)
GDSMF
Gascoyne Demersal Scalefish Managed Fishery (WA)
JASDGDLMF
Joint Authority Southern Demersal Gillnet and Demersal Longline Managed Fishery (Zone 1 & Zone 2) (WA)
WCDGDLIMF
West Coast Demersal Gillnet and Demersal Longline (Interim) Managed Fishery (WA)
WCDSIMF
West Coast Demersal Scalefish (Interim) Managed Fishery (WA)
WL (SC)
Open Access in the South Coast (WA)

Indigenousa Active vesselsb–e

a 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 recreational fishing licence, the non-commercial take by indigenous fishers is covered by the same arrangements as that for recreational fishing.

b The GDSMF fishing season runs from 1 September–31 August.

c The JASDGDLMF and WCDGDLIMF fishing seasons run from 1 June–31 May.

d The WCDSIMF runs from from 1 January–31 December.

e The WL(SC) fishery runs from from 1 January–31 December.

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Catch Chart

Commercial catch of West Australian Dhufish

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Effects of fishing on the marine environment

  • Line fishing—the main fishing method used in the commercial and recreational fishery for West Australian Dhufish—has little physical impact on the benthic environment and hence negligible risk to benthic habitats.
  • A Fisheries Research and Development Corporation study9 examined the past 30 years of catch data by commercial wetline, gillnet and longline fisheries in the West Coast Bioregion and found that the species composition in catches had changed over time. This may be a function of changes in targeting or differences in reporting methods but there was no evidence of a decline in the trophic level or mean size in catches representing a low risk to the ecosystem.
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Environmental effects on West Australian Dhufish

  • Recruitment success of West Australian Dhufish varies, with likely associations with temporal variation in environmental factors such as water temperature, currents and food supply, which would affect relative abundance and future catch rates3,6,10.
  • Climate change effects (for example increased water temperatures, acidification) could influence aspects of the biology of West Australian Dhufish, such as spawning success and recruitment patterns11. Extreme events, such as the marine heatwave in 2010–1112,13, may have severe negative effects, including mortalities.
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References

  1. 1 Berry, O, England, P, Fairclough, D and Jackson, G 2012, Microsatellite DNA analysis and hydrodynamic modelling reveal the extent of larval transport and gene flow between management zones in an exploited marine fish (Glaucosoma hebraicum), Fisheries Oceanography, 21: 243–254.
  2. 2 Fairclough, DV, Edmonds, JS, Jackson, G, Lenanton, RCJ, Kemp, J, Molony, BW, Keay, IS, Crisafulli, BM and Wakefield, CB 2013, A comparison of the stock structures of two exploited demersal teleosts, employing complementary methods of otolith element analysis, Journal of Experimental Marine Biology and Ecology, 439: 181–195.
  3. 3 Wise, BS, St John, J and Lenanton, RC (ed.s) 2007, Spatial scales of exploitation among populations of demersal scalefish: implications for management, Part 1: Stock status of the key indicator species for the Demersal Scalefish Fishery in the West Coast Bioregion. Fisheries Research Report No. 163, Department of Fisheries, Western Australia, Perth.
  4. 4 Fairclough, D, Lai, E and Bruce, C 2009, West Coast Demersal Scalefish Fishery status report, in WJ Fletcher and K Santoro (ed.s) State of the fisheries report 2008–09, Department of Fisheries, Western Australia, Perth, pp 71–79.
  5. 5 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, Perth.
  6. 6 Fairclough, DV, Molony, BW, Crisafulli, BM, Keay, IS, Hesp, SA and Marriott, RM 2014, Status of demersal finfish stocks on the west coast of Australia, Fisheries Research Report No. 253, Department of Fisheries, Western Australia, Perth.
  7. 7 Hesp, SA, Potter, IC and Hall, NG 2002, Age and size composition, growth rate, reproductive biology, and habitats of the West Australian Dhufish (Glaucosoma hebraicum) and their relevance to the management of this species, Fishery Bulletin, 100: 214–227.
  8. 8 Smallwood, CB, Hesp, SA and Beckley, LE 2013, Biology, stock status and management summaries for selected fish species in south-western Australia, Fisheries Research Report No. 242, Department of Fisheries, Western Australia, Perth.
  9. 9 Hall, NG and Wise, BS 2011, Development of an ecosystem approach to the monitoring and management of Western Australian fisheries, Fisheries Research and Development Corporation project 2005/063, Fisheries Research Report No. 215, Department of Fisheries, Western Australia, Perth.
  10. 10 Strzelecki, J, Feng, M, Berry, O, Zhong, L, Keesing, J, Fairclough, D, Pearce, A, Slawinski, D, Mortimer, N 2013, Location and transport of early life stages of West Australian Dhufish, Glaucosoma hebraicum, Fisheries Research and Development Corporation project 2011/016, FRDC, Canberra.
  11. 11 Caputi, N, Feng, M, Pearce, A, Benthuysen, J, Denham, A, Hetzel, Y, Matear, R, Jackson, G, Molony, B, Joll, L and Chandrapavan, A 2014, Management implications of climate change effect on fisheries in Western Australia, Part 1: Environmental change and risk assessment, Fisheries Research Report No. 260, Fisheries Research and Development Corporation project 2010/535, Department of Fisheries Western Australia, Perth.
  12. 12 Pearce, A, Lenanton, R, Jackson, G, Moore, J, Feng, M and Gaughan, D 2011, The “marine heat wave” off Western Australia during the summer of 2010–11, Fisheries Research Report No. 222, Department of Fisheries, Western Australia, Perth.
  13. 13 Caputi, N, Jackson, G and Pearce, A 2014, The marine heat wave off Western Australia during the summer of 2010–11—2 years on, Fisheries Research Report No. 250, Department of Fisheries, Western Australia, Perth. 

Archived reports

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