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Hapuku (2018)

Polyprion oxygeneios

  • Rowan Chick (Department of Primary Industries, New South Wales)
  • Luke Albury (Department of Agriculture and Fisheries, Queensland)
  • Ashley Fowler (Department of Primary Industries, New South Wales)
  • Jeff Norriss (Department of Primary Industries and Regional Development, Western Australia)
  • Paul Rogers (South Australian Research and Development Institute)
  • Ashley Williams (Australian Bureau of Agricultural and Resource Economics and Sciences)
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Summary

The stock structure of Hapuku in Australian waters is unknown. Stock status at the jurisdictional level shows Hapuku is ‘sustainable’ in WA, ‘undefined’ in Qld and NSW, ‘depleting’ in Commonwealth waters and ‘negligible’ in SA.

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Stock Status Overview

Stock status determination
Jurisdiction Stock Fisheries Stock status Indicators
Commonwealth Commonwealth HSF, SESSF (CTS), SESSF (GABTS), SESSF (GHTS) Depleting Catch, fishing mortality
New South Wales New South Wales OTLF Undefined Catch, effort, standardised catch rate
Queensland Queensland RRFFF Undefined Catch, effort
South Australia South Australia MSF Negligible
Western Australia Western Australia GDSMF, WCDSIMF, WL (SC) Sustainable Spawning potential ratio, fishing mortality
GDSMF
Gascoyne Demersal Scalefish Managed Fishery (WA)
HSF
High Seas Fishery (CTH)
MSF
Marine Scalefish Fishery (SA)
OTLF
Ocean Trap and Line Fishery (NSW)
RRFFF
Rocky Reef Fin Fish Fishery (QLD)
SESSF (CTS)
Southern and Eastern Scalefish and Shark Fishery (Commonwealth Trawl Sector) (CTH)
SESSF (GABTS)
Southern and Eastern Scalefish and Shark Fishery (Great Australian Bight Trawl Sector) (CTH)
SESSF (GHTS)
Southern and Eastern Scalefish and Shark Fishery (Gillnet Hook and Trap Sector) (CTH)
WCDSIMF
West Coast Demersal Scalefish (Interim) Managed Fishery (WA)
WL (SC)
Open Access in the South Coast (WA)
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Stock Structure

The stock structure of Hapuku throughout Australian waters is unknown. Life history characteristics, similar to Bass Groper (P. americanus), suggest a broad population structure [Ball et al. 2000]. However, Beentjes and Francis [1999] inferred the likelihood of separate stocks within New Zealand based on tagging studies of Hapuku, despite recorded movements of up to about 1 400 km. Paul [2002] reported on the stock structure of Hapuku (and Bass Groper) in New Zealand, reviewing available data, concluding that stock structure could not be described, and there was insufficient data describing the life history characteristics to distinguish different stocks. Wakefield et al. [2010] described differences in aged-based demography and reproduction of Hapuku among regions of Western Australia, and likely pan-oceanic mixing of the broader P. oxygeneios population (including Indian Ocean). No such investigations have been done on Hapuku throughout eastern and south eastern Australian waters to develop our understanding of stock structure. It is likely Hapuku in eastern and south eastern Australian waters constitute one or more stocks of a greater population and fisheries within this region access this stock or subset of stocks in support of their annual catches. Panmixia could be expected throughout the region, owing to the extended larval/juvenile phase (years) and large-scale genetic homogeneity of congener P. americanus which has similar life-history traits [Ball et al. 2000, Roberts 1996, Sedberry et al. 1996, Wakefield et al. 2010]. Evidence in support of a single biological stock, or stock structuring within broader Australian waters is limited.

Here, assessment of stock status is presented at the jurisdictional level—Commonwealth, Western Australia, Queensland, New South Wales and South Australia.

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Stock Status

Commonwealth

Hapuku are captured in multiple sectors of the Southern and Eastern Scalefish and Shark Fishery (SESSF). Most of the catch is taken by demersal longlines in the Gillnet Hook and Trap (GHAT) Sector and by trawling in the Commonwealth Trawl Sector (CTS) and Great Australian Bight (GAB) Sector. Total annual catches across all sectors declined from over 110 tonnes (t) in 2008 to approximately 26 t in 2013. Since then, catches have increased to approximately 48 t in 2017, mostly due to an increase in catches by the CTS.

In 2012, a Sustainability Assessment for Fishing Effects (SAFE) analysis assessed Hapuku as precautionary extreme high risk in the SESSF due to the cumulative impacts of fishing from the CTS and demersal longline fishing in the GHAT Sector [Zhou et al. 2012]. A residual risk analysis that considered additional scientific information did not reduce the overall risk rating for Hapuku [AFMA 2014]. The SAFE analysis was based on catch data from 2007 to 2010, when the average catch was approximately 82 t, and indicated that it was plausible that Hapuku could have been subject to overfishing during those years.

Due to the risk rating from the 2012 SAFE assessment, Hapuku is currently a priority species in the application of an Ecological Risk Management strategy for the SESSF [AFMA 2015]. Specific management measures adopted by AFMA to reduce the impact of demersal longline fishing on Hapuku include a limit on the number of hooks deployed, spatial and temporal closures, and the mandatory installation of electronic monitoring on all auto longline vessels.

In 2018, a model-assisted catch-only assessment (Catch-MSY  method) [Martell and Froese 2013] was fitted to catches of Hapuku across all sectors of the SESSF from 1986 to 2017 [Penney et al. 2018]. The Catch-MSY method uses population productivity (r) and carrying capacity (K) parameters of an underlying Schaefer production model to estimate the ranges in biomass and harvest rate that could have resulted in the annual catches. The assessment estimated biomass to have been above BMSY from 1986 to 2006 and between BMSY and 20 per cent of unfished biomass (0.2B0) since 2007. The mean estimate of biomass in 2017 was approximately 33 per cent of B0 (95 per cent CI of 11–55 per cent). Reported catch, mostly from the CTS, increased in 2017, but remained below the mean estimated MSY of 51 t. However, the harvest rate in 2017 was estimated to be 0.15, above the FMSY level of 0.11, as a result of the 2017 increase in reported trawl catch. Five year projections at the 2017 catch level of 48 t predicted that biomass would decline slowly at this catch level.

The estimated harvest rates from this assessment are consistent with estimates of fishing mortality derived from the SAFE assessment by Zhou et al. [2012]. However, there is high uncertainty in the estimates of biomass depletion, harvest rate and MSY derived from catch data using the Catch-MSY analysis due to the deterministic and uncertain nature of the analysis, and uncertainty about the stock structure of Hapuku. Given the broad distribution of Hapuku within Australian waters, it is plausible that there are a number of separate biological stocks with limited connectivity across the extent of the SESSF and other jurisdictions, which may have been subject to different exploitation patterns. Resolving the stock structure of Hapuku would help reduce the uncertainty in the status of the species.

On the weight of available evidence, it is plausible that maintaining the current level of fishing pressure will cause the Commonwealth Hapuku stock to decline below its current level and lead to it being recruitment impaired. However, the available evidence indicates that the biomass of the stock is not likely to be depleted and that recruitment is unlikely to be impaired.

On the basis of the evidence provided above, Hapuku in the Commonwealth is classified as a depleting stock.

New South Wales

In New South Wales, Hapuku are primarily caught as a by-product in the Ocean Trap and Line (OTL) Fishery on dropline gear, where target species are commonly Blue-eye Trevalla (Hyperoglyphe antartica). Since 1997–98, commercial catches of Hapuku have been reported independently to Bass Groper (P. americanus). Annual reported commercial catches of Hapuku have steadily declined since the reported peak of 15.6 t in 1999–2000. Within the last decade (2007–08 to 2016–17) the average annual commercial catch of Hapuku reported in New South Wales was 3 t, and within in the last five years (2012–13 to 2016–17) the average annual commercial catch was 1.8 t. Over the same periods of time trends in effort reflect that in catch. Together with information on the mean weight (7.6 kg) of Hapuku caught and retained in the OTL Fishery [Macbeth and Gray 2015], the commercial fishery for Hapuku over the last five years, is responsible for the harvest of an average annual number of < 250 individual fish. Standardised catch rates (kg per day) from droplining in the OTL Fishery has not shown any clear trend since 1997–98, with variance associated with the annual estimates being substantially larger since about 2009–10, associated with fewer reported catches [Chick and Fowler 2018].

Although New South Wales commercial catches are low, the impact of fishing on the Hapuku stock in New South Wales remains uncertain. Indigenous catches of Hapuku are unknown. Recreational catch of Hapuku is not well understood in New South Wales. Henry and Lyle [2003] estimated the New South Wales annual recreational harvest of Rock Cod/Gropers (including Hapuku and nine other ‘offshore/deep’ species) to be 4 770 (± 1 532) individuals, with offshore (> 5 km from shore) recreational fishing effort representing 1.3 per cent of the State-wide total. West et al. [2015] reported no recreational catch of Hapuku in 2013–14, whilst also reporting offshore (> 5 km) fishing effort comprised < 2 per cent (54 773 fisher days) of all reported recreational fishing effort. Available estimates of recreational catch in New South Wales are considered unreliable as large-scale phone and diary surveys like those of Henry and Lyle [2003] and West et al. [2015] underestimate catches from small specific fisheries like the offshore recreational fishery.

A review of indicators (weight-of-evidence approach) was used to assess the status of Hapuku in New South Wales. There are insufficient data available to support more quantitative stock assessment methods. Current uncertainty regarding Hapuku stock structure and biology, low levels of catch and low numbers of reported daily catch between different commercial fishing methods that exacerbate uncertainty surrounding estimates of catch rate, together with uncertain levels of recreational catches, provide insufficient information with which to determine a stock status [Chick and Fowler, 2018].

On the basis of the evidence provided above, Hapuku in New South Wales is classified as an undefined stock.

Queensland

Queensland’s access to Hapuku is limited by their distribution [Kailola et al. 1993] and only minor catches are made in this jurisdiction. There is no formal assessment of Hapuku in Queensland waters. Historically, Hapuku has been targeted in the Deep Water Fin Fish Fishery (DWFFF) with an average harvest of 4 t between 1997–2002. Since this time, the average annual catch has declined below 1 t as overall effort in the fishery has reduced [QDAF 2018]. Current reported catch is incidental harvest from the Rocky Reef Fin Fish Fishery (RRFFF). Catch and effort in 2017 was low with a total of 45 kg and two days effort. There was no recreational harvest of Hapuku reported in Queensland’s latest recreational fishing survey [Webley et al. 2015]. It is unlikely that the Queensland harvest is significantly impacting the overall stock but there is insufficient information available to confidently classify the status of this stock.

On the basis of the evidence provided above, Hapuku in Queensland is classified as an undefined stock.

South Australia

From 1997–98 to 2016–17, the total reported annual commercial catches of Hapuku in South Australia ranged from zero to two tonnes. The annual catch over this period averaged less than 200 kg. South Australia’s recreational catch of Hapuku is not known but the species is not a major component of recreational landings. Stock status for Hapuku in South Australia is reported as Negligible due to historically low catches in this jurisdiction and the stock has generally not been subject to targeted fishing. Fishing is unlikely to be having a negative impact on the stock.

Western Australia

The Hapuku catch in Western Australia is predominantly by commercial line fishers operating along the lower west and particularly south coasts. An age-based assessment from sampling 2005 and 2006 south coast catches estimated fishing mortality (F) to be within target and threshold levels [Wakefield et al. 2010]. More robust modelling of the same data was undertaken in 2018, assuming variable recruitment and age-based selectivity. This updated and unpublished assessment generated two spawning potential ratio estimates (± 95 per cent confidence intervals) using the per recruit and dynamic pool methods: 0.48 (0.43–0.54) and 0.44 (0.38–0.50) respectively, indicating a high likelihood that spawning potential was above the threshold reference level of 0.30. Simultaneously generated estimates of F and natural mortality M per year were 0.045 (0.04–0.05) and 0.09, respectively, giving an F/M estimate of 0.50 (0.42–0.60), well below the threshold reference level of 0.67. The new analysis shows the breeding stock was adequate and fishing mortality sustainable at the time the sample was collected. Since then annual catches declined by about half until returning to 2005/2006 levels in the last two years.

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

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Biology

Hapuku biology [Ball et al. 2000, Paxton et al. 1989, Wakefield et al. 2010]
Biology
Species Longevity / Maximum Size Maturity (50 per cent)
Hapuku 52 years Females 1 114 mm TL Males 702 mm TL Females 7.1 years, 760 mm TL Males 6.8 years, 702 mm TL
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Distributions

Distribution of reported commercial catch of Hapuku

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Tables

Fishing methods
Commonwealth Western Australia Queensland New South Wales South Australia
Commercial
Demersal Longline
Dropline
Demersal Gillnet
Otter Trawl
Handline (mechanised)
Hand Line, Hand Reel or Powered Reels
Unspecified
Hook and Line
Charter
Various
Hook and Line
Recreational
Various
Hook and Line
Indigenous
Hook and Line
Management methods
Method Commonwealth Western Australia Queensland New South Wales South Australia
Charter
Bag limits
Gear restrictions
Licence
Limited entry
Seasonal closures
Spatial closures
Commercial
Effort limits
Gear restrictions
Licence
Limited entry
Quota
Spatial closures
Spatial zoning
Vessel restrictions
Indigenous
Bag limits
Customary fishing permits
Native Title
Section 37 (1d)(3)(9), Aboriginal cultural fishing authority
Recreational
Bag and possession limits
Bag limits
Gear restrictions
Licence
Licence (Recreational Fishing from Boat License)
Seasonal closures
Spatial closures
Active vessels
Commonwealth Western Australia Queensland New South Wales South Australia
2 in HSF, 13 in SESSF (CTS), 2 in SESSF (GABTS), 12 in SESSF (GHTS) <3 in Charter, <3 in GDSMF, 4 in WCDSIMF, 19 in WL (SC) 2 in RRFFF 12 in OTLF 0 in MSF
Charter
Tour Operator (WA)
GDSMF
Gascoyne Demersal Scalefish Managed Fishery (WA)
HSF
High Seas Fishery (CTH)
MSF
Marine Scalefish Fishery (SA)
OTLF
Ocean Trap and Line Fishery (NSW)
RRFFF
Rocky Reef Fin Fish Fishery (QLD)
SESSF (CTS)
Southern and Eastern Scalefish and Shark Fishery (Commonwealth Trawl Sector) (CTH)
SESSF (GABTS)
Southern and Eastern Scalefish and Shark Fishery (Great Australian Bight Trawl Sector) (CTH)
SESSF (GHTS)
Southern and Eastern Scalefish and Shark Fishery (Gillnet Hook and Trap Sector) (CTH)
WCDSIMF
West Coast Demersal Scalefish (Interim) Managed Fishery (WA)
WL (SC)
Open Access in the South Coast (WA)
Catch
Commonwealth Western Australia Queensland New South Wales South Australia
Commercial 310.29kg in HSF, 31.90t in SESSF (CTS), 1.13t in SESSF (GABTS), 15.28t in SESSF (GHTS) 41.91t in GDSMF, WCDSIMF, WL (SC) 45.00kg in RRFFF 1.22t in OTLF
Indigenous Unknown Unknown Unknown Unknown
Recreational Unknown West Coast: 188 fish ± 90 std err South Coast: 121 fish ± 68 Unknown Unknown
GDSMF
Gascoyne Demersal Scalefish Managed Fishery (WA)
HSF
High Seas Fishery (CTH)
OTLF
Ocean Trap and Line Fishery (NSW)
RRFFF
Rocky Reef Fin Fish Fishery (QLD)
SESSF (CTS)
Southern and Eastern Scalefish and Shark Fishery (Commonwealth Trawl Sector) (CTH)
SESSF (GABTS)
Southern and Eastern Scalefish and Shark Fishery (Great Australian Bight Trawl Sector) (CTH)
SESSF (GHTS)
Southern and Eastern Scalefish and Shark Fishery (Gillnet Hook and Trap Sector) (CTH)
WCDSIMF
West Coast Demersal Scalefish (Interim) Managed Fishery (WA)
WL (SC)
Open Access in the South Coast (WA)

Western Australia – Recreational (management methods) Recreational Fishing from Boat Licence is required for use of a powered boat to fish or to transport catch or fishing gear to or from a land-based fishing location.

Queensland – Indigenous (management methods) Under the Fisheries Act 1994 (Qld), Indigenous fishers in Queensland are entitled to use prescribed traditional and Non-commercial fishing apparatus in waters open to fishing. Size and possession limits, and seasonal closures do not apply to Indigenous fishers. Further exemptions to fishery regulations may be applied for through permits.

New South Wales – Indigenous (Management Methods) The Aboriginal Cultural Fishing Interim Access Arrangement allows an Indigenous fisher in New South Wales to take in excess of a recreational bag limit in certain circumstances—for example, if they are doing so to provide fish to other community members who cannot harvest themselves. The Aboriginal cultural fishing authority is the authority that Indigenous persons can apply to take catches outside the recreational limits under the Fisheries Management Act 1994 (NSW), Section 37 (1d)(3)(9), Aboriginal cultural fishing authority. In cases where the Native Title Act 1993 (Cth) applies fishing activity can be undertaken by the person holding native title in line with S.211 of that Act, which provides for fishing activities for the purpose of satisfying their personal, domestic or non-commercial communal needs. In managing the resource where native title has been formally recognised, the native title holders are engaged with to ensure their native title rights are respected and inform management of the State's fisheries resources. 

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Catch Chart

Commercial catch of Hapuku - note confidential catch not shown

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References

  1. AFMA 2014, Residual risk assessment. Teleost and chondrichthyan species: Report for the scalefish automatic longline method of the gillnet hook and trap sector. Australian Fisheries Management Authority.
  2. AFMA 2015, Ecological risk management: Strategy for the southern and eastern scalefish and shark fishery. Australian Fisheries Management Authority.
  3. Ball, AO, Sedberry, GR, Zatcoff, MS, Chapman, RW and Carlin, JL 2000, Population structure of the wreckfish Polyprion americanus determined with microsatellite genetic markers. Marine Biology, 137(5-6): 1077–1090.
  4. Beentjes, MP and Francis MP 1999, Movement of hapuku (Polyprion oxygeneios) determined from tagging studies. New Zealand Journal of Marine and Freshwater Research, 33(1): 1–12
  5. Chick, RC and Fowler, AM 2018, Stock status summary and stock assessment report 2018 - Ocean Trap and Line Fishery (Line Fishing – Eastern Zone). Hapuku (Polyprion oxygeneios). NSW Department of Primary Industries, Port Stephens Fisheries Institute: 32pp.
  6. Francis, MP, Mulligan, KP, Davies, NM, Beentjes, MP 1999, Age and growth estimates for New Zealand hapuku, Polyprion oxygeneios. Fishery Bulletin 97(2): 227–242.
  7. Henry, GW and Lyle, JM 2003, The national recreational and Indigenous fishing survey. Fisheries Research and Development Corporation, Canberra.
  8. 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.
  9. Macbeth, WG and Gray, CA 2015, Observer-based study of commercial line fishing in waters off New South Wales, NSW DPI – Fisheries Final Report Series No. 148. Commercial Fishing Trust Fund Project no. FSC2006/179.
  10. Martell, S and Froese, R 2013, A simple method for estimating MSY from catch and resilience. Fish and Fisheries, 14: 504–514.
  11. Paul, LR 2002, Can existing data describe the stock structure of the two New Zealand groper species, hapuku (Polyprion oxygeneios) and bass (P. americanus)? New Zealand Fisheries Assessment Report 2002/14. 24p.
  12. Paxton, JR, Hoese, DF, Allen, GR, and Hanley, JE 1989, Pisces. Petromyzontidae to Carangidae Zoological Catalogue, 7. Australian Government Publishing Service, Canberra, Australia.
  13. Penney, A, Williams, A and Hobsbawn, P 2018, SESSF Hapuku Stock Status Summary–2018
  14. Queensland Department of Agriculture and Fisheries 2018, Queensland Stock Status Assessment Workshop Proceedings 2018. Species Summaries. 19–20 June 2018, Brisbane.
  15. Roberts, CD 1996, Hapuku and bass: the mystery of the missing juveniles. Seafood New Zealand, 4: 17–21.
  16. Sedberry GR, Andrade CA, Carlin JL, Chapman RW and others 1999, Wreckfish Polyprion americanus in the North Atlantic: fisheries, biology, and management of a widely distributed and long-lived fish. American Fisheries Society Symposium 23, American Fisheries Society, Bethesda, Maryland, 27−50.
  17. Wakefield, CB, Newman, SJ and Molony, BW 2010, Age-based demography and reproduction of hapuku, Polyprion oxygeneios, from the south coast of Western Australia: implications for management. ICES Journal of Marine Science, 67(6): 1164–1174.
  18. Webley, J, McInnes, K, Teixeira, D, Lawson, A and Quinn, R 2015. Statewide Recreational Fishing Survey 2013–14. Department of Agriculture and Fisheries, Queensland Government.
  19. 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.
  20. Zhou, S, Fuller, M and Daley, R 2012, Sustainability assessment of fish species potentially impacted in the Southern and Eastern Scalefish and Shark Fishery: 2007-2010. Report to the Australia Fisheries Management Authority, Canberra, Australia.