*

VONGOLES (2018)

Katelysia spp.

  • Katherine Heldt (South Australian Research and Development Institute)
  • Anthony Hart (Department of Primary Industries and Regional Development, Western Australia)
  • John Keane (Institute for Marine and Antarctic Studies, University of Tasmania)
  • Stephen Mayfield (South Australian Research and Development Institute)
Toggle content

Summary

Vongoles are found in southern coastal waters. They occur in the intertidal zone of shallow bays and estuaries. SA has three management zones, with sustainable stocks in two and depleted stock in one. The stock in TAS is depleted. The WA stock is negligible.

Toggle content

Stock Status Overview

Stock status determination
Jurisdiction Stock Fisheries Stock status Indicators
Tasmania Ansons Bay Vongole Fishery ABVF Depleted Biomass estimate, recruitment
South Australia Coffin Bay Cockle Fishing Zone CBCFZ Sustainable Harvestable biomass estimate, recruitment
South Australia Port River Cockle Fishing Zone PRCFZ Depleted Harvestable biomass estimate, recruitment
South Australia West Coast Cockle Fishing Zone WCCFZ Sustainable Harvestable biomass estimate, recruitment
Western Australia Western Australia Vongole Fishery WAVF Negligible
ABVF
Ansons Bay Vongole Fishery (TAS)
CBCFZ
Coffin Bay Cockle Fishing Zone (SA)
PRCFZ
Port River Cockle Fishing Zone (SA)
WAVF
Western Australian Vongole Fishery (WA)
WCCFZ
West Coast Cockle Fishing Zone (SA)
Toggle content

Stock Structure

Vongole (Katelysia spp.) is a species complex that inhabits southern coastal waters from Augusta in Western Australia to Port Jackson in New South Wales. They are found on sand banks in shallow bays and estuaries from the intertidal zone to a depth of 5 m [Cantin 2010]. Stock structure is unknown. However, given the short larval life span, ~16 days for K. rhytiphora hatchery animals [Gluis and Li 2014], it is likely that Vongole in individual bays would constitute separate stocks.

Due to the potential for there to be a large number of stocks, assessment of stock status is presented at the management unit level—Western Australian Vongole Fishery; Ansons Bay Vongole Fishery (Tasmania); Coffin Bay Cockle Fishing Zone, Port River Cockle Fishing Zone, and West Coast Cockle Fishing Zone (South Australia).

Toggle content

Stock Status

Ansons Bay Vongole Fishery

The harvest strategy for Vongole in Tasmania in the Shellfish Fishery Policy Document [DPIW 2007] uses biomass and size-composition as performance indicators but does not define a limit reference point below which the stock would be classified as recruitment overfished. Biomass surveys of the Ansons Bay Vongole fishery are conducted every 2–3 years with total allowable commercial catches (TACC s) determined to be up to 10 per cent of the biomass estimate (at the 95 per cent confidence interval).

The 2018 estimate of biomass available to the Ansons Bay Vongole Fishery was 23.61 t (19.49–27.73 t), a level that is 11.6 per cent of the peak biomass recorded in 2001. Exploitation rates have been below the maximum of 10 per cent and minimum legal limits (32 mm shell length [SL ]) are set at a size that enables the majority of Vongole to reproduce at least once prior to being available for harvest.

Despite these measures, large stock declines occurred in 2014 and in 2015 there was no evidence of recruitment (no pre-recruits or juveniles identified). The Ansons Bay Vongole Fishery has been closed to commercial fishing from 1 September 2015 on the basis of being recruitment impaired.

The 2018 biomass estimate was the lowest on record and is likely attributable to a combination of mortality of Vongole as a result of extreme rainfall and flood events in the north-east of Tasmania in 2014, followed by recruitment failure in 2015–17 [Keane and Gardner 2017]. Low abundances of juveniles were observed in the 2018 survey but are unlikely to lead to significant stock rebuilding in the short term. The above evidence indicates that spawning stock biomass is likely to have been depleted to the point where average recruitment levels are significantly impaired, primarily as a result of substantial environmental impacts.

On the basis of the evidence provided above, the Ansons Bay Vongole Fishery (Tasmania) management unit is classified as a depleted stock.

Coffin Bay Cockle Fishing Zone

The Coffin Bay Cockle Fishing Zone (CBCFZ) encompasses four principal fishing grounds that are sampled on a triennial basis with at least one principal fishing ground sampled annually on a rotational basis with lower intensity sampling occurring outside the principal area. The 2017 estimate of harvestable biomass in the CBCFZ was 791.8 t and is similar to previous estimates (i.e. 867.7 t, whole weight, from fishery-wide sampling in 2015 and 730.4 t in 2016). As the TACC was 50 t, this represented a harvest rate of 6.3 per cent which is below the maximum exploitation rate of 7.5 per cent prescribed in the harvest strategy [PIRSA 2013]. There was also some evidence of recent recruitment in 2017, noting that recruitment is known to be sporadic [Dent et al. 2016], and that setting of appropriate minimum legal lengths enables a majority of Vongole to reproduce prior to being available for harvest, based on estimates of size at first maturity [Dent et al. 2012, Gorman et al. 2009]. 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 above 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, the Coffin Bay Cockle Fishing Zone (South Australia) management unit is classified as a sustainable stock.

Port River Cockle Fishing Zone

The Port River Cockle Fishing Zone (PRCFZ) was historically important with significant catches reported prior to 2009. The first biomass survey conducted in 2009 estimated that there was low biomass in the PRCFZ [Gorman et al. 2009], but the causes of this biomass decline are unclear. Due to ongoing sustainability concerns, the PRCFZ has been closed to the taking of Vongole by all fishing sectors since 2011–12. Even without fishing mortality, the stocks have not recovered from a depleted state. Biomass surveys in early 2016 showed lack of stock recovery, and a project to develop stock enhancement methods is underway. The above evidence indicates that the biomass of this stock is likely to be depleted and that recruitment is likely to be impaired. Furthermore, the above evidence indicates that there has been no detection of measurable improvements and that the stock has yet to recover from its recruitment impaired state despite management constraints on fishing mortality.

On the basis of the evidence provided above, the Port River Cockle Fishing Zone (South Australia) management unit is classified as a depleted stock.

West Coast Cockle Fishing Zone

The West Coast Cockle Fishing Zone (WCCFZ) encompasses Smoky Bay, Streaky Bay and Venus Bay, with the total TACC set at 16 t. Triennial surveys provide estimates of biomass for each species with each bay being sampled every third year. As a different bay is sampled each year, the weight of evidence is based on the combined sum of harvestable biomass estimates (at 80 per cent probability level) across three years [i.e. Venus Bay in 2015, Streaky Bay in 2016, and Smoky Bay in 2017]. The 2015–17 estimate of harvestable biomass in the WCCFZ was 490 t, which resulted in a low harvest fraction of 3.3 per cent, and thus, the exploitation rate was below the maximum of 7.5 per cent prescribed in the harvest strategy [PIRSA 2013]. There is evidence of recent recruitment of K. rhytiphora in Smoky Bay that occurred between 2015–18 and low level recruitment in Streaky Bay in 2016. Recruitment is sporadic [Dent et al. 2016], and minimum legal lengths in place enable Vongole to reproduce at least once prior to being available for harvest, based on estimates of size at first maturity [Dent et al. 2012, Gorman et al. 2009]. 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 above 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, the West Coast Cockle Fishing Zone (South Australia) management unit is classified as a sustainable stock.

Western Australia Vongole Fishery

Stock status for the Western Australia management unit is reported as Negligible due to low catches by this jurisdiction. The Western Australian harvest was 0.1 tonnes (t) or less in 2004, 2005, 2012–2014 and 2017; and zero in other years. Low levels of fishing effort and thus fishing mortality are unlikely to be having a negative impact on the stock.

Toggle content

Biology

Vongole biology [Dent et al. 2010, Dent et al. 2012, Gorman et al. 2009, Riley et al. 2005]

Biology
Species Longevity / Maximum Size Maturity (50 per cent)
VONGOLES 29 years, 55 mm SL   4 years, 23–31 mm SL * [*Note that differences in maturity (50 per cent) occur among species and locations]
Toggle content

Distributions

Distribution of reported commercial catch of VONGOLES
Toggle content

Tables

Fishing methods
Western Australia Tasmania South Australia
Commercial
Hand collection
Rake
Indigenous
Hand collection
Rake
Bait Pump
Recreational
Hand collection
Rake
Bait Pump
Management methods
Method Western Australia Tasmania South Australia
Commercial
Gear restrictions
Limited entry
Size limit
Spatial closures
Temporal closures
Total allowable catch
Indigenous
Bag limits
Size limit
Spatial closures
Recreational
Bag and possession limits
Bag limits
Size limit
Spatial closures
Active vessels
Western Australia Tasmania South Australia
<3 in SCEMF 8 in CBCFZ, 0 in PRCFZ, 4 in WCCFZ
CBCFZ
Coffin Bay Cockle Fishing Zone (SA)
PRCFZ
Port River Cockle Fishing Zone (SA)
SCEMF
South Coast Estuarine Managed Fishery (WA)
WCCFZ
West Coast Cockle Fishing Zone (SA)
Catch
Western Australia Tasmania South Australia
Commercial 31.47t in CBCFZ
Indigenous Unknown Unknown
Recreational Unknown 12 805 ± 12, n = 574 individuals or 0.14 t per year (2013–14)
CBCFZ
Coffin Bay Cockle Fishing Zone (SA)

Active Vessels Vongole can be collected from beaches and bay on foot therefore, ‘vessels’ are not always used. Hence, numbers of licences and fishers are presented here instead of vessel numbers. Licences refer to the number of licence holders with an endorsement to take Vongole for sale.   

Toggle content

Catch Chart

Commercial catch of VONGOLES - note confidential catch not shown
Toggle content

References

  1. Cantin, A 2010, Population biology of two sympatric mud cockles, Katelysia peronii and K. scalarina (Bivalvia: Veneridae), with implications for their management, PhD thesis, Flinders University, Adelaide.
  2. Dent, J, Mayfield, S and Carroll, J 2016, Harvestable biomass of Katelysia spp. in the South Australian commercial Mud Cockle Fishery, Report to Primary Industries and Regions South Australia, Fisheries and Aquaculture, SARDI Publication F2014/000191-2, SARDI Research Report Series 898, SARDI, Adelaide.
  3. Dent, J, Mayfield, S, Burch, P, Gorman, D and Ward, TM 2012, Distribution, harvestable biomass and fisheries biology of Katelysia spp. in the South Australian commercial Mud-Cockle Fishery, Fishery assessment report for Primary Industries and Regions South Australia Fisheries and Aquaculture, SARDI Publication F2010/000263-2, SARDI Research Report Series 595, South Australian Research and Development Institute (Aquatic Sciences), Adelaide.
  4. Dent, J, Mayfield, S, Ferguson, G, Carroll, J and Burch, P 2014, Harvestable biomass of Katelysia spp. In the South Australian commercial Mud Cockle Fishery, Fishery assessment report for Primary Industries and Regions South Australia Fisheries and Aquaculture, SARDI publication F2014/000191-1, SARDI research report series 766, South Australian Research and Development Institute (Aquatic Sciences), Adelaide.
  5. Department of Primary Industries and Water 2007, Shellfish fishery policy document, Wild Fisheries Management Branch, DPIW, Hobart.
  6. Gluis, MR and Li, X 2014, Hatchery manual for larval rearing of Vongole Katelysia rhytiphora, Fisheries Research and Development Corporation Project 2009/208, South Australian Research and Development Institute (Aquatic Sciences), Adelaide.
  7. Gorman, D, Mayfield, S, Burch, P and Ward, TM 2010, Distribution, harvestable biomass and fisheries biology of Katelysia spp. In the South Australian commercial mud cockle fishery, Fishery assessment report for PIRSA Fisheries, SARDI Publication F2010/000263-1, SARDI Research Report Series 442, South Australian Research and Development Institute (Aquatic Sciences), Adelaide.
  8. Keane, JP and Gardner, C 2017, 2017 Small Bivalve Fishery assessment. Institute for Marine and Antarctic Studies Report, University of Tasmania, Hobart.
  9. Primary Industries and Regions South Australia 2013, Management plan for the South Australian Commercial Marine Scalefish Fishery, South Australian Fisheries Management Series: Paper 59, PIRSA, Adelaide.
  10. Riley, SP, Green, RM, Zacharin, W and Maguire, GB 2005, Growth models and age determination for the intertidal venerid clam Katelysia scalarina (Lamarck 1818) from three sites in Tasmania, Australia, Fisheries Research and Development Corporation Project 93/232, in GB Maguire (ed) Enhancing Tasmanian clam resources, FRDC, Tasmania.
  11. Steer, MA, Fowler, AJ, McGarvey, R, Feenstra, J, Westlake, EL, Matthews, D, Drew, M, Rogers, PJ and Earl, J 2018. Assessment of the South Australian Marine Scalefish Fishery in 2016. Report to PIRSA Fisheries and Aquaculture.SARDI Publication No. F2017/000427-1, SARDI Research Report Series 974, South Australian Research and Development Institute (Aquatic Sciences), Adelaide.

Archived reports

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