*

Swordfish (2018)

Xiphias gladius

  • Heather Patterson (Australian Bureau of Agricultural and Resource Economics and Sciences)

You are currently viewing a report filtered by jurisdiction. View the full report.

Toggle content

Summary

The migratory Swordfish is caught in in Commonwealth waters from two distinct biological stocks. The stocks internationally managed are found in the Indian Ocean and the Pacific Ocean. Both stocks are sustainable.

Toggle content

Stock Status Overview

Stock status determination
Jurisdiction Stock Fisheries Stock status Indicators
Commonwealth South-West Pacific Ocean ETBF, WCPFC Sustainable Spawning stock biomass, fishing mortality
Commonwealth Indian Ocean IOTC, WTBF Sustainable Spawning stock biomass, fishing mortality
ETBF
Eastern Tuna and Billfish Fishery (CTH)
IOTC
Indian Ocean Tuna Commission (CTH)
WCPFC
Western and Central Pacific Fisheries Commission (CTH)
WTBF
Western Tuna Billfish Fishery (CTH)
Toggle content

Stock Structure

Swordfish in the Indian and Pacific Oceans are considered to be two distinct biological stocks and are managed as such under separate regional fisheries management organisations. In the Indian Ocean, genetic research has not indicated more than a single biological stock [Muths et al. 2013]. In the Pacific Ocean, genetic studies have suggested the presence of several biological stocks [Takeuchi et al. 2017], although the degree of genetic variation among these stocks is low [Kasapidis et al. 2008]. Electronic tagging has indicated that there may be limited connectivity between eastern and western parts of the Tasman and Coral Seas [Evans et al. 2012, Sharma and Herrera 2014]. Although considered to be a single biological stock, two sub-stocks are currently assessed in the Pacific Ocean: the South-west Pacific stock and the North Pacific stock. Only the South-west Pacific stock is fished by Australian fishers. The Indian Ocean biological stock falls under the jurisdiction of the Indian Ocean Tuna Commission; and the western and central Pacific Ocean stock falls under the jurisdiction of the Western and Central Pacific Fisheries Commission. These two commissions are intergovernmental organisations established to manage a number of highly migratory fish species.

Here, status is presented at the biological stock level—Indian Ocean; and at the management unit level—South West Pacific Ocean.

Toggle content

Stock Status

Indian Ocean

The Indian Ocean biological stock of Swordfish is fished by Australian fishers endorsed to fish in the Western Tuna and Billfish Fishery (Commonwealth), and members of the Indian Ocean Tuna Commission. The assessments undertaken by the Indian Ocean Tuna Commission take into account information from all jurisdictions.

In the Indian Ocean, the most recent assessment [IOTC 2017] estimates that biomass in 2015 was 31 per cent of the unfished level (range 26–43 per cent). The biological stock is not considered to be recruitment impaired [Williams et al. 2018]. This assessment estimated that fishing mortality in 2013 was below the level associated with maximum sustainable yield (MSY) (76 per cent of fishing mortality at MSY; range 41–104 per cent). This level of fishing mortality is unlikely to cause the biological stock to become recruitment impaired [Williams et al. 2018].

Based on the evidence provided above, the Indian Ocean biological stock is classified as a sustainable stock.

South-West Pacific Ocean

The South-west Pacific Ocean management unit of Swordfish is fished by Australian fishers endorsed to fish in the Eastern Tuna and Billfish Fishery (Commonwealth), and members of the Western and Central Pacific Fisheries Commission. The assessments undertaken for the Western and Central Pacific Fisheries Commission (WCPFC) take into account information from all jurisdictions.

At the time of the most recent assessment [Takeuchi et al. 2017], median spawning biomass across the uncertainty grid of the Swordfish management unit was 35 per cent and ranged from 29–43 per cent of initial unfished spawning biomass. There was a very low probability that the recent spawning biomass has breached the limit reference point [WCPFC 2017]. The management unit is therefore not considered to be recruitment impaired [Larcombe et al. 2018, WCPFC 2018].

The median recent fishing mortality was 86 per cent of the level of fishing associated with MSY [Takeuchi et al. 2017], with a range of 51–123 per cent. There was an approximately 32 per cent probability that the recent level of fishing mortality was above the level that results in MSY [WCPFC 2017]. The assessment of the current level of fishing pressure is therefore considered unlikely to cause the management unit to become recruitment impaired [Larcombe et al. 2018].

Based on the evidence provided above, the South-West Pacific Ocean management unit is classified as a sustainable stock.

Toggle content

Biology

Swordfish biology [Farley et al. 2016, Froese and Pauly 2009]

Biology
Species Longevity / Maximum Size Maturity (50 per cent)
Swordfish 30+ years, 4 550 mm FL  Females: ~4.4 years, ~1 815 mm FL Males: ~1 years, ~1 200 mm FL (Fork length is measured from the lower jaw for Swordfish)
Toggle content

Distributions

Distribution of reported commercial catch of Swordfish
Toggle content

Tables

Fishing methods
Commonwealth
Commercial
Hook and Line
Pelagic Longline
Danish Seine
Purse Seine
Various
Handline
Recreational
Hook and Line
Management methods
Method Commonwealth
Commercial
Area restrictions
Catch limits
Gear restrictions
Individual transferable quota
Limited entry
Recreational
Bag limits
Active vessels
Commonwealth
39 in ETBF, 3 in WTBF
ETBF
Eastern Tuna and Billfish Fishery (CTH)
WTBF
Western Tuna Billfish Fishery (CTH)
Catch
Commonwealth
Commercial 1.18Kt in ETBF, 53.66Kt in IOTC, 21.99Kt in WCPFC, 166.00t in WTBF
Indigenous Unknown
Recreational Unknown
ETBF
Eastern Tuna and Billfish Fishery (CTH)
IOTC
Indian Ocean Tuna Commission (CTH)
WCPFC
Western and Central Pacific Fisheries Commission (CTH)
WTBF
Western Tuna Billfish Fishery (CTH)

Commonwealth Commercial (catch) Catches reported for the Indian Ocean Tuna Commission and Western and Central Pacific Fisheries Commission are for 2016, the most recent year available; data for Eastern Tuna and Billfish Fishery and Western Tuna Billfish Fishery are for 2017. Western and Central Pacific Fisheries Commission catches are for the entire South Pacific Ocean (south of the equator).

Commonwealth – Recreational The Australian Government does not manage recreational fishing in Commonwealth waters. Recreational fishing in Commonwealth waters is managed by the state or territory immediately adjacent to those waters, under its management regulations.

Commonwealth – Recreational and Indigenous Recreational and Indigenous fishing sectors in the Indian Ocean are South Australia, Victoria and Western Australia. Recreational sectors in the Pacific Ocean are New South Wales, Queensland and Tasmania. Measures listed here exist in at least one of these jurisdictions.

Commonwealth – Indigenous The Australian Government does not manage non-commercial Indigenous fishing in Commonwealth waters, with the exception of the Torres Strait. In general, non-commercial Indigenous fishing in Commonwealth waters is managed by the state or territory immediately adjacent to those waters.

Toggle content

Catch Chart

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

References

  1. Evans, K, Kolody, D, Abascal, F, Holdsworth, J, Maru, P and Sippel, T 2012, Spatial dynamics of swordfish in the South Pacific Ocean inferred from tagging data, information paper WCPFC-SC8-2012/SA-IP-05, Western Central Pacific Fisheries Commission Scientific Committee eighth regular session, Busan, Republic of Korea, 7–15 August 2012.
  2. Farley, J, Clear, N, Kolody, D, Krusic-Golub, K, Eveson, P and Young, J 2016, Determination of swordfish growth and maturity relevant to the southwest Pacific stock, working paper WCPFC-SC12-2016/SA-WP-11, Western Central Pacific Fisheries Commission Scientific Committee twelfth regular session, Bali, Indonesia, 3–11 August 2016.
  3. Froese, R and Pauly, DE 2009, FishBase, version 06/2016, FishBase Consortium. www.fishbase.org
  4. Indian Ocean Tuna Commission, 2017, Report of the Twentieth Meeting of the Scientific Committee, Mahe, Seychelles, 30 November – 4 December 2017.
  5. Kasapidis, P, Magoulas, A, Gacía-Cortés, B and Mejuto, J 2008, Stock structure of Swordfish (Xiphias gladius) in the Pacific Ocean using microsatellite DNA markers, working paper WCPFC-SC4-2008/BI-WP-04, Western and Central Pacific Fisheries Commission Scientific Committee fourth regular session, Papua New Guinea, 11–22 August 2008.
  6. Larcombe, J, Patterson, H and Mobsby, D 2018, Eastern Tuna and Billfish Fishery, in H Patterson, J Larcombe, S Nicol and R Curtotti (eds), Fishery status reports 2018, Australian Bureau of Agricultural and Resource Economics and Sciences, Canberra, pp 359–382.
  7. Muths, D, LeCouls, S, Evano, H, Grewe, P and Bourjea, J 2013, Multi-genetic marker approach and spatio-temporal analysis suggest there is a single panmictic population of Swordfish Xiphias gladius in the Indian Ocean, PLoS One, 8: e63558, doi:10.1371/journal.pone.0063558.
  8. Sharma, R and Herrera, M 2014, An age-, sex- and spatially-structured stock assessment of the Indian Ocean swordfish fishery 1950–2012, using Stock Synthesis, working paper IOTC-2014-WPB12-26_Rev 2, Indian Ocean Tuna Commission Working Party on Billfish twelfth session, Tokyo, Japan, 21–25 October 2014.
  9. Takeuchi, Y, Pilling, G and Hampton, J 2017, ‘Stock assessment of swordfish (Xiphias gladius) in the southwest Pacific Ocean’, working paper WCPFC-SC13-2017/SA-WP-013, WCPFC Scientific Committee thirteenth regular session, Rarotonga, Cook Islands, 9–17 August 2017.
  10. Western and Central Pacific Fisheries Commission 2017, Summary report of the thirteenth regular session of the Scientific Committee for the Western and Central Pacific Fisheries Commission, Rarotonga, Cook Islands, 9–17 August 2017.
  11. Western and Central Pacific Fisheries Commission 2018, Summary report of the fourteenth regular session of the Scientific Committee for the Western and Central Pacific Fisheries Commission, Busan, Republic of Korea, 8–16 August 2018.
  12. Williams, A, Patterson, H and Mobsby, D 2018, Western Tuna and Billfish Fishery, in H Patterson, J Larcombe, S Nicol and R Curtotti (eds), Fishery status reports 2018, Australian Bureau of Agricultural and Resource Economics and Sciences, Canberra, pp 404–421.

Downloadable reports

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