Biodiversity

Species Profile and Threats Database


For information to assist proponents in referral, environmental assessments and compliance issues, refer to the Policy Statements and Guidelines (where available), the Conservation Advice (where available) or the Listing Advice (where available).
 
In addition, proponents and land managers should refer to the Recovery Plan (where available) or the Conservation Advice (where available) for recovery, mitigation and conservation information.

EPBC Act Listing Status Listed as Conservation Dependent
Listing and Conservation Advices Non-current Commonwealth Listing Advice on Thunnus maccoyii (Southern Bluefin Tuna) (Threatened Species Scientific Committee (TSSC), 2005bv) [Listing Advice].
 
Commonwealth Listing Advice on Thunnus maccoyii (Southern Bluefin Tuna) (Threatened Species Scientific Committee (TSSC), 2010aw) [Listing Advice].
 
Adopted/Made Recovery Plans
Policy Statements and Guidelines Marine bioregional plan for the South-west Marine Region (Department of Sustainability, Environment, Water, Population and Communities (DSEWPaC), 2012z) [Admin Guideline].
 
Information Sheets Southern bluefin tuna listed as conservation dependent (Department of the Environment, Water, Heritage and the Arts (DEWHA), 2010n) [Information Sheet].
 
Southern bluefin tuna decisions - Frequently asked questions (Department of the Environment, Water, Heritage and the Arts (DEWHA), 2010o) [Information Sheet].
 
Federal Register of
    Legislative Instruments
Amendment to the list of threatened species under section 178 of the Environment Protection and Biodiversity Conservation Act 1999 (100) (23/11/2010) (Commonwealth of Australia, 2010f) [Legislative Instrument].
 
State Government
    Documents and Websites
NSW:Endangered species - southern bluefin tuna (NSW Department of Primary Industries (NSW DPI), 2005g) [Internet].
VIC:Flora and Fauna Guarantee Action Statement no. 197: Southern Bluefin Tuna Thunnus maccoyii (Holliday, I., 2003b) [Information Sheet].
State Listing Status
VIC: Listed as Threatened (Flora and Fauna Guarantee Act 1988 (Victoria): February 2014 list)
Non-statutory Listing Status
IUCN: Listed as Critically Endangered (Global Status: IUCN Red List of Threatened Species: 2013.1 list)
Scientific name Thunnus maccoyii [69402]
Family Scombridae:Perciformes:Actinopterygii:Chordata:Animalia
Species author Castelnau, 1872
Infraspecies author  
Reference  
Distribution map Species Distribution Map

This is an indicative distribution map of the present distribution of the species based on best available knowledge. See map caveat for more information.

Illustrations Google Images

Scientific name: Thunnus maccoyii

Common name: Southern Bluefin Tuna

Conventionally accepted as Thunnus maccoyii (AFD 2010).

The Southern Bluefin Tuna is one of 13 species of tuna in the Family Scombridae. The Southern Bluefin Tuna is a long and muscular fish, with a fusiform and rounded body that is nearly circular in cross section. They are dark blue to black on the dorsal surface and silvery white on the lower sides and belly. They have colourless transverse lines alternating with rows of colorless dots and small scales covering the skin. There are two dorsal fins, the first dorsal fin is yellow or bluish, the anal fin and the finlets are dusky yellow edged with black. Keels are present near the tail and are coloured yellow in adults (Carpenter & Niem 2001).

Southern Bluefin Tuna can grow to 225 cm in length and 200 kg in weight. However, adults are more commonly recorded at around 160 cm (Carpenter & Niem 2001; Phillips et al. 2009). Length-weight correlations are variable in adult fish, depending on physiological conditions (Collette & Nauen 1983). Juveniles recruit to the aggregations of adults at lengths around 55 cm and weighing around 3.5 kg (Phillips et al. 2009).

Adult Southern Bluefin Tuna in Australian waters, ranges widely from northern Western Australia (WA) to the southern region of the continent, including Tasmania, and to northern New South Wales, appearing in eastern Australian waters mainly during winter (Caton 1991; CCSBT 2009; Honda et al. 2010; NSW DPI FSC n.d.). Juveniles of one to two years of age inhabit inshore waters in WA and South Australia (Honda et al. 2010).

The Southern Bluefin Tuna is highly migratory, occurring globally in waters between 30–50° S, though the species is mainly found in the eastern Indian Ocean and in the south-west Pacific Ocean. There is a single known spawning ground between Java and northern WA (TSSC 2010aw).

Australian fisheries context

Juvenile Southern Bluefin Tuna are targeted in the Great Australian Bight by Australian purse seine fishing vessels, and towed to Port Lincoln where they are transferred to grow-out cages and fed intensively for 6–8 months before being harvested and exported to Japan. At the time of capture, these juvenile fish are predominantly in the two to three year age class, with small numbers of one and four year old fish (Phillips et al. 2009). More than 95% of Australia’s total catch of the species is taken by this method (TSSC 2010aw).

Throughout the rest of its global range, Southern Bluefin Tuna are targeted by pelagic longliners, including domestic longliners operating along the Australian east coast. Longliners harvest fish from all age classes, from juveniles about three years old to adults over 12 years old (Phillips et al. 2009).

The Southern Bluefin Tuna is found in the south-west and south-east Atlantic Ocean, eastern and western Indian Ocean and the south-west Pacific Ocean (IUCN 2010).

In 2009 there were an estimated 460 000 mature individuals of Southern Bluefin Tuna (CCSBT 2009a). The species is considered to have a single global population.

The Southern Bluefin Tuna is a slow-growing, long-lived species (NSW DPI FSC n.d.). Individuals reach sexual maturity at approximately 11–12 years and live for 40+ years. The generation length for the species has been estimated to be 16–18 years (NSW DPI FSC n.d.; Gunn et al. 2008; Phillips et al. 2009). The species is warm blooded, maintaining body temperature above ambient water temperatures via counter-current heat exchangers (Carpenter & Niem 2001).

Spawning

A single spawning ground for the Southern Bluefin Tuna is known, in the Indian Ocean between northern WA and Java (7–20° S) (Caton 1991; NSW DPI FSC n.d). The southern most portion of this spawning ground lies within Australia's Exclusive Economic Zone (Phillips & Findlay 2008). Spawning occurs from August–April with a peak from October–February (Honda et al. 2010). Spawning takes place close to the surface in warmer water of 24 °C or greater, which is suggested to be important for egg and larvae survival. Spawning frequency may increase as the female increases in size after maturity. One study showed larger females able to spawn on average every 1.1 days. Spawning in females is not synchronised and the spawning period of each female is not known (Davis & Farley 2001; Farley & Davis 1998). A single female can release up to 15 million eggs during a spawning period, and it is not known whether all mature fish spawn each year (Collette & Nauen 1983). Post spawning, females move south into cooler waters to feed and regain body condition (Farley & Davis 1998).

Juvenile Southern Bluefin Tuna

Juvenile Southern Bluefin Tuna move from spawning grounds within a few months of hatching, most likely utilising the Leeuwin current to help them reach warmer waters around the Great Australian Bight where they stay through summer and move away during winter (NSW DPI FSC n.d). Young fish are known to migrate seasonally between the south coast of Australia and the central Indian Ocean (CCSBT 2009).

Adult Southern Bluefin Tuna

Adults from three years or older are often found in the region of 40–45° S known as the "West Wind Drift" (Caton 1991). After five years of age, Southern Bluefin Tuna are seldom found in near shore surface areas, and their distribution extends over the southern circumpolar area throughout the Pacific, Indian and Atlantic Oceans (CCSBT 2009).

The Southern Bluefin Tuna is described as a high-level apex predator and an opportunistic feeder, preying on a wide variety of fishes, crustaceans, cephalopods, salps, and other marine animals. As larvae, the species mainly consumes microcrustacea and macrozooplanktonic crustacea, and some cannibalism does occur (Caton 1991). As juveniles, a large proportion of the Southern Bluefin Tuna's diet consists of sardines (Ward et al. 2006). Smaller adult Southern Bluefin Tuna feed mainly on crustaceans, and larger adults on fish in deeper, colder waters (Caton 1991; Davis & Farley 2001).

Southern bluefin tuna are highly migratory, occurring globally in waters between 30–50° S, though the species is mainly found in the eastern Indian Ocean and in the south-west Pacific Ocean (TSSC 2010aw). Tuna are suggested to congregate at seamounts, lumps and reefs in the Great Australian Bight where prey species also congregate, and to move depending on water masses, such as influxes of nutrient rich sub-Antarctic waters, and sea temperatures (Fujioka et al. 2010). The species can travel up to 70 km/hr while feeding (TSSC 2010aw).

The Southern Bluefin Tuna's range is associated with age and feeding patterns. Adult southern bluefin tuna in Australian waters range widely from northern WA to the southern region of the continent, including Tasmania, and to northern NSW, appearing in eastern Australian waters mainly during winter (Caton 1991; NSW FSC no date; CCSBT 2009; Honda et al. 2010). Juveniles of one to two years of age inhabit inshore waters in WA and SA (Honda et al. 2010).

Migration to spawning grounds

When moving to spawning grounds, Southern Bluefin Tuna are recorded as favouring temperatures between 19–21 °C, and adjusting their depth of swimming to the vertical temperature distribution. Distinct diurnal diving patterns were observed with adjustment of water depth to maintain constant ambient light levels over a 24 hour period. During this migration, individuals may spend up to 84% of their time within the Australian Fishing Zone (Patterson et al. 2008).

Southern Bluefin Tuna are distinguished from the Bluefin Tuna (Thunnus thynnus), which is mainly found in the northern hemisphere, by the yellow median caudal keel that is dark in the Bluefin Tuna. Southern Bluefin Tuna also have a relatively longer adult pectoral fin (20–23% of length to caudal fork compared with 17–22% in the Bluefin Tuna (Caton 1991). Longtail tuna (Thunnus tonggol) may also be mistaken for Southern Bluefin Tuna, but are distinguished by their shorter pectoral fins and dark caudal keels (NSW DPI 2005g).

Commercial fishing

Commercial fishing is the major threat to the Southern Bluefin Tuna (TSSC 2010aw). The species has undergone very severe reduction in numbers as a result of heavy fishing pressure throughout its range. The Scientific Committee of the Commission for the Conservation of Southern Bluefin Tuna (CCSBT) completed a revised stock assessment of Southern Bluefin Tuna in 2009 (CCSBT 2009). This assessment estimated that the spawning stock biomass of the species was at around 5% or less of unfished levels. The stock assessment also indicated a general decline in recruitment since about 1970, coincident with declining spawning stock sizes. There were four particularly poor recruitment years from 1999–2002, and indications of some further poor recruitment after 2004, which will lead to a further decline in spawning stock biomass (CCSBT 2009a). On the basis of these findings of the stock assessment, the CCSBT recommended the immediate implementation of measures to reduce catch quotas (CCSBT 2009a).

The Southern Bluefin Tuna is one of the most highly valued fish species for sashimi, especially in Japan. The high price paid for the fish encourages targeted fishing, even when stock levels and catch rates are very low (Phillips et al. 2009). It is targeted by fishing fleets from a number of nations, both on the high seas and in the Exclusive Economic Zones of Australia, New Zealand, Indonesia and South Africa (Phillips et al. 2009). Though reasonably fecund, the single known spawning area of the species and the long maturity period means juveniles, most targeted by fishing, are vulnerable to over exploitation (NSW DPI FSC n.d.).

Historic

Commercial fishing for the species began off south-eastern Australia in the 1930s. The species was heavily fished in the 1950s and 1960s, predominantly by Japanese vessels, with the annual global catch peaking at over 81 000 tonnes in the early 1960s (Phillips et al. 2009). There have been continuous stock declines since the 1950s with a very low stock level recorded in the mid 1990s. Further declines were recorded in 2002 and there has been no evidence of stock rebuilding in 2009 (TSSC 2010aw).

Ongoing fishing pressure

Juvenile Southern Bluefin Tuna (20 kg, 2–4 year old fish) are targeted in the Great Australian Bight by Australian purse seine fishers that corral fish which are fed in grow-out pontoons until a harvestable weight is reached. This method targets surface schooling fish and can remain profitable even if low catch rates render pelagic longlining commercially non viable. Fish are caught from December to May, kept and fed for approximately three months or till a marketable size which may be up to eight months. Management issues related to this method include diet and disease associated with penning (Glencross et al 2002; Munday et al. 1997; Phillips et al. 2009). In 2007–08, 99.6% of Australian Southern Bluefin Tuna were harvested using nets and grow-out pontoons (Phillips et al. 2009).

Outside of the Great Australian Bight, Southern Bluefin Tuna are harvested as bycatch by pelagic longliners. Longliners harvest fish from all age classes, from three year old juveniles to adults over 12 years old (Phillips et al. 2009). In 2007–08, this catch constituted 0.4% of the total Australian Southern Bluefin Tuna harvest (Phillips et al. 2009).

Commission for the Conservation of Southern Bluefin Tuna

The Southern Bluefin Tuna is fished by many nations, with Japan, Australia, New Zealand, the Republic of Korea, Taiwan and Indonesia identified as the major nations catching the species commercially (TSSC 2010aw). Given the highly migratory nature of the single stock, cooperative management of the species is undertaken between these countries through the forum of the CCSBT. Established in 1995, the CCSBT was set up in response to concerns about the status of the Southern Bluefin Tuna. It is an organisation based on international consensus that sets national allocations of Total Allowable Catch (TAC) for Member countries, as well as prescribing additional management measures that must be adhered to by Members (TSSC 2010aw).

In addition to allocating TAC to Member countries, the CCSBT also allocates a portion of the global catch of Southern Bluefin Tuna to Cooperating Non Member countries. These are nations with developing fisheries, such as South Africa, the Philippines and the European Union (particularly Spain) (TSSC2010aw).

Australia’s position within the CCSBT is negotiated primarily by the Department of Agriculture, Fisheries and Forestry, with support from other agencies, independent Australian scientists, fishing industry representatives and non-government organisations (TSSC 2010aw). Once the national allocations are agreed within the CCSBT, the day to day management of Australia’s share of the global catch is managed by the Australian Fisheries Management Authority through the Southern Bluefin Tuna Management Plan 1995 (DAFF 1995), having regard to the management measures negotiated within the CCSBT (TSSC 2010aw).

Resolution of the 18th meeting of the CCSBT

In July 2011, a MP (known as the 'Bali Procedure') was reccomended by the CCSBT Scientific Committee. During 10–13 October 2011, the 18th meeting was held and the procedure was adopted by the Extended Comission. The timelines and the total allowable catch parameters outlined (CCSBT 2011) in the agreed MP could be adjusted pending future information. The MP has a 70% probability of rebuilding stock to the interim rebuilding target reference point of 20% of the original spawning stock biomass by 2035 (CCSBT 2011).

Marine bioregional plans have been developed for four of Australia's marine regions - South-west, North-west, North and Temperate East. Marine Bioregional Plans will help improve the way decisions are made under the EPBC Act, particularly in relation to the protection of marine biodiversity and the sustainable use of our oceans and their resources by our marine-based industries. Marine Bioregional Plans improve our understanding of Australia's oceans by presenting a consolidated picture of the biophysical characteristics and diversity of marine life. They describe the marine environment and conservation values of each marine region, set out broad biodiversity objectives, identify regional priorities and outline strategies and actions to address these priorities. Click here for more information about marine bioregional plans.

The southern bluefin tuna has been identified as a conservation value in the South-west Marine Region. The "species group report card - bony fishes" for the South-west Marine Region provides additional information.

Management documents for the Southern Bluefin Tuna include:

  • Southern Bluefin Tuna Management Plan 1995 (DAFF 1995)
  • Resolution on the Total Allowable Catch and Future Management of Southern Bluefin Tuna (CCSBT 2009).

The following table lists known and perceived threats to this species. Threats are based on the International Union for Conservation of Nature and Natural Resources (IUCN) threat classification version 1.1.

Threat Class Threatening Species References
Biological Resource Use:Fishing and Harvesting Aquatic Resources:Commercial harvest Commonwealth Listing Advice on Thunnus maccoyii (Southern Bluefin Tuna) (Threatened Species Scientific Committee (TSSC), 2010aw) [Listing Advice].

Australian Faunal Directory (AFD) (2010). Australian Faunal Directory. [Online]. Available from: http://www.environment.gov.au/biodiversity/abrs/online-resources/fauna/afd/home. [Accessed: 30-May-2010].

Carpenter, K.E. & V.H. Niem, eds. (2001). FAO species identification guide for fishery purposes. The living marine resources of the Western Central Pacific. Volume 6. Bony fishes. Rome: Food and Agriculture Organization.

Caton, A.E. (1991). Review of aspects of southern bluefin tuna biology, population and fisheries. In: Shomura, R.S., J. Majkowski & S. Langi, eds. Proceedings of the First FAO Organization Expert Consultation on interactions of Pacific Tuna Fisheries. [Online]. Food and Agriculture Organization, United Nations. Available from: http://www.fao.org/docrep/005/t1817e/t1817e15.htm.

Collette B.B. & C.E. Nauen (1983). Scombrids of the world. An annotated catalogue of tunas, mackerels, bonitos and related species known to date. FAO species catalogue. 2:87-88. FAO Fisheries Synopsis No 125. Rome: FAO.

Comission for the Conservation of Southern Bluefin Tuna (CCSBT) (2011). Resolution on the Adoption of a Management Procedure. [Online]. Adopted at the CCSBT Eighteenth Annual Meeting, 10-13 October 2011. Indonisia: CCSBT. Available from: http://www.ccsbt.org/userfiles/file/docs_english/operational_resolutions/Resolution_Management_Procedure.pdf.

Commission for the Conservation of Southern Bluefin Tuna (CCSBT) (2009). Report of the Extended Commission of the Sixteenth Annual Meeting of the Commission. 20-23 October 2009, Republic of Korea. CCSBT.

Commission for the Conservation of Southern Bluefin Tuna (CCSBT) (2009a). Report of the Fourteenth Meeting of the Scientific Committee. 5-11 September 2009, Republic of Korea. CCSBT.

Davis, T.L.O. & J.H. Farley (2001). Size distribution of southern bluefin tuna (Thunnus maccoyii) by depth on their spawning ground. Fisheries Bulletin. 99:381-386.

Department of Agriculture, Fisheries and Forestry (DAFF) (1995). Southern Bluefin Tuna Fishery Management Plan 1995. Federal Register of Legislative Instruments F2008C00099. Canberra: DAFF.

Department of the Environment, Water, Heritage and the Arts (DEWHA) (2010n). Southern bluefin tuna listed as conservation dependent. [Online]. Media release. The Honourable Tony Burke, Minister of Parliament - Minister for Sustainability, Environment, Water, Population and Communities . Available from: http://www.environment.gov.au/minister/burke/2010/mr20101124.html.

Department of the Environment, Water, Heritage and the Arts (DEWHA) (2010o). Southern bluefin tuna decisions - Frequently asked questions. [Online]. Available from: http://www.environment.gov.au/epbc/notices/bluefin-tuna-faq.html.

Farley, J.H. & T.L.O. Davis (1998). Reproductive dynamics of Southern Bluefin tuna, Thunnus maccoyii. Fisheries Bulletin. 96:223-236.

Fujioka, K., A.J. Hobday, R. Kawabe, K. Miyashita, K. Honda, T. Itoh & Y. Takao (2010). Interannual variation in summer habitat utilization by juvenile southern bluefin tuna (Thunnus maccoyii) in southern Western Australia. Fisheries Oceanography. 19(3):183-195.

Glencross, B., C. Carter, J. Gunn, R. van Barneveld, K. Rough & S. Clarke (2002). Southern Bluefin Tuna, Thunnus maccoyii. In: Webster, C.D. & C.E. Lim, eds. Nutrient requirements and feeding of finfish for aquaculture. Wallingford, UK: CABI Publishing.

Gunn, J.S., N.P. Clear, T.I. Carter, A.J. Rees, C.A. Stanley, J.H. Farley & J.M. Kalish (2008). Age and growth in southern bluefin tuna, Thunnus maccoyii (Castelnau): Direct estimation from otoliths, scales and vertebrae. Fisheries Research. 92(2-3):207-220.

Honda, K., A.J. Hobday, R. Kawabe, N. Tojo, K. Fujioka, Y. Takao & K. Miyashita (2010). Age-dependent distribution of juvenile southern bluefin tuna (Thunnus maccoyii) on the continental shelf off southwest Australia determined by acoustic monitoring. Fisheries Oceanography. 19(2):151-158.

International Union for Conservation of Nature (IUCN) (2010). IUCN Red List of Threatened Species. Version 2010.4. [Online]. Available from: http://www.iucnredlist.org.

Munday, B.L., P.J. O'Donoghue, M. Watts, K. Rough & T. Hawkesford (1997). Fatal encephalitis due to the scuticociliate Uronema nigricans in sea-caged, southern bluefin tuna, Thunnus maccoyii. Diseases of Aquatic Organisms. 30:17-25.

NSW Department of Primary Industries (NSW DPI) (2005g). Endangered species - southern bluefin tuna. [Online]. Available from: http://www.dpi.nsw.gov.au/fisheries/species-protection/conservation/what-current/endangered-species/southern-bluefin-tuna.

NSW Department of Primary Industries Fisheries Scientific Committee (NSW DPI FSC) (no date). Final Recommendation Thunnus maccoyii - Southern Bluefin Tuna. [Online]. Available from: http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0008/208268/FR26-southern-bluefin-tuna.pdf.

Patterson, T., K. Evans, T.I. Carter & J.S. Gunn (2008). Movement and behaviour of large southern bluefin tuna (Thunnus maccoyii) in the Australian region determined using pop-up satellite archival tags. Fisheries Oceanography. 17(5):352-367.

Phillips, K. & J. Findlay (2008). Southern Bluefin Tuna Fishery. Larcombe J. & G. Begg, eds. Fishery status reports 2007: status of fish stocks managed by the Australian Government. Page(s) 93-102. Canberra; Bureau of Rural Sciences.

Phillips, K., G. Begg & R. Curtotti (2009). Southern Bluefin Tuna Fishery. Wilson D., R. Curtotti, G. Begg & K. Phillips, eds. Fishery Status Reports 2008: status of fish stocks and fisheries managed by the Australian Government. Page(s) 314-323. Canberra: Bureau of Rural Sciences & Australian Bureau of Agricultural and Resource Economics.

Threatened Species Scientific Committee (TSSC) (2010aw). Commonwealth Listing Advice on Thunnus maccoyii (Southern Bluefin Tuna). [Online]. Available from: http://www.environment.gov.au/biodiversity/threatened/species/pubs/69402-listing-advice.pdf.

Ward, T.M., L.J. McLeay, W.F. Dimmlich, P.J. Rogers, S. McClatchie, R. Matthews, J. Kämpf & P.D. van Ruth (2006). Pelagic ecology of a northern boundary current system: effects of upwelling on the production and distribution of sardine (S. sagax), anchovy (E. australis) and southern bluefin tuna (Thunnus maccoyii) in the Great Australian Bight. Fisheries Oceanography. 15(3):191-207.

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This database is designed to provide statutory, biological and ecological information on species and ecological communities, migratory species, marine species, and species and species products subject to international trade and commercial use protected under the Environment Protection and Biodiversity Conservation Act 1999 (the EPBC Act). It has been compiled from a range of sources including listing advice, recovery plans, published literature and individual experts. While reasonable efforts have been made to ensure the accuracy of the information, no guarantee is given, nor responsibility taken, by the Commonwealth for its accuracy, currency or completeness. The Commonwealth does not accept any responsibility for any loss or damage that may be occasioned directly or indirectly through the use of, or reliance on, the information contained in this database. The information contained in this database does not necessarily represent the views of the Commonwealth. This database is not intended to be a complete source of information on the matters it deals with. Individuals and organisations should consider all the available information, including that available from other sources, in deciding whether there is a need to make a referral or apply for a permit or exemption under the EPBC Act.

Citation: Department of the Environment (2014). Thunnus maccoyii in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed Thu, 21 Aug 2014 03:33:49 +1000.