Patagonian Toothfish (2020)
Date Published: June 2021
Patagonian Toothfish is a species found in the southern oceans. Two distinct biological stocks are reviewed here, one at Macquarie Island and one at Heard Island and the McDonald Islands. Both stocks are considered sustainable.
Stock Status Overview
|Commonwealth||Heard Island and McDonald Islands||Sustainable||
Spawning stock biomass, projected biomass
|Commonwealth||Macquarie Island||Sustainable||Spawning stock biomass, projected biomass|
Genetic studies have found that Patagonian Toothfish at Macquarie Island, and at Heard Island and the McDonald Islands, are two distinct biological stocks [Appleyard et al. 2002]. However, there is some level of exchange between the Heard Island and McDonald Islands stock and the Kerguelen Plateau stock [Welsford et al. 2012]. The stock structure of toothfish on the Kerguelen Plateau is being further investigated in collaboration with French scientists so that population models of toothfish in the area can be refined and management can be improved across the Kerguelen Plateau [Péron et al. 2016].
Here, assessment of stock status is presented at the management unit level—Heard Island and McDonald Islands; and at the biological stock level—Macquarie Island.
Heard Island and McDonald Islands
The Heard Island and McDonald Islands Fishery (Commonwealth) (HIMIF) falls within the Convention Area of the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR). This international organisation was established to conserve and manage the Southern Ocean Antarctic ecosystem. CCAMLR employs precautionary harvest strategies that consider the role of target species within the larger ecosystem. For Patagonian Toothfish, the CCAMLR harvest strategy reference points require that the median escapement of the spawning biomass at the end of a 35 year projection period be 50 per cent of median pre-exploitation level and that the probability of the spawning biomass dropping below 20 per cent of the pre-exploitation median level is less than 10 per cent. Although the HIMIF falls within the CCAMLR area, the HIMIF is an Australian territory and is fished by Australian vessels only.
The most recent assessment of HIMIF Patagonian Toothfish estimated that biomass in 2019 was 51 per cent of pre-exploitation levels [Ziegler 2019]. The management unit is not considered to be recruitment overfished [CCAMLR 2019a, Patterson and Steven 2020a]. A catch limit of 3 030 tonnes (t), which meets the CCAMLR harvest strategy requirements, was recommended by CCAMLR for the 2019–20 and 2020–21 fishing seasons [CCAMLR 2019a, CCAMLR 2019b]. It was estimated that the projected biomass will not fall below 50 per cent of the pre-exploitation level after a 35 year projection period under that catch limit. This level of fishing mortality is unlikely to cause the stock to become recruitment overfished [Ziegler 2019, Patterson and Steven 2020a].
Based on the evidence provided above, the Heard Island and McDonald Islands management unit is classified as a sustainable stock.
Macquarie Island is an Australian territory that lies adjacent to, but not within, the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) area. Although not under CCAMLR jurisdiction, for consistency the Macquarie Island Toothfish Fishery (Commonwealth) is managed using the CCAMLR harvest strategy with the same decision rules used in the Heard Island and McDonald Islands Fishery (Commonwealth).
The most recent assessment [Hillary and Day 2019a,b] of Macquarie Island Patagonian Toothfish used a custom-designed model, revised growth parameters [Hillary 2019a] and a revised maturity-at-length relationship that was estimated using the maturity information from the extensive tagging data [Hillary 2019b]. This model estimated that biomass at the start of 2019 was 85 per cent of pre-exploitation levels [Hillary and Day 2019b]. The biological stock is not considered to be recruitment overfished [Patterson and Steven 2020b]. The CCAMLR decision rules were used to calculate the catch limit for the 2021–22 and 2022–23 fishing seasons. This ensures that the projected biomass is not below 50 per cent after a 35-year projection period under that catch limit. This level of fishing mortality is unlikely to cause the stock to become recruitment overfished [Hillary and Day 2019b, Patterson and Steven 2020b].
Based on the evidence provided above, the Macquarie Island biological stock is classified as a sustainable stock.
Patagonian Toothfish biology [Collins et al. 2010, Welsford et al 2012,]
|Species||Longevity / Maximum Size||Maturity (50 per cent)|
|Patagonian Toothfish||~50 years, ~2 000 mm TL||11–15 years (males), 12–17 years (females) ~915 mm TL (males), 1000+ mm TL (females)|
|Individual transferable quota|
Commonwealth – Recreational There is no recreational fishing for Patagonian Toothfish. 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 – Commercial (catch) The most recent data available for the Heard Island and McDonalds Islands Fishery (HIMIF) is for the 2017–18 fishing season. The most recent data available for the Macquarie Island Toothfish Fishery (MITF) is for the 2017–18 fishing season. Commonwealth – Indigenous There is no Indigenous fishing for Patagonian Toothfish.
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.
Commercial catch of Patagonian Toothfish - note confidential catch not shown
- Appleyard, SA, Ward, RD and Williams, R 2002, Population structure of Patagonian Toothfish around Heard, McDonald and Macquarie Islands, Antarctic Science, 14: 364–373.
- Collins, MA, Brickle, P, Brown, J and Belchier, M 2010, Chapter Four – The Patagonian toothfish: Biology, Ecology and Fishery, Advances in Marine Science, 58: 227–300.
- Commission for the Conservation of Antarctic Marine Living resources 2017b, Report of the thirty-eighth meeting of the Scientific Committee, SC-CAMLR-XXXVIII, CCAMLR Scientific Committee, Hobart, 21–25 October 2019.
- Commission for the Conservation of Antarctic Marine Living Resources 2019a, Report of the Working Group on Fish Stock Assessment, WG-FSA-19, CCAMLR Working Group on Fish Stock Assessment, Hobart, 7–18 October 2019.
- Hillary, R 2019a, Estimates of growth parameters for input to the revised stock assessment model, CSIRO Marine and Atmospheric Research, Hobart.
- Hillary, R 2019b, Revised estimates of maturity-at-length for Macquarie Island Patagonian toothfish, CSIRO Marine and Atmospheric Research, Hobart.
- Hillary, R and Day, J 2019b, TAC options given the revised stock assessment and maturity-at-length relationship, CSIRO Marine and Atmospheric Research, Hobart.
- Hillary, R and Day, J 2019a, Proposed new assessment structure for Macquarie Island toothfish using data up to and including 2018, CSIRO Marine and Atmospheric Research, Hobart.
- Patterson, H and Steven, AH 2020a, Heard Island and McDonald Islands Fishery, in H Patterson, J Larcombe, J Woodhams & R Curtotti (eds), Fishery status reports 2020, Australian Bureau of Agricultural and Resource Economics and Sciences, Canberra, 439–449.
- Patterson, H and Steven, AH 2020b, Macquarie Island Toothfish Fishery, in H Patterson, J Larcombe, J Woodhams & R Curtotti (eds), Fishery status reports 2020, Australian Bureau of Agricultural and Resource Economics and Sciences, Canberra, 450–457.
- Péron, C, Welsford, DC, Ziegler, P, Lamb, TD, Gasco, N, Chazeau, C and Duhamel, G 2016, Modelling spatial distribution f Patagonian toothfish through life-stages and sex and its implication for the fishery on the Kerguelen Plateau, Progress in Oceanography, 141: 81–95.
- Welsford, DC, McIvor, J, Candy, SG and Nowara, GB 2012, The spawning dynamics of Patagonian toothfish in the Australian EEZ at Heard Island and the McDonald Islands and their importance to spawning activity across the Kerguelen Plateau, FRDC Project TRF 2010/064, Canberra.
- Ziegler, P 2019, Draft integrated stock assessment for the Heard Island and McDonald Islands Patagonian toothfish (Dissostichus eleginoides) fishery in Division 58.5.2, WG-FSA-2019/32, CCAMLR Working Group on Fish Stock Assessment, Hobart, 7–18 October 2019.