Patagonian toothfish - South East Atlantic|
| Fact Sheet Title Fact Sheet |
| | | Patagonian toothfish - South East Atlantic |
| | Data Ownership | | This document provided, maintained and owned by South East Atlantic Fisheries Organisation (SEAFO) , is part of SEAFO Stock Status Reports data collection. |
| | ident Block | ident Block | | | | Species List: | | Species Ref: en - Patagonian toothfish, fr - Légine australe, es - Austromerluza negra, ru - Клыкач патагонский |
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| ident Block Patagonian toothfish - South East Atlantic Aq Res Ident Aq Res Ident Aq Res Ident | fao Div |
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| 47.C.0 | SEAFO division C.0 |
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| 47.C.1 | SEAFO division C.1 |
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| 47.D.0 | SEAFO division D.0 |
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| 47.D.1 | SEAFO division D.1 |
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| | Aq Res | Biological Stock: Biological Stock Value: Regional
Management Unit: Management Unit Reference Year: 2023
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| Considered a management unit: An aquatic resource or fishery is declared as [Fishery] Management Unit if it is effectively the focus for the application of selected management methods and measures, within the broader framework of a management system. According to the FAO Glossary for Responsible Fishing, "a Fishery Management Unit (FMU) is a fishery or a portion of a fishery identified in a Fishery Management Plan (FMP) relevant to the FMP's management objectives." FMU's may be organised around fisheries biological, geographic, economic, technical, social or ecological dimensions , and the makeup and attribute of a fishery management unit depends mainly on the FMP's management objectives. |
| Jurisdictional distribution: Jurisdictional qualifier (e.g. "shared", "shared - highly migratory") of the aquatic resource related with its spatial distribution. |
| Environmental group: Classification of the aquatic resource according to the environmental group (e.g. pelagic invertebrate, or demersal fish) to which the species belong. |
| | | | | | History Fishing for Patagonian toothfish in the SEAFO CA started around 2002. The main fishing countries working in the area include vessels from Japan, The Republic of Korea, EU (Spain) and The Republic of South Africa. Historically a maximum of four vessels per year fished in the SEAFO CA. The Spanish longline system and the Trotline (Fig. 1) are the fishing gears commonly used.  | Figure 1. Fishing gears used to fish D. eleginoides: Spanish longline system (top) and the Trotline (bottom).  |
Habitat Bio Climatic Zone: Temperate; Polar. Bottom Type: Unspecified. Depth Zone: Abyssal >1000m. Horizontal Dist: Oceanic. Vertical Dist: Demersal/Benthic. Patagonian toothfish is a southern circumpolar, eurybathic species (70-1600m), associated with shelves of the sub-Antarctic islands usually north of 55ºS. Young stages are pelagic (North, 2002). The species occurs in the Kerguelen-Heard Ridge, islands of the Scotia Arc and the northern part of the Antarctic Peninsula (Hureau, 1985; DeWitt et al., 1990). This species is also known from the southern coast of Chile northward to Peru and the coast of Argentina, especially in the Patagonian area (DeWitt, 1990), and also present in Discovery and Meteor seamounts in the SE Atlantic (Figure 3) and El Cano Ridge in the South Indian Ocean (López-Abellán and Gonzalez, 1999; López-Abellán, 2005). In the SEAFO CA the stock structure of the species is unknown. The CCAMLR Scientific Committee in 2009 noted that in most years (since 2003) the main species caught in CCAMLR sub-area 48.6 (adjacent to and directly south of SEAFO Division D) is D. eleginoides. The distribution of the species appears to be driven by the sub-Antarctic front which extends into the SEAFO CA. There were two tags recaptures between SEAFO CA and CCAMLR CA, which suggests connectivity between two waters.  | | Figure 2. Species geographical distribution in the SEAFO CA (source: Species profile on the SEAFO website). |
Geo Dist Geo Dist: Straddling between High Seas and EEZ In the SEAFO CA, the fishery has been conducted in Sub-Area D, being concentrated over seamounts in Division D1 (Meteor), at Discovery seamount (central part of Sub-Area D) and at seamounts located in the western part of Sub-Area D (West) shown as below. Fig. 3 shows the spatial and temporal distribution of fishing using distribution maps of annul catch by set (2009-Aug.,2023) (15 years). 7 historically highest catches were recorded in 2022-2023 (3.0~6.7 tons/set). The overall average catch (1,993 sets) is 0.69 ton/set, while 1.49 ton/set (2022-2023) which is 2.2 times higher.  | | Figure 3. Annual catch distribution by set (Patagonian oothfish) (2009-2023) (SEAFO database) (created by Marine Explorer ver 4.9.33) (Bottom contour data: NOAA ETOPO1) |
Table 1 shows the summary of fishing efforts (number of sets and hooks) by year and area (2009-2023). More fishing efforts have been almost continuously in place in Meteor and Discovery areas and less and discontinuously in the West area.  | | Table 1. Summary of fishing efforts (number of sets and hooks) by year and area (2009-2023) (2023 is preliminary as of Aug 31, 2023) (Data source: SEAFO Secretariat). |
Water Area Overview Spatial Scale: Spatial Scale Water Area Overview  | | Water Area Overview Patagonian toothfish - South East Atlantic
| fao Div | 47.C.0: SEAFO division C.0 | | 47.C.1: SEAFO division C.1 | | 47.D.0: SEAFO division D.0 | | 47.D.1: SEAFO division D.1 |
| | | | | | Water Area Overview |
Water Area OverviewPatagonian toothfish - South East Atlantic Aq Res Struct Biological Stock: Biological Stock Exploit Table 2 presents data on Patagonian toothfish catches and discards (2002-Aug 31, 2023) listed by country and the management area from which catches were taken. Annual catches varied between 12t (2017) and 393t (2003). A small amount (< 1 ton) of Atlantic toothfish (Dissostichus mawsoni) were caught in 2014 by Japan. In the last three years with complete data (2020-2022) retained catches were 63, 16 and133 tons respectively and the annual weight of discarded specimens was less than 1 t in 2020-2021 and 4 t in 2022. Discards were mainly due to parasite infection of fish. Retained and discarded bycatch from the Patagonian toothfish fishery by species are available in the Secretariat. It is noted that the two most dominant bycatch species (in terms of weight) are rattail (GRV) and deep-sea cod (ANT).  | | Table 2. Catches (tonnes) (Retained and Discarded) of Patagonian toothfish (Dissostichus eleginoide), (TOP) exploited by EU (Spain), Japan, Republic of Korea and Republic of South Africa (2002 - Aug 31,2023) |
N/F = No Fishing; Blank fields = No data available; Ret.= Retained catch; Dis. = Discarded catch Bio Assess There are no agreed stock assessments. Data The number of fishing sets sampled for Patagonian toothfish from 2006 onwards indicates a good sampling level in line with the SEAFO guidelines for data collection (Table 4). On average, samplings were conducted in 92% of the total sets and 23 specimens were measured per sampled fishing set, which is considered acceptable given the length range of the exploited population and satisfies with the SEAFO sampling protocol (n=20). Annex A shows number of various biological samples collected for Patagonian toothfish, i.e., fork length, weight, sex, otolith, gonad weight and maturity stage. Information of all biological samples of Patagonian toothfish and bycatch species exploited by Patagonian toothfish bottom longline fisheries are available in the Secretariat’s database.  | | Table 3. Annual biological sampling efforts for Patagonian toothfish (2006- Aug 31, 2023) (SEAFO database) |
Assess Models Length data and frequency distribution Figure 4 shows the annual total length (%) frequency distributions of Patagonian toothfish catch (samples) in the SEAFO CA (2006-Aug 31, 2023). Distribution patterns and modes vary widely from year to year. Around 135cm is the most common mode in the early years (2006-2009), followed by smaller modes down to 100cm, which are indicated by red bars.  | | Figure 4. Annual size (total length) % frequency distributions of D. eleginoides in Sub-Area D (2006-Aug 31, 2023) by 5cm size class. |
Note: Around 135cm is the most common mode in the early years (2006-2009), followed by smaller modes down to 100cm, which are indicated by red bars. Length-weight relationships Figure 5 shows the length-weight relationships by sex based on observer data from the Japanese fleet in 2012. Both are similar, but females have higher variance according to spawning conditions.  | | Figure 5. Total length-weight relationships by sex based on the Japanese exploratory fishing in 2012. |
Age and growth parameters There is no available information for this species in the SEAFO CA. Reproductive parameters There is no available information for this species in the SEAFO CA. Natural Mortality There is no available information for this species in the SEAFO CA. Feeding and trophic relationships (including species interaction) There is no available information for this species in the SEAFO CA. Tagging and migration Table 4 shows the information on tag releases and recaptures in SEAFO and CCAMLR CA, indicating movements between two areas. This implies that the stock is likely to be the same between SEAFO and CCAMLR (area 48.6 adjacent to SEAFO CA and up to Kerguelen adjacent to SIOFA CA). Table 4. Summary of tag releases and recaptures for Patagonian toothfish in SEAFO and CCAMLR CA. | CA | Release | Recapture | | # | year | Area | Vessel | # | year | Area | Vessel | | SEAFO | 11 | 2006 | Sub area D | Viking Bay (Spain) | 1 | | CCAMLR CA | | | 14 | 2010 | | | | | | | 117 | 2023 | Tronio (Spain) | | | | | | CCAMLR | | | | | 1 | 2017 | Sub area D (SEAFO CA) | | | | 2013 | Sub area 48.6 | | 1 | 2020 | Meteor (D1) (SEAFO CA) | Tronio (Sapin) | | | 2017 | Kerguelen 58.5.1 | | 1 | 2022 | Discovery (D0) (SEAFO CA) | Shinsei No 8 (Japan) | (Note 1) Blank: no information available. (Note 2) A total of 142 TOP has been tagged and released in the SEAFO CA (2006~2023). Results Ref Point In 2015, the Commission adopted Harvest Control Rule (HCR) to decide TAC if agreed stock assessment is not available. This HCR had been applied in NAFO (Greenland halibut during 2011-2017), which uses average of slopes of CPUE in recent 5 years (Box 1).  | | Box 1. HCR for Patagonian toothfish adopted by the Commission in 2015. |
In the HCR, standardized CPUE is preferable to apply. Although SC estimated standardized CPUE using generalised linear models (GLM) five times in the past (2014, 2015, 2016-twice and 2018), all results indicated that correlation coefficients (goodness of fitness) were too low (r2 < 30%) to provide the plausible standardized CPUE for the HCR and SC did not agree to use standardized CPUE for HCR. Then SC12 (2016) agreed to apply nominal CPUE for the HCR. As nominal Japanese CPUE in the Meteor and Discovery seamounts areas are available almost every year, SC12 (2016) agreed to use the slope of average of two nominal CPUE and applied in 2016 and afterwards. Using this method, TAC for 2022-2023 is computed as 261t for Sub-Area D in SC (2021). Then SC (2021) recommends TAC for Sub-Area D of 261t and a zero TAC for the remainder of the SEAFO CA for the years 2022 and 2023, which was agreed by the Commission meeting in 2021. The last Commission meeting (2022) requested SC19 (2023) to assess whether the current TAC (261 tonnes) could be carried over to 2024. In this regard, the virtual TAC (2024) was calculated using HCR and resulted in 274 tonnes (Box 2). The stock is considered to be safe and sustainable if the current TAC (261 tons) is extended to 2024 from 3 points of view: (a) recent catches are at the low level (Figure 6), (b) CPUE (2022-2023) shows the increase trend (Figure 7) and the virtual TAC (2024) (274 tons) is higher than the current TAC (261 tons).  | | Box 2. |
Management Management: Management Advice SC (2023) recommends TAC for Sub-Area D of 261 t and a zero TAC for the remainder of the SEAFO CA for 2024. Considering that the TACs set is reviewed every two years, and that the last review was done in 2021 for the period from 2022 – 2023. An assessment was conducted in 2023 to set TACs for 2024 only due to the virtual nature of the SC meeting. During the SC meeting in 2024 a full stock assessment will be conducting to set TACs for the period from 2025-2026. Sources SEAFO. “CM TAC-01 (2023) 32/16 – Total Allowable Catches and related conditions for Patagonian toothfish.” 2016  http://www.seafo.org/media/1945f4cf-663a-4370-ad47-4ccc8e99c659/SEAFOweb/CM/open/eng/CM32-16_pdf Bibliography Arana, P. “Reproductive aspects of the Patagonian toothfish (Dissostichus eleginoides) off southern Chile. Lat. Am. J. Aquat. Res., 37(3): 381-394.” 2009. Dewitt, H.H., P.C. Heemstra and O. Gon. “Nototheniidae. In: Fishes of the Southern Ocean, O. Gon and P.C. Heemstra (Eds.). J.L.B. Smith Institute of Ichthyology, Grahamstown, South Africa: 279-331.” 1990. Horn, P.L. “Age and growth of Patagonian toothfish (Dissostichus eleginoides) and Antarctic toothfish (D. mawsoni) in waters from the New Zealand subantarctic to the Ross Sea, Antarctica Fisheries Research, 56:275-287.” 2002. Hureau, J.C. “Family Nothoteniidae-Antarctic rock cods. In: FAO species identification sheets for fishery purposes. Southern Ocean: Fishing Areas 48, 58 and 88 (CCAMLR Convention Area). Fischer, W. and J.C. Hureau (Eds). FAO, Rome, vols. I-II, 470 p.” 1985. López-Abellán L.J. and J. González. “Results of the longline survey on the seamounts in the southeast Atlantic and in the CCAMLR Subarea 48.6 (Atlantic Ocean) and Division 58.4.4 (Indian Ocean). CCAMLR Science, Vol. 6: 99-116.” 1999 http://www.ccamlr.org/en/system/files/science_journal_papers/08lopez-abellan.pdf López-Abellán, L.J. “Patagonian toothfish in international waters of the Southwest Indian Ocean (Statistical Area 51). CCAMLR Science, 12: 207–214.” 2005 http://www.ccamlr.org/en/system/files/science_journal_papers/13lopez-abellan.pdf |
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