Antarctic Toothfish, *Dissostichus mawsoni* Norman, 1937.

Antarctic Toothfish, Dissostichus mawsoni Norman, 1937.



Map of the management areas within the CAMLR Convention Area. SSRUs 882C to 882I within Subarea 88.2, are shaded in green. Throughout this report, “2021” refers to the 2020/21 CCAMLR fishing season (from 1 December 2020 to 30 November 2021).

Map of the management areas within the CAMLR Convention Area. SSRUs 882C to 882I within Subarea 88.2, are shaded in green. Throughout this report, “2021” refers to the 2020/21 CCAMLR fishing season (from 1 December 2020 to 30 November 2021).



1. Introduction to the fishery

1.1. History

This report describes the exploratory longline fishery for Antarctic toothfish (Dissostichus mawsoni) in Small Scale Research Units (SSRUs) 882C to 882I within Subarea 88.2 in the Amundsen Sea region (Figure 1). The area spans 150\(^{\circ}\)W to 105\(^{\circ}\)W longitude and from the Antarctic Continent to 60\(^{\circ}\)S latitude. Fishing occurs around seamounts and ridges, the Marie Byrd Seamount, the Continental slope, and the Continental shelf areas with polynyas. SSRU 882I has had a catch limit of 0 tons since it was first defined (Conservation Measures 32-02, 41-01, 41-10).

The fishery began in 2003 on the ridge complex in SSRU 882H, and expanded to the continental slope and shelf areas beginning in 2006. The SSRUs were redefined in 2011, moving the northern extent of SSRUs 882C-G from 55\(^{\circ}\)S to 70\(^{\circ}\) 50’S recognising the differences between toothfish inhabiting seamounts and those inhabiting the continental slope regions.

Prior to 2017, this fishery was an exploratory fishery for Dissostichus spp., however, in order to better align the target species with the assessment process the target species was specified as D. mawsoni, with any Patagonian toothfish (D. eleginoides) caught counting towards the catch limit for D. mawsoni.

The only type of fishing gear allowed in this fishery is bottom longline gear. Three types of bottom longline gear are used; Autoline, Spanish Line, and trotline (See the CCAMLR Gear Library for details). Although toothfish do inhabit shallow water to some degree, they are mainly a deep-water species and the fishery is restricted to fishing deeper than 550m (Conservation Measure 22-08). Most fishing occurs between 800 and 1800m depth.

The fishery has started on 1 December of each year. The duration of fishing activities in Subarea 88.2 has decreased over time, from more than two months to less than 4 weeks in recent years. Vessels tend to begin fishing in SSRU 882H, where most of the fishing has occurred, before moving south to fish in the Research Blocks (see Fig. 1). Although in recent years some vessels may gain access to the polynyas in SSRU 882F shortly after the fishery opens.

Sea ice is a major constraint on when and where fishing can occur within open areas. Significant sea ice can prevent access by vessels to many areas, especially early in the fishing season. Typically, a large sea ice bridge occurs along the continental slope and can prevent access to fishing areas in polynyas on the continental shelf and especially to Research Blocks 882_1 and 882_3.


1.2. Conservation Measures currently in force

The limits on the exploratory fishery for D. mawsoni in Subarea 88.2 are defined in Conservation Measure 41-10.

Figure 1: Location of Small Scale Research Units, Areas of directed fishing and Marine Protected Areas in Subarea 88.2. This report discusses fishing in SSRUs 882C to 882I within Subarea 88.2. The fishable depth range (600m-1800m) is highlighted in shades of green.

Figure 1: Location of Small Scale Research Units, Areas of directed fishing and Marine Protected Areas in Subarea 88.2. This report discusses fishing in SSRUs 882C to 882I within Subarea 88.2. The fishable depth range (600m-1800m) is highlighted in shades of green.


1.3. Active vessels

In 2021, 7 vessels participated in this fishery. For the 2022 fishing season, a total of 21 vessels notified their intention to participate in this fishery (2 from Australia; 1 from Japan; 3 from New Zealand; 6 from the Republic of Korea; 3 from the United Kingdom; 5 from Ukraine; 1 from Uruguay).


1.4. Timeline of spatial management

In 2011, the Commission revised the boundaries of the SSRUs in Subarea 88.2 such that 76% of the yield was assigned to the region between 70\(^{\circ}\) 50’S and 65\(^{\circ}\)S (redefined as SSRU 882H) and the remaining 24% of the yield was assigned to the region south of 70\(^{\circ}\) 50’S (SSRUs 882C-G) as outlined in SC-CAMLR-XXX, Annex 7, paragraph 6.127.

In 2014, the Scientific Committee agreed to a two-year research plan in SSRUs 882C-H (for the 2015 and 2016 seasons) in which the catch limit for SSRU 882H was 200 tonnes, the fishing elsewhere was restricted to four Research Blocks (see Fig. 1) and the combined catch limit for the Research Blocks was 419 tonnes with no more than 200 tonnes to be taken from any one of the Research Blocks, this overarching 419 tonne limit was removed in 2019.

In developing the research plan, the Scientific Committee noted (SC-CAMLR-XXXIII, Paragraph 3.169) that:

  1. declining recaptures by year of release in SSRU 882H indicate a loss of tagged fish from the seamounts and annual immigration of untagged fish

  2. increasing rate of decline in recaptures by year of release, i.e., recaptures of tags released in more recent years are declining at a faster rate than the declines observed in tags released in earlier years

  3. all estimates of biomass on the seamounts from tag recaptures are biased high, with the least biased being those from fish which have been at liberty for one year

  4. simulations indicate that the trends observed in the tag-recapture data are difficult to replicate but could be replicated with an exploitation rate on the seamounts of around 20% and an immigration and emigration of tagged fish at around 20%.


2. Reported catch

2.1. Latest reports and limits

The catches of D. mawsoni from Subarea 88.2 are provided in Table 1. In this fishery, the catch of D. mawsoni reached a maximum of 753 tonnes in 2019. In 2021, 531 tonnes of D. mawsoni were caught.

The catches reported from Subarea 88.2 include catch data from particular vessels that CCAMLR has agreed should be quarantined as there is no confidence in the amount and/or the location of those catches. All ancillary data associated with these vessels (e.g., by catch, tagging, observer data) are also quarantined and not included in the data presented in this report.


Table 1. Catch (tonnes) and effort history for Dissostichus mawsoni in this exploratory fishery (SSRUs 882C to 882I). Source: Fine scale data and past estimates for IUU catch (-: no IUU estimate available; q: catch data currently quarantined).
Season Number of vessels Catch limit (tonnes) Catch Estimated IUU catch (tonnes)
2003 1 375 106 0
2004 2 375 362 0
2005 2 375 270 0
2006 7 487 425 15
2007 7 547 347 0
2008 4 567 416 0
2009 10 567 484 0
2010 5 575 314 0
2011 11 575 570
2012 5 530 412
2013 12 530 475 (q: 1)
2014 14 390 392 (q: 34)
2015 7 819 396 (q: 227)
2016 9 619 430 (q: 186)
2017 9 619 466 (q: 158)
2018 9 619 313 (q: 296)
2019 13 1000 753
2020 11 894 643
2021 7 804 531


Table 2: Catch and catch limits by Research Block and in SSRU 882H in 2021 for Dissostichus mawsoni in Subarea 88.2. Source: Fine scale data.
Research Block Catch limit Catch (% of catch limit)
882_1 192 58 (30.2%)
882_2 186 168 (90.3%)
882_3 170 23 (13.5%)
882_4 128 121 (94.5%)
882H 128 154 (120.3%)


2.2. By-catch

Catch limits for by-catch species groups (Macrourus spp., skates and rays, and other species) are defined in Conservation Measures 41-01 and 33-03 and provided in Table 3. The total by-catch in SSRU 882H and in each of the Research Blocks is defined in Annex 41-10/A.

If the by-catch of any one species is equal to, or greater than, 1 tonne in any one haul or set, then the fishing vessel must move at least 5 nautical miles away for a period of at least five days.

If the catch of Macrourus spp. taken by a single vessel in any two 10-day periods in a single SSRU exceeds 1,500kg in a 10-day period and exceeds 16% of the catch of D. mawsoni in that period, the vessel shall cease fishing in that SSRU for the remainder of the season.

Skates thought to have a reasonable chance of survival are released at the surface in accordance with Conservation Measure 33-03.


Table 3. Reported catch and catch limits for by-catch species (Macrourus spp., skates and rays, and others) in this fishery (SSRUs 882C to 882I). see Conservation Measure 33-03 for details. Source: fine-scale data.
Macrourus spp.
Skates and rays
Other catch
Season Catch Limit (tonnes) Reported Catch (tonnes) Catch Limit (tonnes) Reported Catch (tonnes) Number Released Catch Limit (tonnes) Reported Catch (tonnes)
2003 0 18 0 0 0 0 8
2004 60 37 50 0 0 140 8
2005 60 20 50 0 0 140 3
2006 78 84 50 <1 865 100 12
2007 88 54 50 <1 0 100 13
2008 88 17 50 0 0 100 4
2009 90 58 50 <1 265 100 14
2010 92 49 50 0 0 100 15
2011 92 51 50 <1 168 100 13
2012 84 29 50 <1 0 120 11
2013 84 25 q 50 <1 0 120 8 q
2014 62 7 q 50 <1 28 120 3 q
2015 99 14 q 50 <1 q 192 q 120 6 q
2016 99 50 q 50 <1 q 861 q 120 2 q
2017 99 21 q 31 <1 q 314 q 99 2 q
2018 99 16 q 31 <1 q 104 q 99 2 q
2019 160 21 50 <1 217 160 3
2020 143 42 45 <1 571 143 5
2021 128 16 40 <1 194 128 3

2.3. Vulnerable marine ecosystems (VMEs)

All Members are required to submit, within their general new (Conservation Measure 21-01) and exploratory (Conservation Measure 21-02) fisheries notifications requirements, information on the known and anticipated impacts of their gear on vulnerable marine ecosystems (VMEs, as shown in the CCAMLR VME taxa classification guide), including benthic communities and benthos such as seamounts, hydrothermal vents and cold-water corals. All of the VMEs in CCAMLR’s VME Registry are currently afforded protection through specific area closures.

By the end of this fishing season, there were no VMEs and 17 VME Risk Areas designated in SSRUs 882C-H.


2.4. Incidental mortality of seabirds and marine mammals

The risk levels for birds in this fishery is category 1 (low) south of 65\(^{\circ}\)S, category 3 (average) north of 65\(^{\circ}\)S and overall is category 3 (SC-CAMLR-XXVIII, Annex 7, Table 14 and Figure 2).

Conservation Measure 25-02 applies to this fishery and in recent years has been linked to an exemption for night setting in Conservation Measure 24-02 and subject to a bird by catch limit. Offal and other discharges are regulated under annual conservation measures (e.g., Conservation Measures 41-09 and 41-10).

There have been no reports of incidental seabird mortalities in Subarea 88.2 in this fishery.

In 2020, one seal mortality was reported by a vessel in this fishery. In 2021, one Southern elephant seal mortality was reported by a vessel in this fishery.


3. Illegal, Unreported and Unregulated (IUU) fishing

Past estimates of Illegal, unreported and unregulated (IUU) catch in this fishery are shown in Table 1. Following the recognition of methodological issues regarding the estimation of IUU catch levels since 2011, evidence of IUU presence or activity has continued to be recorded but no corresponding estimates of the IUU catch for D. mawsoni have been provided (SC-CAMLR-XXIX, paragraph 6.5). One IUU-listed fishing vessel was observed in Subarea 88.2 in 2006 and 2010. Unmarked fishing gear, potentially from an IUU vessel, was reported in this Subarea in 2016.


4. Data collection

4.1. Data collection requirements

Fishery data is collected by vessels and by observers. Extensive information about location, fishing effort, and catch is recorded by vessels and also documented by observers. The collection of biological data as part of the CCAMLR Scheme of International Scientific Observation (SISO) includes representative samples of length, weight, sex and maturity stage, as well as collection of otoliths for age determination of the target and most frequently taken by-catch species.

This fishery is managed under the umbrella of the exploratory fisheries Conservation Measure 41-01 and, as such, have an associated data collection plan (Annex 41-01/A), a research plan (Annex 41-01/B) and a tagging program (Annex 41-01/C).

The collection of biological data in this fishery is conducted under Conservation Measure 23-05.


4.2. Summary of available data

Both the vessel’s crew and observers collect fishing effort, catch, and by-catch information.

Following Conservation Measure 22-07, vessels participating in this fishery must report the occurrence of VME indicator organisms on hauled lines. To do so, the vessel’s crew observe lines in segments (1000-hook sections or 1200m sections, whichever is the shorter) and report the number of VME indicator units (either one litre of those VME indicator organisms that can be placed in a 10-litre container, or one kilogram of those VME indicator organisms that do not fit into a 10-litre container). Depending on the number of VME indicator units landed, vessels must immediately report and potentially cease fishing in the area (termed a Risk Area) until further review of the data is completed (see Conservation Measure 22-07). Based on the portion of the line monitored, observers further identify VME indicator organisms to the lowest taxonomic level possible.

The vessel’s crew report total catch of non-VME by-catch (mostly fishes) by coarse taxonomic groups given the taxonomic expertise required to discriminate similar species. Observers collect biological information on toothfish and by-catch specimens at a finer taxonomic resolution, as well as data on individual specimens such as size and maturity.

Summaries of data reported to CCAMLR for the past five years are given in Tables 4 and 5.

Table 4. Summary of VME indicator taxa by-catch, by-catch of other species and biological data reported by vessels crew and observers in each of the last five seasons. By-catch records correspond to the number of observations of total weight and count of individuals for each taxon identified. Observers may take further biological measurements on toothfish and by-catch taxa. Taxonomic identification may occur at different levels.
Data source Data class Variable 2017 2018 2019 2020 2021
Vessel crew VME line segments 1690 364 4800 4276 2550
VME indicator units > 5 and < 10 0 0 0 1 2
VME indicator units > 10 0 0 0 1 0
by-catch taxa identified 17 13 22 23 17
records 598 420 1269 1385 676
Observer VME line segments 1141 292 2790 1929 1389
taxa identified 16 11 23 25 17
weight or volume measurements 676 98 451 636 338
toothfish specimens examined 4944 4200 16097 11874 7092
length measurements 4919 4199 16094 11870 7092
weigth measurements 4906 4122 15535 11381 7084
sex identifications 4931 4122 16074 11870 7078
maturity stage identifications 4888 4111 15192 11323 7060
gonad weight measurements 2469 1875 12510 9389 6475
otolith samples 980 1278 5039 2850 2145
by-catch specimens examined 1964 998 5213 4173 2831
taxa identified 16 19 28 33 23
length measurements 1540 810 4586 4127 2397
weigth measurements** 1958 991 4696 4161 2831
standard length measurements* 0 0 863 640 613
wingspan measurements* 18 10 18 107 2
pelvic length measurements* 10 3 16 26 2
snout to anus measurements* 1301 701 3493 1967 1317
sex identifications** 1961 841 4417 2553 623
maturity stage identifications** 1952 804 4186 2275 554
gonad weight measurements** 40 29 184 76 34
otolith samples** 556 2 199 43 239
**: Voluntary records
*: Species-dependent records
Table 5. Summary of biological data for predominant by-catch groups reported by observers (from random subsets of lines) in each of the last five seasons. Taxonomic identification may occur at different levels.
By-catch group Variable 2017 2018 2019 2020 2021
Macrourus spp. specimens examined 1306 695 3508 1983 1326
taxa identified 5 5 5 6 5
length measurements 888 507 2890 1980 1019
weigth measurements** 1304 691 3247 1978 1326
snout to anus measurements* 1301 673 3493 1967 1317
sex identifications** 1305 625 3143 1210 446
maturity stage identifications** 1304 612 3106 1205 414
gonad weight measurements** 25 29 132 38 34
otolith samples** 270 0 191 42 239
Skates and rays specimens examined 19 3 19 110 2
taxa identified 2 2 4 5 1
length measurements 17 3 17 109 2
weigth measurements** 19 1 15 109 2
wingspan measurements* 18 3 18 107 2
pelvic length measurements* 10 3 16 26 2
sex identifications** 19 3 17 110 2
maturity stage identifications** 11 1 12 40 2
gonad weight measurements** 0 0 0 0 0
Other fish specimens examined 639 299 1671 2038 1365
taxa identified 9 11 15 20 13
length measurements 635 299 1669 2038 1363
weigth measurements** 635 298 1419 2032 1365
standard length measurements* 0 0 859 638 604
sex identifications** 637 212 1247 1233 175
maturity stage identifications** 637 190 1068 1030 138
gonad weight measurements** 15 0 52 38 0
otolith samples** 286 2 8 1 0
**: Voluntary records
*: Species-dependent records


4.3. Length frequency distributions

The recent length frequency distributions of D. mawsoni caught in this fishery are shown in Figure 2. These length frequency distributions are unweighted; they have not been adjusted for factors such as the size of the catches from which they were collected. The interannual variability exhibited in the figure may reflect changes in the fished population but is also likely to reflect changes in the gear used, the number of vessels in the fishery and the spatial and temporal distributions of fishing.

The length frequency distribution of the D. mawsoni catch in SSRU 882H appears to be very stable with little evidence of change in length over time (Figure 2). In the Research Blocks there is distinct bimodality and this is reflected in the overall length frequency distribution for the Subarea.


Figure 2. Annual length frequency distributions of *Dissostichus mawsoni* caught in this fishery (top panel) and its five areas. The number of hauls from which fish were measured (N) and the number of fish measured (n) in each year are indicated. Note: length frequency distributions are only shown where more than 150 fish were measured in a given season/area.

Figure 2. Annual length frequency distributions of Dissostichus mawsoni caught in this fishery (top panel) and its five areas. The number of hauls from which fish were measured (N) and the number of fish measured (n) in each year are indicated. Note: length frequency distributions are only shown where more than 150 fish were measured in a given season/area.


4.4. Tagging

Under Conservation Measure 41-01, each longline vessel fishing in exploratory fisheries for toothfish has been required to tag and release D. mawsoni and D. eleginoides according to the CCAMLR tagging protocol and the required tagging rate per tonne of green weight caught specified in the fishery-specific Conservation Measure. In order to ensure that there is sufficient overlap between the length distribution of those fish that are tagged by a vessel and of all the fish that are caught by that vessel, each vessel is required to achieve a minimum tag-overlap statistic of 60% (see Annex 41-01/C, footnote 3). To avoid low sample size artefacts, the requirement for a 60% tag-overlap statistic does not apply to vessels that tag at the required rate but tag less than 30 fish (Table 6).


Table 6. Annual tagging rate (number of fish tagged per tonne of total catch), reported by vessels operating in this exploratory fishery (SSRUs 882C to 882I). The tag-overlap statistics (CM 41-01) for D. mawsoni and D. eleginoides respectively are provided in brackets (NC: Tag-overlap statistic is Not Calculated for less than 30 fish tagged; -: no fish were tagged).
Fishing Season
Flag State Vessel name 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021
Argentina Argenova XXI 1 (NC,-)
Australia Antarctic Chieftain 1.8 (72.8,-)
Australia Antarctic Discovery 3.2 (87.7,-) 3.1 (88.6,-) 3.1 (83.8,-)
Spain Tronio 1.2 (47.9,NC)
Spain Yanque 3.5 (83.3,-)
United Kingdom Argos Froyanes 1 (60.9,NC) 1 (79.6,-) 1 (70.5,-) 1.1 (NC,-) 1.2 (77.4,-) 1.4 (70.3,-) 3.4 (88,-) 3.3 (91.4,-)
United Kingdom Argos Georgia 1.1 (NC,-) 1 (54.2,-) 1.2 (NC,-) 2.4 (76.1,-) 3.3 (82.3,-) 3.4 (88.9,-)
United Kingdom Nordic Prince 3 (88.4,-) 3 (82.2,-) 3.5 (87.8,-)
Republic of Korea Greenstar 3 (84.5,-) 3 (NC,-)
Republic of Korea Hong Jin No. 701 1.3 (NC,-) 3.2 (87.9,-)
Republic of Korea Hong Jin No. 707 0.9 (74.8,-) 1.7 (61.2,-) 3.4 (NC,-) 3.2 (86.4,-)
Republic of Korea Jung Woo No. 3 1.1 (NC,-) 1.1 (86,-)
Republic of Korea Kingstar 3.5 (60.1,-)
Republic of Korea Kostar 1.1 (NC,-) 1 (NC,-) 3.1 (NC,-)
Republic of Korea Sunstar 1.1 (NC,-) 1 (65.8,-) 3.2 (78.7,-) 3.2 (82.3,-) 3.7 (NC,-) 3.9 (88.7,-)
Norway Argos Georgia 3.9 (79.4,-)
Norway Seljevaer 1.2 (NC,-) 1.1 (85,-) 2.9 (75.2,-)
New Zealand Antarctic Chieftain 1 (88.9,-) 1 (91.4,NC) 1.1 (85.6,-) 1 (82,-)
New Zealand Janas 1.1 (79.7,-) 1 (81.2,-) 1.1 (83.4,-) 1.4 (NC,-) 4.3 (94.2,NC) 10 (NC,-)
New Zealand San Aspiring 1.1 (87.3,-) 3.9 (79.8,-)
Russian Federation Chio Maru No. 3 1.4 (54.4,-)
Russian Federation Gold Gate 1.1 (75.1,-)
Russian Federation Mys Velikan 5 (NC,-)
Russian Federation Oladon 1 3.1 (86.5,-)
Russian Federation Palmer 1 (78.8,-) 1 (NC,-) 1.1 (59.5,-)
Russian Federation Sparta 1.2 (75.4,NC) 1.1 (59.8,NC) 1.2 (NC,-) 1 (NC,-) 3.3 (83.2,-)
Russian Federation Ugulan 3.3 (68,-)
Russian Federation Volk Arktiki 3.1 (94.2,-)
Russian Federation Yantar 31 2.2 (NC,-) 1 (NC,-) 3 (NC,-) 3.1 (79.6,-)
Ukraine Calipso 3.5 (74.7,-) 3.3 (85.8,-) 3.1 (87.4,-)
Ukraine Koreiz 3.1 (68.9,-) 3 (65.3,-)
Ukraine Marigolds 3.5 (NC,-) 3.8 (NC,-) 4.1 (NC,-) 3.1 (84,-)
Ukraine Polus 1 2.7 (NC,-)
Ukraine Simeiz 1.7 (NC,-) 1.2 (NC,-) 3.2 (62.9,-) 3.8 (NC,-) 3.1 (75.4,-)
Uruguay Altamar 3.1 (85.8,-)
Uruguay Badaro 3.2 (62,-)
Uruguay Proa Pioneer 3.2 (86.3,-) 3 (77.2,-) 3.1 (81.6,-) 3 (82.8,-)
Uruguay Ross Star 1.1 (NC,-)


To date in this area, 17840 D. mawsoni have been tagged and released (897 have been recaptured; Table 7), and, 6 D. eleginoides have been tagged and released (4 have been recaptured).

Table 7. Number of D. mawsoni tagged in recent fishing Seasons in this exploratory fishery (SSRUs 882C to 882I). The number of fish recaptured by each vessel in each Season is provided in brackets.
Fishing Season
Flag State Vessel name 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021
Argentina Argenova XXI 8 (0)
Australia Antarctic Chieftain 385 (26)
Australia Antarctic Discovery 476 (4) 553 (12) 463 (66)
Spain Tronio 52 (4)
Spain Yanque 57 (1)
United Kingdom Argos Froyanes 250 (38) 68 (2) 210 (49) 15 (4) 67 (3) 262 (8) 337 (11) 110 (10)
United Kingdom Argos Georgia 9 (1) 58 (13) 13 (5) 78 (2) 96 (4) 285 (16)
United Kingdom Nordic Prince 194 (11) 429 (19) 292 (9)
Republic of Korea Greenstar 236 (4) 12 (0)
Republic of Korea Hong Jin No. 701 7 (0) 545 (0)
Republic of Korea Hong Jin No. 707 40 (3) 38 (1) 13 (0) 72 (0)
Republic of Korea Jung Woo No. 3 6 (0) 35 (0)
Republic of Korea Kingstar 50 (2)
Republic of Korea Kostar 11 (0) 10 (0) 5 (0)
Republic of Korea Sunstar 8 (1) 33 (1) 76 (0) 73 (0) 26 (0) 41 (0)
Norway Argos Georgia 45 (2)
Norway Seljevaer 9 (1) 30 (0) 449 (20)
New Zealand Antarctic Chieftain 46 (1) 59 (9) 321 (42) 170 (19)
New Zealand Janas 30 (3) 99 (17) 62 (0) 21 (0) 323 (0) 1 (0)
New Zealand San Aspiring 190 (17) 46 (1)
Russian Federation Chio Maru No. 3 44 (2)
Russian Federation Gold Gate 44 (16)
Russian Federation Mys Velikan 2 (0)
Russian Federation Oladon 1 101 (0)
Russian Federation Palmer 55 (3) 24 (0) 44 (2)
Russian Federation Sparta 50 (3) 36 (10) 12 (3) 27 (0) 178 (0)
Russian Federation Ugulan 61 (0)
Russian Federation Volk Arktiki 159 (2)
Russian Federation Yantar 31 2 (0) 13 (0) 18 (0) 86 (0)
Ukraine Calipso 52 (1) 76 (0) 330 (5)
Ukraine Koreiz 282 (18) 478 (35)
Ukraine Marigolds 13 (0) 5 (0) 13 (0) 226 (9)
Ukraine Polus 1 21 (0)
Ukraine Simeiz 4 (0) 12 (0) 248 (8) 21 (2) 473 (18)
Uruguay Altamar 352 (13)
Uruguay Badaro 208 (9)
Uruguay Proa Pioneer 216 (5) 408 (18) 184 (14) 243 (9)
Uruguay Ross Star 16 (0)
Total 325 (43) 621 (60) 442 (86) 506 (54) 420 (28) 933 (46) 1024 (13) 1490 (9) 1005 (40) 2362 (85) 1995 (146) 1719 (57)


5. Research

5.1. Status of the science

Catch and Effort

Details of catch and effort for this fishery were updated for 2021 in WG-FSA-2021/25. The data are used to develop the catch limits using the trend analysis but data collection is also designed to provide the information necessary to inform a future integrated stock assessment.

Age composition

Little age information is currently available to develop annual age-length keys, particularly in the South. Because of this, data from years that had information were pooled to create a single age-length key for all years. Pooling information may mask changes in the age composition of the catch if length at age varies spatially or through time, further emphasizing the need for more age information. Overall, fish are smaller and younger in the South, but the data show two distinct size modes, of which, the relative magnitude depends on where fishing occurs in a given year. The youngest fish sampled in the South were four years old. The large mode of older fish in 2012 and 2013 is due to fishing that occurred in research block 882_1 in SSRU 882G (WG-FSA-2021/25).

Tag-recapture data

In the South, the required tagging rate for commercial fishing was increased from 1 fish per tonne of catch to 3 fish per tonne beginning in the 2015 season (in addition to constraining fishing to four Research Blocks). The required tagging rate for the North remained at 1 fish per tonne of catch for 2015 and 2016 but increased to 3 fish per tonne from the 2017 season (Conservation Measure 41-10). Tag recapture data are used for mark-recapture biomass estimation and also to detect movements related to stock structure.

5.2. Research plans

No research plans under Conservation Measure 24-01 targeting toothfish have been proposed for this fishery. The Scientific Committee did agree a temporary research plan in 2014 to provide fishery structure on the Continental slope and shelf, and to collect the necessary data for a stock assessment.

An alternative plan for structuring the fishery in the South (SSRU 882H) is needed to improve mark recapture data and to better index the biomass for the seamount complex (WG-FSA-2021/25). To this end, WG-FSA-2021/29 recommended that a workshop be held intersessionally to develop a management plan structuring fishing in SSRU 882H.


6. Stock status

6.1. Summary of current status

As a data-limited fishery, this fishery does not have such estimates.


6.2. Assessment method

Catch limits are determined annually for the research blocks and SSRU 882H using the trend analysis while data are collected to inform an integrated stock assessment (SC-CAMLR-38, Paragraphs 3.141-3.143).


6.3. Year of last assessment, year of next assessment

Research plans for data-limited fisheries are reviewed annually.


7. Climate Change and environmental variability

The impact of Anthropogenic climate change in the short-term could be expected to be related to changes in sea ice and physical access to fishing grounds, whereas longer-term implications are likely to include changes in ecosystem productivity affecting target stocks (FAO 2018).

In anticipation of potential impacts of climate change on targeted fish stocks, the Scientific Committee indicated that changes in productivity parameters may impact assessments and management advice, and these changes may be related to long-term environmental change, shorter-term variability, or potential effects of fishing (SC-CAMLR-XXXVII paragraph 3.51, Annex 9 paragraph 2.28).

The parameters that could be evaluated for the effects of environmental variability and change would include mean recruitment, recruitment variability, mean length-at-age, mean weight-at-length, natural mortality, and maturation ogives.

Other factors that may impact assumptions underlying the assessments that could also be considered, including stock distribution (for example, for its impact on tagged fish distribution or research survey interpretation), sex ratio (indicating maturation or other sex specific changes), and the ages or lengths observed in the fishery (indicating changes in vulnerability patterns or mortality).

There is no formal evaluation of the impacts of climate change and environmental variability available for this particular fishery.


Additional Resources