Patagonian Toothfish, *Dissostichus eleginoides* Smitt, 1898.

Patagonian Toothfish, Dissostichus eleginoides Smitt, 1898.



Map of the management areas within the CAMLR Convention Area. The region discussed in this report is shaded in green. Throughout this report, “2020” refers to the 2019/20 CCAMLR fishing season (from 1 December 2019 to 30 November 2020).

Map of the management areas within the CAMLR Convention Area. The region discussed in this report is shaded in green. Throughout this report, “2020” refers to the 2019/20 CCAMLR fishing season (from 1 December 2019 to 30 November 2020).



1. Introduction to the fishery

1.1. History

This report describes the licensed longline fishery for Patagonian toothfish (Dissostichus eleginoides) in the South African exclusive economic zone (EEZ) at the Prince Edward Islands. Within the CAMLR Convention Area, this EEZ is mostly situated within the boundaries of Subarea 58.7 and overlaps a small portion of Division 58.4.4a and also extends into FAO Area 51 outside the Convention Area. Fishing outside areas of national jurisdiction in either Subarea 58.7 or Division 58.4.4a is currently prohibited.

Reports of substantial illegal fishing prompted South Africa to establish a legal fishery around its EEZ in 1996 and five experimental permits, with a total catch limit of 2,500 tonnes, were issued for 1997.

Some experimental pot fishing was undertaken during 2004 and 2005, but historically, most of the catch was taken with autoline and Spanish longline. In 2008, trotlines were introduced in response to high levels of catch depredation by killer whales (Orcinus orca) and by 2011 these had largely replaced Spanish longlines.


1.2. Conservation Measures currently in force

Within the South African EEZ, catch limits for target and by-catch species, as well as vessel licensing, are assigned by South Africa. In 2005, South Africa licensed five operators with fixed proportional allocations and a catch limit of 450 tonnes, to undertake fishing in its EEZ at the Prince Edward Islands. Between 2006 and 2010, only one operator, holding 27% of the catch limit, had been active in the fishery but in 2010, a second vessel licensed to catch the remaining 73%, entered the fishery.

The limits in force and the advice of WG-FSA to the Scientific Committee for the 2020 season were:

  1. CCAMLR did not provide management advice for the fishery in the South African EEZ at the Prince Edward Islands for the forthcoming season as no new information was available on the state of fish stocks in Subareas 58.6 and 58.7 and Division 58.4.4a outside areas of national jurisdiction

  2. directed fishing for D. eleginoides in Subarea 58.7 and Division 58.4.4a, outside the South African EEZ (Conservation Measure 32-02), shall be prohibited.

Figure 1: Map of the region discussed in this report.

Figure 1: Map of the region discussed in this report.


1.3. Active vessels

In 2020, 2 vessels participated in this fishery.


2. Reported catch

2.1. Latest reports and limits

Reported catches of Dissostichus eleginoides are presented in Table 1. In this fishery, the catch of D. eleginoides reached a maximum of 1345 tonnes in 1997. In 2020, 269 tonnes of D. eleginoides were caught.

No targeted fishing activity is permitted within the Division 58.4.4a sector of the South African EEZ.


Table 1. Catch (tonnes) and effort history for Dissostichus eleginoides in this fishery. Source: Fine scale data and past estimates for IUU catch (-: no IUU estimate available).
Season Number of vessels Catch Estimated IUU catch (tonnes)
1996 5 813
1997 10 1345
1998 4 828
1999 2 95
2000 5 289
2001 3 55
2002 2 75
2004 2 97
2005 1 97
2006 1 149 0
2007 2 189 0
2008 1 124 0
2009 2 43 0
2010 2 150 0
2011 2 128 0
2012 2 245 0
2013 2 179 0
2014 2 276 0
2015 2 291 0
2016 2 213
2017 2 67
2018 2 307
2019 2 266
2020 2 269


2.2. By-catch

Catch limits for by-catch species groups (macrourids, skates (Rajids) and other species) are set by South Africa. The recent catch histories for by-catch species are provided in Table 2.

The by-catch in the South African EEZ consists predominantly of macrourids (Table 2), the majority of which are caught in the Subarea 58.7 sector of the EEZ.


Table 2. Reported catch for by-catch species (Macrourus spp., Rajids and other species) in this fishery. Source: fine-scale data.
Macrourus spp.
Rajids
Other catch
Season Reported Catch (tonnes) Reported Catch (tonnes) Number Released Reported Catch (tonnes)
1997 <1 0 0 <1
1998 0 <1 0 <1
2000 50 4 0 9
2001 14 <1 0 1
2002 4 0 0 <1
2004 <1 0 0 0
2006 10 0 0 <1
2007 31 <1 0 4
2008 8 0 0 5
2009 3 <1 327 <1
2010 5 <1 283 1
2011 5 <1 255 2
2012 15 <1 4 1
2013 20 <1 0 2
2014 19 <1 0 5
2015 19 <1 0 6
2016 11 <1 10 3
2017 7 <1 0 2
2018 20 3 13 6
2019 6 7 240 4
2020 11 14 0 6


2.3. Vulnerable marine ecosystems (VMEs)

As Conservation Measure 22-06 does not apply to this subarea there are no CCAMLR VMEs or VME Risk Areas designated in Subarea 58.7.


2.4. Incidental mortality of seabirds and marine mammals

The three most common species injured or killed in the fishery were Southern giant petrel (Macronectes giganteus), Northern giant petrel (Macronectes halli) and white-chinned petrel (Procellaria aequinoctialis) (Table 3).

The level of risk of incidental mortality of birds in the fishery in the South African EEZ at the Prince Edward Islands (in both Subareas 58.6 and 58.7) is considered to be high (category 5) (SC-CAMLR-XXX, Annex 8, paragraph 8.1).

The requirements of Conservation Measure 25-02 ‘Minimisation of the incidental mortality of seabirds in the course of longline fishing or longline fishing research in the Convention Area’ apply to this fishery. There is an exemption to the requirement for night setting by achieving the sink rates described in Conservation Measure 24-02 and subject to a bird by-catch limit. South Africa has applied the mitigation measures recommended by CCAMLR within its EEZ, with the exception of a seasonal closure.

South Africa is currently in the planning phase of the development of a marine protected area (MPA) and three restricted areas within its EEZ around the Prince Edward Islands with the aim of reducing the by-catch of birds by the fishery and contributing to the long-term recovery of D. eleginoides (Lombard et al., 2007).

Table 3. Number of reported birds caught (killed or with injuries likely to substantially reduce long-term survival) in this fishery in each fishing season.
Season Macronectes giganteus Macronectes halli Procellaria aequinoctialis Other
1996 3 1 131 21
1997 21 8 481 259
1998 11 458 7
2000 1
2001 13
2004 11 5 3


Depredation of the catch, particularly by toothed cetaceans, can contribute up to 50% of loss in catch landings in this fishery.

There have been no reports of incidental mortalities of mammals since 2000 in this fishery.

3. Illegal, Unreported and Unregulated (IUU) fishing

Although the illegal, unreported and unregulated (IUU) fishing in the South African EEZ at the Prince Edward Islands was first detected in 1995, the illegal exploitation of D. eleginoides is thought to have started in 1994 and continued until at least 2005.

An analysis presented by Brandão et al. (2002) estimated that the IUU catch of D. eleginoides for the South African EEZ in 1996 and 1997 was 21,350 tonnes, which is more than the total legal catch taken over the history of the fishery, including all IUU catch subsequent to 1997.

There have been no official reports of IUU fishing in the South African EEZ since 2006 and, following the recognition of methodological issues in its assessment, no estimates of the IUU catch of Dissostichus spp. have been provided since 2011 (SC-CAMLR-XXIX, paragraph 6.5). However, the recovery of IUU fishing gear and unconfirmed reports of IUU vessels in Subarea 58.6 and Division 58.4.4 indicate that undetected IUU activity may continue to occur in this area.


4. Data collection

4.1. Data collection requirements

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.


4.2. Length frequency distributions

The recent length frequency distributions of D. eleginoides caught in this fishery are shown in Figure 2. The majority of D. eleginoides caught by longline range from 50 to 150cm in length, with a broad mode for all seasons at approximately 70cm. 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.


Figure 2. Annual length frequency distributions of *D. eleginoides* caught by longline in this fishery. 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.

Figure 2. Annual length frequency distributions of D. eleginoides caught by longline in this fishery. 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.


4.3. Tagging

To date in this area, 2840 D. eleginoides have been tagged and released (197 have been recaptured, 158 of which were released in this area; Table 4).

Table 4. Number of Dissostichus eleginoides tagged and recaptured in the area for each fishing Season.
Recaptured
Season Tagged 2009 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 Total
2005 173 1 1
2006 155 1 1 2
2007 98 1 1 2
2008 115 3 3 1 2 2 1 12
2009 38 1 1
2010 83 2 1 2 5
2011 83 1 2 1 1 1 6
2012 155 3 3 2 1 2 11
2013 155 5 5 2 2 1 15
2014 291 3 13 10 4 7 1 2 40
2015 298 4 6 5 8 5 3 31
2016 222 1 1 4 3 1 10
2017 63 4 4
2018 326 2 7 5 14
2019 285 4 4
2020 300
Total 2840 158

Only a single tagged fish has been recorded to have moved between the French and South African EEZs and the current management approaches used by France and South Africa do not specifically consider the possibility that these island groups share the same toothfish stock.

5. Research

In 2019, catch removals due to killer and sperm whale interactions across subantarctic fisheries were estimated (WG-FSA-19/33).

6. Stock status

6.1. Summary of current status

As this fishery is under South African jurisdiction, more details may be found here.


6.2. Assessment method

The status of D. eleginoides within the South African EEZ was first assessed in 2002 using an age-structured production model (ASPM) and was last reviewed by the Working Group on Fish Stock Assessment (WG-FSA) in 2007 (see SC-CAMLR-XXVI, Annex 5, Appendix N).

However, differences between the reported catch-per-unit-effort (CPUE) and catch-at-length data resulted in uncertainty in the assessment outputs. Thus, an operational management procedure (OMP) approach to address this uncertainty was developed in 2009 (SC-CAMLR-XXVII, Annex 7, paragraphs 6.1 to 6.3).

The OMP was not formally adopted by South Africa as a basis for management as only one of the five right holders (licensed to catch 27% of the catch limit) was active in the fishery between 2006 and 2010 and the catch limit was kept at 450 tonnes per annum from 2005 to 2010.

A revision of the OMP was attempted in 2011 but was hampered by the fact that the preferred gear type had shifted between 2008 and 2011 from Spanish longline to trotline gear. In order to standardise the catch rates (CPUE) between gear types, a two-year experiment using a general linear mixed model (GLMM), was initiated in 2012 and a precautionary catch limit of 320 tonnes per annum was set:

  1. a research allocation of 68.8% of the annual catch limit (220 tonnes per annum) was set aside for collection of catch data from Spanish longline/trotline pairs in 2012 and 2013 with a target of 100 Spanish/trot pairs per year

  2. for each Spanish longline set, a trotline must be set within 3 nautical miles and within a period of one week either before or after the Spanish longline set

  3. to compensate for the expected loss of revenue associated with setting Spanish longline gear, vessels were eligible to hold the catch from two further trotline sets against the research allocation.


6.3. Year of last assessment, year of next assessment

As this fishery is under South African jurisdiction, more details may be found here.


7. Climate Change and environmental variability

A recent summary of the potential impacts of climate change on Southern Ocean fisheries (FAO 2018) highlights the following key points:

The Antarctic region is characterized by complex interaction of natural climate variability and anthropogenic climate change that produce high levels of variability in both physical and biological systems, including impacts on key fishery taxa such as Antarctic krill.

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.

There are no resident human populations or fishery-dependent livelihoods in the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) Area, therefore climate change will have limited direct implications for regional food security. However, as an “under-exploited” fishery, there is potential for krill to play a role in global food security in the longer term.

The institutional and management approach taken by CCAMLR, including the ecosystem-based approach, the establishment of large marine protected areas, and scientific monitoring programmes, provides measures of resilience to climate change.

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


Additional Resources

References

Brandão, A., D.S. Butterworth, B.P. Watkins and D.G.M. Miller. 2002. A first attempt at an assessment of the Patagonian toothfish (Dissostichus eleginoides) resource in the Prince Edward Islands EEZ. CCAMLR Science, 9: 11-32.

Lombard, A.T., B. Reyers, L.Y. Schonegevel, J. Cooper, L.B. Smith-Ado, D.C. Nel, P.W. Froneman, I.J. Ansorge, M.N. Bester, C.A. Tosh, T. Strauss, T. Akkers, O. Gon, R.W. Leslie and S.L. Chown. 2007. Conserving pattern and process in the Southern Ocean: designing a marine protected area for the Prince Edward Islands. Ant. Sci., 19 (1): 39-54.