Fishery Report 2020:
Dissostichus eleginoides at Crozet Island French EEZ (Subarea 58.6)
CCAMLR Secretariat
26 April 2021
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).
1. Introduction to the fishery
1.1. History
This report describes the licensed longline fishery for Patagonian toothfish (Dissostichus eleginoides) in the French exclusive economic zone (EEZ) established in 1978 around the Crozet Island, which includes a portion of Subarea 58.6, small-scale research units (SSRUs) B, C and D, and extends into FAO Area 51 (north of 45\(^{\circ}\)S), outside the CAMLR Convention Area.
Trawl fishing was conducted by Japanese vessels prior to 1979 and by French vessels from 1983 to 1996 and in 2000. It has since been discontinued. A joint survey between France and Japan first conducted longline fishing in Subarea 58.6 in 1997, and this method has been used in the fishery since then.
The fishery is open year-round, but most fishing effort takes place in February and March when the fishery in the French EEZ at the Kerguelen Islands (Division 58.5.1) is closed. Fishing effort in this area concentrates on the Crozet shelf slope and on the eastern part of the del Cano Rise. The fishery is also charactrised by a high level of catch depredation (Tixier et al., 2010) by killer whales (Orcinus orca).
1.2. Conservation Measures currently in force
Within the French EEZs, catch limits for target species, as well as vessel licensing, are allocated by France (TAAF). A six-year management was adopted in 2019 with the overall objective of ensuring conditions for a sustainable and optimal exploitation of Patagonian toothfish. It also sets catch limits for a period of 3 years.
In the EEZ of Crozet Island, various national conservation and fisheries enforcement measures are applicable, such as:
- Annual catch limit set triennially since 2019
- Limitation on the number of longline vessels authorized to operate in the fishery
- Demersal longlines and pots are the only authorized fishing gears
- Fishing season extends from 1 September to 31 August of the following year, which differs from the CCAMLR fishing season
- A maximum of two vessels fishing simultaneously per 0.5\(^{\circ}\) latitude x 1\(^{\circ}\) longitude rectangle
- Fishing is prohibited within the strict protection areas of the Marine Reserve which include areas not exceeding 500m in depth
- Move-on rule to limit catches of D. eleginoides of 60cm and less
- Cut-off procedure and move-on rules for skates to reduce fishing mortality
- Mitigation measures to reduce bird mortality
- Move-on rule on VME
- One French scientific observer on board each licensed vessel
- Mandatory vessel logbooks
- A single catch landings site at Réunion Island
- Mandatory port inspection
The limits in force and the advice of WG-FSA to the Scientific Committee for the 2020 season were:
The Working Group agreed that the catch limit set by France of 800 tonnes in 2020, which accounts for depredation was consistent with the CCAMLR decision rules for the model runs presented
No new information was available on the state of fish stocks in Subarea 58.6 outside areas of national jurisdiction. The Working Group therefore recommended that the prohibition of directed fishing for D. eleginoides, described in Conservation Measure 32-02, remain in force in 2020
The Working Group noted that the catch composition of the fishery used length observations and recommended that the authors investigate the use of age composition data instead. The Working Group, therefore, suggested to increase the number of otoliths readings to five individuals per 1cm bin for every year when data is available and noted the importance of the readings of historical otoliths to improve the understanding of the YCS estimates.
Figure 1: Map of the region discussed in this report.
1.3. Active vessels
In 2020, 7 vessels participated in this fishery.
2. Reported catch
Since the CCAMLR fishing season (1 December to 30 November of the following year) and the TAAF fishing season (1 September to 31 August of the following year) do not match, data pooled at the annual scale and shown in this document may not match data reported by TAAF. This distinction is particularly relevant if readers wish to compare annual catch in the Convention Area to annual catch limits as set by TAAF.
2.1. Latest reports and limits
Reported catches of Dissostichus eleginoides are shown in Table 1. In this fishery, the catch of D. eleginoides reached a maximum of 1296 tonnes in 2002. In 2020, 718 tonnes of D. eleginoides were caught.
| Season | Number of vessels | Catch | Estimated IUU catch (tonnes) |
|---|---|---|---|
| 1987 | 1 | 488 |
|
| 1988 | 1 | 21 |
|
| 1994 | 1 | 56 |
|
| 1995 | 1 | 114 |
|
| 1996 | 1 | 3 |
|
| 1997 | 1 | 76 |
|
| 1998 | 1 | 12 |
|
| 1999 | 4 | 138 |
|
| 2000 | 5 | 989 | 1430 |
| 2001 | 6 | 1054 | 685 |
| 2002 | 7 | 1296 | 720 |
| 2003 | 6 | 532 | 302 |
| 2004 | 7 | 534 | 380 |
| 2005 | 7 | 596 | 12 |
| 2006 | 8 | 1051 | 55 |
| 2007 | 7 | 421 | 0 |
| 2008 | 7 | 823 | 224 |
| 2009 | 8 | 886 | 0 |
| 2010 | 7 | 663 | 0 |
| 2011 | 7 | 703 | 0 |
| 2012 | 7 | 673 |
|
| 2013 | 7 | 840 |
|
| 2014 | 7 | 778 |
|
| 2015 | 7 | 864 |
|
| 2016 | 8 | 1054 |
|
| 2017 | 8 | 1143 |
|
| 2018 | 7 | 1116 |
|
| 2019 | 7 | 825 |
|
| 2020 | 7 | 718 |
|
2.2. By-catch
Primary by-catch species from the longline fishery at Crozet Islands are the ridge-scaled grenadier (Macrourus carinatus), rajid (Amblyraja taaf) and blue antimora (Antimora rostrata). The latter species is fully discarded, while the others are partly or totally retained.
Avoidance of high level by-catch areas has been promoted with the implementations of move on rules and the cut-off protocol is in force to follow the CCAMLR recommendations.
The by-catch in the French EEZ at Crozet Islands consists predominantly of macrourids (Table 2).
| Season | Reported Catch (tonnes) | Reported Catch (tonnes) | Number Released | Reported Catch (tonnes) |
|---|---|---|---|---|
| 1997 | 10 | <1 | 0 | <1 |
| 1998 | 2 | <1 | 0 | <1 |
| 1999 | <1 | 3 | 0 | <1 |
| 2000 | 96 | 31 | 0 | 11 |
| 2001 | 98 | 6 | 0 | <1 |
| 2002 | 195 | 35 | 0 | 11 |
| 2003 | 148 | 92 | 0 | 19 |
| 2004 | 117 | 73 | 0 | 56 |
| 2005 | 132 | 93 | 0 | 67 |
| 2006 | 147 | 120 | 0 | 52 |
| 2007 | 119 | 85 | 2118 | 43 |
| 2008 | 135 | 46 | 11397 | 64 |
| 2009 | 193 | 46 | 17730 | 79 |
| 2010 | 113 | 56 | 6836 | 78 |
| 2011 | 93 | 29 | 2484 | 23 |
| 2012 | 96 | 75 | 2448 | 21 |
| 2013 | 64 | 29 | 273 | 17 |
| 2014 | 92 | 53 | 9684 | 36 |
| 2015 | 108 | 17 | 22575 | 75 |
| 2016 | 120 | 33 | 28395 | 142 |
| 2017 | 111 | 23 | 26718 | 58 |
| 2018 | 88 | 20 | 33859 | 133 |
| 2019 | 78 | 13 | 21800 | 43 |
| 2020 | 44 | <1 | 9372 | 16 |
2.3. Vulnerable marine ecosystems (VMEs)
All Members are required to submit, within their general fisheries notifications requirements, information on the known and anticipated impacts of their gear on vulnerable marine ecosystems (VMEs), 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.
In this fishery, fishery observers follow protocols to collect information about benthos taxa, including VME taxa.
There are no VMEs or VME Risk Areas designated in Subarea 58.6.
2.4. Incidental mortality of seabirds and marine mammals
A summary of recent bird mortalities by longline fisheries in the French EEZ at Crozet Islands is shown in Table 3. The three most common species injured or killed in the fishery were northern giant petrel (Macronectes halli), white-chinned petrel (Procellaria aequinoctialis) and grey petrel (P. cinerea). Night setting requirements have been highly effective in removing the previously high levels of albatross mortality.
The level of risk of incidental mortality of birds in the French EEZ at Crozet Islands in Subarea 58.6 is considered to be high (category 5) (SC-CAMLR-XXX, Annex 8, paragraph 8.1).
| Season | Macronectes halli | Procellaria aequinoctialis | Procellaria cinerea |
|---|---|---|---|
| 2007 | 1 | ||
| 2008 | 32 | ||
| 2009 | 3 | 19 | 1 |
| 2010 | 27 | ||
| 2011 | 1 | 7 | |
| 2012 | 17 | ||
| 2013 | 13 | ||
| 2014 | 6 | ||
| 2015 | 11 | ||
| 2016 | 5 | ||
| 2017 | 5 | ||
| 2018 | 4 | ||
| 2019 | 5 | ||
| 2020 | 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. France applies these CCAMLR mitigation measures.
Additional measures will also be applied (WG IMAF-11/10 Rev. 1), including:
changes to the bird exclusion device to ensure it is effective in all weather conditions
closure of fishing areas and quota allocation reduction to vessels that have high by-catch rates
education and training will be strengthened by regular meetings between TAAF and fishing masters of vessels with high by-catch
3. Illegal, Unreported and Unregulated (IUU) fishing
Illegal, unreported and unregulated (IUU) fishing was first detected in Subarea 58.6 in 1996 and peaked the following year at an estimated 11,760 tonnes.
IUU fishing activities were not detected in Subarea 58.6 in the Crozet Islands EEZ during 2006 and 2007, however, IUU activities were detected in Subarea 58.6 outside the Crozet Islands EEZ during the winter of 2006. IUU activity in the Crozet Islands EEZ cannot be discounted during 2006 or 2007 due to nearby IUU activity in those years. There was a single IUU vessel sighting in 2008 and two IUU-listed vessels were observed during 2012. A further IUU fishing vessel was sighted during 2013. During the 2014 fishing season, both old and recent IUU fishing gear was recovered on four occasions, however, there were no observations of IUU-listed vessels in this subarea. No IUU fishing activities were detected during 2015 or 2017, however, IUU fishing gear was found during 2016.
Following the recognition of methodological issues in its assessment, no estimates of IUU catch of Dissostichus spp. have been provided since 2011 (SC-CAMLR-XXIX, paragraph 6.5).
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 30 to 150cm in length, with a single strong 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.
4.3. Tagging
Within the French EEZ, vessels are required to tag and release toothfish at a rate of 1 fish per tonne of green weight caught throughout the season.
To date in this area, 12690 D. eleginoides have been tagged and released (993 have been recaptured, 748 of which were released in this area; Table 4).
| Season | Tagged | 2007 | 2008 | 2009 | 2010 | 2011 | 2012 | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | 2020 | Total |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2005 | 90 | |||||||||||||||
| 2006 | 1154 | 1 | 2 | 2 | 1 | 2 | 8 | |||||||||
| 2007 | 518 | 2 | 4 | 4 | 1 | 1 | 3 | 1 | 1 | 17 | ||||||
| 2008 | 547 | 3 | 14 | 4 | 6 | 1 | 8 | 1 | 1 | 1 | 39 | |||||
| 2009 | 679 | 7 | 18 | 10 | 7 | 10 | 5 | 6 | 5 | 4 | 4 | 1 | 1 | 78 | ||
| 2010 | 629 | 5 | 9 | 2 | 3 | 4 | 3 | 3 | 3 | 1 | 1 | 34 | ||||
| 2011 | 726 | 4 | 8 | 6 | 3 | 2 | 1 | 24 | ||||||||
| 2012 | 691 | 1 | 20 | 16 | 8 | 5 | 2 | 1 | 1 | 2 | 56 | |||||
| 2013 | 852 | 8 | 18 | 23 | 16 | 9 | 6 | 2 | 2 | 84 | ||||||
| 2014 | 839 | 4 | 26 | 21 | 10 | 4 | 10 | 1 | 76 | |||||||
| 2015 | 921 | 5 | 31 | 22 | 11 | 11 | 5 | 85 | ||||||||
| 2016 | 1167 | 13 | 37 | 28 | 26 | 3 | 107 | |||||||||
| 2017 | 1182 | 11 | 33 | 14 | 9 | 67 | ||||||||||
| 2018 | 1158 | 15 | 27 | 11 | 53 | |||||||||||
| 2019 | 805 | 10 | 10 | 20 | ||||||||||||
| 2020 | 732 | |||||||||||||||
| Total | 12690 | 748 |
One fish which was tagged in Subarea 58.6 was recaptured in Subarea 58.7 and another in the Southern Indian Ocean Fisheries Agreement (SIOFA) zone. Again, tagged fish from the Kerguelen Plateau (34 from Division 58.5.1 - Kerguelen and 53 from Division 58.5.2 - Heard Island) have been recovered in the Crozet EEZ. Despite these long-distance movements of sub-adult/adult fish, the proportion of exchange between stocks is still unknown and only one fish from Crozet Island has been recovered eastward on the Kerguelen Plateau.
5. Research
An analysis presented in WG-FSA-14/10 estimated that the depredation of D. eleginoides by killer whales and sperm whales (Physeter macrocephalus) over the period 2003 to 2013 was 2,568 tonnes; this implies a depredation rate of 28% of all fish caught for this decade.
A pot trial cruise was conducted in February 2010 (WG-FSA-10/10) to try and find solutions to the depredation problem (and to reduce bird mortality). However, while whale depredation and bird by-catch is eliminated using pot gear, the catch rates of the target species were reduced and the by-catch of king crabs (Lithodes murrayi and Paralomis aculeata) was considerable.
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
According to the 2019 assessment (WG-FSA-19/57 Rev.1), B0 is estimated at 54,610 tonnes (48,560-60,880). The estimate of the current SSB status of the stock is 63% (58.2%-66.6%).
6.2. Assessment method
The stock in this fishery is assessed using a fully integrated single-sex CASAL model (WG-FSA-19/57 Rev.1).
6.3. Year of last assessment, year of next assessment
Assessments are reviewed biennially, the last assessment was in 2019.
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
Tixier, P., N. Gasco, G. Duhamel, M. Viviant, M. Authier and C. Guinet. 2010. Interactions of Patagonian toothfish fisheries with killer and sperm whales in the Crozet Islands Exclusive Economic Zone: an assessment of depredation levels and insights on possible mitigation strategies. CCAMLR Science, 17: 179-195.
Tixier, P., et al., Assessing the impact of toothed whale depredation on socio-ecosystems and fishery management in wide-ranging subantarctic fisheries, Rev. Fish Biol. Fish., vol. 30, p. 203‑217, 2020, doi: 10.1007/s11160-020-09597-w