Fishery Report 2020:
Dissostichus eleginoides at Kerguelen Islands French EEZ (Division 58.5.1)

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 Kerguelen Islands in Division 58.5.1.

The fishery, targeting D. eleginoides, began as a trawl fishery in 1985 but targeting other species between 1979 and 1984 and caught small amounts of toothfish as by catch. Trawling continued to 2001 and intermittently in 2006 and 2010; a longline fishery began in 1992 and continues to the present (Duhamel et al., 2011). The fishery is active throughout the year with the exception of a summer closure period (1 February to either 1 or 15 March) which has been in place since 2004.

Within the French EEZs, fishing seasons, catch limits for target species, as well as vessel licensing, are allocated by France. Since 2019, catch limits are set for a period of 3 years. The season extends from 1 September to 31 August. French management measures, annually established by TAAF, specific to the EEZ, have restricted the longline fishery to waters outside the 12 nautical mile zone and no shallower than 500m. Fishing is also prohibited within the strict protection areas of the Marine Reserve since 2006.

1.2. Conservation Measures currently in force

No new information was available on the state of fish stocks in Division 58.5.1 outside areas of national jurisdiction and thus the prohibition of directed fishing for D. eleginoides, described in Conservation Measure 32-13, shall remain in force.

Within the French EEZs, catch limits for target species, as well as vessel licensing, are allocated by France. A six-year management plan 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. The 2019 catch limit was set at 5200 tonnes.

In the EEZ of Kerguelen, 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 with an annual closure from 1 February to mid-March, which differs from the CCAMLR fishing season
• One vessel at a time fishing per 0.5\(^{\circ}\) latitude x 1\(^{\circ}\) longitude rectangle for a maximum period of 10 days
• 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:

1. WG-FSA-19 agreed that the catch limit set by France of 5,200 tonnes in 2020, that account for depredation, was consistent with the CCAMLR decision rules for the model runs presented.

2. No new information was available on the state of fish stocks in Division 58.5.1 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, shall remain in force for 2020.

3. WG-FSA-19 welcomed the intention by the authors to implement a project to increase the number of otolith readings and recommended to read the otoliths of five individuals per 1 cm bin for every year when data is available. It also noted the importance of the readings of historical otoliths to improve the understanding of the stock recruitment. The Working Group also welcomed the upcoming POKER survey scheduled for 2021 to track juvenile abundance and suggested that the possibility to locally track the juvenile abundance every year was to be considered. These would improve the YCS and recruitment estimations which are critical parameters in the model.

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 9130 tonnes in 2000. In 2020, 5157 tonnes of D. eleginoides were caught.

Table 1. Catch and effort history for Dissostichus eleginoides in this fishery. Source: Fine scale data and past estimates for IUU catch (-: no IUU estimate available).

Season	Longline Catch (tonnes)	Trawl Catch (tonnes)	Pot Catch (tonnes)	Total Catch (tonnes)	Number of vessels	Estimated IUU catch (tonnes)
1992		1588		1588	1
1993		1570		1570	1
1994		4348		4348	1
1995		3997		3997	1
1996		3304		3304	1	833
1997		4011		4011	1	6094
1998	121	3525		3645	1	7156
1999	504	3614		4118	5	1237
2000	2999	6130		9130	8	2600
2001	2589	4335		6924	8	4550
2002	4075	359		4434	11	6300
2003	5452			5452	7	5518
2004	5099			5099	8	536
2005	5034			5034	7	268
2006	4698	254		4952	8	144
2007	5345			5345	7	451
2008	4859			4859	7	720
2009	5238			5238	8	0
2010	4915	235		5151	8	22
2011	5236			5236	7
2012	4904			4904	7
2013	5377			5377	7
2014	5326			5326	7
2015	4392	0		4392	8
2016	5553			5553	8
2017	5098	0		5098	9
2018	4878			4878	7
2019	5270			5270	7
2020	5157			5157	7

2.2. By-catch

Primary by-catch species from the longline fishery in the French EEZ in Division 58.5.1 are the macrourid Macrourus carinatus, rajid skates (Bathyraja irrasa and B. eatonii) and blue antimora (Antimora rostrata). The latter species is fully discarded, while the others are partly or totally retained. The spatial distribution of by-catch indicates specific areas of higher catch rates that differed between species (WG-FSA-10/34).

The catch histories for by-catch species are provided in Table 2.

Table 2. Reported catch for by-catch species (Macrourus spp., Rajids and Antimora rostrata) in this fishery. Source: fine-scale data.

	Macrourus spp.	Rajids		Antimora rostrata
Season	Reported Catch (tonnes)	Reported Catch (tonnes)	Number Released	Reported Catch (tonnes)
1991	0	<1	0	0
1994	0	2	0	0
1997	0	2	0	0
1998	12	19	0	<1
1999	37	48	0	1
2000	164	138	0	1
2001	97	374	0	<1
2002	448	530	0	2
2003	772	929	0	10
2004	938	1133	0	12
2005	779	975	0	47
2006	686	596	0	54
2007	779	546	1954	56
2008	821	376	3593	68
2009	956	415	3432	45
2010	884	455	2	59
2011	861	438	535	52
2012	691	433	15878	26
2013	727	308	12423	67
2014	752	68	32808	72
2015	605	9	33641	69
2016	696	13	53270	56
2017	642	22	44273	49
2018	665	22	44225	38
2019	523	15	52044	43
2020	445	24	62187	60

No stock assessments of individual by-catch species are presently undertaken, but biomass of a part of the stocks is now available from the biomass surveys (POKER 2003, 2010, 2013, 2017) and could help in the future. The Working Group on Fish Stock Assessment (WG-FSA) recommended that, where possible, areas with high by-catch rates should be avoided, particularly those shown in WG FSA-09/43. The requirement for rajids to be ‘cut-off’ at the surface has been in force since 2014.

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 collect information about benthic taxa, including those considered as vulnerable marine ecosystem (VME) taxa.

As Conservation Measure 22-06 does not apply to this area, there are no VMEs or VME Risk Areas designated in Division 58.5.1.

2.4. Incidental mortality of seabirds and marine mammals

CCAMLR mitigation measures are applied in the French EEZ. A summary of the historic bird mortality by longline in the French EEZ in Division 58.5.1 is shown in Table 3. The most common species injured or killed in the fishery was white-chinned petrel (Procellaria aequinoctialis). Night-setting requirements have been highly effective in removing the previously high levels of albatross mortality.

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 halli	Procellaria aequinoctialis	Procellaria cinerea	Other
2007	3	57	10	1
2008	5	271	14
2009	2	111	6
2010	5	63	15	1
2011	8	49	7	1
2012	2	40	5
2013	3	19	2	1
2014		4		2
2015	1	9	3
2016		11	7
2017		13	1
2018		9
2019		22
2020		7

The level of risk of incidental mortality of birds in Division 58.5.1 is category 5 (high) (SC-CAMLR-XXX, Annex 8, paragraph 8.1).

France applies 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’ to this fishery.

Additional measures will also be applied (WG IMAF-11/10 Rev. 1), including:

1. changes to the bird exclusion device to ensure it is effective in all weather conditions

2. closure of fishing areas and quota allocation reduction to vessels that have high by-catch rates

3. education and training will be strengthened by regular meetings between TAAF and fishing masters of vessels with high by-catch

4. data will continue to be collected and submitted using CCAMLR standard methods and forms

5. a demographic study on the white-chinned petrel will be undertaken at Kerguelen Islands, as well as the continued population counts of white-chinned petrels on the Kerguelen archipelago

3. Illegal, Unreported and Unregulated (IUU) fishing

Illegal, unreported and unregulated (IUU) fishing was first detected in this region in 1996 and in some years IUU catches have exceeded legal catches, resulting in total removals exceeding 10,000 tonnes in some seasons.

IUU fishing activity was detected in Division 58.5.1 (Kerguelen EEZ) during 2006, with one IUU-listed fishing vessel observed in the division. Two IUU-listed vessels were sighted during 2007 and three IUU-listed vessels were sighted during 2008. One IUU fishing vessel was observed on the boundary of the Kerguelen EEZ during winter 2007, and reports from France indicate that IUU activities sometimes occurred here during each year from 2008 to 2012. One IUU-listed fishing vessel was sighted in Division 58.5.1 during 2010, two during 2012 and one during the 2013. No IUU-listed vessels were observed during 2014, 2015 and 2016, however, IUU fishing gear was recovered from the region during all three years. 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).

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 presented in Figure 2 (only commercial longline considered). The majority of D. eleginoides caught by longline range from 50 to 125cm 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, 65575 D. eleginoides have been tagged and released (9539 have been recaptured, 8969 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	2007	2008	2009	2010	2011	2012	2013	2014	2015	2016	2017	2018	2019	2020	Total
2006	636
2007	2258	12	58	62	52	37	24	18	11	12	7	5	3	3	1	305
2008	2479		18	87	77	52	46	37	16	13	6	7	9	4	5	377
2009	4367			42	116	118	97	101	48	26	23	19	13	4	8	615
2010	4880				27	123	127	126	79	45	49	32	21	11	13	653
2011	5378					42	231	248	154	107	98	53	46	38	16	1033
2012	4943						52	196	181	137	125	63	50	41	22	867
2013	5489							86	210	179	167	123	88	64	42	959
2014	5400								44	181	203	133	100	86	51	798
2015	4503									60	194	186	112	95	64	711
2016	5631										80	189	265	185	116	835
2017	4947											64	239	245	207	755
2018	4760												43	298	236	577
2019	5093													82	322	404
2020	4811														80	80
Total	65575															8969

The tagging program undertaken by France in its EEZ in Division 58.5.1 has achieved a similar tag-recapture rate to the tagging program undertaken by Australia in Division 58.5.2, which indicates that tagged fish move mainly short distances, but some fish make longer forays around the slope, as well as long-distance movements outside the division. Fish from the tagging program at Heard Island (Division 58.5.2) have also shown movement of sub adult/adult fish between zones (Heard to Kerguelen and also Crozet), but the proportion of exchange between stocks is relatively small (Williams et al., 2002; WG-FSA-07/48 Rev. 1).

5. Research

Four biomass survey cruises (named POKER 1, 2, 3 and 4) have been conducted in 2006 (Duhamel and Hautecoeur, 2009), 2010 and 2013 (see WG-FSA-14/07) and 2017 respectively to estimate biomass and recruitment of D. eleginoides on the whole shelf and surrounding banks (100-1,000m). Such surveys are planned to be conducted every 3 to 4 years.

Collaborative work between France and Australia on analyses of catch, effort and other data (survey, tagging) to be used to progress understanding of fish stocks and fishery dynamics for Divisions 58.5.1 and 58.5.2 is ongoing (see WG-SAM-11/20, 15/37).

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-19/58), B0 is estimated at 206,200 tonnes (CI: 194,130-218,380). The estimate of the current SSB status of the stock is 60.6% (95% CI: 58.1%-60.9%).

6.2. Assessment method

The stock in this fishery is assessed using a fully integrated single-sex CASAL model (WG-FSA-19/58).

6.3. Year of last assessment, year of next assessment

Assessments are reviewed biennially during WG-FSA, 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

• Fishery Summary: pdf, html

• Species Description: pdf, html

• Fisheries Documents Browser

References

Duhamel, G. and M. Hautecoeur. 2009. Biomass, abundance and distribution of fish in the Kerguelen Islands EEZ (CCAMLR Statistical Division 58.5.1). CCAMLR Science, 16: 1-32.

Duhamel G., P. Pruvost, M. Bertignac, N. Gasco and M. Hautecoeur. 2011. Major fisheries events in the Kerguelen Islands: Notothenia rossii, Champsocephalus gunnari, Dissostichus eleginoides. Current distribution and status of stocks. In: Duhamel, G. and D. Welsford (Eds). The Kerguelen Plateau: marine ecosystem and fisheries. Société française d’ichtyologie, Paris: 275-286.

Williams, R., G.N. Tuck, A.J. Constable and T. Lamb. 2002. Movement, growth and available abundance to the fishery of Dissostichus eleginoides Smitt, 1898 at Heard Island, derived from tagging experiments. CCAMLR Science, 9: 33-48.