Fishery Report 2020:
Dissostichus eleginoides in Division 58.4.3a
CCAMLR Secretariat
16 March 2021
Patagonian Toothfish, Dissostichus eleginoides Smitt, 1898.
Map of the management areas within the CAMLR Convention Area. Division 58.4.3a, 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 exploratory longline fishery for Patagonian toothfish (Dissostichus eleginoides) in Division 58.4.3a. The fishery in Division 58.4.3 began as a new fishery in 1997 (Conservation Measure 113/XV). Following the Commission’s decision that high levels of illegal, unreported and unregulated (IUU) fishing for Dissostichus spp. in the Convention Area had rendered it unrealistic to consider this fishery as ‘new’ (CCAMLR-XVIII, paragraph 10.14), along with a renewed interest in this fishery, the fishery was reclassified as exploratory in 2000. 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. eleginoides, with any Antarctic toothfish (D. mawsoni) caught counting towards the catch limit for D. eleginoides.
1.2. Conservation Measures currently in force
The current limits on the exploratory fishery for D. eleginoides in Division 58.4.3a are described in Conservation Measure 41-06.
Figure 1: Location of the Research Block in Division 58.4.3a. The fishable depth range (600m-1800m) is highlighted in shades of green.
1.3. Active vessels
In 2018, 1 vessels participated in this fishery. For the 2021 fishing season, no vessels notified their intention to participate in this fishery.
1.4. Timeline of spatial management
In 2001, the boundaries of Division 58.4.3 were reassigned based on ecological considerations, and two new divisions were formed: Division 58.4.3a (Elan Bank) and Division 58.4.3b (BANZARE Bank). Since 2005, licensed longline vessels have fished in Division 58.4.3a targeting primarily D. eleginoides (Table 1).
2. Reported catch
2.1. Latest reports and limits
Reported catches of Dissostichus spp. are presented in Table 1. In this fishery, the catch of D. eleginoides reached a maximum of 97 tonnes in 2005. In 2018, 3 tonnes of D. eleginoides were caught.
| Season | Number of vessels | Catch limit (tonnes) | D. eleginoides | D. mawsoni | Estimated IUU catch (tonnes) |
|---|---|---|---|---|---|
| 1997 | 1 | 0 |
|
||
| 2005 | 4 | 250 | 97 | 9 | 98 |
| 2006 | 1 | 250 | 88 | 1 | 0 |
| 2007 | 2 | 250 | 3 | 1 | 0 |
| 2008 | 1 | 250 | 9 | 0 | 0 |
| 2009 | 1 | 86 | 31 | 0 | 0 |
| 2011 | 1 | 86 | 4 |
|
|
| 2012 | 1 | 86 | 37 |
|
|
| 2013 | 2 | 32 | 16 |
|
|
| 2014 | 2 | 32 | 32 | 0 |
|
| 2015 | 2 | 32 | 15 |
|
|
| 2017 | 2 | 32 | 11 | 0 |
|
| 2018 | 1 | 38 | 3 |
|
2.2. By-catch
Catch limits for by-catch species groups (macrourids, skates (Rajids) and other species) are defined in Conservation Measure 33-03 and provided in Table 2.
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 1,500 kg in a 10-day period and exceeds 16% of the catch of Dissostichus spp. in that period, the vessel shall cease fishing in that SSRU for the remainder of the season.
Those skates and rays which are caught alive and which have not been tagged (Conservation Measure 41-01, Annex 41-01/C, paragraphs 2v and vii), should be released by cutting the snood and, when practical, removing the hooks, and the number recorded and reported.
The by-catch in Division 58.4.3a consists predominantly of Rajids (Table 2).
| Season | Catch Limit (tonnes) | Reported Catch (tonnes) | Catch Limit (tonnes) | Reported Catch (tonnes) | Number Released | Catch Limit (tonnes) | Reported Catch (tonnes) |
|---|---|---|---|---|---|---|---|
| 2005 | 26 | 2 | 50 | 17 | 985 | 20 | 2 |
| 2006 | 26 | <1 | 50 | 7 | 0 | 20 | 1 |
| 2007 | 26 | <1 | 50 | <1 | 0 | 20 | <1 |
| 2008 | 26 | <1 | 50 | 2 | 0 | 20 | <1 |
| 2009 | 26 | 2 | 50 | 2 | 57 | 20 | 2 |
| 2011 | 26 | <1 | 50 | <1 | 0 | 20 | <1 |
| 2012 | 26 | 4 | 50 | 32 | 0 | 20 | 3 |
| 2013 | 26 | 2 | 50 | <1 | 3666 | 20 | 1 |
| 2014 | 26 | 2 | 50 | 2 | 6148 | 20 | 1 |
| 2015 | 26 | <1 | 50 | <1 | 683 | 20 | <1 |
| 2017 | 5 | <1 | 2 | <1 | 717 | 5 | <1 |
| 2018 | 6 | <1 | 2 | <1 | 1054 | 6 | <1 |
In 2019, an analysis of bycatch data from this fishery indicated strong effects of gear and bathymetry on bycatch composition and biomass (WG-FSA-19/56).
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), 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.
There are no VMEs or VME Risk Areas designated in Division 58.4.3a.
2.4. Incidental mortality of seabirds and marine mammals
In 2012, a single mortality of a white-chinned petrel (Procellaria aequinoctialis) was reported. There have been no observed bird mortalities reported by vessels since 2012.
In 2005, two incidental mortalities of Southern elephant seal (Mirounga leonina) were observed in Division 58.4.3a. There have been no observed mammal mortalities reported by vessels since 2005.
The requirements of Conservation Measure 25-02, including the ‘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.
The risk level for birds in the fishery in Division 58.4.3a is category 3 (average) (SC-CAMLR-XXX, Annex 8, paragraph 8.1).
3. Illegal, Unreported and Unregulated (IUU) fishing
According to French surveillance data, there was little evidence of IUU fishing in Division 58.4.3a between 2006 and 2008, however, IUU fishing activities were observed during the 2009 and remained prevalent until 2013. IUU fishing activities have not been observed in this division since 2013, however, considering the previous interest in this region, IUU activity may still be occurring but remaining undetected. Furthermore, information from satellite surveillance trials indicated the presence of unidentified vessels in this division in 2016. Since 2011, following the recognition of methodological issues in its assessment, no estimates of the IUU catch of Dissostichus spp. have been provided for this division (SC CAMLR-XXIX, paragraph 6.5).
4. Data collection
4.1. Data collection requirements
The collection of biological data under Conservation Measure 23-05 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 length frequency distributions of D. eleginoides 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 majority of D. eleginoides caught in the Division 58.4.3a fishery ranged from 30 to 175cm in length (Fig. 2). The variability in size distributions in this fishery may reflect changes in fishing operations.
Figure 2. Annual length frequency distributions of Dissostichus eleginoides caught in Division 58.4.3a. 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
Since 2012, vessels have been required to tag and release Dissostichus spp. at a rate of 5 fish per tonne of green weight caught. The tag-overlap statistic estimates the representative similarity between the size distributions of those fish that are tagged by a vessel and of all the fish that are caught by that vessel (Table 3). Each vessel catching more than 10 tonnes of each species of Dissostichus is required to achieve a minimum tag-overlap statistic of 60% (Annex 41-01/C).
| Flag State | Vessel name | 2011 | 2012 | 2013 | 2014 | 2015 | 2017 | 2018 |
|---|---|---|---|---|---|---|---|---|
| France | Le Saint Andre | 6.4 (NC,77.1) | 9.2 (-,73.9) | 5.6 (-,84.8) | 10 (-,NC) | 6.8 (NC,NC) | ||
| France | Mascareignes III | 6 (-,NC) | ||||||
| Japan | Shinsei Maru No. 3 | 3.9 (-,NC) | 6 (-,64.8) | 6.9 (NC,84.6) | 5.8 (-,61.8) | 7.6 (NC,81.7) |
To date in this area, 1221 D. eleginoides have been tagged and released (68 have been recaptured; Table 4).
| Flag State | Vessel name | 2011 | 2012 | 2013 | 2014 | 2015 | 2017 | 2018 |
|---|---|---|---|---|---|---|---|---|
| France | Le Saint Andre | 235 (9) | 60 (11) | 90 (22) | 6 (3) | 13 (3) | ||
| France | Mascareignes III | 15 (3) | ||||||
| Japan | Shinsei Maru No. 3 | 14 (0) | 56 (1) | 110 (3) | 84 (3) | 72 (0) | ||
| Total | 14 (0) | 235 (9) | 116 (12) | 200 (25) | 90 (6) | 85 (3) | 15 (3) |
5. Research
5.1. Status of the science
Catch limits for CCAMLR’s fisheries for D. mawsoni and D. eleginoides for the ‘assessed’ fisheries are set using fully integrated assessments; more basic approaches are used for the ‘data-poor’ fisheries (in Subarea 48.6 and in Area 58 outside the exclusive economic zones (EEZs)). The management of these data-poor fisheries has been a major focus of attention in CCAMLR in recent years after the acknowledgement that commercial fishing by itself had resulted in too few data to develop a full assessment of the targeted stocks in these areas. CCAMLR has developed a framework for designing and undertaking research fishing designed to lead to an assessment of these toothfish stocks in the short to medium term, established under the provisions of Conservation Measure 41-01. This research planning framework has three phases: prospecting phase, biomass estimation phase and assessment development phase, with a set of decisions and review for the progression between stages.
In order to obtain the data necessary for a stock assessment, catch limits for research fishing by commercial vessels are set at a level intended to provide sufficient information (including sufficient recaptures of tagged fish) to achieve a stock assessment within a time period of 3 to 5 years. These catch limits are also set so that they provide reasonable certainty that exploitation rates at the scale of the stock or research unit will not negatively impact the stock. Appropriate exploitation rates are based on estimates from areas with assessed fisheries and are not more than 3-4% of the estimated stock size.
In 2012 and 2013, CCAMLR put in place a more structured approach to setting catch limits, and spatially constraining research, in data-poor fisheries. This process attempts to use all available information combined with a regular review process to make progress, while recognising the inherent uncertainties and data limitations in data-poor fisheries.
5.2. Research plans
5.2.1. Background
A robust stock assessment that provides advice on catch limits according to the CCAMLR decision rules has not been developed due to lack of information in some areas (namely, Subarea 48.6 and Divisions 58.4.1, 58.4.2 and 58.4.3a). Thus, this subarea and these divisions have been designated as ‘data-poor fisheries’ (SC-CAMLR-XXX, paragraph 3.122). The Scientific Committee noted that the number of research hauls and tagging rate should be increased in fine-scale rectangles in which tags had been released in the past few years to increase the likelihood of tagged fish being recaptured (SC-CAMLR-XXX, paragraphs 3.126 and 3.128). The Scientific Committee agreed that the Research Blocks with the high numbers of tags available for recapture identified in WG-FSA-12/60 Rev. 1 could be used as a basis for research fishing in the data-poor fisheries, and agreed that research in 2013 should be concentrated within these blocks to maximise the likelihood of recapturing tags that had been released in the previous season (SC-CAMLR-XXXI, paragraph 3.171).
France and Japan had proposed research in Division 58.4.3a under Conservation Measure 21-02 (SC CAMLR-XXXI, paragraph 3.146). The Scientific Committee welcomed the development of an assessment framework using CASAL during the meeting of the Working Group on Fish Stock Assessment (WG-FSA) and agreed that this work should be progressed to develop an assessment that is suitable to provide management advice.
The Scientific Committee endorsed the continuation of this research with a catch limit of 32 tonnes during the past three years (SC-CAMLR-XXXI, paragraph 3.147; SC-CAMLR-XXXII, paragraph 3.208; SC-CAMLR-XXXIII, paragraph 3.192).
The Scientific Committee noted that a substantial number of tags were now being recaptured in this fishery and there was an expectation that a robust assessment was likely for this division in the near future (SC-CAMLR-XXXIII, paragraph 3.194).
In 2018, a revised research plan was submitted by France and Japan (WG-FSA-18/61).
5.2.2. Objectives
The research plan submitted by France and Japan aims at acheiving five objectives (WG-FSA-18/61).
Objective 1: Collect data required for an assessment of the status and productivity of toothfish stocks in Division 58.4.3a. Standard catch, fishing effort, tagging and biological data will be collected under Conservation Measures 41-01 and 41-06.
Objective 2: Collect data on the spatial and depth distributions of bycatch species, and inform bycatch mitigation measures.
Objective 3: Record marine mammal sightings to study potential depredation.
Objective 4: Improve benthic invertebrate populations’ knowledge and their related conservation issues.
Objective 5: Collect and use environmental data to improve understanding of ecosystem function. It is a first step to spatial management and ecosystem-based fisheries management approaches. Collection of environmental data will start during the 2018/19 CCAMLR season.
5.3. Advice by the Scientific Committee
A multi-year tag-recapture experiment undertaken jointly by France and Japan was initiated and continued under the following advice by the Scientific Committee: SC-CAMLR-XXXI, paragraph 3.147; SC-CAMLR-XXXII, paragraphs 3.205 to 3.207; and SC-CAMLR-XXXIII, paragraphs 3.191 and 3.192.
In 2015, the Scientific Committee noted that integrated stock assessment models for this division were not yet sufficiently robust to provide management advice using the CCAMLR decision rules and also that methods for the provision of management advice in data-poor fisheries affected by illegal, unreported and unregulated (IUU) fishing were applicable to this division. It further recommended that growth and maturity parameters be further developed for this area.
In 2018 research was carried out by the and the French vessel Mascareignes III. At SC-CAMLR-XXXVII in 2018 France and Japan had agreed to a pause in fishing activities in this division while undertaking analysis of previous research for consideration by the Scientific Committee and its working groups.
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
A preliminary stock assessment for Division 58.4.3a was detailed in WG-SAM-08/05 and employed a biomass dynamic surplus production model to assess the status of the stock using the tag/release of 199 individuals and recapture of six individuals from 2005 and 2006 data respectively, as well as legal and estimated illegal catches. Resultant stock size estimates were then used to estimate long-term yields (using the CCAMLR decision rules) under four different assumptions about the additional uncertainty in future stock dynamics, beyond that already accounted for in the stock assessment. This gave a range of potential long-term yields of 113, 105, 103 and 86 tonnes, which encompassed a wide range of future stock dynamic uncertainty assumptions.
Stock biomass and catch limits in data-limited fisheries are estimated using the trend analysis.
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
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.