CCAMLR Exploratory Toothfish Fisheries

Chapter 27: CCAMLR exploratory toothfish fisheries

H Patterson and AH Steven

FIGURE 27.1 CCAMLR Convention area

TABLE 27.1 Status of the CCAMLR Exploratory Toothfish Fisheries
Status20172018Comments
Biological status Fishing mortality BiomassFishing mortalityBiomass 

Division 58.4.1, toothfish (Dissostichus mawsoni)

Not subject to overfishingUncertainNot subject to overfishingUncertain

No estimate of current biomass available.

Division 58.4.2, toothfish (Dissostichus mawsoni) a

--Not subject to overfishingUncertain

No estimate of current biomass available.

Subarea 88.1, toothfish (Dissostichus mawsoni)

 Not subject to overfishing Not overfishedNot subject to overfishingNot overfished

Most recent estimate of biomass is above the limit reference point under the CCAMLR harvest strategy. The TAC is conservative relative to current biomass.

Subarea 88.2, toothfish (Dissostichus mawsoni, D. eleginoides)

Not subject to overfishingNot overfishedNot subject to overfishingNot overfished

Most recent estimate of biomass is above the limit reference point under the CCAMLR harvest strategy. The TAC is conservative relative to current biomass.

Economic statusEstimates of NER are not available, and NER remain uncertain. Australian fishers have been active across the CCAMLR exploratory areas from 2014–15 to 2017–18.

a This stock was not assessed in 2017.
Notes: CCAMLR Commission for the Conservation of Antarctic Marine Living Resources. NER Net economic returns. TAC Total allowable catch.

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27.1 Description of the fishery

Area fished

The Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) was established in 1982 to conserve and manage the Southern Ocean Antarctic ecosystem. The objective of the CCAMLR is the conservation of Antarctic marine living resources. The CCAMLR Convention area is defined as the area south of the Antarctic Convergence, as well as the area south of 60ºS where the Antarctic Treaty (1959) applies (Figure 27.1).

The CCAMLR defines ‘new and exploratory’ fisheries for particular areas, and places emphasis on acquiring biological and other information during the development of the fisheries. Participation in such fisheries requires Member States to implement management measures, and a research plan detailing the scientific data that a country plans to collect and contribute to the CCAMLR.

Exploratory fisheries are defined under Conservation Measure 21-02:

  1. an exploratory fishery shall be defined as a fishery that was previously classified as a ‘new fishery’, as defined by Conservation Measure 21-01
  2. an exploratory fishery shall continue to be classified as such until sufficient information is available
    1. to evaluate the distribution, abundance and demography of the target species, leading to an estimate of the fishery’s potential yield
    2. to review the fishery’s potential impacts on dependent and related species
    3. to allow the Scientific Committee to formulate and provide advice to the Commission on appropriate harvest catch levels, as well as effort levels and fishing gear, where appropriate.

CCAMLR subareas 88.1 and 88.2 (Figure 27.1) lie within the Ross and Amundsen seas. A CCAMLR exploratory fishery operates in each of these subareas. These fisheries are managed separately, with distinct stock assessments. During the 2017–18 season, one Australian vessel participated in these exploratory fisheries.

CCAMLR divisions 58.4.1 and 58.4.2 lie adjacent to East Antarctica (Figure 27.1), and exploratory fisheries operate in both these divisions. During the 2017–18 fishing season, two Australian vessels participated in the fishery in division 58.4.1, and one Australian vessel participated in the fishery in division 58.4.2.

Fishing methods and key species

Demersal longline is the primary method used to target Antarctic toothfish (Dissostichus mawsoni) and Patagonian toothfish (D. eleginoides) in CCAMLR toothfish fisheries. Before 2017, the exploratory fisheries described here were for Dissostichus spp. (that is, both species). To better align the assessments with the target species, the fisheries now have the sole target species D. mawsoni (noting that, if any D. eleginoides are caught, they are decremented against the catch limit for D. mawsoni). New and exploratory fisheries have catch limits for bycatch species, such as skates and rays, whiptails (Macrourus spp.) and other species, as well as move-on provisions. The bycatch limits may be based on a percentage of the catch of toothfish (for example, 5% of the catch limit for Dissostichus spp.), or may be set as a specific limit (for example, 50 t) for each CCAMLR subarea or division that constitutes a new and exploratory fishery.

Management methods

Harvest strategies for the target species are consistent with the precautionary approach implemented by the CCAMLR that has been used to set catch limits since the mid 1990s. The harvest strategy for toothfish developed by the CCAMLR is consistent with the guidelines of the Commonwealth Fisheries Harvest Strategy Policy (Department of Agriculture and Water Resources 2018). For toothfish, the reference points in the CCAMLR harvest strategy dictate that median escapement of the spawning biomass at the end of a 35-year projection period is 50% of its median pre-exploitation level, and that the probability of the spawning biomass dropping below 20% of its median pre-exploitation level is less than 10% over the projection period. In exploratory fisheries, total allowable catches (TACs) are fished by approved vessels that have nominated to fish specific subareas or divisions. Shares of the toothfish TAC are not allocated to particular CCAMLR members in exploratory fisheries; however, members may receive allocations to conduct specific research programs. Daily catch-and-effort reporting is required by all vessels, and fishing must cease when the catch limit is reached. Vessels fishing in exploratory fisheries are required to carry scientific observers, and to tag and release toothfish at pre-specified levels as part of the scientific data collection process.

Fishing effort

Australia fished subarea 88.1 for the first time in 2016–17, but began fishing in subarea 88.2 in 2014–15. There was no previous effort by Australian vessels in these subareas, although other CCAMLR members have fished them previously. Division 58.4.1 was fished for the first time by an Australian vessel in 2015–16 (excluding some experimental trawling in the division in 1999–2000). Similarly, in division 58.4.2, Australian fishers undertook some experimental trawling in 1999–2000, but this division was properly fished for the first time by Australia in 2017–18.

TABLE 27.2 Main features and statistics for the CCAMLR exploratory toothfish fisheries

Fishery statistics a

2016–17 fishing season

2017–18 fishing season

Fishery

TAC
(t) b

Catch
(t) c

GVP

(2016–17)

TAC
(t) b

Catch
(t) c

GVP
(2017–18)

Division 58.4.1, toothfish

660

10

Confidential

545

91

Confidential

Division 58.4.2

35

42

28

Confidential

Subarea 88.1, toothfish

2,870

­81

Confidential

3,157

100

Confidential

Subarea 88.2, toothfish

619

151

Confidential

619

43

Confidential

Fishery-level statistics

Effort

Division 58.4.1: 123,250 hooks
Division 58.4.2: 0 hooks
Subarea 88.1: 33,150 hooks
Subarea 88.2: 347,225 hooks

Division 58.4.1: 408,250 hooks
Division 58.4.2: 140,250 hooks
Subarea 88.1: 293,250 hooks
Subarea 88.2: 41,750 hooks

Fishing permits

Division 58.4.1: 1
Division 58.4.2: 1
Subarea 88.1: 1
Subarea 88.2: 1

Division 58.4.1: 1
Division 58.4.2: 1
Subarea 88.1: 1
Subarea 88.2: 1

Active vessels

Division 58.4.1: 1
Division 58.4.2: 0
Subarea 88.1: 1
Subarea 88.2: 1

Division 58.4.1: 2
Division 58.4.2: 1
Subarea 88.1: 1
Subarea 88.2: 1

Observer coverage d

100% vessel coverage

100% vessel coverage

Fishing methods

Demersal longline

Primary landing ports

Hobart (Tasmania); Nelson (New Zealand)

Management methods

Input controls: limited entry, gear restrictions, temporal and spatial closures
Output controls: TACs
Other: move-on provisions if bycatch thresholds are reached

Primary markets

International: China, Japan, United States—frozen

Management plan

No formal management plan; operations consistent with CCAMLR conservation measures

a Fishery statistics are provided by fishing season, unless otherwise indicated. Season is 1 December – 31 August. Value statistics are by financial year. b Total available TAC for all participating fleets. c Australian catch only. Total catches are provided in Figures 27.2, 27.3, 27.4 and 27.5. d All Australian vessels carry two observers on each trip; 100% of hauls are observed, but generally less than 100% of each haul.
Notes: CCAMLR Commission for the Conservation of Antarctic Marine Living Resources.GVP Gross value of production.TAC Total allowable catch. – Not applicable.

27.2 Biological status

Antarctic toothfish (Dissostichus mawsoni) in division 58.4.1

Patagonian toothfish (Dissostichus eleginoides)

Line drawing: FAO

Stock structure

Toothfish in division 58.4.1 is considered a single stock for management purposes.

Catch history

Exploratory fishing is permitted in research blocks within CCAMLR division 58.4.1. Fishing has occurred in the division under licence since 2005, with TACs ranging from 210 to 724 t (Figure 27.2). Australia did not participate in the fishery before 2015–16, although some experimental trawling did occur in 1999–2000.

FIGURE 27.2 Total catch and TAC for CCAMLR division 58.4.1, 2005–2018

Note: TAC Total allowable catch.
Source: CCAMLR

Stock assessment

No reliable and accepted integrated stock assessment is available for division 58.4.1. Although some earlier studies applied different tag-based methods to obtain some indication of stock status, these were considered unreliable because of low tag returns (Agnew et al. 2008). The current level of biomass in division 58.4.1 is therefore unknown.

Fishing in the established research blocks, where previous tagging occurred and is ongoing, is intended to provide data for a future stock assessment. The participation of CCAMLR members in the fishery is restricted, and participants must provide a multiyear research plan that will provide data for a future stock assessment. Illegal, unreported and unregulated (IUU) fishing, which has been a significant problem in CCAMLR toothfish fisheries in the past, has been largely eliminated by international enforcement efforts.

To set catch limits for exploratory fishing, biomass in each research block is estimated independently based on tag recoveries, or on mean catch rate compared with an assessed area scaled by the seabed area in the block. The catch limits are then set so that they do not exceed 4% of the estimated stock size. Previous modelling work has demonstrated that this level of harvest will likely allow an overfished stock (<20% of unfished biomass [B0]) to recover in the long term (Welsford 2011); it is unknown whether the stock in division 58.4.1 is overfished.

Stock status determination

Given that there is no stock assessment for the entire division and no current overall estimate of biomass, the stock is classified as uncertain for overfished status. The catch limits set for each research block are based on assessed fisheries, and are set to a level low enough that an overfished stock could recover in the long term. The total catch for the division was below the TAC. In addition, IUU fishing has been largely eliminated, and participation in the fishery has been restrained to a very low level. Given these factors, the stock is considered not subject to overfishing.

Antarctic toothfish (Dissostichus mawsoni) in division 58.4.2

Stock structure

Toothfish in division 58.4.2 is considered a single stock for management purposes.

Catch history

CCAMLR division 58.4.2 contains one research block where exploratory fishing is permitted. Fishing has occurred in the division under licence since 2004, with TACs ranging from 35 to 780 t (Figure 27.3). Australia did not participate in the fishery before 2017–18, although some experimental trawling did occur in 1999–2000.

FIGURE 27.3 Total catch and TAC for CCAMLR division 58.4.2, 2004–2018
Stock assessment

No reliable and accepted integrated stock assessment is available for division 58.4.2. Although some earlier studies applied different tag-based methods to obtain some indication of stock status, these were considered unreliable because of low tag returns (Agnew et al. 2008). The current level of biomass in division 58.4.2 is therefore unknown.

Fishing in the established research block, where previous tagging occurred and is ongoing, is intended to provide data for a future stock assessment. The participation of CCAMLR members in the fishery is restricted, and participants must provide a multiyear research plan that will provide data for a future stock assessment. IUU fishing, which has been a significant problem in CCAMLR toothfish fisheries in the past, has been largely eliminated by international enforcement efforts.

To set catch limits for exploratory fishing, biomass in each research block is estimated independently based on tag recoveries, or on mean catch rate compared with an assessed area scaled by the seabed area in the block. The catch limits are then set so that they do not exceed 4% of the estimated stock size. Previous modelling work has demonstrated that this level of harvest will likely allow an overfished stock (<20% B0) to recover in the long term (Welsford 2011); it is unknown whether the stock in division 58.4.2 is overfished.

Stock status determination

Given that there is no stock assessment for the entire division and no current overall estimate of biomass, the stock is classified as uncertain for overfished status. The catch limits set for each research block are based on assessed fisheries, and are set to a level low enough that an overfished stock could recover in the long term. The total catch for the division was below the TAC. In addition, IUU fishing has been largely eliminated, and participation in the fishery has been restrained to a very low level. Given these factors, the stock is considered not subject to overfishing.

Antarctic toothfish (Dissostichus mawsoni) in subarea 88.1

Stock structure

Genetic examination of Antarctic toothfish from widely separated CCAMLR statistical areas (Atlantic Ocean sector, Pacific Ocean sector, Indian Ocean sector) has produced mixed results. Early studies found some weak variation by ocean sector (Kuhn & Gaffney 2008; Smith & Gaffney 2005), whereas a more recent study was unable to detect any genetic variation among fish from the different sectors (Mugue et al. 2014). Tagging studies from numerous locations in the CCAMLR Convention area have indicated that most adult toothfish are sedentary and are recaptured relatively close (<50 km) to where they were tagged (Hanchet et al. 2008; Petrov & Tatarnikov 2010; Welsford et al. 2011). However, a small proportion of tagged fish have been found to travel long distances (CCAMLR Secretariat 2017), and, together with some level of large-scale egg and larvae dispersal, this can result in a lack of differentiation in the genetic stock structure. Newer genomic techniques are being used to better understand stock structure. Preliminary otolith chemistry work has also provided evidence of regional stock structuring (Tana et al. 2014).

The stock assessment boundaries for the Ross Sea (described here) include subarea 88.1, and small-scale research units (SSRUs) A and B from subarea 88.2.

Catch history

Catches were relatively small in the early years of the fishery, but have increased since 2002 as the TAC has increased (Figure 27.4). Most of the catch has been Antarctic toothfish; Patagonian toothfish has accounted for 5% or less of the catch since 2010.

FIGURE 27.4 Total catch and TAC for CCAMLR subarea 88.1, 1997–2018

Note: TAC Total allowable catch.
Source: CCAMLR

Stock assessment

The most recent full stock assessment of Antarctic toothfish from CCAMLR subarea 88.1, and subarea 88.2 SSRUs A and B was conducted in 2017 using the CASAL integrated assessment model; it is a Bayesian sex- and age-structured assessment (Mormede 2017). The assessment included catch data and catch-at-age frequencies from 1998 to 2016 for the three areas of the Ross Sea (shelf, slope and north). In addition, tag–recapture data were included, as were survey-based standardised local abundance and catch-at-age frequencies from the survey of the Ross Sea shelf (Large, Robinson & Parker 2017).

The recommended model estimated the current level of biomass at 72% of unfished levels (B2016/B0 = 0.72; range 0.69–0.75). This is higher than the 2015 estimate of unfished biomass; the difference is likely the result of revised estimates of the effective tag survival and detection rates. The yield that satisfied the CCAMLR decision rules was estimated using a number of options to split the catch between the three areas (shelf, slope and north), or between areas north and south of 70°S and the special research zone of the Ross Sea region marine protected area.

All the estimates for yield (3,213–3,378 t) were higher than the pre-specified catch limit in Conservation Measure 91-05, which gives a range of 2,583–3,157 t as the total catch limit. Given this, a catch limit of 3,157 t for the 2017–18 and 2018–19 seasons was recommended (CCAMLR 2017a, b). Previous research has demonstrated that toothfish stocks that are fished at a rate of 3% of the estimated current biomass are likely to rebuild to the target level within two decades, even if currently near the limit reference point of 20% of unfished biomass (Welsford 2011). The catch limit for subarea 88.1 equates to 4.3% of the estimated current biomass. Given the relatively high estimate of current biomass in subarea 88.1, this TAC is therefore regarded as conservative.

Stock status determination

Given the relatively high spawning biomass, which is above the target reference point under the CCAMLR harvest strategy, the stock is classified as not overfished. The TAC was set at a conservative level based on previous research. IUU fishing has been largely eliminated by enforcement efforts. Given this precautionary approach, the limited entry to the fishery and the extensive CCAMLR review process, the stock is classified as not subject to overfishing.

Antarctic toothfish (Dissostichus mawsoni) in subarea 88.2

Stock structure

CCAMLR subarea 88.2 is divided into SSRUs that are labelled A to H. The stock assessment boundaries for the Amundsen Sea region (described here) consider SSRUs C–H to be a distinct stock (Hanchet & Parker 2014; Parker, Hanchet & Horn 2014). It is thought that spawning takes place on the northern seamounts in subarea 88.2 (SSRU H), with the larvae being transported by oceanographic processes to the east (SSRUs F–G).

Catch history

No catches were reported before 2001. Catches have generally increased since 2002 as the TAC has increased (Figure 27.5).

FIGURE 27.5 Total catch and TAC for CCAMLR subarea 88.2, 1997–2018

Note: TAC Total allowable catch. Catches from subarea 88.2 SSRUs A–B are included in the total catches, despite being assessed as part of subarea 88.1.
Source: CCAMLR

Stock assessment

The most recent full stock assessment of Antarctic toothfish from CCAMLR subarea 88.2 SSRUs C–H was conducted in 2013 using the CASAL integrated assessment model (Mormede, Dunn & Hanchet 2013). The assessment included catch data and catch-at-age frequencies from 2003 to 2013 for each SSRU. In addition, tag–recapture data for SSRU H were included because fishing in the other SSRUs has been inconsistent. Constant recruitment was assumed across the SSRUs.

The model runs produced some conflicting results, with some runs estimating unfished biomass to be lower than that estimated by earlier assessments completed in 2011 and 2013. The conflict was largely driven by the tagging data from SSRU H, which was considered reliable as a result of improved tagging and data collection procedures. In addition, the model runs with a reduced estimate of unfished biomass down-weighted the age data, which were limited and did not include SSRU H, the area from which most of the catch was taken.

The recommended model run down-weighted the age data and used the tagging data (Mormede, Dunn & Hanchet 2013). This model estimated the current level of biomass at 65% of unfished levels (B2013/B0 = 0.65; range 0.52–0.75). This is lower than the 2011 estimate of 82% of unfished biomass, but remains above the target reference point of 50%. The 2013 Working Group on Fish Stock Assessment could not reach consensus on the assessment, and it was not accepted. The working group noted that the assessment may not be representative of SSRUs C–G because most of the data driving the results came from SSRU H (CCAMLR 2013).

The CCAMLR Scientific Committee provided updated advice on the TAC in 2014 based on two biomass estimates for SSRU H, using the mark–recapture data and Petersen models (Goncharov & Petrov 2014; Parker & Mormede 2014). These were simple models using tagging data for SSRU H only, and excluded all the other data that would be used in an integrated assessment. They did not provide new biomass depletion estimates for subarea 88.2, and consequently the estimate from the 2013 integrated assessment (65%) remains the best biomass depletion estimate available, despite the lack of agreement on the assessment.

Based on the results of the Petersen models, the TAC for subarea 88.2 SSRUs C–H was set at 619 t, with 200 t designated for SSRU H and the remaining 419 t for SSRUs C–G (CCAMLR 2015a, b). A yield of 619 t equates to 3% of the estimated current biomass. Previous research has demonstrated that toothfish stocks that are fished at a rate of 3% are likely to rebuild to the target level within two decades, even if currently near the limit reference point of 20% of unfished biomass (Welsford 2011). Given the relatively high estimate of biomass in subarea 88.2, this TAC is therefore regarded as conservative.

In 2018, additional progress was made on updating the full assessment for SSRUs C–H using age-structured population models developed in CASAL (Mormede & Parker 2018) and data derived from the research plan for the area. While the model runs provide information on the biomass in two areas (north and south) and migration rates, the model should be considered indicative and not used for management advice at this stage. This is due to a lack of year-specific age-frequency data, limited spatial scale of the recaptures in the south and the changing spatial coverage in the northern area. Additional data and further work to rectify these gaps are recommended.

Stock status determination

Given the relatively high spawning biomass estimated in 2013, which is above the target reference point under the CCAMLR harvest strategy, the stock is classified as not overfished. The TAC was set at a conservative level based on previous research and was fully taken. IUU fishing has been largely eliminated by enforcement efforts. Given this precautionary approach, the limited entry to the fishery and the extensive CCAMLR review process, the stock is classified as not subject to overfishing.

27.3 Economic status

Key economic trends

Toothfish is a high-value species with well-established markets and supply chains, but fishing is undertaken in remote areas and under difficult operating conditions. Although there is potential for positive net economic returns (NER) to be generated by fishers in these exploratory areas, fishing has been sporadic and opportunistic, indicating some uncertainty for NER.

Subarea 88.2 was the first of the CCAMLR exploratory fisheries to be fished by Australia, in the 2014–15 fishing season, when Australia’s catch was 34% of the global TAC. Since then, Australia’s catch has decreased to 24% of the global TAC in 2016–17 and 7% in 2017–18.

Australia first started fishing in division 58.4.1 in the 2015–16 fishing season. Australia caught 2% of the global TAC in 2016–17 and 17% in 2017–18.

Australia first began fishing subarea 88.1 in the 2016–17 fishing season, catching 3% of the global TAC in the 2016–17 and 2017–18 fishing seasons.

Most recently, Australia began fishing in division 58.4.2 in 2017–18, catching 80% of the global TAC.

Management arrangements

The CCAMLR harvest strategy requires that the spawning biomass be 50% of pre-fished levels at the end of a 35-year projection period. For subarea 88.2, however, the TAC was set by calculating current biomass and setting the TAC at 4% of that biomass. This has previously been shown to be a precautionary method of setting the TAC, which is likely to allow stocks near the limit reference point to recover to the target level within two decades. A similar method is used to set the TAC for the research blocks in subarea 88.1 and division 58.4.1. Since the current biomass in subarea 88.2 is estimated to be above the target reference point, the TAC is considered conservative. When the TAC is fully caught, the fishery is closed. It is likely that operators currently incur high management costs given the ‘new and exploratory’ nature of the fishery. Given the precautionary TAC limits, there is likely potential for improvement in NER derived from these exploratory areas over the longer term for CCAMLR Member States fishing the area.

27.4 Environmental status

The fishery for toothfish in CCAMLR subareas 88.1 and 88.2 has been assessed as exempt from export controls under the Environment Protection and Biodiversity Conservation Act 1999 until 31 October 2019. The fishery in CCAMLR divisions 58.4.1 and 58.4.2 is exempt until 27 November 2020. No special recommendations were included in the assessments beyond the usual requirements to ensure proper reporting and notification of changes to management arrangements, and to implement relevant CCAMLR conservation measures. No ecological risk assessment has been undertaken for these fisheries; however, catch limits apply for all species, including bycatch.

In the 2017–18 fishing season, no logbook or observer reports noted interactions between an Australian vessel and protected species in the CCAMLR
exploratory fisheries.

27.5 References

Agnew, DJ, Edwards, C, Hillary, R Mitchell, R & López-Abellán, LJ 2008, Revised assessment of toothfish stocks in divisions 58.4.1 and 58.4.2, WG-FSA-08/43, report to the Commission for the Conservation of Antarctic Marine Living Resources Working Group on Fish Stock Assessment, Hobart.

CCAMLR 2013, Report of the Working Group on Fish Stock Assessment, WG-FSA-13, CCAMLR, Hobart.

—— 2015a, Report of the thirty-fourth meeting of the Scientific Committee, SC-CAMLR-XXXIV, CCAMLR, Hobart.

—— 2015b, Report of the Working Group on Fish Stock Assessment, WG-FSA-15, CCAMLR, Hobart.

—— 2017a, Report of the thirty-sixth meeting of the Scientific Committee, SC-CAMLR-XXXIV, CCAMLR, Hobart.

—— 2017b, Report of the Working Group on Fish Stock Assessment, WG-FSA-17, CCAMLR, Hobart.

CCAMLR Secretariat 2017, Long-distance movements of Patagonian (Dissostichus eleginoides) and Antarctic toothfish (D. mawsoni) from fishery-based mark–recapture data, WG-FSA-17/06, report to the CCAMLR Working Group on Fish Stock Assessment, Hobart.

Department of Agriculture and Water Resources 2018, Commonwealth Fisheries Harvest Strategy Policy, Department of Agriculture and Water Resources, Canberra.

Goncharov, SM & Petrov, AF 2014, Stock assessment and proposed TAC for Antarctic toothfish (TOA) in the subarea 88.2 H in the season 2014–15 (rev. 1), WG-FSA-14/14 rev. 1, report to the CCAMLR Working Group on Fish Stock Assessment, Hobart.

Hanchet, SM & Parker, SJ 2014, Towards the development of an assessment of stock abundance for subarea 88.2 SSRUs 88.2C–G, WG-FSA-14/59, report to the CCAMLR Working Group on Fish Stock Assessment, Hobart.

——, Rickard, G, Fenaughty, J, Dunn, A & Williams, M 2008, ‘A hypothetical life cycle for Antarctic toothfish (Dissostichus mawsoni) in the Ross Sea region’, CCAMLR Science, vol. 15, pp. 35–53.

Kuhn, KL & Gaffney, PM 2008, ‘Population subdivision in the Antarctic toothfish (Dissostichus mawsoni) revealed by mitochondrial and nuclear single nucleotide polymorphisms (SNPs)’, Antarctic Science, vol. 20, pp. 327–38.

Large, K, Robinson, L & Parker, SJ 2017, Results of the sixth Ross Sea shelf survey to monitor abundance of sub-adult Antarctic toothfish in the southern Ross Sea, January 2017, WG-SAM-17/01, report to the CCAMLR Working Group on Statistics, Assessments and Modelling, Hobart.

Mormede, S 2017, Assessment models for Antarctic toothfish (Dissostichus mawsoni) in the Ross Sea region to 2016/17, WG-FSA-17/37 rev. 1, report to the CCAMLR Working Group on Fish Stock Assessment, Hobart.

—— & Parker, S 2018, Progress towards an assessment of Antarctic toothfish (Dissostichus mawsoni) in subarea 88.2 SSRUs 882C–H for the years 2002/03 to 2017/18 using a two-area model, WG-FSA-18/37, report to the CCAMLR Working Group on Fish Stock Assessment, Hobart.

——, Dunn, A & Hanchet, SM 2013, Assessment models for Antarctic toothfish (Dissostichus mawsoni) in subarea 88.2 SSRUs 88.2C–H for the years 2002–03 to 2012–13, WG-FSA-13/52, report to the CCAMLR Working Group on Fish Stock Assessment, Hobart.

Mugue, NS, Petrov, AF, Zelenina, DA, Gordeev, II & Sergeev, AA 2014, ‘Low genetic diversity and temporal stability in the Antarctic toothfish (Dissostichus mawsoni) from near-continental seas of Antarctica’, CCAMLR Science, vol. 21, pp. 1–9.

Parker, SJ & Mormede, S 2014, Seamount-specific biomass estimates from SSRU 88.2H in the Amundsen Sea derived from mark–recapture data, WG-FSA-14/58, report to the CCAMLR Working Group on Fish Stock Assessment, Hobart.

——, Hanchet, SM & Horn, PL 2014, Stock structure of Antarctic toothfish in statistical area 88 and implications for assessment and management, WG-SAM-14/26, report to the CCAMLR Working Group on Statistics, Assessments and Modelling, Punta Arenas, Chile.

Petrov, AF & Tatarnikov, VA 2010, ‘New data on migrations of Antarctic toothfish Dissostichus mawsoni in the Dumont d’Urville Sea in the 2008/2009 season’, Journal of Ichthyology, vol. 50, pp. 140–1.

Smith, PJ & Gaffney, PM 2005, ‘Low genetic diversity in the Antarctic toothfish (Dissostichus mawsoni) observed with mitochondrial and intron DNA markers’, CCAMLR Science, vol. 12, pp. 43–51.

Tana, R, Hicks, BJ, Pilditch, C & Hanchet, SM 2014, Preliminary examination of otolith microchemistry to determine stock structure in Antarctic toothfish (Dissostichus mawsoni) between SSRU 88.1C and 88.2H, WG-SAM-14/33, report to the CCAMLR Working Group on Statistics, Assessments and Modelling, Punta Arenas, Chile.

Welsford, DC 2011, ‘Evaluating the impact of multiyear research catch limits on overfished toothfish populations’, CCAMLR Science, vol. 18, pp. 47–55.

——, Candy, SG, Lamb, TD, Nowara, GB, Constable, AJ & Williams, R 2011, ‘Habitat use by Patagonian toothfish (Dissostichus eleginoides Smitt 1898) on the Kerguelen Plateau around Heard Island and the McDonald Island’, in G Duhamel & DC Welsford (eds), First symposium on the Kerguelen Plateau: marine ecosystems and fisheries, Societe Francaise d’Ichtyologie, Paris, pp. 125–36.

 



Last reviewed: 4 November 2019
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