Biological State and Trend
History
Fishing for Patagonian toothfish in the SEAFO CA started around 2002. The main fishing countries working in the area include vessels from Japan, South Korea, Spain and South Africa. Historically a maximum of four vessels per year fished in the SEAFO CA. The Spanish longline system and the Trotline (Fig. 1) are the fishing gears commonly used.
 |
Figure 1 Fishing gears used to fish D. eleginoides: Spanish longline system (top) and the Trotline (bottom).  |
Habitat and Biology
Climatic zone: Temperate; Polar. Bottom type: Unspecified. Depth zone: Abyssal ( >1000m). Horizontal distribution: Oceanic. Vertical distribution: Demersal/Benthic.
Patagonian toothfish is a southern circumpolar, eurybathic species (70-1600m), associated with shelves of the sub-Antarctic islands usually north of 55ºS. Young stages are pelagic (North, 2002). The species occurs in the Kerguelen-Heard Ridge, islands of the Scotia Arc and the northern part of the Antarctic Peninsula (Hureau, 1985; DeWitt et al., 1990). This species is also known from the southern coast of Chile northward to Peru and the coast of Argentina, especially in the Patagonian area (DeWitt, 1990), and also present in Discovery and Meteor seamounts in the SE Atlantic (Figure 3) and El Cano Ridge in the South Indian Ocean (López-Abellán and Gonzalez, 1999, López-Abellán, 2005).
In SEAFO CA the stock structure of the species is unknown. The CCAMLR Scientific Committee in 2009 noted that in most years (since 2003) the main species caught in CCAMLR sub-area 48.6 (adjacent to and directly south of SEAFO Division D) is
D. eleginoides. The distribution of the species appears to be driven by the sub-Antarctic front which extends into the SEAFO CA.
 |
| Figure 3 Species geographical distribution in the SEAFO CA (source: Species profile on the SEAFO website). |
Geographical Distribution
Jurisdictional distribution: Straddling between High Seas and EEZ
In SEAFO CA, the fishery from 2010 to 2013 took place in Sub-Area D, being concentrated over seamounts in Division D1, at Discovery seamount and also at seamounts located in the western part of Sub-Area D (Fig. 2).
 |
| Figure 2 Reported catch of Patagonian toothfish (Dissostichus eleginoides) aggregated to 100km diameter hexagonal cells (2010, 2011, 2012, 2013 and 2014). |
Table 1 Number of sets by year and location.
| Year |
Western |
Discovery |
D1- Meteor |
| 2010 |
27 |
5 |
118 |
| 2011 |
1 |
207 |
54 |
| 2012 |
68 |
207 |
25 |
| 2013 |
0 |
108 |
57 |
| 2014 |
100 |
64* |
13 |
*No catch information provided for 56 sets
Table 1 shows that the main fishing ground is located on Discovery seamount and also in D1 but less hauls were deployed in the western seamounts of Sub-Area D.
Resource Structure
Considered a single stock: No
Exploitation
Table 2 presents data on Patagonian toothfish catches and discards listed by country, as well as fishing gear used and the management area from which catches were taken. Annual catches varied between 18t (2002) and 413t (2007). Discards were mainly due to parasite infection of fish. In the last three years with complete data (2012, 2013 and 2014) retained catches were 122, 61 and 74 t respectively and the annual weight of discarded specimens was 3, 3 and 2 t in the three year period.
Table 2 Catches (tons) of Patagonian toothfish (Dissostichus eleginoides) by South Africa, Spain, Japan and Korea.
| Nation |
Spain |
Japan |
Korea |
South Africa |
| Fishing method |
Longlines |
Longlines |
Longlines |
Longlines |
| Management Area |
D0 |
D0 |
D1 |
D0 |
D1 |
D0 |
D1 |
| Catch details (t) |
Ret. |
Dis. |
Ret. |
Dis. |
Ret. |
Dis. |
Ret. |
Dis. |
Ret. |
Dis. |
Ret. |
Dis. |
Ret. |
Dis. |
| 2002 |
18 |
|
|
|
|
|
|
|
|
|
|
|
|
|
| 2003 |
101 |
|
47 |
|
|
|
245 |
|
|
|
|
|
|
|
| 2004 |
6 |
|
124 |
|
|
|
|
|
|
|
|
|
|
|
| 2005 |
N/F |
N/F |
158 |
|
|
|
10 |
|
|
|
|
|
|
|
| 2006 |
11 |
|
155 |
|
|
|
|
|
|
|
|
|
|
|
| 2007 |
N/F |
|
166 |
|
|
|
|
|
|
|
|
|
|
|
| 2008 |
N/F |
N/F |
122 |
0 |
N/F |
N/F |
76 |
|
|
|
|
|
|
|
| 2009 |
N/F |
N/F |
86 |
0 |
74 |
0 |
16 |
0 |
46 |
0 |
N/F |
N/F |
N/F |
N/F |
| 2010 |
26 |
0 |
N/F |
N/F |
54 |
2 |
N/F |
N/F |
N/F |
N/F |
N/F |
N/F |
N/F |
N/F |
| 2011 |
N/F |
N/F |
159 |
6 |
N/F |
N/F |
N/F |
N/F |
N/F |
N/F |
15 |
0 |
28 |
0 |
| 2012 |
N/F |
N/F |
86 |
3 |
N/F |
N/F |
N/F |
N/F |
N/F |
N/F |
24 |
0 |
12 |
0 |
| 2013 |
N/F |
N/F |
41 |
2 |
19 |
1 |
N/F |
N/F |
N/F |
N/F |
N/F |
N/F |
N/F |
N/F |
| 2014 |
N/F |
N/F |
68 |
<1 |
6 |
<1 |
N/F |
N/F |
N/F |
N/F |
N/F |
N/F |
N/F |
N/F |
| 2015* |
N/F |
N/F |
51 |
<1 |
0 |
0 |
N/F |
N/F |
N/F |
N/F |
N/F |
N/F |
N/F |
N/F |
N/F = No Fishing; Blank fields = No data available; *Provisional (Sep 2015); Ret.= Retained catch; Dis. = Discarded catch
Table 3 Catches (tons) of Antarctic toothfish (Dissostichusmawsoni) by South Africa, Spain, Japan and Korea.
| Nation |
Spain |
Japan |
Korea |
South Africa |
| Fishing method |
Longlines |
Longlines |
Longlines |
Longlines |
| Management Area |
D0 |
D0 |
D1 |
D0 |
D1 |
D0 |
D1 |
| Catch details (t) |
Ret. |
Disc. |
Ret. |
Disc. |
Ret. |
Disc. |
Ret. |
Disc. |
Ret. |
Disc. |
Ret. |
Disc. |
Ret. |
Disc. |
| 2014 |
N/F |
N/F |
˂ 1 |
0 |
0 |
0 |
N/F |
N/F |
N/F |
N/F |
N/F |
N/F |
N/F |
N/F |
| 2015* |
N/F |
N/F |
0 |
0 |
0 |
0 |
N/F |
N/F |
N/F |
N/F |
N/F |
N/F |
N/F |
N/F |
N/F = No Fishing; Blank fields = No data available; *Provisional (Sep 2015); Ret. = Retained; Disc. = Discarded
Retained and discarded bycatch from the Patagonian toothfish fishery are presented in Table 4. The two most important species (in terms of weight) are grenadiers (GRV) and Blue antimora (ANT).
Table 4 Retained and discarded bycatch from the Patagonian toothfish fisheries (kg).
| |
2009 |
2010 |
2011 |
| |
Ret. |
Dis. |
Ret. |
Dis. |
Ret. |
Dis. |
| Species |
D0 |
D1 |
D0 |
D1 |
D0 |
D1 |
D0 |
D1 |
D0 |
D0 |
| GRV |
|
|
89 |
5833 |
4047 |
1936 |
93 |
2601 |
|
22414 |
| ANT |
|
|
126 |
4786 |
|
|
453 |
1348 |
|
4794 |
| BYR |
1221 |
|
573 |
|
|
|
|
|
|
|
| MCC |
|
|
336 |
896 |
|
|
|
|
|
|
| BYR |
|
|
|
|
|
|
|
|
|
|
| BEA |
360 |
|
|
|
|
|
|
|
|
|
| MZZ |
|
|
|
|
|
|
|
168 |
|
|
| SRX |
|
|
|
|
|
|
|
|
|
30 |
| MRL |
|
|
108 |
|
|
|
|
1 |
|
2 |
| COX |
|
|
2 |
|
|
|
|
|
|
21 |
| SKH |
|
|
90 |
|
|
|
|
|
|
|
| LEV |
|
|
36 |
|
|
|
4 |
|
|
|
| KCX |
|
|
|
1 |
|
|
3 |
35 |
|
|
| HYD |
|
|
|
|
|
|
|
|
|
|
| BUK |
|
|
|
|
|
|
17 |
|
|
|
| NOX |
|
|
|
|
|
|
|
|
|
7 |
| MWS |
|
|
|
|
|
|
|
|
|
6 |
| ETF |
|
|
|
|
|
|
|
|
|
|
| SEC |
|
|
|
|
|
|
|
|
|
|
| SSK |
|
|
|
|
|
|
2 |
|
|
|
| CKH |
|
|
|
|
|
|
1 |
1 |
|
|
| KCF |
|
|
1 |
|
|
|
|
|
|
|
| TOA |
|
|
|
|
|
|
|
|
|
|
| RTX |
|
|
|
|
|
|
|
|
|
|
| |
2012 |
2013 |
2014 |
| |
Ret. |
Dis. |
Ret. |
Dis. |
Ret. |
Dis. |
| Species |
D0 |
D1 |
D0 |
D1 |
D0 |
D1 |
D0 |
D1 |
D0 |
D0 |
| GRV |
2012 |
2013 |
2014 |
2012 |
2013 |
2014 |
2012 |
2013 |
2014 |
2012 |
| ANT |
Ret. |
Dis. |
Ret. |
Ret. |
Dis. |
Ret. |
Ret. |
Dis. |
Ret. |
Ret. |
| BYR |
D0 |
D1 |
D0 |
D0 |
D1 |
D0 |
D0 |
D1 |
D0 |
D0 |
| MCC |
|
|
23705 |
|
|
23705 |
|
|
23705 |
|
| BYR |
|
|
4442 |
|
|
4442 |
|
|
4442 |
|
| BEA |
|
|
|
|
|
|
|
|
|
|
| MZZ |
|
|
|
|
|
|
|
|
|
|
| SRX |
|
|
|
|
|
|
|
|
|
|
| MRL |
|
|
|
|
|
|
|
|
|
|
| COX |
|
|
|
|
|
|
|
|
|
|
| SKH |
|
|
124 |
|
|
124 |
|
|
124 |
|
| LEV |
|
|
37 |
|
|
37 |
|
|
37 |
|
| KCX |
|
|
75 |
|
|
75 |
|
|
75 |
|
| HYD |
|
|
|
|
|
|
|
|
|
|
| BUK |
|
|
|
|
|
|
|
|
|
|
| NOX |
|
|
|
|
|
|
|
|
|
|
| MWS |
|
|
31 |
|
|
31 |
|
|
31 |
|
| ETF |
|
|
|
|
|
|
|
|
|
|
| SEC |
|
|
|
|
|
|
|
|
|
|
| SSK |
|
|
|
|
|
|
|
|
|
|
| CKH |
|
|
|
|
|
|
|
|
|
|
| KCF |
|
|
2 |
|
|
2 |
|
|
2 |
|
| TOA |
|
|
|
|
|
|
|
|
|
|
| RTX |
|
|
|
|
|
|
|
|
|
|
ANT: Blue antimora (
Antimora rostrata); BEA: Eaton's skate (
Bathyraja eatonii); BYR: Kerguelen sandpaper skate (
Bathyraja irrasa); COX: Conger eels, etc. nei (
Congridae); CKH: Abyssal grenadier (
Coryphaenoides armatus); BUK: Butterfly kingfish (
Gasterochisma melampus); HYD: Ratfishes nei (
Hydrolagus spp); LEV:Lepidion codlings nei (
Lepidion spp); KCX: King crabs, stone crabs nei (
Lithodidae); MCC: Ridge scaled rattail (
Macrourus carinatus); GRV: Grenadiers nei (
Macrourus spp); MWS: Smallhead moray cod (
Muraenolepis microcephalus); MRL: Moray cods nei (
Muraenolepis spp); NOX:Antarctic rockcods, noties nei (
Nototheniidae); MZZ: Marine fishes nei (
Osteichthyes); KCF: Globose king crab (
Paralomis formosa); Blackbelly lantern shark (
Etmopterus lucifer); SEC: Harbour seal (
Phoca vitulina); SRX: Rays, stingrays, mantas nei (
Rajiformes); SKH: Various sharks nei (
Selachimorpha(Pleurotremata)); (Rajiformes); SSK: Kaup's arrowtooth eel (
Synaphobranchus kaupii).
Ret.= Retained catch. Dis. = Discarded catch
Assessment
There are no agreed stock assessments.
Data
The number of fishing sets sampled from 2006 onwards indicates a good sampling level in line with the SEAFO preliminary guidelines for data collection (Table 5). On average 20 specimens were measured per sampled fishing set, which is considered acceptable given the length range of the exploited population. It will be necessary to apply in future this sampling effort of 20 individuals in all sampled fishing sets (Figure 4).
Table 5 Annual analysis of sampling effort conducted on board fishing vessel.
| Year |
No. of Sets sampled |
Mean number of Individuals sampled per set |
Min. Individuals sampled per set |
Max. Individuals sampled per set |
Mean sample size/tonne |
| 2006 |
146 |
22.16 |
1 |
31 |
- |
| 2007 |
222 |
11.61 |
1 |
57 |
- |
| 2008 |
120 |
23.69 |
2 |
110 |
- |
| 2009 |
275 |
17.97 |
1 |
58 |
0.13 |
| 2010 |
125 |
26.91 |
1 |
60 |
0.32 |
| 2011 |
263 |
32.95 |
1 |
60 |
0.16 |
| 2012 |
298 |
20.58 |
1 |
57 |
0.17 |
| 2013 |
164 |
19.87 |
1 |
70 |
0.32 |
| 2014 |
176 |
25.50 |
3 |
50 |
0.35 |
Assessment Model
Length data and frequency distribution
Figure 5 shows the annual total length frequency distributions of Patagonian toothfish catches based on the observer data from all fleets submitted to SEAFO. Length frequency distributions for the period 2006-2013 suggest a shift towards smaller lengths in the catches in more recent years. The proportion of large fish appears to be declining.
 |
| Figure 5 Annual total length frequency distributions D. eleginoides raised to total catches per year for SEAFO CA Sub-Area D. |
Length-weight relationships
Table 6 shows the length-weight relationships by sex based on observer data from Japanese fleet in 2013.
| Samples |
a |
b |
r2 |
n |
| Males |
1E-06 |
3.4484 |
0.9768 |
405 |
| Females |
2E-06 |
3.4296 |
0.9579 |
860 |
Results
Reference Point
The harvest control rule (below) was adopted in 2014.
Where ‘Slope’ = average slope of the Biomass Indicator (CPUE) in the recent 5 years; and
λu :TAC control coefficient if slope > 0 (Stock seems to be growing) : λu=1
λd :TAC control coefficient if slope < 0 (Stock seems to be decreasing) : λd=2
The TAC generated by this HCR is constrained to ± 5% of the TAC in the preceding year.
Management
Management unit: Yes
Management Advice
In 2014 the Commission adopted a TAC of 276t in Sub-Area D, and zero tonnes for the remainder of the SEAFO CA for 2014 and 2015 (CM 29/2014). SC (2015) suggests a TAC of 264 tons in Sub-Area D and zero tonnes for the remainder of the SEAFO CA for 2016.
Bibliography
Arana, P. “Reproductive aspects of the Patagonian toothfish (Dissostichus eleginoides) off southern Chile. Lat. Am. J. Aquat. Res., 37(3): 381-394.” 2009.
Dewitt, H.H., P.C. Heemstra and O. Gon. “Nototheniidae. In: Fishes of the Southern Ocean, O. Gon and P.C. Heemstra (Eds.). J.L.B. Smith Institute of Ichthyology, Grahamstown, South Africa: 279-331.” 1990.
Horn P. L. “Age and growth of Patagonian toothfish (Dissostichus eleginoides) and Antarctic toothfish (D. mawsoni) in waters from the New Zealand subantarctic to the Ross Sea, Antarctica Fisheries Research, 56:275-287.” 2002.
Hureau, J.C. “Family Nothoteniidae-Antarctic rock cods. In: FAO species identification sheets for fishery purposes. Southern Ocean: Fishing Areas 48, 58 and 88 (CCAMLR Convention Area). Fischer, W. And J.C. Hureau (Eds). FAO, Rome, vols. I-II, 470 p.” 1985.
López-Abellán L.J. and J. González “Results of the longline survey on the seamounts in the southeast Atlantic and in the CCAMLR Subarea 48.6 (Atlantic Ocean) and Division 58.4.4 (Indian Ocean). CCAMLR Science, Vol. 6: 99-116.” 1999 
http://www.ccamlr.org/en/system/files/science_journal_papers/08lopez-abellan.pdf López-Abellán, L.J. “Patagonian toothfish in international waters of the Southwest Indian Ocean (Statistical Area 51). CCAMLR Science, 12: 207–214.” 2005 http://www.ccamlr.org/en/system/files/science_journal_papers/13lopez-abellan.pdf Prager, M. “User’s Manual for ASPIC: A Stock-Production Model Incorporating Covariates (ver. 5) and auxiliary programs, Population Dynamics Team, Center for Coastal Fisheries and Habitat Research, National Oceanic and Atmospheric Administration, 101 Pivers Island Road, Beaufort, North Carolina 28516 USA: National Marine Fisheries Service Beaufort Laboratory Document BL-2004-01.” 2004.
to turn layers on and off 