Although the stock structure has not been conclusively determined, Patagonian toothfish in the South American Plateau is thought to constitute a single stock (Laptikhovsky et al., 2006; Ashford et al 2012). There are indications that the fish inside the EEZ migrate from central to southern Chile to spawn (Oyarzun et al. 2003; Cespedes et al. 2005 Young et al.1998). However there is no estimate of the population size in the South American Plateau.
The stock assessments for this species are indirect (age-structured model), using data from the fleet, the Fisheries Development Institute (IFOP), and onboard observers. The stock is assessed considering only the southern area (47ºS-57ºS.). In addition, this part of the population is assessed considering it as isolated from the northern fishing area. The northern stock or northern portion of the stock is not assessed through a formal stock assessment, due to the lack of biological and fishery data from this region where the artisanal fishery (<18 mts vessels) is conducted (SUBPESCA, 2015c). However, it is assessed analyzing the historical landings and a Catch-MSY based reference point suggested by the scientific body IFOP (SUBPESCA, 2013b).
The Deep Waters Demersal Resources Scientific-Technical Committee (CCT-RDAP) evaluated the different stock assessment models (under different stock scenarios) presented by IFOP; however the CCT-RDAP did not achieve consensus for selecting one model and made recommendations for improvements (SUBPESCA, 2014a). The 2014 stock assessment is not publicly available because it is currently under revision.
After the amendments to the Fisheries and Aquaculture Law in 2013, the scientific advice for this fishery – concerning the Total Allowable Catch (TAC) – is given in three stages each year: a recommendation is given by IFOP for each management unit the year before. The Deep Waters Demersal Resources Scientific-Technical Committee (CCT-RDAP) analyzes IFOP technical and stock assessments reports and proposes a biologically acceptable catch (CBA). Finally, SUBPESCA submits a final TAC recommendation to be considered by the Ministry of Economy, Development and Tourism (Ministerio de Economia, Fomento y Turismo, MEFT).
Considering the observations to the analysis and results presented by IFOP to the Scientific Committee and taking into account that these studies are currently being subjected to a Peer Review process by international experts, as well as the need for a recommendation of setting the annual within the schedule of the administrative process for the year 2015 and the absence of indicators of an increased risk of deterioration of the stock during 2014, the Committee recommended for 2015 adopting the same ranges of CBA as for 2014, on both Patagonian toothfish fishery units. i.e. 988 tonnes and 1098 tonnes for the management areas North 47°S and South 47°S, respectively. SUBPESCA adopted the same recommendation as the Scientific Committee (SUBPESCA, 2014b).
The Scientific Committee recommended as well to: i) maintain the mark-recapture program at national level (including both the northern and southern stock distribution regions); ii) study the possible existence of spawning grounds north of parallel 47°S; iii) study the size/depth/fishery relationship along the entire Chilean coast (SUBPESCA, 2014a).
Last updated on 7 August 2015
The Deep Waters Demersal Resources Scientific-Technical Committee (CCT-RDAP) recommended for 2015 adopting the same ranges of CBA as for 2014, i.e. 1098 tonnes. SUBPESCA adopted the same recommendation as the Scientific Committee (SUBPESCA, 2014b).
Last updated on 07 Aug 2015
The Fisheries and Aquaculture Law states that, for all stocks, exploitation should be around the maximum sustainable yield. Patagonian toothfish stock assessment for the south 47°S management area, uses an age structure method. However, due to the unavailability of a statistically satisfactory estimation of the stock/recruit relationship, MSY proxy reference points relative to the virgin biomass (B0) are used. These reference points are expressed in relative terms.
More precautionary reference points were proposed for this fishery by international peer reviewers in 2014 and these have been adopted by IFOP and the Deep Waters Demersal Resources Scientific-Technical Committee (CCT-RDAP, SUBPESCA, 2015d), as follows:
- Biomass limit reference point Blim: 22.5% of SSB0
- Biomass target reference point, BMSY proxy: 45% of SSB0
- Fishing mortality target reference point, FMSY proxy: F45% SSBPR
Previous biomass target reference point was BMSY proxy= 40% of SSB0 and Blim= 20% SSB0.
In 2013, the Technical Committee reported that, based on the proposed BMSY proxy (=2,325 tonnes) the resource north 47°S was over-exploited (B2012 << BMSY). In 2014, the status of the stock was analyzed assuming different stock units. Although none of the models was finally adopted, considering the biological reference points for this resource recommended by the peer review and the different scenarios presented by IFOP, there was consensus within the Committee members that the resource is in an over-exploitation status and spawning biomass is below Blim (SUBPESCA, 2014a,b).
Patagonian toothfish started to be commercially exploited in Chile by the artisanal fleet in the 1970s, in central Chile. After a couple of years, the fishing areas extended to the north and mainly to the south of 47ºS. The Chilean fishery, which is inside the EEZ, is harvested by two different fleets: artisanal or small-scale – between 15 and 18 meters – and industrial or large-scale. They operate north and south of 47º S respectively. The northern area did not have any restrictions other than limited access until 2013. Since then, both fishery units have restricted access to new operators until 2017, and both management areas have a quota system; however in the north 47º S area it is a global TAC, while in the south unit it is an individual fishing quota system (IFQs).
From 1980 to 1989, the landings were mainly of the artisanal fleet operating in the VIII Region, with an increasing trend, reaching 6,000 tons in 1986.From 1990, a gradual decrease is observed in the northern region, because the fleet moved southward looking for higher yields, mainly found in the X Region. As a result of a research project in the southern zone, the landings increased to over 14,000 tons in 1992, which was before the Undersecretariat of Fisheries declared a “fishery unit” (Unidad de Pesqueria, UP) south of the in “Incipient Development Regime” (Regimen de Desarrollo Incipiente). However, after reaching that peak, the trend in the landings changed, decreasing from one year to the next, with catch levels of less than 7,000 tons total for both areas, which includes a catch level of less than 3,000 tons for the southern area. From 2005 to 2012, production has stabilized in both areas; average of 1900 tons and 2500 tons were harvested in the north and south management areas, respectively.
The first TAC for the industrial long-liners (south 47ºS management area) started at 5,000 tonnes in 1993, increased to 7,500 tonnes in 1996 and began to be reduced the next year to 6,000 tonnes, was set at 3,500 tonnes in 2003. Since 2005, the TAC has been set between 2,700 and 3,000 tonnes, however, the landings have been lower than those TACs. For 2014 and 2015, TACs in the southern management area were set at 1,098 tonnes (MEFT, 2014a).