The Argentine Patagonian toothfish (Dissostichus eleginoides) fishery has established itself as one of the most selective in the world thanks to a management scheme based on applied science, strict monitoring, and cooperation between the public and private sectors. This is demonstrated by a recent study conducted by the National Institute for Fisheries Research and Development (INIDEP), which documents how Argentina managed to drastically reduce juvenile catches in the Argentine Sea, guaranteeing the long-term sustainability of the resource, as reported by Revista Puerto.

The scientific paper, titled “Towards a more selective Patagonian toothfish fishery: How measures implemented in Argentina reduced the proportion of juveniles in catches”, has been accepted for publication in the international journal MAFIS (Marine and Fishery Sciences).

The research team was led by INIDEP research director Otto Wöhler, together with researchers Patricia Martínez, Gonzalo Troccoli, Germán Lukaszewicz, and Emiliano Di Marco. The study analyzes the evolution of the fishery and documents the process through which it moved from worrying levels of juvenile capture to minimal proportions compatible with stock health.

Distribution area of ​​toothfish in the Southwest Atlantic. (Source: INIDEP)

The challenge of achieving selective fishing

The Patagonian toothfish presents biological characteristics that make management complex. Unlike many other commercial species, juvenile individuals can exceed 80 centimeters in length, which limits the effectiveness of traditional selectivity measures.

In most fisheries, selectivity is improved by increasing the mesh size of trawl nets or the hook size in longline fishing. However, in the case of the Patagonian toothfish, these modifications proved to be ineffective and operationally unfeasible.

This forced Argentine scientists and fisheries managers to look for alternative solutions based on the behavior and distribution of the species.

Source: INIDEP/MAFIS

The key: depth

The answer emerged from the analysis of the species’ bathymetric distribution. Researchers confirmed that adult Patagonian toothfish inhabit depths that can reach 2,500 meters, while juveniles concentrate in considerably shallower waters.

In particular, juveniles are mainly found at depths shallower than 800 meters.

This scientific knowledge made it possible to design a management strategy based on protecting the strata where immature individuals concentrate, significantly reducing their capture.

Click on the image to enlarge it. Source: INIDEP/MAFIS

Management measures that transformed the fishery

Based on the scientific evidence generated by INIDEP, Argentine fisheries authorities implemented a set of measures that are now considered a management model.

The main tools applied include:

• Depth restrictions: prohibition of directed fishing in strata where juveniles predominate.

• Creation of the Patagonian Toothfish Juvenile Protection Area (APJMN).

• Institutional coordination: establishment of the Patagonian Toothfish Fishery Monitoring Commission (CASPMeN).

• Control and monitoring system: mandatory presence of INIDEP scientific observers on board and exhaustive monitoring of landings.

Photos Diego Izquierdo/Revista Puerto

The results were clear. According to the analysis of fishery data between 1993 and 2024, after the implementation of these measures in 2001, the proportion of juveniles in catches dropped significantly and has since remained below the biological safety thresholds established by authorities with scientific advice.

The central role of CASPMeN

One of the pillars of the Argentine success model is the functioning of the Patagonian Toothfish Fishery Monitoring Commission (CASPMeN).

This body brings together scientists, fisheries authorities, and representatives of the industry, and acts as a permanent forum for evaluation and decision-making.

The active participation of private companies in verifying catches, combined with detailed monitoring of landings and the presence of INIDEP scientific observers on 100% of the voyages of the directed fleet, guarantees a high level of transparency and real-time data availability.

Frequency distributions of Patagonian toothfish lengths weighted by total catch by the trawl fleet (A) and longline fleet (B). Years 2000 and 2003-2023. The vertical line indicates the minimum catch length established by regulations based on the species’ length at first sexual maturity (TL50%: 82 cm). Source: INIDEP/MAFIS

This continuous flow of information allows rapid responses to any sign of biological warning.

A model that stands out internationally

The results obtained by Argentina contrast with the situation of other international Patagonian toothfish fisheries.

One of the most cited examples is the fishery around South Georgia Island, where catches are mainly made using longlines, a fishing gear theoretically considered more selective than trawling. However, that fishery has reported significant levels of juvenile catch, generating concern in international forums such as the CCRVMA (Commission for the Conservation of Antarctic Marine Living Resources).

 

Source: merluzanegraargentina.org

The Argentine model demonstrates that a well-managed trawl fishery, with strict spatial and depth closures, can achieve levels of selectivity even higher than those of hook-based fisheries.

In this way, it challenges the idea that the type of fishing gear is the only determining factor in selectivity.

Science and governance to secure the future

The INIDEP study reinforces the importance of integrating scientific research, effective regulation, and industry participation to ensure the sustainability of marine resources.

Source: merluzanegraargentina.org

The Patagonian toothfish of the South Atlantic, considered one of the most valuable products of Argentine fisheries and known as the deep-sea “black gold”, demonstrates that it is possible to maintain a productive industrial fishery without compromising the natural renewal of the resource.

As highlighted by Revista Puerto, this model positions Argentina as an international benchmark in science-based fisheries management.

The complete article can be consulted in MAFIS (Marine and Fishery Sciences) under the title “Towards a more selective Patagonian toothfish fishery”, currently in press.