Most of the reported expansion in production in Area 41 in the last three decades has been due to the increased catches of hake and other demersals as well as squids on the Patagonian shelf and slope. There are two well-known species of hake in this region, the Argentine hake (Merluccius hubbsi) and the Patagonian or southern hake (M. australis). A third hake species (M. patagonicus, sp. nov, Lloris and Matalallanas, 2003) has also recently been described.

In the first years of rapid development of this fishery, there was great uncertainty and concern regarding the state of this stock and the risk of overexploitation. This concern was addressed through the joint and coordinated research and management actions undertaken by Argentina and the United Kingdom of Great Britain and Northern Ireland within the South Atlantic Fisheries Commission. The results of these studies have contributed to improved assessment, monitoring and control of fishing  operations of local and long-range fleets. Regardless of the high year-to-year variability in abundance and resulting catches, the Argentine shortfin squid as well as the Patagonian squid are considered fully exploited (Csirke, 2005; Maguire et al., 2006).

The environmental conditions range from typically tropical in the north to sub-Antarctic in the south. Towards the northern part of Area 41, the marine environmental conditions are dominated by the South Equatorial Current. This current flows from the coast of Africa until it hits the South American coast. There, it branches into the North Brazil Current, which flows along the north Brazilian coast, and the Brazil Current, which flows south along the central and southern Brazilian coast. The northern part of Area 41 is further influenced by the great flow of freshwater from the Amazon River. Further south, the marine environment is dominated by the warmer southward-flowing Brazil Current and then by the colder northward-flowing Falkland Current (Malvinas Current). These currents merge into an offshore flow of subtropical convergence just off the Plate River. This is a region where there is also a large flow of freshwater into the coastal ecosystems (Emílsson, 1959; Hempel, 1971; Dias Neto and Mesquita, 1988; Bakun and Parrish, 1991; Bakun, 1993; Castro and Miranda, 1998).

Area 41 covers a total surface of 17.65 million km² off the east coast of South America, between latitudes 05°00’N off northern Brazil and 60°00’S off southern Argentina, and includes a total shelf area of 1.96 million km² (Figure B6.1). In the north, the continental shelf may extend as far as 160 nm (320 km) offshore from the Amazon River, where the bottom is mostly river deposits and debris. As one moves south away from the influence of the Amazon River, the shelf becomes narrow, coralline and mostly unsuitable for trawling. The shelf is also narrow and mostly rocky further south off central and southern Brazil. Closer to the southern extent of Area 41, it widens and becomes more suitable for trawling. The best and largest areas for trawling are found around the Plate River and over the Patagonian shelf and the area of the Falkland Islands (Malvinas). In these regions, the shelf extends well beyond the 200‑nm limit (more than 370 km) off the coastline. This makes this region the largest area of continental shelf in the Southern Hemisphere.
The variety and abundance of fishery resources and types of fisheries in Area 41 are determined by a combination of physical and environmental characteristics. Shrimps and lobsters, and to a lesser extent reef fishes and other tropical demersals, tend to be of particular relevance towards the northern part of Area 41. Further south, important populations of small pelagics are found in nutrient-rich coastal regions where water masses mix off central Brazil and off Uruguay–northern Argentina. This mostly occurs around the Plate River. Coastal demersals are particularly important off southern Brazil and in the vicinity of the Plate River. Whereas mid-water and deepwater demersals tend to dominate over most of the continental shelf in the vicinity of the Plate River, the Patagonian shelf and the Falkland Islands (Malvinas). The region of the Falkland Islands (Malvinas) is also important for squids. Large pelagics are mostly caught off central Brazil and the Plate River.

Figure B6.1 The Southwest Atlantic (Area 41)

Most capture fish production from Area 41 comes from demersals and squids. This is one of the FAO Statistical Areas where capture fisheries grew rapidly until the late 1990s. In the last decade, total catches from Area 41 have stabilized, although with marked interannual fluctuations. In 1950, the total catch for the whole of Area 41 was only 172 000 tonnes. At that time, most of the known fish stocks were only lightly or moderately exploited, and several important stocks were still virtually unexploited.
A number of new fisheries have developed since, and total annual catches increased steadily at an average rate of 7.4 percent per year to reach a maximum of 2.4 million tonnes in 1987. There was an exceptional spike in catches between 1966 and 1968, with a peak catch of 599 000 tonnes in 1967 caused by an intense pulse of fishing for hake and probably other demersals by the then Soviet Union fleet (Figure B6.2). Catches declined after 1987, to a low 2.0 million tonnes in 1990 and 2.1 million tonnes in 1994. A new maximum was reached in 1997 at 2.8 million tonnes. Since then, catches have been fluctuating between 2.0 and 2.5 million tonnes (Figure B6.2 and Table D6).
Demersal species in ISSCAAP Group 32 (cods, hakes, haddocks) and molluscs in Group 57 (squids, cuttlefishes, octopuses) are the major contributors to the catches from this region. The next most-important catch groups are the coastal species in Group 33 (miscellaneous coastal fishes such as croakers and weakfishes), the small pelagics in Group 35 (herrings, sardines, anchovies), and other demersals in Group 34 (miscellaneous demersal fishes such as toothfish and cusk-eel) and Group 38 (sharks, rays, chimaeras). The dominant species in the demersals of Group 32, in terms of volume, are the Argentine hake (Merluccius hubbsi), the Patagonian grenadier (Macruronus magellanicus), and the southern blue whiting (Micromesistius australis). Among the other groups, the Argentine shortfin squid (Illex argentinus) in Group 57, and the Brazilian sardinella (Sardinella brasiliensis) in Group 35 contributed the largest catches.

Figure B6.2 Annual nominal catches by ISSCAAP Groups in the Southwest Atlantic (Area 41)

The Argentine hake sustains one of the most important fisheries in the region of the Plate River and over most of the Patagonian shelf. Total catches of this species steadily increased from 1950 to 102 000 tonnes in 1965. Catches were at first all taken by the coastal States (Argentina, Brazil and Uruguay). Following the exceptionally high catches of hake reported by the then Soviet Union in 1967 (513 000 tonnes), catches declined to 70 000 tonnes in 1969. The total catch from this region then increased steadily to 462 000 tonnes in 1979, and then gradually increased to a record high of 682 000 tonnes in 1996. Since then, total catches of Argentine hake rapidly declined to a record low of 243 000 tonnes in 2000 and have fluctuated since. Reported catches in 2009 were 331 000 tonnes (Figure B6.3).
The Argentine hake is mostly exploited by Argentine and Uruguayan fleets. Both fleets increased in the 1980s to the early 1990s, and the Argentine fleet continued to increase in the 1990s. Other deepwater demersals in Group 32 that make a significant contribution to the total fish production in Area 41 are the Patagonian grenadier and the southern blue whiting (Figure B6.3). These species produced 135 000 tonnes and 32 000 tonnes, respectively, in 2009. They are particularly abundant in the southern Patagonian shelf and slope, where they are exploited by long-range fleets from the region as well as by distant-water fleets.

Figure B6.3 Annual nominal catches of selected species in ISSCAAP Group 32, Southwest Atlantic (Area 41)

The miscellaneous demersals in Group 34 (Figure B6.4) that contribute most to total fish production in Area 41 are the pink cuskeel (Genypterus blacodes) and Patagonian toothfish (Dissostichus eleginoides), with 21 000 tonnes and 5 000 tonnes, respectively, in 2009. These species are exploited by both coastal and long-range fleets from the region and from other FAO Statistical Areas. Coastal demersal species within Group 33 also produce significant catches within Area 41, particularly the Argentine croaker (Umbrina canosai), the striped weakfish (Cynoscium striatus), the whitemouth croaker (Micropogonias furnieri), and other weakfishes (Cynoscion spp.). These species have reported relatively high and stable catches in the past few years, with a total of 140 000 tonnes for the four species in 2009. These species are all exploited by coastal fleets.

Figure B6.4 Annual nominal catches of selected species in ISSCAAP Groups 33 and 34, Southwest Atlantic (Area 41)

The main small pelagic species within Group 35 are the Brazilian sardinella (S. brasiliensis) and the Argentine anchovy (Engraulis anchoita). After the record catches of 228 000 tonnes of Brazilian sardinella reported in 1973, total catches of this species declined. The total catch of Brazilian sardinella hit a low of 17 000 tonnes in 2000. Since then catches have been steadily increasing, reaching 83 000 tonnes in 2009 (Figure B6.5). Catches of Argentine anchovy reached a maximum of 44 000 tonnes in 2005 and 2006, declining to 28 000 tonnes in more recent years. Catches of tunas and other large pelagics in Group 36 have been more or less stable at 50 000–70 000 tonnes per year, after reaching a maximum of 74 000 tonnes in 1996.

Figure B6.5 Annual nominal catches of selected species in ISSCAAP Groups 35, 36, Southwest Atlantic (Area 41)

Another very important fishery in Area 41 is that for squids (Group 57). The main species is the Argentine shortfin squid (Illex argentinus). It represented 87 percent of the squid catches and 14 percent of total marine catches in Area 41 in 2009. The overall abundance and actual catches of Argentine shortfin squid have been very variable since the fisheries started in the late 1970s. After reaching 638 000 tonnes in 1993, total catches of this species declined to 506 000 tonnes in 1994, before increasing to a record high of 1.1 million tonnes in 1999. From 2000 to 2009, catches fluctuated widely between 179 000 tonnes and 955 000 tonnes. Catches in 2009 (261 000 tonnes) were among the lowest catches in the last two decades (Figure B6.6). Although less abundant, total catches of Patagonian squid (Loligo gahi) also fluctuated between a maximum of 89 000 tonnes in 1989 and a low of 22 000 tonnes in 1997. In 2009, the total catch of this species was 35 000 tonnes. Another squid species caught occasionally is the seven-star flying squid (Martialia hyadesi). Catches are usually low, ranging between 0 and 1 000 tonnes/year in most years. The exception was a record high catch of 24 000 tonnes in 1995. This exceptional catch was followed by catches of 3 800 tonnes and 8 300 tonnes in 1996 and 1997. Catches of other non-identified squids has declined sharply in recent years, suggesting great improvements in the identification at species level of squid catches from Area 41.

Figure B6.6 Annual nominal catches of selected species in ISSCAAP Group 57, Southwest Atlantic (Area 41)

Shrimps, prawns, lobsters, crabs and other crustaceans in Groups 42, 43 and 45 also sustain important local fisheries throughout Area 41 from the tropics to the sub-Antarctic zone. Altogether, these species groups have yielded total catches of more than 100 000 tonnes since 2000 (Figure B6.7). These are important volumes considering their relatively high market value. The single crustacean species yielding the largest catches is the Argentine red shrimp (Pleoticus muelleri). It has highly variable catches ranging from 3 000 to 50 000 tonnes/year since the fishery started in the 1980s. The highest record catch of 79 000 tonnes was reported in 2001. In 2009, the total catch of this species was 54 000 tonnes. About 3 percent of the total catches in Area 41 (55 779 tonnes in 2009) are reported as “not identified marine fishes” in the official FAO statistics. These species are grouped under ISSCAAP Group 39 (marine fishes not identified). These mostly come from smallscale fisheries, particularly in Brazil, where the variety of species and landing sites makes the recording of catches by species a difficult task.

Figure B6.7 Annual nominal catches of selected species in ISSCAAP Groups 42, 43 and 45, Southwest Atlantic (Area 41)

International fisheries research, stock assessment and fisheries management activities in Area 41 are mostly dealt with through bilateral arrangements. Argentina and Uruguay cooperate mainly through the Joint Technical Commission for the River Plate Maritime Front (CTMFM, http://ctmfm.org). This organization was established in 1973 to promote bilateral cooperation between neighbouring Argentina and Uruguay regarding the assessment and management of shared stocks in the River Plate Maritime Front. In so doing, the CTMFM has been organizing or coordinating joint research surveys and other research activities in its convention area. It has also actively promoted scientific publications and meetings of regional and international relevance. At these meetings, various stock assessment and fisheries management issues of interest to the two member countries and other stakeholders are addressed. While very active in the 1980s and 1990s, the activities of this regional commission have decreased, particularly in relation the wider regional or international significance of their scientific activities. However, in November, the CTMFM signalled the start of a new, more active era by holding a scientific symposium. This symposium, titled “The ecosystem approach and its implementation in fisheries management in the Fisheries Common Zone of Argentina and Uruguay”, was the first in a decade and was attended by more than 100 scientists from more than 20 institutions. Argentina and the United Kingdom of Great Britain and Northern Ireland also cooperate in the assessment of fish stocks and management of fisheries in the region of the Falkland Islands (Malvinas). In November 1990, the Governments of Argentina and the United Kingdom of Great Britain and Northern Ireland signed a joint statement on the conservation of fisheries. This statement led to the establishment of a South Atlantic Fisheries Commission, composed of delegations from both States. The South Atlantic Fisheries Commission met regularly and provided a forum for the exchange of information on marine living resources. It discussed the implementation of measures to improve the conservation and management of commercially important fish stocks in the Southwest Atlantic, particularly those around the Falkland Islands (Malvinas). However, it has been less active in recent years. Brazil has about ten technical working groups (Grupos Permanentes do Estudos), which have had variable degrees of activity over the years. In certain circumstances, these groups have been instrumental in coordinating research work. They have also provided technical advice on the assessment and management of important fisheries in Brazil, such as tunas, shrimps, lobsters, sardines and coastal demersals. Through some of these working groups covering the northernmost part of Area 41, there is active cooperation with the WECAFC covering Area 31 regarding the study and assessment of fish stocks in the Guyana–Brazil region.

Most of these fisheries are under some kind of management scheme with specific management measures varying from one country to another and from one fishery to another. However, enforcement is not always as effective as desired. Only a few fisheries are under an open-access regime, and these are mostly coastal small-scale fisheries. In most cases, there is a limited-access scheme for which a fishing licence is required. These licensing requirements are usually combined with other fishing effort and total catch restrictions to keep fishing mortality under control. In addition, regulations on the size at first capture and seasonal and area closures are used to protect juveniles and spawners. In particular, Argentina and Uruguay, and their  subregional organization,the Frente Marítimo, have been compelled to adopt more severe restrictive regulations, combining TAC limits, size-at-first-capture limits, and seasonal and area closures to address the critical situation of the Argentine hake stock.