For hake trawling, the two panel bottom trawls are being progressively replaced by high opening bottom trawls, Cosmos trawl type, and polyvalent otterboards are replaced by "Super V" doors.
In the shrimp trawling fishery with outriggers trawlers (Patagonian littoral and Buenos Aires coast, in particular S.Jorge Gulf and Camarones Bay, from June to March) the traditional wooden otterboards are being replaced more and more by steel ones, with more hydrodynamic shapes.
It is now recognized that several fish stock are over-exploited, in particular, hake and blue whiting (Micromesistius australis) but also patagonian toothfish, sea trout and flathead. Drastic measures are necessary to reduce the fishing effort. Relevant regulations to control the exploitation of these fish stocks will be strengthened by the fishery authorities. In this respect, it is worth mentioning that advanced communication systems (associating GPS and Inmarsat-C) have been installed on hundreds of vessels; by keeping permanent communication with the fishery administration and the concerned fishery research institution, it makes it possible for a number of vessels to report daily on their catch and to send other information required by the administration.
Due to the over-exploitation of some fish stocks traditionally fished, fleets of large freezer trawlers are now planning to move to other fishing grounds to exploit other fish stocks, such as hoki, known locally as "merluza de cola" ( Macruronus magallanicus), now under-exploited, South of 47th Parallel.
Concerning fishing methods other than trawling, an important longline fishery has developed in the Gulf of San Matias, involving almost sixty boats, 8 to 15m in length. The longlines used are bottom or semi-pelagic, 3,000 to 4,000 hooks per day, baited with anchovy ( Engraulis anchiota) for catching hake (Merluccius hubbsi), Brazilian sandperch, known locally as "salmon de mar" (Pseudopercis semifasciata), grouper (Acantistius brasilianus). The fish is iced, often in filet, for export to Spain.
It is worth noting that large vessels, in many cases, now have equipment for measuring sea temperature and salinity on board; both of which are considered very important for finding fish.
INIDEP (Instituto de Investigacion y Desarrollo Pesquero) is the institution dealing with fishing technology research.
INIDEP has a section dealing with fish product technology. In this field, the priorities are: - Preservation of the quality of fish on board; - Utilization of sub-products (for instance for medicine or as food additives: skin or cartilage of sharks, oil extracted from squid guts, etc.) ;
- Utilization of by-catch (when discarding any by-catch is prohibited relevant processing inboard fish technology has to be developed); - New products (for instance for the optimal utilization of large captures of anchovy).
INIDEP regularly issues three series of publications: - Revista de Investigación y Desarrollo Pesquero; - INIDEP Informe Técnico; - INIDEP Documento Cientifico.
Project on fishing gear selectivity and fishing technology development
The objective is the improvement of species and fish size selection in trawling fisheries; direct observation using underwater cameras.
Regarding fishing technology in general, the objective is to improve the efficiency of the technology in use for a rational exploitation of the resources, including for coastal fisheries.
The project makes an essential contribution to the assessment of the fisheries, advising on the selection, design and construction of sampling equipment and its function.
All these activities are oriented towards a rational use of fishing resources and imply the assessment and selection of fishing gears and materials, their adaptation to local conditions, tests and evaluation of their performance.
The on-going programme includes, among others:
- Development of a sorting device, consisting in two grids for the shrimp (Pleoticus muelleri) fishery which will allow the escapement of fish;
- Development (based on under-water images) of a sorting device for trawls which will allow the escapement of juvenile fish through a single grid. In this repect, it is worth mentioning that the utilization of selective devices on trawls for the escapement of juvenile fish will be made compulsory shortly.
- Design of trawls with computer assistance, including simulation of the trawls shape when in operation.
Selective fishing for "corvina" or whitemouth croaker (Micropogonias fournieri) and for hake (Merluccius hubbsi; in co-operation with JICA) are studied within other projects. In this respect, it is worth mentioning that researchers from INIDEP share their experience concerning selective devices, particularly sorting grids, with scientists working in other parts of the world who are members of the ICES Working group on Grid Sorting Systems in Trawls, Beam Trawls and Seine Nets.
As part of a project for hake fisheries, the biologic impact resulting from the utilization of selective devices which are developed within the above mentioned project on fishing gear selectivity is carefully studied.
Within a Shrimp project, research is carried out concerning the fishing gear, trawls in particular, which are used for sampling within the stock assessment programme. The medium term impact resulting from the utilization of a sorting grid allowing the escapement form trawls of fish juveniles is also studied.
As mentioned above, while fishing technologists are carrying out research for reducing by-catch (fish juveniles in particular) and discards, fish technologists of the same institution work on for the optimal utilization of unavoidable incidental catch; i.e. elaboration of high value by-products.
INIDEP already co-operates in the field of fishing technology with INATEC in Nicaragua.
The on-going co-operation within the ICES Working group on Grid Sorting Systems in Trawls, Beam Trawls and Seine Nets has already been mentioned. As a matter of fact, the experience with hake (a species which is assumed having a behaviour and reaction not so different to that of other hake species met in other fishing areas), using the same types of sorting or selective devices being developed or already in use in other parts of the world, would be of potential interest to a number of other fisheries in the world.
