1. The Fifth Session of the Working Party on Fishery Resources of the Commission for Inland Fisheries of Latin America (COPESCAL), was held at the FAO Regional Office for Latin America and the Caribbean (RLAC), in Santiago, Chile, from 24 to 28 September 1990. The meeting had been initially planned and organized to be held in Leticia (Colombia) in November 1989 but it had to be postponed and now finally held at the FAO Regional Office in Santiago.
2. The opening ceremony was attended by the Under-Secretary of Fisheries of Chile, Mr. Andrés Couve, the Director of the FAO/ECLAC Joint Agricultural Division, Mr. Luis López Cordovez, and the Regional Fisheries Officer, Dr. Elda Fagetti, in her capacity of COPESCAL Secretary.
3. Mr. López-Cordovez welcomed the participants on behalf of FAO and COPESCAL and thanked, very especially, the generous hospitality offered by Colombia to host during 1989 the sessions of the two Working Parties (on Fishery Technology and Fishery Resources) of COPESCAL, both of which had to be postponed.
4. He stressed the importance of objectives of this Working Party which have been focusing for many years on issues that are very important to the Region, such as the evaluation and rational exploitation of lake and river resources, the pollution of inland waters and the impacts of the introduction of exotic species into the countries of the Region.
5. He recognized the progress made by this Working Party, which was reflected in the numerous technical publications that have been appearing under COPESCAL series on the above mentioned subjects, the promotion of scientific events organized locally and, what is even more important, the attainment of a better and more integrated knowledge, needed for a sustainable development of the biologic resources of Latin America's inland waters; and, finally, the establishment of measures for the protection of the environment and of the genetic resources of its endemic species.
6. He also expressed that the positive impact of cooperative activities undertaken by this Working Party was the result of the successful relationship and cooperation between its members and the Technical Secretariat, that has been maintained since its establishment eight years ago, as well as to the excellence and great expertise of its members.
7. In the official opening address, the Under-Secretary of Fisheries of Chile expressed his personal interest in the Agenda items of the meeting, particularly in those related to the Code of Practice for the Introduction of Exotic Species and the environmental impact of fish cage cultures in natural lakes. As far as inland fishery resources are concerned, he explained that the introduction of exotic species in Chile had not yet caused any devastating effects; to the contrary, the country had benefitted from sport fishing, which is presently based on species introduced early this century from European countries and, later on, from the United States.
8. He also pointed out the successful results obtained in Chile with the culture of several salmon species whose production for the current year is estimated in over 20,000 tons, representing an income of about 100 million dollars. Chile has thus become one of the main exporters of cultured salmon in world markets. He admitted, however, that in spite of its prosperity, confined cultivation in lakes was facing some obstacles due to possible eutrophication effects and environmental impacts, damaging other users of the lakes.
9. The participants (see Annex I) unanimously agreed to elect the expert from Colombia, Mr. Mauricio Zárate, as Chairman and the participant from Chile, Mrs. Irma Vila, as Vice-Chairman. The Agenda, given in Annex II, was approved and a rapporteur was appointed for each of the main items of the Agenda.
10. The Secretary of COPESCAL introduced the participants invited by the Regional Office with the purpose of expanding the Working Party, so to include experts from the host country and from other countries of the Region, who could contribute with their personal experience on certain Agenda items. She also provided information on the main inter-sessional activities, accomplished in compliance with the mandate given to the Commission in its Fifth Session, held in Panama in June 1988. She also pointed out that the Sixth Session of the Commission is tentatively scheduled to be held in Peru from 18 to 22 February, 1991.
11. In compliance with recommendations from the Fifth COPESCAL Session (paragraph 38 of the report), the Working Party on Fishery Resources during its meeting in Santiago, Chile, analyzed the Code of Practice for the Introduction of Aquatic Species issued by EIFAC (EIFAC, Occ. Doc. 23, 1988) with the purpose of adjusting it for its application in Latin America.
12. As a result of this analysis and discussion, the Working Party adopted a modified version of this Code which was distributed among the participants and that will be submitted to the Commission's consideration.
13. In addition, the Working Party put forth suggestions conerning the procedures for its future enforcement and operation that are attached to the Code of Practice.
14. With the support provided by the COPESCAL's Secretariat, the FAO Regional Office for Latin America and the Caribbean, Unesco and the University of Chile, the “II International Workshop on Integrated Approaches to the Study of Lakes and Reservoirs as Basis for their Management”, was held in Santiago, Chile from 28 to 31 September 1987, immediately after the Fourth Session of the Working Party on Fishery Resources (Puerto Montt, Chile, 21–25 September, 1987). The papers presented at the Workshop are at present being printed at the FAO Regional Office and will be published as COPESCAL Technical Document № 9.
15. In connection with recommendations on the need to compile information on biological data and the culture of endemic important species, the FAO Regional Office recently published a document entitled “Manual para el Cultivo del Bagre Sudamericano (Rhamdia sapo)”, RLAC/PES-20. The synopsis of the “pejerrey argentino” (Odontesthes bonariensis), has also been completed and will be published soon.
16. It is recommended to complete as soon as possible the synopsis on Colossoma macropomum and that the “Manual sobre la Acuicultura en Cuba” (Technical Document COPESCAL № 6, 1988) be translated into English, being of interest to English-speaking countries of this Region and of Africa.
17. Considering the relevant proposals formulated in former meetings of this Working Party, the information recently published and/or in preparation on the characteristics of limnological and fishery production of the Region's lakes and reservoirs, the Working Party agreed on the urgency of carrying out a workshop on the methodology used and results obtained in the referred studies so as to prepare a compendium on the matter. It was suggested that this Workshop could take place after the Sixth Session of the Working Party.
18. In view of the advanced status of knowledge on biology and management of tilapia, the Working Party proposed that financial resources for the preparation and publication of a manual summarizing the information available in the Region should be sought.
19. The Working Party also recommended to hold an International Congress on the “Ecology, Production and Fishery Management of Lakes and Reservoirs” during 1993. To that effect, it requested FAO's assistance to find the host country and the necessary funds to finance that event. The proposed Congress should deal with the following subjects: a) limnological and fishery characteristics of lakes and large flooded reservoirs; b) direct and indirect methods for estimating fishery production; c) application of models and other procedures in fishery management; d) socio-economic aspects applied to fisheries; and e) the impact of the reservoirs' construction on fisheries.
20. Some data supplementing the information contained in previous country reports is summarized as follows:
21. Argentina and Uruguay, Research on the evaluation of fishery resources and monitoring the modification of fish communities in the “Salto Grande” reservoir, located in the Rio Uruguay, a section that is common to both countries, had been re-initiated. The tasks accomplished so far include biomass estimations through hydroacoustic techniques and exploratory fishing, sampling by means of bateries of gill nets and studies on reproduction, based on fish eggs and larvae sampling. This bi-national activity is being carried out by Governmental fishery institutions of both countries under the auspices of the “Comisión Adminstradora del Río Uruguay” (CARU) and the “Comisión Mixta de Salto Grande” (CMT).
22. Brazil. Due to constant and periodic severe droughts, the development of fisheries in reservoirs of the Northeastern Region of Brazil is essential to supplement internal demand, particularly that of low-income population groups. In the State of Ceará there are about 10,000 reservoirs, both private and public, that together cover 170,000 has. This State develops projects to support inland fisheries as a means of reducing dependency on the catch of other regions, in order to satisfy the State's internal demand. The programme for the introduction of fingerlings of Colossoma, carps, tilapia and other species, that are essential for increasing production, as well as programmes aimed at developing catching technology are worth mentioning.
23. Bolivia. This country has one million hectares of water reservoirs but uses less than 10% for fishery activity. Up to 1940, peasants' fishing practices were rudimentary and based on the catch of native species. After the introduction of trouts, carps, silversides and tilapia, fishculture is being explored. From 1980 on, fishery activity has intensified in the Bolivian Amazon area, with interesting prospects.
24. Colombia. The “Guájaro” reservoir fishery, covering 16,000 hectares, is focused on some twelve commercial species. Outstanding among them is the Nile tilapia (Oreochromis niloticus), introduced in the early 80s; however, in the last two years (1989–1990), the volume of catches decreased substantially to almost disappear. The present catch is based on “arenca” (Triportheus magdalenae), which constitutes 48%, tilapia (Oreochromis niloticus) 11%; “pacora” (Plagioscion surinamensis) 6% and other species 35% among the latter, mention can be made of mullet (Mugil incilis). In the 1984–85 period, the catch reached 1,110 tons with a fishing yield of 82 tons/hectare/year, whereas in 1988 the catch fell to 83 tons/year.
25. Costa Rica. Inland fishery is not substantially developed or important at the national level. It is mostly an artisanal or subsistance small scale exploitation. The bulk of fish extraction activities, particularly of guapote Cichlassoma dovii, takes place at the Arenal hydroelectric dam. Sport fishermen catch these species with a fishing rod, whereas commercial fishermen who sell these species at least in two villages nearby, catch them with harpons. The dam offers several development prospects: on one hand, there is interest in promoting sport fishing and building touristic infrastructures; on the other, experiments are being carried out for fattening tilapias in cages, in order to promote this activity at the small producers' level. These two initiatives, added to the extraction of “guapote” for consumption, should be evaluated because they may conflict with the optimum use of present and potential living resources of the dam. The German Government has recently concluded an evaluation of these resources. Information on the trophic dynamics of some of the dam's species is also being analyzed. No fishery statistics are being collected for the time being.
26. Cuba. Inland fishery landings in 1989 amounted to 18,000 tons. According to medium-term plans, landing will reach 50,000 tons by the year 2000. Semi-intensive culture will be given great importance in future aquaculture development plans; therefore, the policulture of tilapia with chinese carps is being carried out. To this effect, waters from reservoirs are fertilized with the purpose of improving natural foodstuffs, thus increasing the carrying capacity for fingerling seeding.
27. Chile. Salmon farming activities that were started in 1979 with the culture of coho salmon (Oncorhynchus kisutch), have reached an outstanding development with the additional culture of the Atlantic salmon (Salmo salar), the anadromas rainbow trout (Oncorhynchus mykiss) and the Chinook salmon (Onchorhynchus tsawystcha). In Chile, there are approximately 300 concessions for the culture of salmon species. Of these, seventy operate with different stages of culture. The estimated production is of 20,000 tons for 1990 with an export value of about 100 million dollars. Another important species in Chilean waters is the Argentinean silverside (Odontesthes bonariensis), for sport fishing and minor trade purposes. There is an on-going study on the utilization of this resource to develop small scale artisanal coastal fisheries.
28. Mexico. Nationwide, there are 1.4 million hectares of fresh water bodies, some of which, on account of their environment and size characteristics, have become the main suppliers, both of native and introduced fish to important fisheries. Mexican inland ichthyofauna includes about 500 species widely distributed throughout the country. Records of catches during the 1980–87 period of the main commercial species are as follows: “mojarra-tilapia” 64.1%, carps 21.9%, “charal” 7.1%, catfish 2.3%, black seabass 1.2% and other fish 3.4%. A sustained growth has been observed since 1972 and according to records, the volume of catches has increased from 4.500 to 175.000 tons. In 1988, fish landings amounted to 216.815 tons.
29. Panamá. A tilapia fishery has recently started its operation in Lake Gatún (430 Km2), where catches are carried out by divers provided with harpons. Also, the accidental introduction of a snail of the genus Pomacea in this dam has resulted in an efficient biologic control of Hydrilla verticilata. Information was also provided on the re-stocking of Lake Alajuela (50 Km2) with “silver carps” and “cachamas”, (C. macropomum).
30. The Technical Secretary outlined the activities carried out on this subject during the inter-sessional period. Acting in response to the Working Party's concern for the effects of the construction of the hydroelectric dams on river fishery resources and measures to be taken for compensating or mitigating their impact, the technical document “Structures assisting the Migration of Non-Salmonid fish in Latin America ” (COPESCAL Tech. Doc. . № 5) was prepared and published in Spanish and later translated into English.
31. Another important activity in connection with this Working Party was the execution of the Symposium on Great Latin American Rivers (SISGRIL) in Venezuela, organized by La Salle Foundation, in which COPESCAL actively participated playing a catalytic role. This meeting was attended by 120 participants. Papers submitted and discussed in this meeting referred in general to the four main watersheds of the Region: Orinoco, Amazonas, Paraná and Magdalena. Besides subjects directly related with fishery resources, limnological, socio-economic and institutional subjects were also discussed.
32. Of particular importance for the Working Party was the reinterpretation of fishery yields of river systems prepared on the basis of African river data, in order to adjust them to the Latin American river system. Basically, Latin American rivers perform as those in Africa, but in general they are less exploited. Catches can be considered as approaching the maximum potential yield level only for some river segments.
33. Other subjects of interest were: a) the establishment of a communication network on river systems and b) the recognition that progress in research on rivers and the management of their fishery resources will require the operation of efficient communication channels among the various wastershed research and management groups, particularly when watersheds are shared by several countries.
34. On the request of some members of the Working Party the Technical Secretary made a detailed statement of the conclusions reached by SISGRIL on the application of yield models, grouped in three categories:
yield models based on the morphological characteristics of the river or drainage watershed (length, total area, flooded area);
models for forecasting yield on the basis of hydrological conditions prevailing in previous years, and
models relating to catches with fishery efforts. In the latter case, emphasis was placed on the importance of studies on the behaviour of artisanal fishermen with regard to the variation of individual catches, in order to correct distorsions in estimating the fishery effort.
35. The Working Party also considered the importance of analyzing the socio-economic consequences of the increase in fishery effort levels in some areas within the most important river watersheds in the Region, where the number of local stocks of the more important commercial species is apparently decreasing. The members of the Working Party from Colombia and Peru provided infrmationon the occurrence of such processes in the Magdalena River and in the Amazon, near Iquitos. A similar situation in the Paraguay River fisheries, in the Asunción area, was detected by a recent mission undertaken by FAO in Paraguay.
36. The Working Party agreed that the present situation required more intensive monitoring activities, in order to follow up the evolution of river fisheries and to adopt a timely decision regarding the establishment or strengthening of regulatory measures.
37. The Working Party recommended Governments to define the objectives and policies in connection with the utilization of river fishery resources, taking into consideration models to forecast in “general terms” the direction of transformation of fish communities as a result of the intensification of fishing effort and the analysis of its socio-economic consequences.
38. Due to the inter-relationship among various river segments and the migratory nature of most river fish of commercial importance for the Region, it is essential that the adoption of management policies and the application of management measures be carried out in a coordinated manner at the watershed level. In this connection, the establishment of proper institutional mechanisms or the strenthening of those existing at the bilateral or multilateral levels is advisable.
39. With the purpose of contributing to the inclusion of inland fishery subjects within the wider context of integrated watershed planning and management, the Working Party agreed on the advisability of actively participating in the Technical Cooperation Networks on Watershed Management and on the Development of Lowlands subject to Flooding, both coordinated by the FAO Regional Office for Latin America and the Caribbean (RLAC).
40. As a result of the analysis and discussion of the above mentioned subjects, the Working Party made the following recommendations:
Intensify the monitoring of fishery activities in the Region's main wastersheds, including information on total catches and on catches by species, fishing effort, distribution of total length and weight of the most important species, in order to properly monitor the evolution of fisheries.
Support the research aimed at improving models for predicting yield and evolution of multi-species river fisheries.
Carry out specific studies at the watershed level on biology and population dynamics of species of main fishery interest, as well as studies aimed at the identification of population and sub-population units.
Insist on the incorporation of fishery matters in global programmes for the utilization of water resources.
To foster the implementation of workshops or consultations concerning large river watersheds in the Region, with the participation of biologists, technologists, fishery administrators, sociologists and economists, in order to define objectives and management alternatives for fisheries.
41. According to reports from Bolivia, Brazil, Colombia and Peru, there is a clear reduction of large size species in favour of the smaller ones with a short life-cycle, as well as the presence of medium size specimens of the species of the genus Prochilodus, which form the largest catch volumes in the Amazonian fisheries. Consequently, the Working Party detected the need to improve management policies of the various fisheries existing in this Region.
42. The Working Party was informed about the preparations for a Meeting on Planning the Management of Amazonian Living Aquatic Resources, that is being organized under the framework of the Inter-Governmental agreement for the Protection of the Amazonian Environment. The Working Party welcomed this initiative as a very appropriate measure to ensure the sustained utilization of the fishery resources. It was suggested to include the “Convenio de Investigaciones Ictiológicas del Beni” (Universidad Técnica del Beni and Corporación Regional de Desarrollo del Beni) from Bolivia, and the “Subsecretaría de Pesquería de la Region del Amazonas”, from Peru, as participants in this meeting.
43. COPESCAL's Technical Document № 8 “La Contaminación de las Aguas Continentales de Bolivia, Colombia, Costa Rica, Ecuador, Panamá, Perú y Venezuela” was summarized by Mr. U. Barg, FAO Fishery Resources Officer and commented by Mr. J. Escobar from the Permanent Commission for the South Pacific (CPPS) in relation to recent developments in the use of agricultural chemicals, the growing migration to cities, and the increase of industrial and mining effluents.
44. The Research Institute of the Peruvian Amazon has undertaken studies on pollution effects of oil in Amazonian rivers. Lead was detected in waters of the Chane River in the Department of Santa Cruz, Bolivia and waste from a sugar mill located in the same Department has caused fish death due to decrease in dissolved oxygen. The Beni River is being affected by the use of mercury in gold extraction activities. Traces of mercury biomagnification in “Surubíes” (Pseudoplatystoma spp.) have been observed in the Paraguay River. The problem of the use of mercury in artisanal mining in Brazil was also stressed.
45. It was recommended to update the information contained in the Technical Document № 8 on aquatic pollution and include information from countries of the Region not visited in 1983. It was also proposed that aquatic pollution be considered in the framework of watershed management. Mr. Escobar offered to collect pertinent information by mail.
46. The Working Party decided to expand the activities of the Sub-Group on pollution and change its name to “Effects of Environmental Changes on Fishery Resources”. Mr. Espinach (Argentina) will prepare a document on the impacts of dams and other hydrographical works on fish and fisheries in the Region's rivers.
47. The Working Party has taken note of the celebration in 1992 of the World Conference on Environment and Development and the preparations that at various levels are being made by several international, governmental and non-governmental agencies. In view of the fact that inland superficial waters of Latin America, their resources and fisheries play a very important role in the social and economic development of the Region, the Working Party requested COPESCAL Secretariat to make pertinent arrangements before corresponding agencies, so that this fact may be reflected and discussed in Agenda items and reports of the preparatory conferences and that a relevant position paper of the Region be presented at the above mentioned World Conference.
48. In compliance with the decision adopted by the Commission in its last session, the Working Party prepared the programme of work for the next biennium on the basis of the draft submitted by the Secretariat (see Annex III).
49. In order to attend a demonstration exercise on the methodology for a hydro-acoustic evaluation, a visit was made to the Peñuelas Reservoir located 100 Km away from Santiago. Biological and fishery studies on Argentinean silverside are being undertaken at present in this reservoir by a research team from the Department of Ecological Sciences of the University of Chile.
50. In view of the delay in the celebration of this meeting, which was initially planned for 1989, the Working Party recommended that the Sixth Session be held by the end of 1991. The participant from Uruguay officially submitted the offer of his Government to host the Sixth Session.
51. The report was approved by the participants on 28 September, 1990.
