1. The Second Session of the COPESCAL Working Party on Fishery Resources was held in Iquitos, at the kind invitation of the Government of Peru, form 26 to 30 September 1983.
2. The opening ceremony was attended by His Excellency, Dr Fortunato Quesada Lagarrigue, Minister of Fisheries of Peru, Vice-Admiral Daniel Masías Abadía, Chairman of the Consejo Directivo (Managing Board) of the Instituo del Mar del Perú (Peruvian Institute of the Sea), Dr Jaime Moro Sommo, Prefect of Loreto Department and Chairman of the Instituto de Investigaciones de la Amazonía Peruana (Research Institute of the Peruvian Amazonia Region), Dr Elda Fagetti, Secretary of COPESCAL and Dr Robin Welcomme, COPESCAL Technical Secretary. His Excellency the Minister of Fisheries was Chairman of the Officers at the opening session.
3. The Chairman of IMARPE welcomed the participants and expressed the interest of his country and IMARPE in hosting the Working Party at this session in view of the importance of inland fisheries in Peru. He expressed thanks for the support of FAO in organizing the session, and for the collaboration of the Instituto de Investigaciones de la Amazonía del Perú (IIAP (Research Institute of the Peruvian Amazonia Region)) for its logistic support to the session, and the Marina de Guerra del Perú (Peruvian Navy) which was to make the BAP (Buque de Armada Peruana (Peruvian Navy Boat)) “Stiglich” available to enable the participants to make a short cruise and observe fishery conditions in the Amazon basin rivers, and the Corporación Departamental de Desarrollo de Loreto (CORDELOR (Loreto Departmental Development Corporation)).
4. Dr R. Welcomme, Technical Secretary of the Working Party, thanked the Government of Peru and the local authorities on behalf of the Director-General of FAO, Dr Edouard Saouma, and the Assistant Director-General of the Fisheries Department, Mr J. Carroz, and the FAO Representative in Peru, Dr Gert Berehndt, for the generous hospitality offered to the session. He welcomed the participants of the Latin American countries and outlined the topics to be discussed and the objectives of this Working Party, whose results and recommendations were to be endorsed by the Commission during its Third Session to be held in Mexico from 29 November to 6 December 1983. He also communicated the objectives of the World Conference on Fisheries Management and Development to be held in Rome from 27 June to 6 July 1984.
5. In opening the session, the Minister of Fisheries of Peru stressed the importance of inland fisheries in his country where at one time catch volumes were estimated at 80 000 t for the Amazon area alone, a quantity which at that time constituted one third of total fish captures for direct human consumption. He described national plans aimed at harmonious development of fisheries in inland waters and pointed out that in order to achieve this aim throughout the region there must be joint action by the governments of Latin America in close collaboration with the international agencies.
6. In introducing the Working Session, Dr Elda Fagetti, Secretary of COPESCAL, briefly described the structure, functions and working methods of COPESCAL and its three Working Parties, and communicated the dates for holding the Session of the Working Party on Aquaculture (Santiago de Veraguas, Panama, 18–22 April 1983) and of the Seminar on Handling, Preservation, Processing, Marketing and Distribution of Fish Products to be held in Mexico together with the Third Session of COPESCAL. She also informed the participants of the existence and aims of the other FAO Commissions on fishery for Latin America.
7. The Session then elected the Chairman and approved the Provisional Agenda. Dr E. Wilhelm, Director-General of “Investigaciones de Recursos en Aguas Continentales” (Inland Water Resources Research) of the Instituto del Mar del Perú was elected as Chairman. The Session adopted the agenda reproduced in Appendix 1.
8. The Chairman requested the participants from the 14 countries (see Appendix 2) to briefly describe their areas of interest and work projects so as to be mutually informed of the personal experience and specific interest of each participant.
Moderator: R. Welcomme
9. The report of the First Session of the Working Party on Fishery Resources was presented at the Second Session of COPESCAL (Santo Domingo, 2–4 December 1981). Its conclusions and recommendations were discussed point by point, and some of the sectors identified by the Working Party were modified or merged by the session. The conclusions and recommendations adopted by the Commission and the actions undertaken during the period between sessions were as follows.
International River Basins
10. The Commision considered that the riverain countries within the various basins should collaborate on topics of common interest. These should include problems such as migration and introduction of exotic species, which had been discussed as separate items by the Working Party. The Provisional Agenda of the present session of this Working Party therefore includes an item on problems of international river basins so that they can be discussed in greater depth.
Training
11. The Commission considered this item sufficiently important to be discussed separately rather than as part of one of the Working Party's activities.
Improvement of Catch Statistics
12. Because training courses of this type have already been given under other auspices in the region, and also because of the problems of financing such courses, the Commission did not endorse the recommendation to organize a course on this subject. The recommendation to hold a workshop on this topic in association with another specific sector, such as reservoir development and management, was not implemented during the interim between sessions due to lack of funds.
Environmental Effects including Pollution
13. As partial implementation of this recommendation a Consultant, Dr J. Escobar of Colombia, was engaged by FAO to conduct an investigation on the situation in several countries in the region. His report was presented to this Working Party, and the topic of environmental effects was discussed under the third item of the Agenda.
Bad Land Use Practice and Integrated Rural Development
14. A workshop for planning of activities affecting fishery was held under the auspices of the Indo-Pacific Fisheries Commission (IPFC) in Manila in August 1982. The report of this workshop has been made available to the participants. A similar workshop is being planned for the COPESCAL area and will be organized when the necessary funds are obtained.
Documentation
15. The Secretariat was aware of the difficulties encountered in obtaining FAO documents. It was decided that discussions on the possible mechanisms for better distribution of relevant documentation in the region should be considered under item 6 of the Agenda.
Bad Fishing Practices
16. The recommendation on this item was transmitted to the Working Party on Fisheries Technology for consideration in the future.
Migration of Fishes
17. No actions were taken on this important topic during the biennium except those related to the preparation of material for the present session. The topic will be considered under item 5 of the Agenda.
Ornamental Fish
18. This topic was discussed again during the first Working Party on Aquaculture (see item 6).
Relative Productivity of Different Types of Water
19. The studies made by scientists individually on different types of aquatic systems are considered under item 4 of the Agenda of the present session.
Moderator: J. Escobar Ramírez
Bio-Assays and Toxicity Tests
20. The Ad Hoc Working Sub-Group, established by correspondence at the previous session of the Working Party on Fishery Resources under the coordination of Dr Jairo Escobar of Colombia, did not make the progress hoped for due to the failure of several of the selected countries to reply to the correspondence sent by the Coordinator. Nevertheless, the present session considered that this corresponding Working Sub-Group should be continued because of the importance of the subject of toxicity tests in the region, and considering that there are not many professionals working on this topic in the countries selected initally, or in others in the region. Similarly, aspects of water quality have not been addressed to special situations of aquatic pollution in the region such as inland waters fisheries.
Review of Pollution in Selected Countries in the Region
21. In accordance with specific requests for action formulated at the Santo Domingo session, the Working Party on Fisheries Resources examined the consultant's Report on Pollution of Surface Waters of Bolivia, Costa Rica, Colombia, Ecuador, Panama, Peru and Venezuela prepared by Dr J. Escobar. It approved the conclusions and recommendations of that report and recommended to the Secretariat of COPESCAL that, after making the appropriate corrections, it be published in the COPESCAL Technical Series.
22. The technical report presented contains general aspects of the pollution situations in each of the selected countries, the present regulations in force concerning the problem, and the national institutions for its management.
23. In general, contamination of inland surface waters is partly due to the concentration of human activities in certain places; the absence of treatment of the effluents from the said activities before they are poured into river basins; the demand for and requirements of agricultural inputs, especially pesticides with a certain toxicity level for particular types of major crops which are usually located near river courses and other aquatic environments; water requirements in certain agro-industrial processes and the absence of treatment of the resulting effluents such as waters derived from coffee cultivation and sugar mills.
24. The use of water in mining activities, especially ore washings, characterizes the magnitude and importance of pollution in some of the countries considered, particularly Bolivia, Peru and to a lesser extent Colombia and Venezuela, while agricultural activities play a leading role in pollution of the inland waters of Panama, Venezuela and Colombia; contamination form effluents with high organic matter content predominates in Costa Rica, Ecuador and others. Thus the countries examined show different types of pollution prevailing in the economic development of each country individually. In the same way, there are differences in the coverage of regulations applied for pollution control. Most of the countries have specific regulations for pollution control in the form of laws and general framelaws; some of these include specific regulations, as in Peru, Colombia and Venezuela which establish water quality criteria for different uses, set limits on different types of residue disposal for particular areas such as the present regulation in force for the lake of Valencia in Venezuela. Likewise, the inland surface waters pollution control administrations in the countries considered show wide participation by institutions and have common action by the national health and agricultural sector authorities. In some countries harmonization of national interests in matters of water pollution prevention and control is handled at the level of special intersectorial committees.
25. Considering the existence of countless pollution factors as well as their variability and the difficulty of managing them separately, it was necessary for purposes of the report to reduce the number of parameters. To give an idea of the magnitude of pollution in terms of agricultural, industrial, household and mining water uses, the load factors reported by each country were used and, where these were lacking, the disposal factors given by the scientific literature for specific uses like acid drainage from mining activities, disposal of non-degradable organic matter, discharge of nutrients through agricultural runoff, organic load from industrial effluents and household waste discharges in equivalent population terms were employed.
26. In general, the surface water resources of the countries examined are utilized to satisfy the use demands in each country. Their quantity depends on the development of each of those uses in the national economy. For example, the water requirements for mining and petroleum activities are larger in Venezuela, Ecuador, Peru and Bolivia; agricultural activity has a high demand in Costa Rica, Colombia, Venezuela, Ecuador and Panama; industrial requirements are substantial in Venezuela, Colombia and Peru and, generally, water requirements for municipal household consumption are concentrated in the countries which have mountain chains sloping toward the Pacific Ocean, except Colombia, and are obviously absent in the Caribbean. Speaking generally, use demands are less marked in those countries with mountain chains sloping to the Amazon River, the Western Atlantic and the La Plata.
Agricultural Use and Pollution
27. Agricultural use is a primary source of pollution. Its magnitude and extent depends on the farming area, crop type and agricultural input requirements, as well as individual runoff factors existing in the basins where the farm areas are located. The estimated input of nutrients like P t/year through farm runoff shows levels of 158 P t/year for Costa Rica; in Peru the estimate for farm areas located on the agricultural Pacific side was a load of 354.6 P t/year; similarly, in Panama for areas located on that side the estimate was 215 P t/year; in Venezuela for 27 basins with pollution not limited to isolated points, nutrients introduced through farm runoff in terms of P t/year comes to 126.5; in Bolivia the estimated quantity was 110.6; in Colombia for farm areas located in the Magdalena-Cauca basin and the Region Norte (north region), it is 1 385.6 t P/year; in Ecuador the estimated figure is 63 t P/year. The main source of this type of pollution is the input of nutrients through farm runoff mainly produced by areas devoted to sugar-cane crops, and it is usually concentrated in the Chiriquiveraguas and Los Santos Rivers in Panama; the Tempisque, Cañas, Zapia Reventazón, Grande de Tárcoles in Costa Rica; the medium high Magdalena River basin in Colombia; Lake Valencia and the Yurucay, Turbio and Tocuyo Rivers in Venezuela. In the latter country nutrients have increased in Lake Valencia exceeding hypereutrophic lake levels. In Ecuador, out of 75 hydrographic basins those receiving the largest input of nutrients from agricultural activities are the Pastaza, the Guayas and Esmeraldas Rivers; and in Bolivia the introduction of nutrients through farm runoff and leaching of land treated with fertilizers in the Lake Titicaca basin is well known.
28. Pesticides application is also a constant source of surface water pollution. Colombia markets 21 000 kg of solid pesticides and 18 400 000 litres of liquid formulas annually; in Peru in 1981 imports reached about 16 011 275 kg corresponding to 74% of insecticides; in Panama average consumption is about 2 t with weedkillers representing 56%; in Bolivia in 1978 imports reached 729 907 kg; in Venezuela, in 27 basins with non-isolated pollution a total of 1 746 kg of solid formula pesticides and 2 482 201 litres of liquid formulas were applied; in Ecuador pesticide imports in 1980 came to a total of 5 079 310 kg of which herbicides represented about 36.5%.
29. The main hydrographic basins receiving drainage from areas treated with pesticides are: Tártacoles, Reventazón, Tempisque, Grande de Terraba, Morote, Parrita, Tortuguero, Moin and San Carlos in Costa Rica; in Ecuador, the littoral rivers, especially the Guayas, in Panama, about 80% of pesticides are consumed on the Pacific side, mainly affecting the Chirigui, Veraguas, Los Santos, and Bayano Rivers; in Colombia, the rivers of the Magdalena high basin are affected; in Venezuela drainage of pesticide-treated areas affects mainly the waters of Lake Valencia, and the Turbio, Yarucay, Tocuyo, Tuy, Arama and Neveri Rivers; in Peru pesticide application mainly affects some streams running off on the Pacific side.
30. Among agricultural uses of water and pollution from agro-industrial activities, that due to waters from coffee cultivation and sugar mills is especially high. In Costa Rica about 70% of coffee plantations are concentrated in the Tárcoles/Virilla basin and receive an organic load of 275 t/day in BOD terms from November to February, equivalent to that produced by a town of 5.1 million inhabitants. As a consequence of that activity the basins of the Tárcoles/Virillas, Grande de Terraba, Reventazón, Parrita and San Carlos Rivers are affected. Moreover, in 1981 coffee production in Panama required the use of 60 876 m3 of water which was returned as an effluent of cultivation with an estimated load of 10 790 kg/BOD/day, equivalent to that produced by a town of 96 000 inhabitants, mainly affecting the rivers of Chirigui Province and the western area. In Colombia one kilogramme of coffee pulp has a biochemical oxygen requirement equal to that produced by the excretions of 3–5 inhabitants/day. Coffee cultivation mainly affects the river courses in the departments of Quindío, Caldas and Risaralda. In Peru, coffee production in the first semester of 1983 required a volume of 606 000 m3 of water for its cultivation which produced an organic load of 27 775 kg/BOD/day. In Bolivia, coffee production in 1982 on an area of 23 682 ha produced a load equivalent to 12 100 kg/BOD/day, the same as that produced by a town of 20 000 inhabitants, mainly affecting the La Plata river system. In Ecuador, coffee cultivation, which is exercised in 113 906 agricultural production units produces an organic load estimated at 120 t/BOD/day, equivalent to that produced by a town of 1 844 131 inhabitants. Moreover, the waters coming from sugar cultivation constitute another major source of pollution in inland surface waters. The level reported for a single sugar mill in Venezuela averaged 6 003 mg/litre/BOD, the same as that produced by wastes from a town of 183 046 inhabitants.
31. Deforestation, overgrazing and improper agricultural practices are a sizeable source of water-course sedimentation in the countries examined. In Colombia, due to high and medium intensity of erosion, the main Colombian water courses carry off 140 million m3 of sediments each year. The sediments transported to Calamar City by the Magdalena River have been measured at 26 million m3. In Peru, average annual deforestation comes to 102 444 ha, but with the opening of the access road to the selva it is estimated that the figure may reach 200 000 ha with a total of 5 122 000 deforested hectares in the departments of Junín, Pasco, Guayaco, Cuzco, San Martín and Amazonas. In Costa Rica in 1979, deforestation came to 60 000 ha and in 1980 reached 34% with deforested area total 3 122 400 ha. In Ecuador, erosion mainly affects the river courses in the Provinces of Carchi, Ibamburu, Pichincha and the low river basins in Oro and Guayas Provinces. In Panama, forest cover decreased by 57% in 1974; according to present estimates forest cover is of the order of 40–45%, affecting the Bayano and Chucunague River basins and the rivers in the Azuero and Donaso district peninsulas.
Household Use and Wastes
32. The main source of inland surface water pollution from this type of use in the countries considered is lack of treatment of municipal discharges before final runoff and that produced by the dispersed rural population lacking mechanisms for disposal of excretions. In Costa Rica in 1982 coverage for disposal of excretions reached 91% of the urban population (43% with sewerage service) and 87% of the rural inhabitants. The organic load reported was 23 307 t/BOD/year with a volume of 76.5 million m3 of sewage waters mainly affecting the Grande River of Tárcoles with a load of 14 777 t/BOD/year. The Grande de Terraba River also receives and estimated volume of 10.02 m3 of municipal used waters with an organic load of 1 333.4 t/BOD/year. The Reventazón, Parismina and Parrita Rivers are also water courses polluted by this type of waste. In Ecuador in 1980 the sewer system network coverage reached only 34% of the population, and the organic load of household wastes in river basins was estimated at 78 531.8 t/BOD/year mainly effecting the Guayas and Esmeraldas Rivers with 18.73% of the total load. In Panama the population branched on the sewer system in the provinces came to 85 438 inhabitants in 1982. Total municipal discharge produced an organic load of 3 685.07 t/BOD/year to which the Chirigui and the metropolitan area provinces were the main contributors. Distribution of that load at river basin level indicates that the main water courses contaminated by this type of use are the Chirigui, Caimito and Chagres Rivers. Other polluted waterways in the metropolitan area are Matasnillo, Curuadu, Matíaz-Hernández and Juan Díaz. In Peru in 1983 a total of 1 253 248 dwellings had household water service, of which 20% were provided with sewerage. Of the total urban population, 54.9% was branched onto the sewer system, and this system introduced a volume of 551.1 million m3 of used waters into the surface waters, or a load of 444 441 t/BOD/year. On the country's Pacific side the volume of sewer water from a town of 516 283 inhabitants is of the order of 38 902 m3/day and the recorded organic load is 11 875.5 t/BOD/year affecting the Chira, Santa, Piura and Rímac Rivers. In Colombia in 1981, 833 urban localities had piped-water service with 629 of them branched on the sewer service with a coverage of 11 306 800 inhabitants. Of total rural localities in the area, 206 had such service, covering 257 000 inhabitants. The estimated organic load was 276 310 t/BOD/year mainly affecting the Magdalena-Cauca basin Rivers, especially the Bogotá, Medellín, Cauca and Magdalena. In Venezuela 84% of the population lives in urban centres. Of the total, 6 720 000 (51%) inhabitants are connected to the sewer service. In the 18 hydrographic basins with organic pollution examined, annual volume of sewage is 845 million m3/year with an organic load of 259 320 t/BOD/year mainly affecting the Tuy River, and the Maracaibo and Valencia Lakes. Other affected water courses are the Turbio, Torbes and Neveri Rivers.
Industrial Use and Industrial Waste Discharges
33. Most of the industries in Panama, Ecuador, Costa Rica and Peru are concentrated on the Pacific side, especially in the coastal region. In Venezuela they are concentrated on the Caribbean basin, especially the Maracaibo and Valencia Lake basins, and in Colombia on the Magdalena-Cauca basin. There was no information available on chemical composition of industrial effluents by type of industry. However, it is generally estimated that the main contribution to pollution from water use is of an organic type since most of the industries are raw material processors or producers and transformers of articles having high organic matter content. In Venezuela organic load due to industrial activity is 0.8% of the total produced by household discharges and reaches a level of 2 248.8 t/BOD/year, with a volume of effluents of 46 470 000 m3/year mainly affecting the Valencia and Maracaibo Lakes and the Tuy, Turbio, Aracuy and Torbes Rivers. In Ecuador, industry produces an organic load of 136 310 t/BOD/year equivalent to 3% of the total organic load from municipal household wastes, and mainly affects the Guayas and Esmeraldas River basins. In Costa Rica most of the industries use the sewer network to evacuate their wastes, of which 95% lack treatments of the disposal. The organic load deposited by 1 768 industries is of the order of 72 902 kg/BOD/day mainly affecting the water quality of the Tárcoles, Reventazón Rivers and the water courses of Puntarenas, Limón and San Carlos. In Colombia, the Bogotá River receives the drainage of more than 470 industries which release a load of 29 626 kg/BOD/day into it; in Medellín, the Medellín River receives the effluents of about 580 industries giving it a load of 10 000 kg/BOD/day; in Cali, the Cauca River in the Yumbo locality has levels of approximately 306 634 kg/BOD/day, and in Barranquilla, the Magdalena River receives drainage from about 36 industries near its outlet which release a load of 10 000 kg/BOD/day into it. In Panama, industry is usually located at the mouths of rivers draining on the Pacific side or in the coastal ports so that the pollution produced by it is of the coastal type. In Peru the industries set on the Pacific side total 875, of which the food industry represents 20%, the textile industry 12%, and the paper industry 11%.
Mining Use and Mining Discharges
34. The main problem in inland surface water pollution in the countries examined is constituted by acid discharges and lack of adequate treatments in mine washing. This situation is flagrant in Bolivia and Peru. In Peru on the Pacific side, annual volume of discharges in eight hydrographic basins has been reported at 61 720 096 m3/year through 24 different discharges. Estimated acid drainage for a reported mineral production of 11 663 t is 886 388 m3/year. This drainage affects most of the water courses of the Pacific basin and is acute in the Mantaro, Locoma, and Rímac Rivers and Lake Junín. In Bolivia, mining affects mainly the rivers in the enclosed altiplano (highland) basin, especially the San Juan de Sora-Sora, Sepultura, Poopo, and el Chorro Rivers and the Poopo and Uro-Uro Lakes. In Colombia, the Zocacón coal mining produces acid drainage reported at 338 million m3/year, which affects the Orinoco and Catatumbo basins and the rivers of the Sierra Nevada. In Panama, Costa Rica, and Ecuador the effect of mining on water quality has been identified as that produced by turbidity and subsequent sedimentation, mainly from alluvial gold exploitation activities.
35. In Peru, discharges of non-degradable organic matter from petroleum production has been estimated at 2 394 t in 1981. However, information is lacking on the effect of these discharges on aquatic environments. Nevertheless, we have been informed on effects of barriers on migratory fish populations in the mountain slope waters due to introduction of waters from the formation of production wells located on slopes having natural water courses. In Ecuador crude petroleum production in the Santa Elena peninsula and the Oriente region discharge non-degradable organic matter estimated at 2 419 t/year into surface waters. In Colombia non-degradable organic matter discharges from petroleum production have been reported at 288.8 t/year, mainly affecting the rivers in the Catatumbo, Putumayo and Magdalena basins. In Venezuela discharges affect mainly the rivers of the Lake Maracaibo basin and emissions into the Orinoco basin are expected.
Conclusions and Recommendations
36. In light of the situation described above, it was suggested that Dr J. Escobar continue to organize this Working Sub-Group. To this end it was considered appropriate to vary the initial coordination scheme so as to include in the Toxicity Tests Sub-Group other professionals interested in checking pollution in selected countries in the region.
37. The Working Party considered that the Sub-Group should also evaluate other environmental activities which can produce harmful effects on inland fishery. Consequently the terms of reference of the Sub-Group should be:
to collect information on the pollution situation and its effects on the ecosystems in the region;
promote intercalibration and standardization of methods of toxicity bio-assays on aquatic organisms in the region;
collect information on the harmful effects of human activities on aquatic environments and fisheries.
38. As its first activity this Sub-Group, in collaboration with the Secretariat, should work out guidelines for evaluating impacts of other activities affecting the aquatic environment and for their subsequent monitoring.
39. To facilitate the task of the Working Sub-Group, the countries interested were invited to send all their observations and evidence on harmful impacts due to pollution and other human activities.
Moderator: Irma Vila
40. The participants in the Second Session of COPESCAL discussed the state of knowledge of natural and artificial lakes in Latin America. It was foreseen that there would be a growing increase of knowledge of these ecosystems. There is a large number of them and their ecological characteristics vary widely, ranging from tropical lakes and reservoirs to temperate lakes and the cold ones of Patagonia, through high lakes above 4 000 m in the case of those of the Andean highland, those in the central valley of the Andes, coastal lakes and small agricultural reservoirs.
41. There is a large quantity of inland aquatic environments in the region and they are being increased from day to day by construction of reservoirs. From the point of view of fishery they have been underutilized. It would be of fundamental importance to update an inventory of these resources and diagnose the present state of knowledge of their main fishery resources. Some lakes groups have now been evaluated both from the standpoint of limnology and fish biology, and the biological cycles of economically important fish species have also been studied.
42. In several regions in Latin America it is believed that it would be useful to apply the morpho-edaphic index (MEI) to assess the fishery potential of their lakes and reservoirs. As some countries have good fishery statistics and others have unexploited fishery resources, the strategies pursued are slightly different. For example, the application of this method in the Argentine Patagonian region gives significant correlations between cpue, determined by use of row of gillnets and the logarithm of the morpho-edaphic index. The correlations between cpue and concentration of photosynthetic pigments are somewhat less significant. It is considered that this approach can be applied in cases of unexploited or underexploited lake and reservoir groups so that they can be arranged in relative order of potential fishery production. Using the basic information available on Cuban reservoirs, an attempt was made to calculate the MEI equation to obtain estimates of potentials. It should be mentioned that in this first attempt we wished to obtain a result quickly, and the reservoirs were classified in groups with common characteristics since the available information did not allow this type of analysis. However, these reservoirs were mainly built for sugar-cane and rice irrigation. In those reservoirs water use is subject to the demand existing in plantations during the main season for tending these crops; therefore in some cases there are considerable fluctuations in the volume of water stored.
44. This situation introduces into these systems sizeable tropical gradients in measurements of total dissolved solids and electrical conductivity. In managing these reservoirs efforts should be made to continue collecting catch and effort history series repeating the analysis of the MEI after classification of the reservoirs.
45. The Working Sub-Group considered that the development of alternative approaches for estimating the potential fishery production of lakes and reservoirs was of fundamental importance.
46. Knowledge of the temperate lakes and reservoirs in the Chilean area dates from the past two decades and about 60% of their limnological characteristics are known. There is no commercial or artisanal fishery in these inland systems; however, there is intensive sports fishing of Salmonidae species introduced at the beginning of the century together with Atherinidae species. In sustained monthly fisheries attempts are being made to compile fundamental biological (condition, fertility, mortality, growth rates) and fishery parameters which, together with the experimental cpue over long periods, could help to make up a population dynamics model. In order to accelerate knowledge of biological production it would be desirable to use indexes such as the MEI and similar ones which can give a global view, together with study of population ecological parameters of economically important species.
47. The Mexican lakes and reservoirs have been studied, inventoried, and limnologically characterized. The extent of their exploitation varies. The Venezuelan reservoirs have been inventoried and limnologically characterized and there is limnological information on them. Although they are not being commercially exploited at present, it is planned to select two reservoirs for introduction of species from neighbouring basins and their subsequent exploitation.
48. In several Latin American countries fishery and aquaculture planning and development have basic information requirements which coincide at many points with the properties of water for consumption and irrigation, as well as conservation of the environment. In some of these countries studies are being made on lakes and reservoirs selected because of the present or potential importance of their fishery resources. Those resources are generally not being exploited or else are underexploited, as in the case of Lake Gatún in the Panama Canal area.
49. It was considered important to estimate the impact produced by introduction of exotic species into lakes and reservoirs.
50. In order to have an updated listing of lakes and reservoirs in Latin America, and to collect climatic, morphometric, hydrological, limnological and fishery biology data, two lists of parameters considered as important (Tables 1 and 2) were prepared. In these lists the fundamental parameters for a first stage are indicated by (*). The importance of having the countries make or update a total listing of their lakes and reservoirs was emphasized.
Conclusions and Recommendations
51. Bearing in mind the problems involved in better and more speedy knowledge and exploitation of the fishery resources in lakes and reservoirs, the Working Party suggested the recommendations and activities listed below.
Table 1
Basic parameters for listing lakes and reservoirs
| * | Type of environment | ||||||
| * | Geographic location: Lat. - Long. | ||||||
| * | Altitude | ||||||
| * | Soil type | ||||||
| * | Type of basin use: | ||||||
| * | Basin surface: | ||||||
| - | Morphometry: | * | - | Area | |||
| - | Coast length | ||||||
| - | Volume | ||||||
| * | - | Depth | |||||
| Maximum | |||||||
| Average | |||||||
| - | Hydrology | - | Annual average discharge | ||||
| * | - | Average retention time | |||||
| - | Climate: | - | Annual average rainfall | ||||
| * | - | Temperature | - | Maximum | |||
| - | Minimum | ||||||
| - | Annual average | ||||||
| - | Average wind velocity | ||||||
| * | - | Ice-free season | |||||
| Limnological characteristics (specify time of sample, or if a single sample was taken) | |||||||
| * | - | PH | |||||
| * | - | “Secchi” disc reading | |||||
| * | - | Surface and bottom dissolved oxygen (saturation %) | |||||
| * | - | Total dissolved solids | |||||
| * | - | Electricity conductivity | |||||
| - | Total alkalinity | ||||||
| * | - | Water ionic composition. Water type | |||||
| - | Total phosphorus | ||||||
| - | Total nitrogen or total organic nitrogen | ||||||
| - | Chlorophyll equivalent | ||||||
| - | Chlorophyll “a” | ||||||
| - | Real colour | ||||||
| - | to Max. | ||||||
Min. | |||||||
* Also give source of information
52. It was recommended that at the next session of this Working Party a workshop be held on a specific theme in which methodological papers on evaluation of the fishery potential in lakes and reservoirs would be discussed.
53. The Working Party recommended that the Commission encourage governments to develop a policy for optimum use of water resources, including fisheries activities.
54. The Working Party considered that it would be appropriate to establish a Working Sub-Group whose terms of reference would be: to collect and elaborate, in collaboration with the Secretariat, available national data in order to define the present state of ecological and fisheries knowledge of the region's natural and man-made lakes.
55. In order to establish this Working Sub-Group, the following specialists will be designated as correspondents: J. Alvarez (Ecuador), P. Arias (Colombia), G. Chediak (Uruguay), M. Fukushima (Peru), S. Gordillo (Guatemala), J.C. Maturell (Panama), S. Montenegro (Nicaragua), A. Marí (Cuba), D. Novoa (Venezuela), M. Petrere (Brazil), R. Quirós (Argentina), J. Rojas (Mexico), F. Zuna (Bolivia). Mrs Irma Vila (Chile) was appointed Coordinator.
56. As a methodology of work it was decided that the Coordinator, in collaboration with the Secretariat, should plan a simple survey which could obtain the basic information for: (a) an inventory of lake systems; (b) their climatological, hydrological, morphological and physiochemical characteristics; and (c) their most important fishery resources (economically important and sports species) and their respective catch data.
57. The correspondents should collect the information at national level as soon as possible and send it to the Coordinator and the Secretariat using the FAO national representatives' office in each country.
58. It was decided that the data obtained will be evaluated in FAO for preparation of a document, if possible for publication in the COPESCAL Technical Series.
59. The correspondents were asked to collaborate so that the replies to the survey can be available in time for discussion during the FAO/Unesco Workshop on Fisheries Ecology and Management in Lakes and Reservoirs planned to be held in Santiago, Chile in September 1984.
Table 2
Fisheries and biological parameters for listing lakes and reservoirs
| * | Type of fishery |
| * | Inventory of predominant fish species |
| * | No. of fishermen |
| * | Total catches or exploratory fishery |
| - | Fishing gear |
| - | Demographic processing: |
| - Total length (standard total length) | |
| - Total weight | |
| - | Condition index |
| - | Gonad condition |
| - | Fecundity |
| - | Size frequency graph |
| - | Lepidometry (Bertalanffy, Walford) |
| - | Mortality coefficient (“Z”) |
* Also give source of information
Moderators: A. Espinach Ros and D. Novoa
60. As decided in the First Working Session, and considering the importance of river fishery resources to the countries participating in the meeting, the management of rivers for fishery, including a study of environmental effects of human activities on fisheries resources, was considered an aspect of special interest. With this in view, the following provisional scheme to guide the discussion was submitted for consideration by the Working Party.
Bio-ecological studies of the most economically important fish species
Distribution
Reproduction strategies
Feeding
Migration
Evaluation
Discussions of fishery productivity indexes
Assessment of fish populations (direct methods)
Evaluation of fisheries
Socio-economic diagnosis
Management
Management strategies
Measures to reduce the negative effects of development works
Collaboration at regional level
Basic data collection
Analysis of available information
Technological aspects (exchanges)
River basin uses; conservation standards, etc.
61. Following the list of subjects, there was wide discussion of the bio-ecological characteristics specified and their influence on the establishment of equilibrium situations in regional fisheries. The experience obtained in the Orinoco fisheries seems to demonstrate that intensified exploitation has been creating qualitative changes in composition by catch species, shifting the balance toward quick-growing, migratory, high fertility, widely distributed and short life cycle (type A) species to the detriment of other, long-life, non or scarcely migratory, carnivorous species, with low fertility and more limited distribution (type B). The combination of favourable biological attributes was found in Prochilodus, Pseudoplatystoma, the predominant species in the fisheries, while the large “Pimelodidos” catfish (Brachyplatystoma, etc.) belong more to the other category, and thus have shown symptoms of decline in relative abundance.
Evaluation
62. The discussion of this aspect began with a review of the practical indicators used to estimate river productivity taking into account morphological and edaphic factors. It was felt that direct and uncritical application of African experiences was not advisable in all cases and that they would need to be revised, evaluated and modified for application in Latin America. For example, the existing rivers having black waters are certainly special cases. Another aspect mentioned as a specific requirement for Latin America is a revision of the relation between river length and basin area, which is different from that found for the African continent.
63. The usefulness of hydrological indexes as indicators of flood intensity and its relationship with the capture was emphasized. In the case of the Orinoco a better adjustment was obtained when the type B species were separated from total captures. There was also a discussion of the case of the Orinoco “Zapoara” (Semaprochilodus laticeps) whose population abundance seems to depend on flood intensity. Seasons of intensive rainfall allow a larger number of individuals to enter the canal where they are fished, establishing a direct relation between catch and the hydrological index for the same year due to more accessibility to the fishery exercised in the canal. The application of the logistic model to adjust the relationship and the relation between IH and “Zapoara” abundance was also discussed, finding that the correlation was satisfactory in this particular case.
64. An effort was made to know the situation in other countries and their river basins. It was found that it is similar to the situation described. Nevertheless, in the case of Prochilodus differences arose concerning the two population units living in the Orinoco system with synchronization in the gonad maturation process. As in the case of the Orinoco, this genus is very abundant in the Paraná, Magdalena and Amazonas.
65. Concerning migrations, a special collection of the studies made in Latin America and prepared for this meeting was examined. Experiences, types of migrations and their significance were reviewed in detail and gave rise to an exhaustive discussion on the subject. It was recommended that this work be completed with recent experiences for possible publication in the FAO series of technical studies, given the interest of the subject.
66. There was also a description and discussion of application in the Orinoco River of a method to assess its fishery potential based on control of commercial activities in the area or particular stretches of the river and intensive sampling in stocking centres. Indexes such as kg/fisherman/year for a given area were obtained as basic data which when related to total basin area give an estimate of fishery potential by assuming that fishermen density is the same as that of the stretch examined. It was considered that this method could contribute further to those mentioned previously to obtain an approximation of fishery potential.
67. The participants then considered some of the direct methods employed in the different countries to evaluate fishery potential. In regard to the Pacaya and Samiria Rivers in the Peruvian Amazonia region, it was reported that rattan was used in open lagoon environments where it was possible to work with small mesh nets, and methodological aspects were discussed contrasting this with the experience conducted in the Magdalena River lagoons.
68. The Working Party took note of the forthcoming implementation of a fishery evaluation project in the lower Uruguay River and the Salto Grande reservoir using hydro-acoustic methods with simultaneous control of fishery.
69. In regard to evaluation of fisheries, the discussion centred on the case of the Magdalena River basin, the results of the integrated sampling system, and catch estimates through the cpue indexes and total effort in the strata and zones into which the system has been divided. The discussion focused on interpretation of the catch data corresponding to the past three years between 1981 and 1983, which showed a significant decrease compared to the 1974–80 time series. This tendency was also reflected in the data obtained from stocking centres. Various possible causes were mentioned to explain this:
irregularity of hydrological cycles;
authorization of the use of the trammel net having 4-in mesh diameter;
pollution;
effects of other uses of the basin such as mining (explosives), reclamation of marshes for agriculture, deforestation, etc.
However, possibly underestimates of fishing effort when the type of fishing method changed, might have caused catches to be somewhat underestimated.
70. The case of the Peruvian Amazonas region was mentioned, where catch estimates were obtained by consumption surveys in a pilot area in relation to a flooded area determined by use of LANDSAT satellite images and extrapolating these values to the total area. Capture estimated by this procedure was 77 700 t.
71. The Working Party felt that it was necessary to discuss the socio-economic aspects related to fishery, since the marginal condition of artisanal fishermen and abandonment of any official action concerning them is a common feature in many river systems in the region. If this situation continues, we may witness the decapitalization of a highly specialized human resource which plays a role as a major food producer for most of the countries in the area. In this regard, no appropriate conditions exist for control and management of the resource. The participants discussed data on income per fisherman available for some of the region's river basins.
Management
72. In connection with management, a model developed for multispecies fisheries was presented. Contrary to traditional surplus yield models, sustainable maximum yield remains constant during a long interval of fishing effort levels, followed by an irregular phase which would ultimately result in the collapse of the fishery. While the total level of catches remains constant, the species composing them is gradually replaced leading to predominance of those of the A type strategy. Further discussions concerned other implications of the model in relation to species diversity, stability of the system, etc.
73. On the bases of this model, three strategies for management of a fishery can be designed with the following characteristics:
management to optimize capture of a few high value species;
management which can obtain maximum protein yield;
management which can increase effort up to the maximum allowable limit making possible employment of the maximum number of people.
Concerning the regulations in force in Latin America, the Working Party considered that in general there is a tendency to fall into the situation created by the A type strategy.
74. A preliminary table (Table 3) was presented indicating the types of regulation employed in fisheries resource administration in the region.
75. The Working Party considered that FAO should play a leading role in assisting governments to adopt measures to reduce the harmful effects of hydraulics works on fisheries resources and to take full advantage of the new situation.
76. In the La Plata basin, studies have been started with the participation of several Working Parties to determine the biological parameters needed for the location, design and sizing of fish passes (selection and ecological characterization of the species which are to use the passes; determination of the magnitude and timing of migrations; rates of activity of the main species; behaviour of the selected species in presence of laminar flows and turbulences of different magnitudes; determination of critical velocities). For example, in the dam project of the middle Paraná River a considerable effort is being made to optimize engineering of facilities for fishes, so as to adapt them to the needs of the local fish fauna.
Conclusions and Recommendations
77. Considering the problems arising in connection with knowledge and utilization of river fishery resources, the Working Party decided as follows.
78. To recommend the more widespread use of rapid methods of evaluating the fisheries productivity of river systems, with regional application. To suggest, as a mechanism to facilitate the implementation of this recommendation, the preparation and dissemination by the COPESCAL Secretariat of a document on the subject, and afterwards the holding of a workshop organized by FAO in which the data provided by the participants would be analysed and discussed.
79. To recommend intensification of studies on the biology of economically important fish species, giving priority to those most important for fisheries management.
80. To suggest the collection and organization of data on standards applied in the countries of the region for regulating inland fisheries, including an evaluation of their effects. This activity could be conducted by a consultant who would prepare a basic report.
81. To recommend, on the basis of the experiences of the different countries, that the Commission should urge governments to implement programmes to organize the productive sectors of inland fisheries, not only to promote improvement of the people's living conditions, but also adequate control and management of fisheries.
82. To suggest that the Commission request FAO to allocate the necessary funds to organize a workshop on identification of the environmental effects of development projects on river basins from the point of view of fishery resources.
83. To recommend that encouragement be given to the preparation and publication of specific case histories to illustrate the effects of dams and other works on fish stocks and fisheries in Latin America.
84. To suggest that it would be appropriate to form a Working Sub-Group on river fishery resources with the following terms of reference:
to collect available information on the biological characteristics of the Orinoco River in order to make comparisons and possible generalizations on the validity of this adaptive approach;
to prepare a brief general summary of fish species of major economic interest, starting with Prochilodontidos and Colossoma;
to preapre a document on freshwater fish migration in Latin America, based on the information contributed and discussions held at this meeting. (Coordination: A. Espinach Ros and M. Petrere);
to define and collect, with the assistance of the Technical Secretariat, the information required for the application of rapid methods for assessing fish productivity in river basins;
to appoint the following people as correspondents constituting the Sub-Group: J. Alvarez (Ecuador), P. Arias (Colombia), G. Chediak (Uruguay), A. Espinach Ros (Argentina), S. Gordillo (Guatemala), J.S. Maturell (Panama), S. Montenegro (Nicaragua), V.H. Montreuil (Peru), D. Novoa (Venezuela), and F. Zuna (Bolivia). Mr D. Novoa was proposed and accepted as Coordinator of this Sub-Group.
85. The programmes and recommendations referring to the three main items of the Agenda are specified in the reports of the three respective sub-groups. Other activities proposed refer to the topics indicated below.
Documentation and Dissemination of Information
86. In order to ensure that relevant documentation and information produced by FAO be distributed to all the national inland fisheries centres, the participants updated the list made available by the Secretariat and agreed that the pertinent publications of FAO should be sent only to the libraries of those centres and not to the researchers themselves.
Table 3
Forms of regulation
| Country | Nos. of fishermen or fishing units | Mesh size | Size limit or fish caught | No. of gear | Closed areas or reserves | Prohibition of gear | Limitation of access | Total prohibition | Closed seasons |
| ARGENTINA | X | X | X | X | X | X | |||
| BRAZIL | X | X | X | X | X | X | |||
| CHILE | X | X | |||||||
| COLOMBIA | X | X | X | X | X | ||||
| CUBA | X | X | X | X | X | ||||
| PERU | X | X | X | X | |||||
| ECUADOR | X | X | X | X | X | ||||
| GUATEMALA | X | X | X | ||||||
| MEXICO | X | X | X | X | X | ||||
| PANAMA | X | X | |||||||
| URUGUAY | X | X | |||||||
| NICARAGUA | X | X | X | X | |||||
| VENEZUELA | X | X | X | X | X |
87. It was requested that the Secretariat distribute to the participants the list of documents published by FAO on fisheries.
88. It was recommended that the “Bibliography of Latin American Freshwater Fish” (COPESCAL Technical Paper No. 2, 1979) be updated. To this end, the participants agreed to send the Secretariat bibliographical references - more recent than 1979 - of papers published in their countries. It was recommended that, as soon as this information reached the Secretariat, FAO arrange for it to be compiled and published.
89. The Working Party recommended the issuing of an Information Bulletin to be published biannually, for dissemination throughout the region of short-term information, which should include: (a) scientific-technical information; (b) changes of address of experts, research centres, director, etc.; (c) lists of recent national publications and other information of interest to the region. The participants should act as correspondents and Mrs Irma Vila as regional Coordinator and Editor. To implement this recommendation it was suggested that the FAO Regional Office in Santiago be asked to collaborate.
Training
90. Given the limited availability of funds at international level for training of personnel in the different aspects of fisheries research, the Working Party considered it appropriate to recommend that governments use their best endeavours to facilitate exchanges of experience among the countries in the region. To this end it was suggested, as a possible mechanism, that the host country should be responsible for the daily subsistence costs, and the country of the person needing training should be responsible for travel costs.
Exotic (Introduced) Species
91. The Working Party recommended that a Technical Document be prepared on the effects, positive and/or negative, of the introduction of exotic species into the countries in the region.
Ornamental Fish Species
92. The Working Party considered that this subject, which has also been discussed by the Working Party on Aquaculture, is not of sufficiently high priority to be discussed again during this meeting.
93. The Working Party considered necessary and recommended that the Third Session be held within the next biennium (see Sections III, IV and V of the Report).
94. The participants from Panama and Venezuela offered to host the next session, subject to authorization by their respective Governments.
95. The Working Party adopted the Report on 30 September. The COPESCAL Secretariat thanked IMARPE for the assistance provided in organizing this working session and also IIAP, CORDELOR and the Peruvian Navy for their collaboration and support provided during the session itself. The thanks of the Secretariat and the participants were also extended to the administrative support personnel. It was recognized that the enthusiastic collaboration of all, participants and organizers as well as collaborators, enabled the session to be productive and pleasant.
96. The Chairman, on behalf of Peru, thanked the participants and the numerous observers for their attendance and valuable contribution to the discussions, and expressed the wish that the recommendations of this Working Party would be favourably received by governments and FAO at the next session of the Commission.
97. The closing ceremony was held aboard the BAP (Peruvian Navy Boat) “Stiglich”, with a speech by Vice-Admiral of the Peruvian Navy (r) Daniel Masias Abadia closing the session. In his speech the Vice-Admiral stressed the full and generous spirit of collaboration which marked the entire course of the Session, and urged the participants to continue to exert all their efforts in the cause of improving the diet and welfare of our peoples making use of the forms of close cooperation between Latin American countries. Lastly, he expressed sincerest thanks to all the organizations, institutions and persons who had contributed in any way to the success of the Session.
98. Mr Salvador Montenegro Guillén spoke on behalf of the experts. He stressed the wide collaboration received which, he said, had made it possible to work in ideal conditions. He expressed appreciation for the hospitality received and, through Admiral Masías, added most sincere thanks to all the participants, organizers, and the support personnel.
