Inland fisheries in multiple-purpose river basin planning and development in tropical Asian countries Three case studies


Edited by
T. Petr
Fishery Resources Officer (Inland Fisheries)
Inland Water Resources and Aquaculture Service
FAO Fishery Resources and Environment Division

The designations employed and the presentation of material in this publication do not imply the expression of any opinion whatsoever on the part of the Food and Agriculture Organization of the United Nations concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries.

ISBN 92-5-102327-1

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying or otherwise, without the prior permission of the copyright owner. Applications for such permission, with a statement of the purpose and extent of the reproduction, should be addressed to the Director, Publications Division, Food and Agriculture Organization of the United Nations, Via delle Terme di Caracalla, 00100 Rome, Italy.



The Indo-Pacific Fisheries Commission (IPFC) Workshop on Inland Fisheries for Planners, at its meeting in April 1982 in Manila, stressed the need for supportive information and data relevant to fishery policy formulation and decision-making options in river basin development schemes. Among such needs was the preparation of several case studies from the region, which would critically analyse the inland fisheries component in the context of multiple use of a river basin. In response to the recommendation of the Workshop, which was further endorsed by the Working Party of Experts on Inland Fisheries of the IPFC at a meeting in January 1984 in New Delhi, the present document containing three individual case studies was prepared.

Distribution:For bibliographic purposes this document should be cited as follows:
FAO Fisheries Department
FAO Regional Fisheries Offices
Selector SI
Petr, T. (ed.), 1985 Inland fisheries in multi-purpose river basin planning and development in tropical Asian countries: three case studies. FAO Fish.Tech.Pap.,, (265): 166 p.

This technical paper presents three case studies of inland fisheries in the context of a multiple-use of land and water resources in the humid tropics of Asia. Two of the three river basins are situated on islands, i.e. the Agno in the Philippines and the Mahaweli in Sri Lanka; one is on mainland Asia, i.e. the Nam Pong Basin in Thailand. Although the river basins have a number of features in common, such as, for example, their size, forest cover and population density, they differ in a number of other environmental aspects and changes induced by the development taking place in their basins. Inland fisheries in all three catchments is represented both by capture and culture components with reservoir fisheries gaining in importance. The studies have shown that while the major constraint to the riverine fisheries has been identified as being the high level of transported sediments originating from eroding lands and mine waste discharge (the Agno Basin), in the reservoirs of Nam Pong and Mahaweli basins it has been the high fishing pressure, in one case non-regulated (Nam Pong), which has caused deterioration of fish stocks. Another constraint in force until recently was of a social (religious) character (Mahaweli Basin). The three studies have shown that in most situations inland fisheries can successfully develop under conditions of the multiple use of the resource.
Details are given on the current fish yields, on long-term changes (Nam Pong reservoir), on problems associated with introductions and stocking (Nam Pong and Mahaweli), and on some other aspects of reservoir fisheries and aquaculture developments in these basins. The studies have stressed the need for regular monitoring of fish stocks and fishing effort for successful management. A fishery development sub-model prepared for the Nam Pong reservoir has clearly shown the need for introducing regulatory measures of reservoir fishery, if it is to improve. One of the major constraints for sound fisheries development appears to be the lack of a coordinating river basin authority, both during the planning and design, as well as during the implementation and management phases. Among the recommendations put forward in Chapter 4 “Summary and Future Needs” are the need for improved monitoring of selected limnological, fish and fishery data, for better information on the impact of introductions, for a manual on suitable fish species for stocking the Indo-Pacific reservoirs and lakes, as well as for evaluation guidelines of technical character to advise fisheries planners and managers on measures against constraints imposed on fisheries by other uses and by human induced environmental changes.

Hyperlinks to non-FAO Internet sites do not imply any official endorsement of or responsibility for the opinions, ideas, data or products presented at these locations, or guarantee the validity of the information provided. The sole purpose of links to non-FAO sites is to indicate further information available on related topics.


A. The Agno Basin (The Philippines) by Elvira A. Baluyut
B. The nam pong basin (Thailand) by Thiraphan Bhukaswan
C. The Mahaweli Basin (Sri Lanka) by Sena S. De Silva