FAO FISHERIES TECHNICAL PAPER 298
Reservoirs of Sri Lanka and their fisheries
Sena S. de Silva
Department of Zoology
University of Ruhuna
Matara, Sri Lanka
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.
FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS Rome, 1988
PREPARATION OF THIS DOCUMENT
This document is the result of on-going interest of the Working Party of Experts on Inland Fisheries of the Indo-Pacific Fisheries Commission in the development and management of reservoir fisheries in the Indo-Pacific countries. It reviews the development of the inland fishery of Sri Lanka, where the introduction of the exotic cichlid, Oreochromis mossambicus, has led to an unprecedented growth in reservoir fish yields.
The following is a list of documents published by FAO which deal with reservoir fisheries management in the Indo-Pacific region, planning for inland fisheries under constraints from other users, and management strategies including stocking.
Baluyut, E.A., 1982 Assessment of problems in planning river basin development involving a hydroelectric scheme. FAO Fish.Circ., (753):24 p. Issued also in Spanish
Baluyut, E.A., 1983 Stocking and introduction of fish in lakes and reservoirs in the ASEAN (Association of South East Asian Nations) countries. FAO Fish.Tech.Pap., (236):82 p.
Baluyut, E.A., 1986 Planning for inland fisheries under constraints from other uses of land and water resources: general considerations and the Philippines. FAO Fish.Circ., (798):44 p.
Bhukaswan, T., 1980 Management of Asian reservoir fisheries. FAO Fish.Tech.Pap., (207):78 p.
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.
Sreenivasan, A., 1986 Inland fisheries under constraints from other uses of land and water resources: Indian subcontinent and Sri Lanka. FAO Fish. Circ., (797):68 p.
FAO Fisheries Department
FAO Regional Fisheries Officers
|For bibliographic purposes this document|
should be cited as follows:
De Silva, S.S.,1988 Reservoirs of Sri Lanka
and their fisheries. FAO Fish. Tech. Pap., (298):128 p.
Sri Lanka, a continental tropical island of 65,000 km2, is reputed for its ancient irrigation reservoirs, constructed over the last 2000 years. The island, which is devoid of natural lakes has 3 ha of artificially created lentic waters for every km2. These reservoirs are mostly confined to the dry zone which receives less than 187 cm of rainfall per annum.
The reservoirs vary in age, size, hydrology, catchment characteristics and usage. In the perennial reservoirs the development of fisheries is very recent and is associated with the introduction of the cichlid Oreochromis mossambicus (Peters) in 1952. The inland fishery yields approximately 27,000 to 30,000 tons year-1 and the average production of the perennial reservoirs is estimated to be 283 to 307 kg ha-1 year-1, with a range of 40 to 497 kg ha-1year-1, based on natural recruitment of these fish stocks.
The strategies for optimization of the yield from perennial reservoirs are different from those for seasonal reservoirs, which are small reservoirs that tend to dry out for three to four months a year. The latter group of reservoirs accounts for about 30% of the known total reservoir surface area on the island, and fisheries depends on regular stocking of fish, largely carps.
This study reviews the development of the fishery and its management and the biology of the constituent species. The possibility of using the Sri Lankan reservoir fishery as a model for tropical reservoirs is discussed.
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.
|2.7||Human settlement patterns|
|3.2.1||Gal Oya Scheme|
|3.2.2||Walawe Ganga Scheme|
|3.2.3||Mahaweli Ganga Scheme|
|3.2.4||Kirindi Oya Scheme|
|3.4||Perennial and seasonal reservoirs|
|4.2||Inland fish fauna and introductions|
|5.1||Reservoir fish fauna|
|5.2||Biology of reservoir fishes|
|5.2.1||Biology of O.mossambicus|
|5.2.2||Other exotic fish|
|5.3||Reservoir capture fishery|
|5.3.1||The development of the fishery|
|5.3.2||The fishery, gear & crafts|
|5.3.3||Individual reservoir fisheries|
|5.3.4||Collection of statistics|
|5.3.5||Management of the fishery|
|5.3.7||Socio economic aspects|
|5.4||Reservoir culture fisheries|
|5.4.1||Seasonal tank aquaculture programmes|
|5.4.2||Culture fishery in major perennial reservoirs|
|6.1||Success of Oreochromis mossambicus|
|6.2||Future of Oreochromis mossambicus|
|6.3||Use of irrigation canals for fish production|
|6.6||Freshwater fish as a protein source|