WORKING PAPERS - BOBP/WP/23
Review Of Experiences With
And Present Knowledge About Fish Aggregating Devices
By
M. Bergstrom
Fishery Biologist (Associate Expert); Bay of Bengal Programme
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WORKING PAPERS - BOBP/WP/23 Review Of Experiences With
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Executing Agency: FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS Funding Agency: SWEDISH INTERNATIONAL DEVELOPMENT AUTHORITY Development of Small-Scale Fisheries in the Bay of Bengal Madras, India, November 1983 |
| 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. |
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© FAO 2004
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A review of experiences worldwide and of present knowledge about fish aggregating devices (FADs) was carried out by the BOBP during 1981. Nearly 150 institutions and experts were requested to contribute. This paper draws on these replies as also on other published material. The paper describes a spectrum of FADs ranging from very simple and cheap traditional applications for nearshore waters to modern, highly sophisticated and expensive products for off-shore aggregation of tunas and tuna-like fishes. Some of the experimental designs described here are worth considering for indicative fishing trials. The preparation of this paper is an activity of the Bay of Bengal Programme for Small-Scale Fisheries Development, referred to in brief as BOBP. The BOBP is funded by the Swedish International Development Authority (SIDA) and the United Nations Development Programme (UNDP) and executed by the Food and Agriculture Organisation of the United Nations. Countries bordering the Bay of Bengal are members of the Programme. Its main aims are to develop, demonstrate and promote methodologies to improve the conditions of smallscale fisherfolk and to assess and monitor fishery resources. |
PREFACE
2. FADS IN GENERAL
3. AGGREGATING DEVICES
3.1 FADs placed on the bottom (also known as artificial reefs or as bottom FADs)
— old tyres
— concrete
— fibreglass reinforced plastic (FRP)
— sandbags
— mangrove wood
— mangrove/coconut tree
— trees or branches
— bundled twigs
— shipwrecks
— other examples:
— piled stones
— boat with stones
— steel cubes
— bus shell3.2 FADs anchored or drifting on or near the water surface (surface FADs)
— lures for flying fish
— anchored floats
— brushwood
— free-drifting vessel
— objects of different shapes
— bamboo rafts3.3 FADs anchored in the water column (mid-water FADs)
(a) Traditional
— coconut leaves
— bamboo baskets
— Payaw” rafts(b) Modern FADs—experimental
— multityre
— pvc pipes
— prisms
— pyramids and cones
— petroleum platforms
— other(c) Modern FADs — under commercial fishing trials
— Fiji
— Japan
— American west coast
— Hawaii
— Maldives
— Samoa
— Australia
— New Zealand
— Palau
— Guam
— Marianas
4. SELECTION OF SITES FOR AND ANCHORING OF FADS OF MODERN TECHNOLOGICAL DESIGN
— type and weight of anchor
— material, dimension and length of anchoring line
— types of connections between parts, their materials and dimensions
— shock absorber for anchoring line
— possibilities for recovery of anchoring device if raft or buoy is lost
— possible risks of FAD loss
— FADs placed on the bottom (bottom FADs)
— FADs anchored or drifting on or near the water surface (surface FADs)
— FADs anchored in the water column (mid-water FADs)
— The Indonesian Rumpon
— The Malaysian Unjang
— Japanese cuttlefish baskets
— Payaws of different types and modern-designed rafts and buoys
6. OTHER GENERAL CONSIDERATIONS
— biological
— maintenance, ownership and access rights
— legal aspects and hindrance for vessels
— economy
— employment
— design of appendage
— ways to decrease the maximum stress
— cost-benefit ratio
— the design, size and deployment of anchors
— chafing
— corrosion
— the small-scale FAD