Improvement of Large-Mesh Driftnets for Small-Scale Fisheries in Bangladesh

WORKING PAPERS - BOBP/WP/5

Improvement of Large-Mesh Driftnets for Small-Scale Fisheries in Bangladesh




by
G. Pajot
Fishing Technologist


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, September 1980

Table of Contents


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SUMMARY

Driftnets account for nearly 30 per cent of the total marine catch in Bangladesh. With the polyamide (PA) or nylon twine used for constructing the nets getting scarcer and costlier, the driftnetters tend to carry less and less gear, affecting fish catch and incomes.

It is therefore desirable to devise ways to ensure that driftnets cost less and/or produce more. This was the rationale for an experimental project conducted during the 1979/80 winter season.

The boats used three kinds of fishing gear-the traditional large-mesh driftnets (45 ply), modified nets of thinner netting twine (27 ply) and nets of polyethylene material.

Details of fish catch were recorded daily for thethree types of nets with the assistance of extension workers from the Kalidaha fishing project.

A comparative study of the data obtained reveals that nylon nets of thinner twine size, which cost approximately 40% less than the traditional nets, caught about 40% more fish. Thus the thinner twine nets are clearly preferable to the traditional. Following from these results, a promotional effort to extend the merits of this net is recommended, with the Bay of Bengal Programme assisting in the effort.

As for the nets of polyethylene netting material, they also caught 45% more fish tha n the traditional nets, but sustained greater damages.

Further studies are recommended on the efficacy of polyethylene netting material and on the optimum mesh sizes for large-mesh driftnets. Study tours of large-mesh driftnet fisheries in other countries are also recommended for Bangladesh national officers.


TABLE OF CONTENTS


WORKING PAPERS - BOBP/WP/5pdf

PREFACE

1. INTRODUCTION

2. THE DRIFTNETS

3. CONDUCT OF EXPERIMENTS

4. FINDINGS

5. RECOMMENDATIONS

TABLES

1. CATCH RECORDS OF EXPERIMENTAL FISHING WITH LARGE-MESH DRIFTNETS IN KALIDAHA. NYLON NETS OF THICKER TWINE (TRADITIONAL) VS. NYLON NETS OF THINNER TWINE .
2. CATCH RECORDS OF EXPERIMENTAL FISHING WITH LARGE-MESH DRIFTNETS IN KALIDAHA. POLYETHYLENE NETS VS. NYLON (TRADITIONAL) NETS

APPENDICES

1. DESIGN OF THE TRADITIONAL LARGE-MESH DRIFTNET
2. DESIGN OF THE EXPERIMENTAL DRIFTNET (NYLON)
3. DESIGN OF THE EXPERIMENTAL DRIFTNET (POLYETHYLENE)
4. MAP INDICATING THE LOCATION OF THE FISHING AREA
5. PHOTOGRAPHS OF BOATS USED FOR THE FISHING TRIALS

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