MARINE FISHERY RESOURCES OF SIERRA LEONE: A REVIEW OF EXPLOITED FISH STOCKS
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MARINE FISHERY RESOURCES OF SIERRA LEONE: A REVIEW OF EXPLOITED FISH STOCKS |
| PROGRAMME FOR THE DEVELOPMENT OF FISHERIES IN THE EASTERN CENTRAL ATLANTIC FISHERY COMMITTEE FOR THE EASTERN CENTRAL ATLANTIC | CECAF/ECAF SERIES 86/34 (En) |
by
G. W. Ssentongo FAO Fisheries Department, Rome
and
M. Ansa-Emmim CECAF Project, Dakar
This document has been prepared with financial support from projects: INT/81/014 - Development of Fisheries in the Eastern Central Atlantic, and GCP/RAF/215/USA - Support to the CECAF Project.
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FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS Rome 1986
©FAO
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2. TOPOGRAPHIC AND OCEANOGRAPHIC CONDITIONS
2.2.1 Bottom types and littoral morphology
2.2.1 Thermal stratification and salinity factors
3.1 Fishing Grounds and Fish Landing Sites
3.2.1 Canoes and fishing gear in the artisanal sector
3.2.2 Vessel types and fishing gear for the industrial sector
4. MAJOR EXPLOITED FISH STOCKS
4.1.1 Estuarine and creek sciaenid sub-community
4.1.2 Offshore suprathermoclinal sciaenid sub-community
4.1.3 Inshore suprathermoclinal sand and rocky bottom sparid community
4.1.4 Deep-water sub-thermocline sparid community
4.2 Biology and Ecology of Some Commercially Exploited Fish Species
5. POTENTIAL RESOURCES AND PRESENT STATE OF EXPLOITED STOCKS
5.2 Catch Per Unit Effort (cupe) Data
5.3 Population Structure and Parameters
5.4 Biomass and Potential Estimates of Finish Species
5.4.1 Potential of shrimp resources
6. MAIN DEVELOPMENT AND MANAGEMENT ISSUES FACING THE FISHING INDUSTRY
6.1 Standardization of Fishery Statistics
6.2 Fishery Legislation, Regulations and Surveillance
6.3 Interactions and Conflicts Between Artisanal and various Industrial Fisheries
6.4 Development and Management of Fisheries
7. MANAGEMENT GUIDELINES AND OPTIONS
| SUMMARY | ||||||||
| Sierra Leone is located in the southwestern sector of the great bulge of West Africa. It lies between 7°N and 10°N and is bordered on the North and East by the Republic of Guinea, and on the South by Liberia. Sierra Leone has a territorial sea limit of 200 mi. Its coastline is about 506 km and is characterized by extensive mangrove swamps, a number of estuaries and rivers that are navigable for short distances. | ||||||||
| The hydrographic regime of Sierra Leone waters is characterized by a relatively stable, shallow thermocline lying at mid-shelf depth and affecting the distribution of fish. Seasonal changes are due to the following effects of the monsoonal wet season: high river discharges, reduced surface water salinities, lowered solar radiation and a slight dip in mixed layer temperatures. The multiple stock fisheries are exploited with a variety of fishing gears (gillnets, cast nets, beach seines, trawls, purse seines, ringnets, traps and hooks), operated from different artisanal canoes and industrial fishing boats. Before the introduction of trawlers in 1955, fishing was purely artisanal. Even today, the catch of the artisanal fishery accounts for more than 80% of the total national fish landings. | ||||||||
| There are not yet enough data to use in formulating guidelines for managing the industrial and artisanal coastal fisheries. There is, however, somewhat adequate knowledge to be able to warn against uncontrolled increase in exploitation of available fishery resources without a sound evaluation of present-day fishing trends. | ||||||||
| The available data show that the catch of the artisanal fishery rose from about 22 500 t in 1971 to about 62 000 t in 1982, whereas the catches of the national and local industrial fleet were only 1 000 t and 6 000 t in 1971 and 1982, respectively. On the other hand, the total catch of foreign fleets (trawlers, purse seiners, lo=gliners and shrimpers) jumped from 4 000 t in 1971 to about 106 000 t in 1982. There is evidence that fishing effort of the foreign industrial fleets is becoming excessive. | ||||||||
| Fishery surveys of R/V DR F. NANSEN and R/V MONOCRYSTALL at depth below 20 m on the continental shelf of Sierra Leone for an area about 14 942 km2 lead to the following biomass estimates: | ||||||||
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| The biomass of the demersal fish species possibly ranges from about 49 000 t to about 105 000 t, whereas the biomass of Balistes is put at 80 000–100 000 t. | ||||||||
| The potential of the demersal and pelagic fishery resources are not exactly known. But the potential of pelagic fish stocks is probably less than 100 000 t and that of the demersal fish is around 30 000 t. It is hoped that the data results and questions presented in this paper will stimulate enough interest in the maintenance of a reliable fishery data system on which can be based long-term fishery policies. It is also expected that the declining catches and catch rates will create increased awareness of the importance of rational management of the various fisheries. | ||||||||
| The fishery administrators should now take a wider view of fishery management, which calls for Government attention on a number of fishery activities for example, overall control of fishing effort; support to artisanal fishermen; improvement of infrastructures at fish landing sites; construction of landing piers and access roads; establishment of appropriate control on foreign fishing vessels; control on fish imports and fish exports - all of which affect the fishing pattern in the EEZ. | ||||||||
| Rational management of fisheries could bring tremendous nutritional and economic benefits to Sierra Leone. Whether or not these benefits can be realized in the near future will depend on fishery administrator's commitment to make the right policy and choose the best fishery objective at the right time, collect the necessary information on various fisheries, consider carefully practicable management options and take the necessary actions at the right time. |
The authors express their thanks to Mr E.T. Golley-Morgan, Chief, Fisheries Officer, Fisheries Division, Freetown, for assisting this study in various ways.
They are very grateful to Mr K.N. Fergusson, Deputy Chief, Fisheries Officer for collaborating with them and providing useful suggestions.
Special thanks go to the following:
Mr J.J. Shorunkeh-Sawyer, former Chief, Fisheries Officer, with whom we had useful discussions concerning this work;
Mr S.E. During (Fisheries Division) for coordinating well our visits to various institutions collecting data;
Dr V.E. Strasser-King, Department of Geology (University of Sierra Leone) for making available information on bottom types and littoral morphology of the continental shelf;
Mr H.G. Moore, Director (Meteorology Department) and Mr A. Harleston, Chief Engineer (Ministry of Energy and Power) for making accessible to us information in their departmental archives;
Messrs A.E. Kamara, Principle Fisheries Officer (Fisheries Division); A.C.V. Forde, Co-project Manager (Fisheries Pilot Project Tombo); U. Beck, Project Manager (Fisheries Pilot Project Tombo); Abdul Cole (Tombo Boat-owner Cooperative Society); O.L.A. Gordon, Director (Land and Water Development Division); E.A. Redwood-Sawyer, Director (Surveys and Lands Department); Mrs D. Awuta-Coker, Remote Sensing Officer (Land and Water Development Division); Prof. D.E.B. Chaytor, Institute of Marine Biology and Oceanography (University of Sierra Leone); Messrs I.J. May-Parker, Deputy Director (Central Bank of Sierra Leone); Giacomo D'Aguanno, Managing Director (Maryland Fishing Company Ltd.); Phil Roberts, General Manager (Marine Development Company Ltd.); D. Sklavounos, Captain/Skipper (Marine Development Company Ltd.); T. Nittis, Captain/Skipper (Marine Development Company Ltd); V.B. Castelino, Engineer (Marine Development Company Ltd.); S.S. Deen, Company Secretary (Sierra Fishing Company); A. Goodlad, Fleet Manager (Sierra Fishing Company); and Mrs Lilian Lisk, Managing Director (Okeky Agencies Ltd.) with whom we had useful discussions on the fisheries of Sierra Leone.