The IUCN/SSC Shark Specialist Group
Shark News 10: January 1998
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Shark populations are possibly under serious threat in the Bijagos archipelago (Biosphere Reserve), Guinea Bissau, West Africa
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P. Tous1, M. Ducrocq1, D. Bucal2 and E. Feron1
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In the Bijagos archipelago of Guinea Bissau (declared a Biosphere Reserve in April 1996), sharks and other cartilaginous fish have never been the target of sustained fishing by the small-scale indigenous fishermen. The unavailability of sophisticated equipment, the absence of a local market for the product and traditional beliefs (these animals are still considered by the Bijagos to hold mysterious powers and are consistently represented in religious activities in the form of masks, dances, and wall paintings) had made the archipelago a safe breeding ground for cartilaginous fish.
The growth of the shark fin market in the region over the last decade, for export to the far east, has prompted specialist fishermen from neighbouring Senegal and Guinea, or from further away in Sierra Leone and even Ghana, to come to the archipelago to catch cartilaginous fish. These professionals are well-organised, and use sophisticated and efficient sailing and catching equipment. Highly specialised, they only harvest the fins, which are sun-dried or smoke dried on island beaches, and discard the rest of their catch. On occasions, large quantities of rotting sharks have been found on beaches.
In the absence of consistent scientific data on the existing populations and because of the poor national capacity for law enforcement, the increased pressure that these new activities have caused has raised considerable concern for the sustainability of this industry, the loss of national resources from Guinea Bissau and the archipelago in particular, and the survival/conservation of the target species. Indeed, all actors present in the archipelago seem to agree on the fact that the populations of cartilaginous fish have undergone significant modifications over the last five years or so.
The IUCN Guinea Bissau Programme, in partnership with the national Centro de Investigação Pesqueira Applicada (Centre of Applied Fisheries Research), organised a two-month mission to set up a monitoring mechanism for the cartilaginous fish of the archipelago. All of the seven private game fishing operations who rely heavily on shark fishing for their business and some of the artesanal fishermen participated in this preliminary undertaking.
Initial surveys provided some valuable yet fragmented information. For example, in the case of the great hammerhead shark Sphyrna mokarran, catches of juveniles seem to be increasingly frequent and most of the adults caught are pregnant females. The bull shark Carcharinus leucas and the milk shark Rhizopronodon acutus seem to be more frequently caught than before. For the blacktip shark Carcharhinus limbatus, catches of adults, particularly of pregnant females, have become exceptional and juveniles of birth size constitute over one third of the small sharks found during the survey of fishing catches at local harbours. The populations of guitar fish Rhinobatos rhinobatos and R. cemiculus, up to now the main targets of the specialised fishing teams, seem to have diminished substantially.
Although it is still too early to draw definite conclusions for all the above species, the situation seems to be clearer and more alarming for others. The three species of saw-fish Pristis microdon, P. pectinata and P. pristis have not been reported at all for several years and it is thought that the genus is locally extinct.
The economic significance of this sector of activity is substantial. Indeed, on the basis of the declared catches of the industrial fishing operators and past surveys of the artesanal fishing sector, together with calculations of the profitability threshold of specialised ships, it is possible to estimate the overall catches of cartilaginous fish within the Bissau Guinean EEZ to circa 25,000 tons per year. This represents a yearly production of around 250 tons of dried fins exported from the archipelago to neighbouring countries. The price paid for this product by traders in the region varies between US$50 and US$80 per kg, depending on the species. The total turnover of this trade would be of around US$16 million per year, yielding no benefit at all to Guinea Bissau and no return to the monitoring of the status of the resource base.
At regional level, Mauritania is also witnessing increased pressure on cartilaginous fish. In particular, the local Imraguen fishermen traditionally specialising in white mullet Mugil curema are being forced by the diminishing stocks to convert to other activities, including the catching of cartilaginous fish.
To follow up on the results of the mission, IUCN Guinea Bissau and the Fondation Nationale du Banc d'Arguin in Mauritania, in collaboration with the national institutions in their respective countries, are currently initiating a joint three-year research programme for the monitoring of the shark populations in the Banc d'Arguin National Park and the Bijagos archipelago Biosphere Reserve. It is expected that this programme will result, in 1999, in the formulation of national conservation plans and policies within the framework of new IUCN West Africa Regional Marine Conservation network.
Eric M. Feron
Conseiller Scientifique et Technique Principal
IUCN Guinee Bissau
AP 23, 1031 Bissau Codex, Guinee Bissau, Afrique
Tel. : + 245 20 12 30 Fax : + 245 20 11 68
Article submitted July 1997
1IUCN Guinea Bissau, AP 23 Bissau Codex 1031, Guinea Bissau. Tel: + 245 20 12 30. Fax: + 245 20 11 68.
Email: iucn.bi@sol.gtelecom.gw
2CIPA CP 102, Bissau, Guinea Bissau. Tel: + 245 21 16 95. Fax: + 245 20 11 57.
Editor's note: West African regional meeting on coastal zone management, Bissau, 10-15 November 1997
A paper on exploitation of sharks in the West African region, with particular emphasis on Guinea-Bissau (see above), was presented by Philippe Tous of IUCN Guinea-Bissau in Bissau in November. Although a representative of the Shark Specialist Group was invited to attend the African meeting, this was unfortunately impossible due to the overlap of this meeting with the Shark Specialist Group meetings and workshop in Noumea, New Caledonia. We may be able to report on the African meeting in a future issue of Shark News. In the absence of consistent scientific data on the existing populations and because of the poor national capacity for law enforcement, the increased pressure that these new activities have caused has raised considerable concern for the sustainability of this industry, the loss of national resources from Guinea Bissau and the archipelago in particular, and the survival/conservation of the target species. Indeed, all actors present in the archipelago seem to agree on the fact that the populations of cartilaginous fish have undergone significant modifications over the last five years or so.
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