Abstract
Muni is a closed lagoon that opens to the sea when the water level is high, especially during the rainy season. During the dry period, the water level is very low and the salinity of the lagoon water increases sometimes exceeding that of seawater. Only three finfish species and 8 shellfish species (live animals and empty shells) were found in the lagoon and surrounding wetlands during the study which was conducted in March–June 1994. The blackchin tilapia Sarotherodon melanotheron (Cichlidae) is the dominant species. The castnet is the most important fishing gear used in the lagoon followed by various finfish and shellfish traps. The fishing effort in the lagoon is high and, like catch rates, it was found to be inversely related to the volume of water in the lagoon and the fishing situation in the sea. The estimated exploitation level (E = 0.65) indicates that S. melanotheron in the Muni lagoon could be considered as over-exploited. From the gonadosomatic index, S. melanotheron appears to spawn continuously in the Muni lagoon between the months of March and June. The von Bertalanffy growth parameters were estimated for S. melanotheron as L∞ = 12.5 cm standard length (SL), K = 0.70 yr−1 and t0 = 0.01 yr. The longevity of the fish is estimated as ca. 4.2 yr. Taboos and cultural practices contribute to the management and conservation of fisheries in the lagoon. However, additional formal management is required to ensure sustainability of the fisheries in the lagoon. In addition, there is a need to manage the lagoons physical and chemical environment including planting of mangroves around the lagoon in order to restore its mangrove cover. The poverty problem in the fishing community needs to be addressed to divert labour from the lagoon.
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References
Biney CA (1995) Ghana Coastal Wetlands Management Project, Environmental Baseline Report, Limnology. Prepared for the Ghana Wildlife Department, Government of Ghana
Blay J Jr and Asabere-Ameyaw A (1993) Assessment of the fishery of the cichlid Sarotherodon melanotheron (Rüppel) in a 'closed' lagoon in Ghana. Journal of Applied Ichthyology 9: 1–11
Costanza R, Kemp WN and Boynton WR (1993) Predictability, scale and biodiversity in coastal estuarine ecosystems: implications for management. AMBIO 22(2–3): 88–96
Doyi BA (1984) Catalogue of small-scale fishing gear of Ghana. CECAF/ECAF Series 84/31 (En) FAO, Rome, 71 pp
Edmunds J (1978) Sea Shells and Other Mulluscs Found on the West African Coast and Estuaries. Ghana Universities Press, 136 pp
FOE (Friends of the Earth, Ghana) (1994) Wetlands Management in Ghana. A research project sponsored by the IDRC, Canada (summary report)
Gayanilo FC Jr, Sparre J and Pauly D (1995) FAO-ICLARM stock assessment tools (FiSAT) user's manual. FAO Comp. Information Series (Fisheries) 8: 126
Gulland JA (1971) The fish resources of the ocean. Fishing News Books, West Byfleet, UK, 255 pp
Koranteng KA (1993) Size at first maturity of the anchovy (Engraulis encrasicolus) in Ghanaian waters and suggestions for appropriate mesh size in its fishery. NAGA, ICLARM Quarterly 16(1): 29–30
Koranteng KA (1995) Ghana Coastal Wetlands Management Project, Environmental Baseline Report, Fisheries. Prepared for the Ghana Wildlife Department, Government of Ghana
Koranteng KA, Ofori-Danson PK and Entsua-Mensah M (1998) Comparative Study of the Fish and Fisheries of Three Coastal Lagoons in West Africa (in press). International Journal of Ecology and Environmental Sciences 24: 371–382
Laevastu T (1965) Manual of Methods in Fisheries Biology. FAO, Rome
Mensah MA (1979) The hydrology and fisheries of the lagoons and estuaries of Ghana. Marine Fishery Research Report No. 7. Fisheries Research and Utilization Branch, Tema, 14 pp
Ni I-H and Sandeman EJ (1984) Size at maturity for Northwest Atlantic Redfish (Sebastes). Canadian Journal of Fisheries and Aquatic Sciences 41: 1753–1762
Ntiamoa-Baidu Y (1991) Conservation of coastal lagoons in Ghana. The traditional approach. Landscape and Urban Planning 20: 41–46
Ntiamoa-Baidu Y and Gordon C (1991) Coastal Wetlands Management Plans: Ghana. A Report to the World Bank. Department of Zoology, University of Ghana, Legon, Ghana
Ntiamoa-Baidu Y and Hollis GE (1988) Planning the management of coastal lagoons in Ghana. In: Conservation and Development of the Sustainable Use of Wetland Resources. Proceedings of the Third International. Wetlands Conference. The IUCN Wetlands Programme, pp 113–121
Pauly D (1976) The biology, fishery and potential for aquaculture of Tilapia melanotheron in a small West African lagoon. Aquaculture 7: 33–49
Pauly D (1980) On the interrelationship between natural mortality, growth parameters and mean environmental temperature in 175 fish stocks. Journal du Conseil International pour l'Exploration de la Mer 39(3): 175–192
Pauly D (1984) Fish population dynamics in tropical waters: a manual for use with programmable calculators. ICLARM, Manila, Philippines, 325 pp
Pauly D and Munro JL (1984) Once more on the comparison of growth in fish and invertebrates. ICLARM Fishbyte 2(1): 21
Schneider W(1990) Field Guide to the Commercial Marine Resources of the Gulf of Guinea. FAO Species Indentification Sheets for Fishery Purposes. RAFR/F1/90/2
Sparre P, Ursin E and Venema SC (1989) Introduction to tropical fish stock assessment. Part 1. Manual. FAO Fisheries Technical Paper No. 306.1, FAO, Rome, 337 pp
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Koranteng, K., Ofori-Danson, P. & Entsua-Mensah, M. Fish and fisheries of the Muni lagoon in Ghana, West Africa. Biodiversity and Conservation 9, 487–499 (2000). https://doi.org/10.1023/A:1008903813222
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DOI: https://doi.org/10.1023/A:1008903813222