JEP  Vol.4 No.12 , December 2013
Fish Assemblages in the Degraded Mangrove Ecosystems of the Coastal Zone, Benin, West Africa: Implications for Ecosystem Restoration and Resources Conservation
Abstract: Mangrove forests are unique habitats in their function as potential food source and nurseries, and support an important fisheries resource. In the Benin coastal zone, the mangrove fishes have been surveyed to investigate fish species diversity, community structures and ecosystem degradation impacts in order to protect and to improve the mangrove fish resources. Results from wet, high-water and dry season samplings revealed that the two dominant mangrove species, Rizophora racemosa and Avicennia africana, are being intensively degraded for domestic use such as firewood and house building. Fifty one (51) fish species belonging to 25 families were recorded with Eleotridae (7 species), Cichlidae (5 species), and Mugilidae (5 species), the most speciose families. Dominant trophic guilds were detritivores (54.57%) and planktinovores/microcarnivores (30.41%). Six (6) species, Sarotherodon melanotheron, Dormitator lebretonis, Gerres melanopterus, Hemichromis fasciatus, Ethmalosa fimbriata, and Aplocheilichthys spilauchen, dominated the samples and accounted for about 80.27%. Sarotherodon melanotheron constituted the major dominant species and accounted numerically for about 29% of the total catches and 46.7% of the total biomass. The Margalef index of species richness ranged between 2.42 and 4.43, the Shannon-Weaver index of species diversity between 1.39 and 2.27, and the evenness between 0.50 and 0.62. Lower indices were observed for the highly degraded and the moderately degraded sites whereas higher indices were recorded for the less degraded and the restored sites. Species richness, species diversity and dominant species abundance were positively correlated with depth and transparency and negatively correlated with temperature. Multi-species fisheries dominate the coastal zone with Sarotherodon melanotheron, Dormitator lebretonis, Gerres melanopterus, Ethmalosa fimbriata, Liza falcipinus, Mugil sp. and Chrysichthys nigrodigitatus, the major species in the commercial catches. In addition to the mangrove destruction, the hydro electrical dam have greatly modified the Mono River flooding regime, water quality and the fish composition of the Benin coastal lagoon system. An integrated approach of the mangrove resource management/conservation, including intensive mangrove restoration, management of key fish species, freshwater prawns (Macrobrachiun sp.), peneids shrimps, mangrove oysters (Crassostrea sp.), and crabs (Callinectes sp., Cardiosoma sp.), and habitat protection is required for ecosystem recovery and sustainable exploitation.
Cite this paper: A. Adite, I. ImorouToko and A. Gbankoto, "Fish Assemblages in the Degraded Mangrove Ecosystems of the Coastal Zone, Benin, West Africa: Implications for Ecosystem Restoration and Resources Conservation," Journal of Environmental Protection, Vol. 4 No. 12, 2013, pp. 1461-1475. doi: 10.4236/jep.2013.412168.

[1]   F. K. E. Nunoo, E. Sossoukpe, A. Adite and E. D. Fiogbe, “Foods Habits of Two Species of Pseudotolithus (Scianidae) off (West Africa) near Shore Waters and Implications for Management,” International Journal of Fisheries and Aquaculture, Vol. 5, No. 6, 2013, pp. 142-151.

[2]   R. L. Welcomme, “Fisheries Ecology of Floodplain Rivers,” Longman, New York, 1979.

[3]   D. J. Vance, M. D. Haywood, D. S. Heales, R. A. Kenyon and N. R. Loneragan, “How Far Prawns and Fish Move into Mangroves? Distribution of Juvenile Banana Prawns, Penaeus merguiensis and Fish in a Tropical Mangrove Forest in Northern Australia,” Marine Ecological Progress Series, Vol. 131, 1996, pp. 115-124.

[4]   G. W. Thayer, D. R. Colby and W. F. Hettler Jr., “Utilization of the Red Mangrove Prop Root Habitat by Fishes in South Florida,” Marine Ecological Progress Series, Vol. 35, 1987, pp. 25-38.

[5]   A. Adite, “Fishery Ecological Survey of Natural Coastal Lakes of Benin, West Africa,” Master of Sciences Thesis, Texas A&M University, College Station, 1995.

[6]   A. Roberston and N. C. Duke, “Mangrove as a Nursery Sites: Comparisons of the Abundance and Species Composition of Fish and Crustaceans in Mangroves and Other near Shore Habitats in Tropical Australia,” Marine Biology, Vol. 96, No. 2, 1987, pp. 193-206.

[7]   W. N. Tzeng and Y. T. Wang, “Structure, Composition and Seasonal Dynamics of the Larval and Juvenile Fish Community in the Mangrove Estuary of Tanshui River, Taiwan,” Marine Biology, Vol. 113, No. 3, 1992, pp. 481-490.

[8]   P. Laegdsgaard and C. R. Johnson, “Mangrove Habitats as Nurseries: Unique Assemblages of Juvenile Fish in Subtropical Mangroves in Eastern Australia,” Marine Ecological Progress Series, Vol. 126, No. 1-3, 1995, pp. 67-81.

[9]   R. L. Welcomme, “A Description of Certain Indigenous Fishing Methods from Southern Dahomey,” African Journal of Tropical Hydrobiology and Fisheries, Vol. 1, No. 2, 1971, 129-140.

[10]   A. Adite and R. Van Thielen, “Ecology and Fish Catches in Natural Lakes of Benin, West Africa,” Environmental Biology of Fishes, Vol. 43, No. 4, 1995, pp. 381-391.

[11]   P. Lalèyè, C. Niyonkuru, J. Moreau and G. G. Teugels, “Spatial and Seasonal Distribution of the Ichthyofauna of Lake Nokoué, Benin, West Africa,” African Journal of Aquatic Science, Vol. 28, No. 2, 2003, pp. 151-161.

[12]   A. Adite, Y. Abou, E. Sossoukpe and E. D. Fiogbe, “The Oyster Farming in the Coastal Ecosystem of Southern Benin (West Africa): Environment, Growth and Contribution to Sustainable Coastal Fisheries Management,” International Journal of Development Research, Vol. 3, No. 10, 2013, pp. 087-094.

[13]   H. Lopez-Fernandez, K. O. Winemiller, A. Adite, D. A. Arrington and C. A. Layman, “Freshwater Fish Diversity in Benin, West Africa, and Challenge for Its Conservation,” Proceedings University of Abomey-Calavi Conference African Fish and Fisheries, Abomey-Calavi, 2003, pp. 85-86.

[14]   C. Levêque, D. Paugy and G. G. Teugels, “The Fresh and Brackish Water Fishes of West Africa,” Tome 1, Editions ORSTOM/MRAC, Paris, 1990.

[15]   C. Levêque, D. Paugy and G. G. Teugels, “The Fresh and Brackish Water Fishes of West Africa,” Tome 2, Editions ORSTOM/MRAC, Paris, 1990.

[16]   M. Holden and W. Reed, “West African Freshwater Fish,” Longman Group Ltd. London, 1972.

[17]   R. H. Lowe McConnell, “Fish Communities in Tropical Freshwaters,” Longman, London, 1975.

[18]   R. H. Lowe McConnell, “Ecological Studies in Tropical Fish Communities,” Cambridge University Press, Cambridge, 1987.

[19]   R. Margalef, “Perspective in Ecological Theory,” University of Chicago Press, Chicago, 1968.

[20]   C. Shannon and E. Weaver, “The Mathematical Theory of Communication,” University of Illinois Press, Urbana, 1963.

[21]   C. J. Krebs, “Ecological Methodology,” Harper & Row Publishers, New York, 1989.

[22]   B. McCune and M. J. Mefford, “Multivariate Analysis of Ecological Data. Version 2.0. MJM Software Design,” Gleneden Beach, Oregon, 1995.

[23]   S. J. M. Blader and T. G. Blader, “Factors Affecting the Distribution of Juvenile Estuarine and Inshore Fish,” Journal of Fish Biology, Vol. 17, No. 2, 1980. pp. 143-162.

[24]   R. M. Morton, “Community Structure, Density, and Standing Crop of Fishes in a Subtropical Australian Mangrove Area,” Marine Biology, Vol. 105, No. 3, 1990, pp. 385-394.

[25]   I. A. Halliday and W. R. Young, “Density, Biomass and Species Composition of Fish in a Subtropical Rhizophora stylosa Mangrove Forest,” Marine Freshwater Resources, Vol. 47, No. 4, 1996, pp. 609-615.

[26]   A. Adite and K. O. Winemiller, “Trophic Ecology and Ecomorphology of Fish Assemblages in Coastal Lakes of Benin,” Ecoscience, Vol. 4, No. 1, 1997, pp. 6-23.

[27]   A. Adité, K. O. Winemiller and E. D. Fiogbe, “Ontogenetic, Seasonal; and Spatial Variation in the Diet of Heterotis niloticus (Osteoglossiformes: Osteoglossidae) in the So River and Lake Hlan, Benin, West Africa,” Environmental Biology of Fishes, Vol. 73, No. 4, 2005, pp. 367-378.

[28]   G. A. Morgan, O. V. Grieggo and G. W. Gloekner, “SPSS for Windows: An Introduction to Use and Interpretation in Research,” Lawrence Erlbaum Associates, Publishers, Mahwah, 2001.

[29]   F. W. Tesh, “Age and Growth,” In: W. E. Ricker, Ed., Methods for Assessment of Fish Production in Fresh Waters, Blackwell Scientific Publication, London, 1971.

[30]   I. Williamson and C. B. King Mather, “A Comparison of Fish Communities in Unmodified and Modified Inshore Habitats of Raby Bay, Queensland,” Estuarine, Coastal and Shelf Sciences, Vol. 39, No. 4, 1994, pp. 401-411.

[31]   A. Yanez-Arancibia, A. Lara-Dominguez and J. W. Day Jr., “Interactions between Mangrove and Sea Grass Habitats Mediated by Estuarine Nekton Assemblages: Coupling of Primary and Secondary Production,” Hydrobiologia, Vol. 264, No. 1, 1993, pp. 1-12.

[32]   M. Louis, C. Bouchon and Y. Bouchon-Navaro, “Spatial and Temporal Variations of Mangrove Fish Assemblages in Martinique (French West Indies),” Hydrobiologia, Vol. 295, No. 1-3, 1995, pp. 275-284.

[33]   GCLME, “Guinea Current Large Marine Ecosystem Report,” GEF/UNIDO/UNDP/UNEP/US-NOAA, 2006.

[34]   S. H. Bowen and B. R. Allanson, “Behavioral and Trophic Plasticity of Juvenile Tilapia mossambica in Utilization of the Unstable Littoral Habitat,” Environmental Biology of Fishes, Vol. 7, No. 4, 1982, pp. 357-362.

[35]   K. O. Winemiller, “Spatial and Temporal Variation in Tropical Fish Trophic Network,” Ecological Monographs, Vol. 60, No. 3, 1990, pp. 331-367.

[36]   S. H. Bowen, “Detrivory in Neotropical Fish Communities,” Environmental Biology of Fishes, Vol. 9, No. 2, 1983, pp. 137-144.

[37]   K. O. Winemiller, “Ecomorphological Diversification in Lowland Freshwater Fishes,” National Geographic Research & Exploration, Vol. 8, No. 3, 1992a, pp. 308-327.

[38]   K. O. Winemiller, “Fish Assemblages across a Complex, Tropical Freshwater/Marine Ecotone,” Environmental Biology of Fishes, Vol. 34, No. 1, 1992, pp. 29-50.