Status of Large Marine Flagship Faunal Diversity Within Cameroon Estuaries of Central African Coast

Abstract

An assessment of the status of large marine flagship faunal species along Cameroon estuaries within the Central African coast was carried out through several surveys, interviews, literature reviews and experience to compile species checklists, causes of their presence (migration, reproduction, feeding, etc.), the conservation status and different threats to species. Results showed that four species of sea turtles were identified and common along Cameroon estuaries: Dermochelys coriacea, Lepidochelys olivacea, Chelonia mydas and Eretmochelys imbricata for nesting and feeding activities. Eight cetaceans (Sousa teuszii, Delphinus capensis, Delphinus sp,. Tursiops truncatus, Stenella attenuata or S. frontalis, S. coeruleoalba, Megaptera novaeangliae, Physeter macrocephalus) and one sirenian species (Trichechus senegalensis) were found to be common, seasonal or rare. We recorded up to 61 waterbird species represented by 17 families from monthly counts within 20 km of the Sanaga River estuary and associated rivers and lakes in the Douala-Edea Wildlife Reserve between March 1999 and December 2012. The families of Ardeidae, Scolopacidae, Charadriidae and Alcedinidae were top with 12, 10, 8 and 7 species, respectively. Twenty-two (36.1 %) of the 61 species appeared to be resident, while 21(34.4 %) and 16(29.5 %) were seasonal and occasional visitors, respectively. Of particular significance is the high abundance of African Skimmers, Grey Pranticoles, Open-billed Storks and Common green shanks with monthly numbers of up to 811, 583, 336 and 189, respectively. In spite of the existing laws and conservation policies on these threatened species in Cameroon, most are facing many threats. By-catches in gillnets and other fishing gears and the potential for increasing direct takes may be the most severe threats and causes of significant mortality rates. Other threats of varying magnitude of concern include the following: habitat encroachment through coastal development (e.g. port and road construction), over-fishing, chemical and acoustic pollution, ship collisions and ghost nets. The almost complete lack of scientific data on the biology, distribution, stock structure and abundance of sea turtles and cetaceans in Cameroon waters makes it difficult to properly assess the impact of these threats, let alone addressed them. An acceleration of research is urged with the involvement of national Universities and Research Institutes. More faunal surveys are needed to unveil the potentials of the area and the need for the establishment of important relationships between species abundance, site temporal conditions (sandbank dynamics) and socio-economic activities with a view to identifying sustainable wetlands ecosystem utilization options.