Structure and Operation of a Bushmeat Commodity Chain in Southwestern Ghana

Abstract:  The bushmeat trade is perceived as a major threat to wild animal populations in the tropics. Little is known of how the trade is organized, however, or of the actors involved in it, impeding the development of effective conservation policy. We investigated the structure and operation of a bushmeat commodity chain in West Africa that supplies a typical urban market, the city of Takoradi in southwestern Ghana. Data were collected from January through February 2000, describing 2430 bushmeat transactions encompassing 17 different taxa from 70 different actors, through a combination of direct observation and semistructured interviews. Five different types of actor traded along the commodity chain: commercial hunters, farmer hunters, wholesalers, market traders, and chopbar (cafe) owners. Bushmeat was traded freely among all these actors, although the primary trade route for terrestrial mammals was from commercial hunters via wholesalers to chopbars. In contrast, invertebrates were only traded by farmer hunters, market traders, and chopbars. Wholesalers captured the largest per capita share of the market (4% of all sales were handled by each wholesaler), whereas the most important vendors were chopbars, which as a group made 85% of all bushmeat sales to the public. Variation in the price of bushmeat was largely explained by transport costs and taste preferences. Transport costs were most significant for hunters and greatest on long journeys involving large loads. Nevertheless, hunters obtained the greatest income per kilogram of bushmeat sold of all actor groups. Our results suggest that there is no single best entry point along the bushmeat commodity chain for conservation intervention. On the contrary, the successful monitoring and management of the bushmeat trade is likely to require a multiactor approach that encompasses most or all actor groups.     

Adsorption of methylene blue from aqueous solution by chemically treated water hyacinth

Water hyacinth (WH), an aquatic plant macrophyte, was investigated for its ability to perform as a suitable adsorbent for methylene blue (MB) from aqueous solution. The non-living biomass of WH was subjected to several chemical treatments, namely, washing with hot water, washing with hot dilute HCl, soaking in NaOH, soaking in HNO₃, and sulfonation. The system variables studied also include pH and MB concentration. The Langmuir isotherm was found to represent the measured adsorption data well except for WH soaked in NaOH, which was found to be better represented by the Freundlich isotherm. Values of the dimensionless separation factor, K _R, indicated that the adsorption systems in this study are all favorable. Values of the first layer of adsorption were calculated by the non-linear multilayer adsorption model, and the specific surface area values were found to be high and comparable to commercially activated carbons.