Water for small-scale biogas digesters in sub-Saharan Africa

Acknowledgements This work was part-funded by the UK Natural Environment Research Council funded ESPA project, NE/K010441/1 ‘ALTER – Alternative Carbon Investments in Ecosystems for Poverty Alleviation’. We are also grateful to the AUC for funding part of this work under the Afri-Flame project on ‘Adapta- tion of small-scale biogas digesters for use in rural households in sub-Saharan AfricaPeer reviewedPublisher PD

The Economics of Kappaphycus Seaweed Cultivation in Developing Countries: A Comparative Analysis of Farming Systems

The farming of the red seaweed Kappaphycus alvarezii and related species as raw material for the hydrocolloid carrageenan rapidly spread from the Philippines in the late 1960s to Indonesia, Tanzania, and other tropical countries around the world. Although numerous studies have documented positive socioeconomic impacts for seaweed farming, factors such as diseases and distance to export markets have led to an uneven development of the industry. Using standard budgeting techniques, this study adapted production and market data from a FAO-led global review of seaweed farming to develop comparative enterprise budgets for eight farming systems in six countries (Indonesia, the Philippines, Tanzania, India, Solomon Islands, and Mexico). Although the basic technology package is the same across countries, the study revealed large differences in the economic performance of systems due to wide variations in farm prices and the scale of operations. Although seaweed farming is a suitable activity for small-scale producers, a minimum of 2,000m of cultures lines are still necessary to ensure adequate economic returns. Greater farming plots may be needed if farm prices are well below the average farm prices paid in Indonesia and the Philippines. Policy recommendations are made to improve the economic potential of underperforming systems

Capturing Ecosystem Services, Stakeholders' Preferences and Trade-Offs in Coastal Aquaculture Decisions : A Bayesian Belief Network Application

Aquaculture activities are embedded in complex social-ecological systems. However, aquaculture development decisions have tended to be driven by revenue generation, failing to account for interactions with the environment and the full value of the benefits derived from services provided by local ecosystems. Trade-offs resulting from changes in ecosystem services provision and associated impacts on livelihoods are also often overlooked. This paper proposes an innovative application of Bayesian belief networks - influence diagrams - as a decision support system for mediating trade-offs arising from the development of shrimp aquaculture in Thailand. Senior experts were consulted (n = 12) and primary farm data on the economics of shrimp farming (n = 20) were collected alongside secondary information on ecosystem services, in order to construct and populate the network. Trade-offs were quantitatively assessed through the generation of a probabilistic impact matrix. This matrix captures nonlinearity and uncertainty and describes the relative performance and impacts of shrimp farming management scenarios on local livelihoods. It also incorporates export revenues and provision and value of ecosystem services such as coastal protection and biodiversity. This research shows that Bayesian belief modeling can support complex decision-making on pathways for sustainable coastal aquaculture development and thus contributes to the debate on the role of aquaculture in social-ecological resilience and economic development

Factors influencing the Environmental and Financial Sustainability of Aquaculture Production in Jamaica

We use the Analytic Hierarchy Process (AHP) and the Cost Benefit Analysis (CBA) to evaluate the profitability and sustainability of aquaculture in Jamaica. We also examine the combined application of these methods to provide holistic and reliable information. In March 2010 we administered the AHP and the CBA survey instruments among 27 Jamaicans engaged in large- and medium-scale tilapia production and marketing. The overall ranking of criteria is reliable, with an inconsistency ratio (IR) of 0.075. Participants classified ‘better feed conversion ratio’ as their first criteria for increasing profitability and sustainability, with a rank score (RC) of 0.050. In second and third places were ‘decreased disease problems’ and ‘decreased mortality,’ with RCs of 0.036 and 0.031, respectively. The net operating income ($33,103.05), the IRR of 30.36% and P.I of 1.55 shows that tilapia production is profitable and feasible. When participants’ preferences of methods for improving fish production and marketing from the AHP results were considered, fish production and marketing in Jamaica became more profitable and sustainable. The results show that the AHP method provides unique ranking of stakeholders’ preferences and, when combined with the CBA, generates solid analyses for evaluating the profitability and sustainability of aquaculture enterprises