The Economic Importance and Social Values of Traditional Aquaculture in Rural Sierra Leone

The economic viability and social value of traditional aquaculture in rural Sierra Leone were evaluated. The hypothesis tested was that traditional methods of farming fish in ponds were not economically viable, so farmers were investing their time/labour in less risky and more profitable livelihoods activities. The assumption in this assessment was that fish farming is an economic activity, and that for farmers to adopt or choose it over other livelihoods, the benefit-cost ratio of fish farming must be higher than that of alternative livelihoods. The main objective of the study was to assess why local farmers failed to adopt modem market oriented aquaculture production systems introduced by the Ministry of Fisheries and Marine Resources in rural Sierra Leone. Two hundred farmers owning fishponds on family lands were interviewed using semi-structured questionnaires and farmers＇ responses were analyzed using statistical tools （SPSS 16.0）. The mean contributions of different livelihoods to total annual incomes of farmers and the social values they attached to these livelihoods were compared. Results of the study suggested that traditional fish fanning was economically viable across the range of pond sizes sampled; but the medium-sized ponds were more profitable than the smallest and largest ponds, and labour accounted for 70% of total annual production costs in the systems assessed. The average benefit-cost ratio of 2.3 for fish fanning was favorable compared with that of 0.83 for rice farming, which was ranked as most popular livelihood activity by farmers. The payback period for traditional aquaculture investments was less than five years using informal investment loans （without interest）, and was favorably compared with that for tree crops fanning, which was also popular among farmers. Additional benefits of fish fanning included social capital and maintenance of kinship relationships.

Hydrocarbon-Based Contaminants in Drinking Water Sources and Shellfish in the Soku Oil and Gas Fields of South-South Nigeria

Environmentally unfriendly Oil exploration activities have been ongoing in the Soku area of the Niger Delta of Nigeria since 1956. This study evaluated the concentration of hydrocarbons and heavy metals in Shellfish and drinking water sources in the study area. It revealed the absence (<0.001 mg/l) of most heavy metals (Ni, Ch, Cd, Pb mg/l) in the water column;a high concentration of the major ion composition of seawater (sulphates 5 - 1018;calcium 0.502 - 53.502;sodium 1.247 - 63.337;potassium 0.508 - 102.745;magnesium 0.354 - 42.574 mg/l);and high PAHs (<0.001 - 0.032 mg/l) levels occurring above WHO limits (0.007 mg/l) with some risk of exposure to cancer. Results from the analysis of shellfish showed that concentrations of chromium and zinc were below permissible limits while cadmium concentrations were slightly above permissible limits of the European Community. Nickel and lead were above permissible limits in the fish samples in all standards while PAHs occurred at the cancer risk levels of 10?6. A review of the public health situation in the Soku area with a view to understanding current trends, sources of perturbations and preferable solutions to the potential public health challenges raised in this study is hereby recommended. Also, this study recommends that relevant agencies and developmental partners should launch a national drive to create awareness among people/environmental/public health professionals’/health workers/administrators on this regional concern.

Persistence of Dioxin TCDD in Southern Vietnam Soil and Water Environments and Maternal Exposure Pathways with Potential Consequences on Congenital Heart Disease Prevalence in Vietnam

Waterlogged soils and submerged sediments in wetlands and agricultural lands used for rice paddies and aquaculture have anaerobic conditions that slow and prevent the photo and microbial degradation of dioxin TCDD (2,3,7,8-tetracholorodibenzo-p-dioxin), enabling it to persist in environments for long periods. Over 1.6 million ha of land in southern Vietnam were sprayed with 2,4,5-T herbicides (e.g. Agent Orange) contaminated with dioxin TCDD during the Vietnam War (1961-1971);45% of these ha received four or more spray flight missions. Dioxins are endocrine disrupters and may induce cardiovascular disease, growth, and developmental defects, diabetes, hormonal dysfunctions and disruptions, certain cancers, and chloracne. Outpatient screening clinic 2020 data on Vietnamese children suspected of congenital heart disease (CHD) showed the childhood CHD prevalence rate in Vietnam of 13.356/1000, significantly elevated compared to the Asian CHD prevalence rate of 3.531/1000. CHD prevalence rate differences between North Vietnam (2.541/1000) and south of the 17th parallel (10.809/1000) were significant. Vietnamese farmers, especially pregnant women whose occupations involve daily contact with soil and sediments where dioxin TCDD persists in the environment may be at risk of dioxin accumulation from dermal exposure and bioaccumulation via diet. There is an urgent need for funded longitudinal genetic and clinical studies to assess CHD and other organ system childhood malformations due to in utero TCDD exposure. We recommend an integrated research design involving 1) site-specific locations that received high volumes and multiple spray loads of herbicides during the Vietnam War;2) soil sampling of submerged and waterlogged soils and sediments where TCDD may not have degraded;3) production areas of agriculture, fisheries, and other aquatic products;4) risk assessment dioxin levels in foods where TCDD is likely to bioaccumulate;5) child-bearing age and pregnant women with potentially high sensitivity to long-term low dose exposure, and 6) men and women in occupations that are in daily contact with contaminated soil and sediments as part of their job routines.

Cascading adaptation of rural livelihood to changing environment:Conceptual framework and experiment from the Koshi River basin

Rural communities in the Koshi River basin,a trans-boundary river basin in the Hindu Kush-Himalayas,have been experiencing unprecedented difficulties for adapting with the livelihood challenges arising from floods,droughts and other climatic,environmental and socio-economic stresses.The single purpose adaptation approach often fails to address the multiple challenges arises from cascading effects of climate change at different scales and stages.To fill this gap,we developed a multi-dimensional flexible adaptation framework looking at the four dimensions of adaptation,structure,issue,time,and space(SITS).The SITS framework provides a comprehensive approach for cascading adaptation at trans-boundary river basin level and it could effectively enhance the adaptive capacity and transform livelihood outcome if properly implemented.Following the SITS framework,we examined four cascading adaptation pathways for:i)reducing disaster stressors on livelihoods,ii)enhancing access to crucial livelihood capitals,iii)improving equal rights to livelihood,and iv)strengthening synergies and exploiting complementarities at trans-boundary river basin level.The findings revealed that in the context of changing climate,it is necessary to employ different livelihood adaptation strategies and multiple responses simultaneously or sequentially to successfully adapt to the cascading effects of changing climate.The cascading adaptation may provide a sound basis on which to cope with the climate uncertainty through realistic scenarios of structure,issue,time and space.Its implementation,however,has several obstacles,for example,differences in national system,investment capacity,complexity of trans-boundary basin,remained particularly in trans-boundary river basin where managing transnational trade-offs and harness spatial synergies are critically important.