High and low value fish chains in the Mekong Delta: challenges for livelihoods and governance

This paper investigates the structure, function and wealth distribution within the Pangasius hypophthalmus and Henicorhynchus spp./Labiobarbus spp. value chains in the Mekong Delta of Vietnam. The analysis is driven by key questions relating to the form and function of value chains, their contribution to the livelihoods of farmers and fishers, the effectiveness of government policy and the potential for value chain governance mechanisms, such as contracts and certification, to steer towards sustainable production. The results indicate that actors in the high value Pangasius hypopthalmus export chain have a higher potential income, but face considerably higher economic vulnerability from global markets. Alternatively, Henichorhychus/Labiobarbus spp. fishers are severely constrained in their ability to negotiate higher prices for their fish but appear to be less vulnerable to economic and environmental change. The paper concludes that for value chain governance to improve the livelihoods of fishers and farmers in both high and low value chains, new arrangements are needed that better accommodate customary institutions and informal market relations.     

Evaluation of leaching and extraction procedures for soil and waste

Laboratory leaching tests may be used for source term determination as a basis for risk assessment for soil-groundwater pathways on contaminated sites. In order to evaluate different leaching procedures, batch extraction tests and percolation tests were performed using three reference materials produced from contaminated soil, demolition waste and municipal solid waste incinerator bottom ash. Emphasis was placed on the investigation of the leachability of the heavy metals copper and chromium, polycyclic aromatic hydrocarbons (PAHs) and the anions chloride and sulfate. Significant discrepancies between column experiments and batch/extraction tests were found for the release of PAHs and to a lesser extent for the heavy metals Cu and Cr. Additionally interlaboratory comparisons were conducted based on different leaching tests with the reference materials and evaluated using the criteria of comparability and reproducibility. The best reproducibility was achieved for all investigated substances in column tests. The reproducibility of batch tests was acceptable except for PAHs. The results from the experimental work will help establish standardized and feasible laboratory procedures as fundamental for substance specific risk assessment of contaminated sites.     

Plasma concentration of organochlorine compounds is associated with age and not obesity

It has been suggested that obese individuals, because of an increased dilution space (body fat) for lipophilic organochlorines compounds, may have greater levels of toxic pollutants than lean sedentary individuals. It is important to further examine this possibility because of the potential contribution of organochlorine pesticides in the development of Parkinson's disease and other neurological diseases. The aim of this study was to further investigate the relationship between the magnitude of obesity and the plasma concentration of organochlorines for a wide range of BMI (with participants at steady state body weight). Fifty-three individuals were selected on the basis of their body mass index (BMI): lean controls (n=16; mean BMI 22.8+/-2.2 kg/m(2); mean age 38.8+/-9.4 years), obese individuals (n=19; mean BMI 33.4+/-3.0 kg/m(2); mean age 38.6+/-7.6 years) and morbidly obese individuals (n=18; mean BMI 49.3+/-6.5 kg/m(2); mean age 44.3+/-9.2 years). Blood samples were analyzed for organochlorine compounds. The relationship between the total plasma organochlorine concentration and BMI was tested using a multiple regression analysis. Age was included in the model. There was no relationship between the total plasma organochlorine concentration and BMI. Organochlorine concentrations, however, were correlated with age (BMI-adjusted R(2)=0.46; p<0.001). At steady state body weight, toxic pollutant concentrations are not associated to obesity but strongly correlate with age.     

Environmental impact of the substitution of imported soybean meal with locally-produced rapeseed meal in dairy cow feed

Growing public concerns about the traceability, safety and environmental-friendliness of food products provide an incentive for shorter supply chains in agricultural production. Here, we assessed the environmental impacts of the substitution of imported soybean meal with locally-produced rapeseed meal in French dairy production systems, using a life-cycle approach. Two feeding rations based on either French-produced rapeseed meal or Brazilian-produced soy meal as concentrates, were compared for nine impact categories, including global warming, ecotoxicity and eutrophication. Crop production was the main contributor to most impacts, while overseas transport of soy meal only had a marginal effect. The “Soybean” ration appeared more environmentally-efficient than the “Rapeseed” ration because it involved less intensive management practices, in particular regarding synthetic fertilizers consumption. However, land use changes brought about by soybean cultivation should also be examined.     

Innovations in the water chain – experiences in The Netherlands

Innovations in water chain are discussed based on experiences in the Netherlands. The available and new technological options, as well as their dissemination in the Netherlands, are presented for the prevailing system with add-on technologies (elongation), and for the emerging separation system with technologies at the source. Numerous new options are available for both systems but these options are rarely used. The low use is explained using economic theories and with practical examples from the Netherlands. In order to foster innovations, the mainstream, evolutionary, and behavioral theories pinpoint respectively the pricing of common goods, broad support of concerted action, and support for innovators’ entry. These actions may all be needed. Experiences with a stakeholder cluster in water management suggest that markets for high value water use invoke innovations and low-cost technology adaptations. The systematic development of services that foster high value water-based activities is recommended.     

Mobilisation of sediment-associated metals from historical Pb working sites on the River Sheaf, Sheffield, UK

Spatial and temporal patterns of metal mobilisation from former water-powered, Pb working sites in a suburban area of Sheffield (UK) were investigated. Twelve time-integrated mass flux samplers were strategically deployed over two contrasting campaign periods (summer and winter). Suspended sediment samples were characterised magnetically and subjected to metal analysis. Metal levels in the upper River Sheaf showed a marked spatial and temporal variability. Pb concentrations in particular were relatively high (maximum 2132 mg kg(-1)). Their distribution tended to reflect the historical contamination of the valley by 17th to 19th century industry, especially during summer high discharge conditions. The mean suspended sediment Pb concentration (803 mg kg(-1)) exceeds contamination guidelines. It is unclear whether ground remediation of one of the seven floodplain sites in the catchment has been successful. The river is still affected by the legacy of at least two other Pb working sites.     

Nitrogen deposition increases the acquisition of phosphorus and potassium by heather Calluna vulgaris

Increased plant productivity due to nitrogen pollution increases the strength of the global carbon sink, but is implicated in plant diversity loss. However, modelling and experimental studies have suggested that these effects are constrained by availability of other nutrients. In a survey of element concentrations in Calluna vulgaris across an N deposition gradient in the UK, shoot concentrations of N and more surprisingly phosphorus and potassium were positively correlated with N deposition; tissue N/P ratio even decreased with N deposition. Elevated P and K concentrations possibly resulted from improved acquisition due to additional enzyme production or mycorrhizal activity. Heather occurs on organic soils where nutrient limitations are likely due to availability constraints rather than small stocks. However, if this effect extends to other plant and soil types, effects of N deposition on C sinks and plant competition may not be as constrained by availability of other nutrients as previously proposed.     

Climate change,adaptation and Eco-Art in Singapore

Eco-Art has recently emerged as a potential means to place emphasis on environmental issues such as climate change, recycling and the metabolism of the city experienced both materially and conceptually within local, regional and global contexts. Such art presents the possibility of shaping civic practices in arenas beyond those of traditional planning domains. Adopting a pragmatic approach, which recognises the contextual pluralism that exists in debates regarding climate change, this paper is interested in how Eco-Art projects encourage the re-imagining of urban spaces within the context of sustainability, and flows of materials and the recycling of plastic in art specifically.