Evolution of a Mediterranean Coastal Zone: Human Impacts on the Marine Environment of Cape Creus

This study presents an integrated analysis of the evolution of the marine environment and the human uses in Cape Creus, a Mediterranean coastal area where intense commercial fisheries and recreational uses have coexisted over the last fifty years. The investigation synthesizes the documented impacts of human activities on the marine environment of Cap de Creus and integrates them with new data. In particular, the evolution of vulnerable, exploited species is used to evaluate the fishing impacts. The effects of area protection through the establishment of a marine reserve in the late 1990s and the potential climate change impacts are also considered. The evolution of the human uses is marked by the increasing socioeconomic importance of recreational activities (which affect species and habitats) in detriment to artisanal and red coral fisheries (which principally affect at a species level). Overall, populations of sedentary, vulnerable exploited species, hard sessile benthic invertebrates, and ecologically fragile habitats, such as seagrass meadows, the coralligenous and infralittoral algal assemblages have been the most negatively impacted by anthropogenic activities. Albeit human uses currently constitute the largest negative impact on the marine environment of Cap de Creus, climate change is emerging as a key factor that could have considerable implications for the marine environment and tourism activities. The establishment of the marine reserve appears to have had little socioeconomic impact, but there is some evidence that it had some positive biological effects on sedentary, littoral fishes. Results demonstrate that the declaration of a marine reserve alone does not guarantee the sustainability of marine resources and habitats but should be accompanied with an integrated coastal management plan.     

Selecting optimal hyperspectral bands to discriminate nitrogen status in durum wheat: a comparison of statistical approaches

Hyperspectral data can provide prediction of physical and chemical vegetation properties, but data handling, analysis, and interpretation still limit their use. In this study, different methods for selecting variables were compared for the analysis of on-the-ground hyperspectral signatures of wheat grown under a wide range of nitrogen supplies. Spectral signatures were recorded at the end of stem elongation, booting, and heading stages in 100 georeferenced locations, using a 512-channel portable spectroradiometer operating in the 325–1075-nm range. The following procedures were compared: (i) a heuristic combined approach including lambda-lambda R² (LL R²) model, principal component analysis (PCA), and stepwise discriminant analysis (SDA); (ii) variable importance for projection (VIP) statistics derived from partial least square (PLS) regression (PLS-VIP); and (iii) multiple linear regression (MLR) analysis through maximum R-square improvement (MAXR) and stepwise algorithms. The discriminating capability of selected wavelengths was evaluated by canonical discriminant analysis. Leaf-nitrogen concentration was quantified on samples collected at the same locations and dates and used as response variable in regressive methods. The different methods resulted in differences in the number and position of the selected wavebands. Bands extracted through regressive methods were mostly related to response variable, as shown by the importance of the visible region for PLS and stepwise. Band selection techniques can be extremely useful not only to improve the power of predictive models but also for data interpretation or sensor design.     

Material and energy recovery from Automotive Shredded Residues (ASR) via sequential gasification and combustion

Shredding is the common end-of-life treatment in Europe for dismantled car wrecks. It produces the so-called Automotive Shredded Residue (ASR), usually disposed of in landfill. This paper summarizes the outcome of a study carried out by Politecnico di Milano and LEAP with the support of Actelios SpA on the prospects of a technology based on sequential gasification and combustion of this specific waste stream. Its application to the treatment of ASR allows the recovery of large fractions of metals as non-oxidized, easily marketable secondary raw materials, the vitrification of most of the ash content and the production of power via a steam cycle. Results show that despite the unfavourable characteristics of ASR, the proposed technology can reach appealing energy performances. Three of four environmental impact indicators and the cumulative energy demand index are favourable, the main positive contributes being electricity production and metal recovery (mainly aluminium and copper). The only unfavourable indicator is the global warming index because, since most of the carbon in ASR comes from fossil sources, the carbon dioxide emissions at the stack of the thermal treatment plant are mainly non-renewable and, at the same time, the avoided biogas production from the alternative disposal route of landfilling is minor.     

The impact of the electricity tariff reform on renewable energies and energy efficiency investments: The case of the Italian residential market

This article investigates the impact that the electricity tariff reform is likely to have on investments in renewable energies (i.e., photovoltaics) and the adoption of energy efficiency measures (i.e., installation of heat pumps and efficient home appliances) in the residential market in Italy. The study develops detailed cost comparisons and simulations considering two different investment scenarios (before and after the reform) to conclude that the reform will: (i) have a negative impact on investments in photovoltaic systems; (ii) favor the adoption of energy efficiency measures, such as efficient home appliances.     

A comparison of octanol-water partitioning between organic chemicals and their metabolites in mammals

Bioaccumulation models take various elimination and uptake processes into account, estimating rates from chemical lipophilicity, expressed as the octanol-water partition ratio (K_ow). Here, we focussed on metabolism, which transforms parent compounds into usually more polar metabolites, thus enhancing elimination. The aim of this study was to quantify the change in lipophilicity of relevant organic pollutants undergoing various biotransformation reactions in mammals. We considered oxidation reactions catalyzed by three enzyme groups: cytochrome P450 (CYP), alcohol dehydrogenase (ADH), and aldehyde dehydrogenase (ALDH). Estimated log K_ow values of a selected dataset of parent compounds were compared with the log K_ow of their first metabolites. The log K_ow decreased by a factor that varies between 0 and −2, depending on the metabolic pathway. For reactions mediated by CYP, the decrease in K_ow was one order of magnitude for hydroxylated and epoxidated compounds and two orders of magnitude for dihydroxylated and sulphoxidated xenobiotics. On the other hand, no significant change in lipophilicity was observed for compounds N-hydroxylated by CYP and for alcohols and aldehydes metabolized by ADH and ALDH. These trends could be anticipated by the calculus method of log K_ow. Yet, they were validated using experimental log K_ow values, when available. These relationships estimate the extent to which the elimination of pollutants is increased by biotransformation. Thus, the quantification of the K_ow reduction can be considered as a first necessary step in an alternative approach to anticipate biotransformation rates, which are hard to estimate with existing methods.     

Geographic distribution and environmental characterization of livestock production systems in Eastern Africa

The central role played by livestock in the livelihoods of rural households in the developing world is seldom fully appreciated by policy makers, development agencies and donors. Knowledge gaps in the geographic distribution and environmental determinants of farming systems, especially if viewed through the livestock lens, compound this problem. We have produced a map of pastoral, agro-pastoral and mixed farming systems across Eastern Africa, by analysing datasets collected in the framework of livelihood analysis. Input data were gathered between 2000 and 2007 by various emergency and development agencies for Djibouti, Eritrea, Kenya, Somalia, Uganda and parts of Ethiopia and Sudan. A quantitative definition of the production systems is adopted, based on the ratio of livestock- to crop-derived income. The resulting livelihood-based map of livestock production systems was compared through correspondence analysis to an alternative livestock production systems map, produced independently from environmental data. Convergence between the two mapping approaches was evident. The geographic distribution of the livestock production systems was also modelled using multivariate analysis of remotely sensed and other geospatial datasets. Models show high statistical accuracy, and were thus used to fill the gaps in the observed distribution of livestock production systems. Finally, selected environmental factors underpinning the systems (agro-climatology, human and livestock populations and land cover) were analysed in detail, enabling the livestock production systems to be characterized in terms of them. The regional scope of the map, as well as its direct link with a vast amount of livelihood information, render it a valuable tool for a range of development and research applications, including those related to global change.     

Photochemical behaviour of musk tibetene

BACKGROUND: Synthetic musk compounds are widely used as additives in personal care and household products. The photochemical degradation of musk tibetene in aqueous solutions or in acetonitrile/water mixtures under different conditions was studied in order to assess its environmental fate. METHODS: Musk tibetene dissolved (or suspended) in water and/or acetonitrile/water mixtures was irradiated at different times by UV-light and by solar light. The irradiation mixtures were analyzed by NMR and TLC. The photoproducts formed were identified by GC-MS and NMR data. RESULTS: The experimental results indicated that musk tibetene was photodegradable in water or acetonitrile/water mixtures with half-life reaction times close to 20 minutes. The irradiation mixtures were separated by chromatographic techniques yielding three photoproducts (3,3,5,6,7-pentamethyl-4-nitro-3H-indole, 3,3,5,6,7-pentamethyl-4-nitro-1H-indoline and 3,3,5,6,7-pentamethyl-4-nitro-3H-indolinone) identified by means of spectroscopic analysis. DISCUSSION: The numerical modelling of the photodegradation concentration-time profiles gave (8.13 +/- 0.15) x 10(-2) and (1.34 +/- 0.04) x 10(-2) mol/E for the overall primary quantum yield of direct photolysis for musk tibetene and the major intermediate (3,3,5,6,7-pentamethyl-4-nitro-3H-indolinone), respectively, in the wavelength range 305-366 nm. The half-life times of photodegradation of the both substances varied from 1-1.5 hours at 20 degrees N during the summer season to 6-10 hours for highest latitudes in winter. CONCLUSIONS: Under solar light, musk tibetene was photolabile in acetonitrile and acetonitrile/water 1/1, while it was slowly degraded when suspended in water. In all media, musk tibetene was photodegraded into three photoproducts. By using a kinetic model, the overall primary quantum yields of direct photolysis of musk tibetene and its main photoproduct, in the wavelength range 305-366 nm, were estimated, indicating that the photodegradation rate for musk tibetene is faster than the photolysis rate of the major by-product. RECOMMENDATIONS AND PERSPECTIVES: The results indicate that, in order to assess the environmental impact of musk tibetene on the aquatic ecosystem, great attention should be focused on the major photoproduct which is proved to be more persistent than the parent compound under light irradiation. The predicted half-life times of direct photolysis for both substances ranged from 1-1.5 hours at 20 degrees N during the summer season to about 6-10 hours for highest latitudes in winter, indicating that, from a photochemical point of view, the environmental persistence of these substances increases by increasing the latitudes and during the cold seasons, making more realistic an intake of these xenobiotic molecules into the food chain of aquatic living organisms. Tanabe reports in his Editorial (Tanabe 2005) that "It is necessary to have knowledge of the global picture of synthetic musk pathways. So, it is conceivable that now is the time to study the transport, persistency, distribution, bioaccumulation and toxic potential of this new environmental menace on a global scale, especially in developing countries". Therefore, the future environmental analysis and investigations on the eco-toxicity of nitro musk compounds should take into account not only the presence of the parent compounds but also their photochemical intermediates or end-by-products.     

Ecosystem services and hydroelectricity in Central America: modelling service flows with fuzzy logic and expert knowledge

Because ecosystem services are generally not produced and used in the same place, their assessment should consider the flows of services from ecosystems to users. These flows depend on the characteristics and spatial distribution of ecosystems and users, the spatial relationships between them, and the presence of filters or barriers between ecosystems and users. The objective of this paper is to map the ecosystem services provided to the Costa Rican and Nicaraguan hydroelectric sectors, which are crucial sectors for national sustainable development and depend directly on hydrological ecosystem services. The paper presents an approach for modelling the flows of multiple services from diverse ecosystems to diverse users through different kinds of filters in a landscape. The approach uses expert knowledge and fuzzy numbers to handle uncertainties. The analyses for Costa Rica and Nicaragua show how the approach helps identify priority areas for the conservation and restoration of forests for the services they provide to the hydroelectric sector. As such, it is a useful tool for defining spatially targeted policies for the conservation of ecosystem services and for involving the users of ecosystem services in ecosystem management.