Distribution and sources of polyfluoroalkyl substances (PFAS) in the River Rhine watershed

The concentration profile of 40 polyfluoroalkyl substances (PFAS) in surface water along the River Rhine watershed from the Lake Constance to the North Sea was investigated. The aim of the study was to investigate the influence of point as well as diffuse sources, to estimate fluxes of PFAS into the North Sea and to identify replacement compounds of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). In addition, an interlaboratory comparison of the method performance was conducted. The PFAS pattern was dominated by perfluorobutane sulfonate (PFBS) and perfluorobutanoic acid (PFBA) with concentrations up to 181 ng/L and 335 ng/L, respectively, which originated from industrial point sources. Fluxes of ΣPFAS were estimated to be ∼6 tonnes/year which is much higher than previous estimations. Both, the River Rhine and the River Scheldt, seem to act as important sources of PFAS into the North Sea.     

Synthesis of polychlorinated [14C]alkanes (PCA) of high specific activity

The synthesis of certain ¹⁴C-labelled polychlorinated alkanes is described. The compounds used as starting material were [1-¹⁴C]lauric acid, [1-¹⁴C]hexadecane and [U-¹⁴C]palmitic acid. The carboxylic acids were reduced with lithium aluminium hydride. The alcohol obtained was treated with triphenylphosphine dichloride which gave the corresponding 1-chloroalkane. The chlorination of the alkanes was performed in tetrachloromethane by use of sulphuryl chloride with benzoyl peroxide or UV-light as initiators. Three mixtures of polychlorinated dodecanes (45.9%, 55.9% and 68.5% chlorine) and two polychlorinated hexadecanes (34.1% and 69% chlorine) were synthesized. The products of higher chlorine content prepared were only available via the photoinduced chlorination.     

The species flocks of East African cichlid fishes: recent advances in molecular phylogenetics and population genetics

With more than 3,000 species, the fish family Cichlidae is one of the most species-rich families of vertebrates. Cichlids occur in southern and central America, Africa, Madagascar, and India. The hotspot of their biodiversity is East Africa, where they form adaptive radiations composed of hundreds of endemic species in several lakes of various sizes and ages. The unparalleled species richness of East African cichlids has been something of a conundrum for evolutionary biologists and ecologists, since it has been in doubt whether these hundreds of species arose by allopatric speciation or whether it is necessary to invoke somewhat less traditional models of speciation, such as micro-allopatric, peripatric, or even sympatric speciation or evolution through sexual selection mediated by female choice. Ernst Mayrs analyses of these evolutionary uniquely diverse species assemblages have contributed to a more direct approach to this problem and have led to a deeper understanding of the patterns and processes that caused the formation of these huge groups of species. We review here recent molecular data on population differentiation and phylogenetics, which have helped to unravel, to some extent, the patterns and processes that led to the formation and ecological maintenance of cichlid species flocks. It is becoming apparent that sexually selected traits do play an important role in speciation in micro-allopatric or even sympatric settings. Species richness seems to be roughly correlated with the surface area, but not the age, of the lakes. We observe that the oldest lineages of a species flock of cichlids are often less species-rich and live in the open water or deepwater habitats. While the species flocks of the Lake Malawai and the Lake Victoria areas were shown to be monophyletic, the cichlid assemblage of Lake Tanganyika seems to consist of several independent species flocks. Cichlids emerge as an evolutionary model system in which many fundamental questions in evolution and ecology can be tested successfully, yet for other fish species flocks the relative importance of alternative mechanisms of speciation is likely to differ from that in cichlid fish.Dedicated to Prof. Ernst Mayr     

Mitigation Options for Enteric Methane Emissions from Dairy Animals: An Evaluation for Potential CDM Projects in India

Enteric fermentation in livestock is an important source of anthropogenic methane emission. India, with its large livestock population, is estimated to contribute 10.8 Tg of methane annually from this source. An evaluation of various methane mitigation options indicate that some of the available technologies like, diet supplementation with feed additive and molasses urea product are highly cost effective in reducing enteric methane emissions. The gross cost of methane abatement from use of feed additive monensin premix ranges from €0.6 to €1.8/ton CO₂ equivalent, for buffaloes and indigenous cows, respectively. The gross cost of enteric methane mitigation from supplementing molasses urea products and dietary manipulation through increased concentrate feeding is much higher. But, as the monetary value of the increased milk production on application of these technologies was higher than the annual cost of reduction strategy for buffaloes and crossbred cows, the net costs of the former mitigation option was negative for buffaloes (€-28.1/ton CO₂) and of the latter for crossbred cows (€-7.0/ton CO₂,). The availability of cost-effective technologies suggest that the methane mitigation projects under CDM, can be planned in the Indian dairy sector to the mutual benefit of countries with emission targets and India. The vast dairy animal population of India and resulting methane emissions provide good opportunity these countries to buy reasonable quantum of emission credits from projects in India. Such projects will work to the benefit to India by providing a tool for technology transfer to increase animal productivity and attract capital that assists in more prosperous and environmental friendly milk production in the country.     

Better regulation by new governance hybrids? Governance models and the reform of European chemicals policy

The EU is presently in a transition phase from environmental policy-making by law towards other governance approaches based upon networking, voluntary commitments, benchmarking and other forms of “soft law”. Those new governance approaches often claim to lead to “better regulation”, while adopting a more consensus-oriented and participatory style, taking economic aspects more seriously into account, allowing for more flexibility and autonomy for the private sector and Member States alike, mobilising a broader knowledge base or adopting more integrated and holistic approaches than previous sectoralised and compartmentalised policies.While the limitations of traditional regulatory approaches are widely accepted and cited, it is far from evident, that “new modes of governance” have greater capacity to solve problems than the old ones. There is an argument, that “better regulation” might by synonymous to a withdrawal and weakening of the regulatory state and hence effectively of the aspirations and objectives of environmental policies.An interesting case for an approach, combining the strengths of the old and the new approaches is the ongoing reform of chemicals policies. While some observers claim, that the proposed directive, “REACH” might belong to the outdated category of overcomplex and bureaucratic regulation, a closer look shows that there are many new forms of governance in REACH. This mixture or old and new may open a more realistic and promising perspective on the reform of European policy-making.In our paper we assess the effects and the interplay of the combination of different modes of governance using the example of REACH. We are particularly concerned with the question in how far the representation of interests may change when new modes of governance are introduced.     

Hidden Markov models for circular and linear-circular time series

We introduce a new class of circular time series based on hidden Markov models. These are compared with existing models, their properties are outlined and issues relating to parameter estimation are discussed. The new models conveniently describe multi-modal circular time series as dependent mixtures of circular distributions. Two examples from biology and meteorology are used to illustrate the theory. Finally, we introduce a hidden Markov model for bivariate linear-circular time series and use it to describe larval movement of the fly Drosophila. Received: September 2003 / Revised: March 2004     

CDM potential of SPV lighting systems in India

In view of the increasing interest in the development and dissemination of technologies for harnessing new and renewable sources of energy in India, there have also been some efforts towards their use in the domestic lighting sector. However, the cumulative number of Solar Photovoltaic (SPV) lighting systems such as SPV lanterns and solar home lighting systems in India is far below their theoretical potential despite government subsidy programmes. One of the major barriers is the high capital investment in these systems. The Clean Development Mechanism (CDM) provides industrialized countries with an incentive to invest in emission reduction projects in developing countries to achieve a reduction in CO₂ emissions at lowest cost that also promotes sustainable development in the host country. SPV lanterns and solar home lighting systems could be of interest under the CDM because they directly displace greenhouse gas emissions while contributing to sustainable rural development. However, only two SPV projects have been submitted under the CDM so far. This study assesses the maximum theoretical as well as the realistically achievable CDM potential of SPV lanterns and solar home lighting systems in India. The SPV lantern project is financially viable at a certified emissions reductions (CER) price of 34 € whereas the solar home lighting project is financially viable at a CER price of 46 €. While the maximum mitigation volume is about 35 million tonne CO₂ on an annual basis, an estimate of achievable CER levels is done using the past diffusion trends of SPV systems. We find that annual CER volumes could reach 0.8 to 2.4 million by 2012 and 5.6 to 13.6 million by 2020. This would require that the government sets the subsidy level for SPV lighting systems at a level that allows them to become viable with the CER revenue. From a macro-economic point of view this makes sense if the sustainability benefits are deemed sufficiently high to warrant promotion of this type of project.