Behavioral type–environment correlations in the field: a study of three-spined stickleback

Behavioral type–environment correlations occur when specific behavioral types of individuals are more common in certain environments. Behavioral type–environment correlations can be generated by several different mechanisms that are probably very common such as niche construction and phenotypic plasticity. Moreover, behavioral type–environment correlations have important ecological and evolutionary implications. However, few studies have examined behavioral type–environment correlations in natural populations. In this study, we asked whether some behavioral types of three-spined stickleback were more likely to occur in certain social environments (alone or in a shoal with other stickleback) or in certain microhabitats in a river (in the open or under cover). We found that individuals that were in shoals with other stickleback at the time of collection from the field emerged from a refuge more quickly compared to individuals that were found alone. In addition, fish that were alone in an open microhabitat explored more of a pool compared to fish that were alone in cover, but this difference did not occur among fish that were in shoals at the time of collection. Subsequent analyses of gut contents suggested that differences in microhabitat use were consistent over time. Our study provides some of the first evidence for behavioral type–environment correlations in a natural population of non-human animals.     

Identifying source correlation parameters for hydrocarbon wastes using compound-specific isotope analysis

A preliminary evaluation of compound-specific isotope analysis (CSIA) as a novel, alternative method for identifying source correlation compounds in soils contaminated with residual heavy or weathered petroleum wastes is presented. Oil-contaminated soil microcosms were established using soil (sandy-loam, non-carbonaceous cley) amended with ballast-, crude- or No.6 fuel oil. Microcosms were periodically sampled over 256 days and delta(13)C values (which express the ratio of (13)C to (12)C) determined at each time point for five n-alkanes and the isoprenoid norpristane using gas chromatography-isotope ratio mass spectrometry (GC-IRMS). Although some temporal variation was observed, no significant temporal shifts in the delta(13)C values for the five n-alkanes were measured in all three oils. Isoprenoid isotope ratios (delta(13)C) appeared to be least affected by biotransformation, especially in the No.6 fuel oil. The research suggests that the delta(13)C of isoprenoids such as norpristane, may be of use as source correlation parameters.     

Evaluating fugacity models for trace components in landfill gas

A fugacity approach was evaluated to reconcile loadings of vinyl chloride (chloroethene), benzene, 1,3-butadiene and trichloroethylene in waste with concentrations observed in landfill gas monitoring studies. An evaluative environment derived from fictitious but realistic properties such as volume, composition, and temperature, constructed with data from the Brogborough landfill (UK) test cells was used to test a fugacity approach to generating the source term for use in landfill gas risk assessment models (e.g. GasSim). SOILVE, a dynamic Level II model adapted here for landfills, showed greatest utility for benzene and 1,3-butadiene, modelled under anaerobic conditions over a 10 year simulation. Modelled concentrations of these components (95,300 microg m(-3); 43 microg m(-3)) fell within measured ranges observed in gas from landfills (24,300-180,000 microg m(-3); 20-70 microg m(-3)). This study highlights the need (i) for representative and time-referenced biotransformation data; (ii) to evaluate the partitioning characteristics of organic matter within waste systems and (iii) for a better understanding of the role that gas extraction rate (flux) plays in producing trace component concentrations in landfill gas.     

Managing Water Stress: The Logic of Demand Side Infrastructure Planning

Management of water supply in Britain is increasingly facing up to the problems posed by supply-led strategies. Although the eradication of water stress has traditionally been viewed as a techno-managerial problem, with supply being increased to meet rising demand, this is no longer possible as a general solution. Pressures both from government and from voluntary bodies are leading to approaches which manage the level of demand, and which recognize that water may, for various reasons, be in relatively short supply. The issues are illustrated by a case study of a recent tourist development, in which demand side management measures were extensively utilized.