19th century London dust-yards: A case study in closed-loop resource efficiency

The material recovery methods used by dust-yards in early 19th century London, England and the conditions that led to their development, success and decline are reported. The overall system developed in response to the market value of constituents of municipal waste, and particularly the high coal ash content of household ‘dust’. The emergence of lucrative markets for ‘soil’ and ‘breeze’ products encouraged dust-contractors to recover effectively 100% of the residual wastes remaining after readily saleable items and materials had been removed by the thriving informal sector. Contracting dust collection to the private sector allowed parishes to keep the streets relatively clean, without the need to develop institutional capacity, and for a period this also generated useful income. The dust-yard system is, therefore, an early example of organised, municipal-wide solid waste management, and also of public–private sector participation. The dust-yard system had been working successfully for more than 50 years before the Public Health Acts of 1848 and 1875, and was thus important in facilitating a relatively smooth transition to an institutionalised, municipally-run solid waste management system in England. The dust-yards can be seen as early precursors of modern materials recycling facilities (MRFs) and mechanical–biological treatment (MBT) plants; however, it must be emphasised that dust-yards operated without any of the environmental and occupational health considerations that are indispensable today. In addition, there are analogies between dust-yards and informal sector recycling systems currently operating in many developing countries.     

Heterozygosity‐Fitness Correlations and Inbreeding Depression in Two Critically Endangered Mammals

The relation among inbreeding, heterozygosity, and fitness has been studied primarily among outbred populations, and little is known about these phenomena in endangered populations. Most researchers conclude that the relation between coefficient of inbreeding estimated from pedigrees and fitness traits (inbreeding‐fitness correlations) better reflects inbreeding depression than the relation between marker heterozygosity and fitness traits (heterozygosity‐fitness correlations). However, it has been suggested recently that heterozygosity‐fitness correlations should only be expected when inbreeding generates extensive identity disequilibrium (correlations in heterozygosity and homozygosity across loci throughout the genome). We tested this hypothesis in Mohor gazelle (Gazella dama mhorr) and Iberian lynx (Lynx pardinus). For Mohor gazelle, we calculated the inbreeding coefficient and measured heterozygosity at 17 microsatellite loci. For Iberian lynx, we measured heterozygosity at 36 microsatellite loci. In both species we estimated semen quality, a phenotypic trait directly related to fitness that is controlled by many loci and is affected by inbreeding depression. Both species showed evidence of extensive identity disequilibrium, and in both species heterozygosity was associated with semen quality. In the Iberian lynx the low proportion of normal sperm associated with low levels of heterozygosity was so extreme that it is likely to limit the fertility of males. In Mohor gazelle, although heterozygosity was associated with semen quality, inbreeding coefficient was not. This result suggests that when coefficient of inbreeding is calculated on the basis of a genealogy that begins after a long history of inbreeding, the coefficient of inbreeding fails to capture previous demographic information because it is a poor estimator of accumulated individual inbreeding. We conclude that among highly endangered species with extensive identity disequilibrium, examination of heterozygosity‐fitness correlations may be an effective way to detect inbreeding depression, whereas inbreeding‐fitness correlations may be poor indicators of inbreeding depression if the pedigree does not accurately reflect the history of inbreeding. Correlaciones Heterocigosidad‐ Adaptabilidad y Depresión Endogámica en Dos Especies de Mamíferos Críticamente en Peligro     

Environmental quality assessment combining sediment metal levels, biomarkers and macrobenthic communities: application to the óbidos coastal lagoon (Portugal)

Macroinvertebrate benthic communities are one of the key biological components considered for the assessment of benthic integrity in the context of the Water Framework Directive (WFD). However, under moderate contamination scenarios, the assessment of macrobenthic alterations at community level alone could be insufficient to discriminate the environmental quality of coastal and transitional waters. Keeping this in view, sediment quality of moderately contaminated sites in a coastal lagoon (óbidos lagoon, Portugal) was assessed by the combination of sediment metal levels, Carcinus maenas biomarkers (accumulated metals and oxidative stress responses) and macrobenthic communities. Two sites were selected in confined inner branches (BS and BB) and a third one in the middle lagoon (ML). The site BB presented slightly higher levels of metals in sediment but biological variables calculated for macrobenthic data were not significantly different between sites. The biotic index M-AMBI that is being applied to assess environmental quality of transitional waters in the scope of the WFD pointed either to high (site ML) or good quality status (BS and BB) in the selected sites. However, crabs from BB site presented significantly higher levels of Ni in hepatopancreas than those from ML and macrobenthic community structure was significantly different between BB and ML. Additionally, spatial differences were obtained for oxidative stress parameters suggesting that BB site presented stressors for crabs (higher GST and lower GSH_t at BB site). Factor analysis (PCA) integrating sediment contamination, biomarkers in crabs and macrobenthic data also distinguished BB site as the most environmentally disturbed. On the other hand, at ML site, some macrobenthic variables (equitability and polychaetes’ diversity) were found to be enhanced by current environmental conditions, suggesting the existence of a better sediment quality. Current results pointed to the usefulness of integrating macrobenthic community alterations with responses at organism level (bioaccumulation and biochemical endpoints) in order to increase the accuracy of environmental quality assessment in lagoon systems. Moreover, the application of different statistical methods was also found to be recommendable.     

NOAA satellite data: a useful tool for macro inventory

This article discusses some of the demonstrated and potential uses of data from satellites with large fields of view and high frequency of coverage, such as NOAA AVHRR data and Nimbus-7 CZCS data. The use of such data is discussed for three types of applications: (a) stratification, (b) change detection, and (c) area estimation. It is concluded that such data have considerable promise as an aid to a variety of large-area inventory and monitoring tasks.     

Cadmium uptake by the water hyacinth: Effects of root mass,solution volume,complexers and other metal ions1

At a fixed Cd²⁺ concentration water hyacinth ($\text{Eichhornia crassipes}$) plants with greater root mass (dry weight) take up more metal ions as a function of time, and more metal ions are taken up by a plant as the solution volume is increased. Experiments in which several different metal ion complexers were present suggest that (1) the roots possess sites which initially reversibly bind free Cd²⁺, (2) some added complexers can compete with these root sites for free Cd²⁺, and (3) with time Cd²⁺ bound to the roots is translocated into into the root tissues effectively removing it from the equilibrium processes in solution. Many metal ions are taken up by the plant but only the micronutrient Zn²⁺ competes well with Cd²⁺ for uptake. Thus, there may be binding sites on the roots for specific metal ions.