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Urban areas are the primary habitat for a majority of the global population. The development of cities not only entails a fundamental change in human settlement patterns but also a dramatic transformation of the physical environment. Thus, urban areas and their development are at the centre of all discussions on sustainability and/or sustainable development. This review essay introduces the notion of Urban Metabolism (UM), a term that provides a conceptual framework to study how a city functions, and hence, a way to address the sustainability issue of a city. Due to the significance and scope of the subject, the notion of UM is interpreted and thus approached differently across diverse disciplines from both the natural and social science fields. In order to comprehend the commonalities and controversies between them, the present review also briefly introduces the historical roots of the term. This review reveals the increasing significance of a rich and rapidly evolving field of research on the metabolism of urban areas.

The deuterium excess of polar ice cores documents past changes in evaporation conditions and moisture origin. New data obtained from the European Project for Ice Coring in Antarctica Dome C East Antarctic ice core provide new insights on the sequence of events involved in Termination II, the transition between the penultimate glacial and interglacial periods. This termination is marked by a north–south seesaw behavior, with first a slow methane concentration rise associated with a strong Antarctic temperature warming and a slow deuterium excess rise. This first step is followed by an abrupt north Atlantic warming, an abrupt resumption of the East Asian summer monsoon, a sharp methane rise, and a CO 2 overshoot, which coincide within dating uncertainties with the end of Antarctic optimum. Here, we show that this second phase is marked by a very sharp Dome C centennial deuterium excess rise, revealing abrupt reorganization of atmospheric circulation in the southern Indian Ocean sector.

Made available in DSpace on 2018-12-11T17:29:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-10-19 Terrestrial mammals are experiencing a massive collapse in their population sizes and geographical ranges around the world, but many of the drivers, patterns and consequences of this decline remain poorly understood. Here we provide an analysis showing that bushmeat hunting for mostly food and medicinal products is driving a global crisis whereby 301 terrestrial mammal species are threatened with extinction. Nearly all of these threatened species occur in developing countries where major coexisting threats include deforestation, agricultural expansion, human encroachment and competition with livestock. The unrelenting decline of mammals suggests many vital ecological and socio-economic services that these species provide will be lost, potentially changing ecosystems irrevocably. We discuss options and current obstacles to achieving effective conservation, alongside consequences of failure to stem such anthropogenic mammalian extirpation. We propose a multipronged conservation strategy to help save threatened mammals from immediate extinction and avoid a collapse of food security for hundreds of millions of people. GlobalTrophic Cascades Department of Forest Ecosystems and Society Oregon State University Forest Biodiversity Research Network Department of Forest Ecosystems and Society Oregon State University Department of Fisheries and Wildlife Oregon State University School of Natural Sciences University of Stirling Institut de Recherche en Ecologie Tropicale CENAREST Grims�Wildlife Research Station Department of Ecology Swedish University of Agricultural Sciences Department of Biology Stanford University Universidade Estadual Paulista (UNESP) Instituto Bioci�ncias Departamento de Ecologia Department of Bioscience Ecoinformatics and Biodiversity Aarhus University Panthera, 8 West 40th Street, 18th Floor Mammal Research Institute Department of Zoology and Entomology University of Pretoria Wildlife Conservation Research Unit Department of Zoology University of Oxford The Recanati-Kaplan Centre, Tubney House Department of Biological Sciences Florida International University School of Life and Environmental Sciences Centre for Integrative Ecology Deakin University, Burwood campus School of Life and Environmental Sciences The University of Sydney School of Environmental and Forest Sciences University of Washington School of Environmental Sciences University of East Anglia Centre for Compassionate Conservation School of Life Sciences University of Technology Sydney, PO Box 123 Broadway Universidade Estadual Paulista (UNESP) Instituto Bioci�ncias Departamento de Ecologia

Arctic Ocean primary productivity is limited by light and inorganic nutrients. With sea ice cover declining in recent decades, nitrate limitation has been speculated to become more prominent. Although much has been learned about nitrate supply from general patterns of ocean circulation and water column stability, a quantitative analysis requires dedicated turbulence measurements that have only started to accumulate in the last dozen years. Here we present new observations of the turbulent vertical nitrate flux in the Laptev Sea, Baffin Bay, and Young Sound (North-East Greenland), supplementing a compilation of 13 published estimates throughout the Arctic Ocean. Combining all flux estimates with a Pan-Arctic database of in situ measurements of nitrate concentration and density, we found the annual nitrate inventory to be largely determined by the strength of stratification and by bathymetry. Nitrate fluxes explained the observed regional patterns and magnitudes of both new primary production and particle export on annual scales. We argue that with few regional exceptions, vertical turbulent nitrate fluxes can be a reliable proxy of Arctic primary production accessible through autonomous and large-scale measurements. They may also provide a framework to assess nutrient limitation scenarios based on clear energetic and mass budget constraints resulting from turbulent mixing and freshwater flows.

Diatoms exist in almost every aquatic regime; they are responsible for ∼20% of global carbon fixation and ∼25% of global primary production, and are regarded as a key food for copepods, which are subsequently consumed by larger predators such as fish and marine mammals. A decreasing abundance and a vulnerability to climatic change in the North Atlantic Ocean have been reported in the literature. In the present work, a data matrix composed of concurrent satellite remote sensing and Continuous Plankton Recorder (CPR) in situ measurements was collated for the same spatial and temporal coverage in the Northeast Atlantic. Artificial neural networks (ANNs) were applied to recognize and learn the complex non-monotonic and non-linear relationships between diatom abundance and spatiotemporal environmental factors. Because of their ability to mimic non-linear systems, ANNs proved far more effective in modelling the diatom distribution in the marine ecosystem. The results of this study reveal that diatoms have a regular seasonal cycle, with their abundance most strongly influenced by sea surface temperature (SST) and light intensity. The models indicate that extreme positive SSTs decrease diatom abundances regardless of other climatic conditions. These results provide information on the ecology of diatoms that may advance our understanding of the potential response of diatoms to climatic change.

The effects of unnatural disturbances on the behaviour and energetics of animals are an important issue for conservation and commercial animal production. Biologging enables estimation of the energy costs of these disturbances, but not specifically the effect these costs have on growth; a key outcome measure for animal farming enterprises. We looked at how natural and anthropogenically induced activity and energy expenditure of king scallops Pecten maximus varies with temperature. These data were then used to model growth time of king scallops reared in an aquaculture facility under different temperatures and anthropogenic disturbance levels. The scallops exhibited a typical total metabolic rate (MR)-temperature curve, with a peak reached at a middling temperature. The percentage of their total MR associated with spinning and swimming, behavioural responses to disturbance, was considerable. Interestingly, as temperature increased, the activity MR associated with a given level of activity decreased; a hitherto unreported relationship in any species. The model results suggest there is a trade-off in the ambient temperature that should be set by hatcheries between the optimal for scallop growth if completely undisturbed versus mitigating against the energy costs elicited by anthropogenic disturbance. Furthermore, the model indicates that this trade-off is affected by scallop size. Aquaculture facilities typically have controls to limit the impact of human activities, yet the present data indicate that hatcheries may be advised to consider whether more controls could further decrease extraneous scallop behaviours, resulting in enhanced scallop yields and improved financial margins.

Climate change is currently one of the main driving forces behind changes in species distributions, and understanding the mechanisms that underpin macroecological patterns is necessary for a more predictive science. Warming sea water temperatures are expected to drive changes in ectothermic marine species ranges due to their thermal tolerance levels. Here, we develop a mechanistic tool to predict size- and season-specific distributions based on the physiology of the species and the temperature and food conditions in the sea. The effects of climate conditions on physiological-based habitat utilization was then examined for different size-classes of two commercially important fish species in the North Sea, plaice, Pleuronectes platessa, and sole, Solea solea. The two species provide an attractive comparison as they differ in their physiology (e.g. preferred temperature range). Combining dynamic energy budget (DEB) models with the temperature and food conditions estimated by an ecosystem model (ERSEM), allowed spatial differences in potential growth (as a proxy for habitat quality) to be estimated for 2 similar to years with contrasting temperature and food conditions. The resulting habitat quality maps were in broad agreement with observed ontogenetic and seasonal changes in distribution as well as with the recent changes in distribution which could be attributed to an increase in coastal temperatures. Our physiological-based model provides a powerful tool to explore the effect of climate change on the spatio-temporal fish dynamics, predict effects of local or broad-scale environmental changes and provide a physiological basis for observed changes in species distributions.

The Common Fisheries Policy in the Mediterranean has been so far based on technical measures that have been relatively stable for a long time, and it did not prevent the efficiency increase in both vessels and gears that have counterbalanced the fleet reduction. The new Multiannual Plan for Demersal fish stocks in the western Medi-terranean Sea introduces a fishing effort regime as a new approach to reduce significantly fishing time, allowing stocks to approach MSY in the medium term. However, different approaches to reduce fishing time may have different socio-economic impacts that have to be considered. The reduction of fishing time has to be com-plemented with selectivity improvements, temporal and permanent closures and local co-management plans to protect both juveniles and spawners. The combination of several measures will soften the need for effort reduction and it will contribute significantly to the sustainability of Mediterranean Fisheries. Sí