Evaluation of long-term trends in hydrographic and nutrient parameters in a southeast US coastal river

The Nassau River estuary is located in northeast Florida adjacent to the eutrophic St. Johns River. Historically, development has been sparse in the Nassau River's catchment; thus, the system may provide a relatively undisturbed aquatic environment. To monitor the condition of the Nassau River estuary and to discern spatial and temporal trends in water quality, nutrients and hydrographic variables were assessed throughout the estuary from 1997 to 2011. Hydrographic (temperature, salinity, total suspended solids, and turbidity) and nutrient parameters (total phosphorus, ortho-PO₄ ^3?, total nitrogen, NH₄ ⁺, total Kjeldahl nitrogen, and NO₃ ^?) were monitored bimonthly at 12 sites in the mesohaline and polyhaline zones of the river. Nonparametric Kendall's Tau was implemented to analyze long-term water quality patterns. Salinity was found to increase with time, particularly in the mesohaline sampling sites. Dissolved oxygen decreased over time in the estuary and hypoxic conditions became increasingly frequent in the final years of the study. Nutrients increased in the estuary, ranging from 149 to 401 %. Rainfall data collected in adjacent conservation areas did not correlate well with nutrients as compared with stream discharge data collected in the basin headwaters, outside of the conservation lands, attributed here to expanding urbanization. During the study period, the Nassau basin underwent rapid human population growth and land development resulting in commensurate impacts to water quality. Nutrient and physical data collected during this study indicate that the Nassau River estuary is becoming more eutrophic with time.     

An investigation of environmental and sustainability discourses associated with the substantive purposes of environmental assessment

This paper investigates the discursive construction of the substantive purposes of environmental assessment (EA). It addresses these purposes by exploring the complex and often multifaceted linkages between political factors and plural views of democracy, public participation, and the role of science that are embedded in environmental and sustainability discourses. The interaction between policy-making and public actors leads to the formulation of divergent and potentially competing rationales for public participation, and for social appraisal more generally. Participatory approaches have also given impetus to the development of several interpretations on the role of science in assessment procedures. Science is important in mediating public participation and the two are therefore reciprocally linked. This leads to discourses that become manifest in the construction of substantive purposes. Discourse analysis in EA is a relevant method for examining trends and patterns in sustainable development. It is argued that public participation is an important, if not decisive, variable in the articulation and civil legitimacy of certain purposes. A general proposition that results from this paper is that EA, although typically presented as an objective scientific tool, is an intrinsically normative process. Enhanced knowledge on the construction, and reconstruction over time, of substantive purposes is required if environmental and sustainability discourses are to be used and understood as meaningful analytical instruments to assess the socio-political implications of EA.     

Discrimination between related and unrelated individuals in the Australian lizard Egernia striolata

We examined evidence for kin-related signal discrimination in the Australian scincid lizard Egernia striolata, using 41 juvenile lizards from 14 litters from a population in the Mount Lofty Ranges, South Australia. We characterised each juvenile at four polymorphic microsatellite DNA loci, determined genetic relatedness among pairs of juveniles, and assigned for each litter one other litter that was genetically closest and one other litter that was genetically most distant. Lizards responded significantly more strongly, with tongue flicks and time in contact, to skin secretion stimuli from more distant than genetically close, unfamiliar conspecific juveniles. When presented with an intruder, juvenile lizards basked for shorter periods when the intruder was more distantly related, and aggressive lizards directed more aggressive acts towards more distantly related than closely related conspecific intruders. We deduce from these results that there is kin recognition in juvenile E. striolata, and that they are able to discriminate related from unrelated individuals among unfamiliar conspecifics.     

Transport and attenuation of metal(loid)s in mine tailings amended with organic carbon: Column experiments

A laboratory-scale column experiment was conducted to evaluate the effect of organic carbon amendments on the mobility of As, Cu, Fe, Mn, Mo, Ni, Pb, Sb, Tl and Zn in mine tailings. Three columns were packed with sulfide- and carbonate-rich tailings, which were amended with a 1:1 (vol.) mixture of peat and spent brewing grain at proportions of 0, 2 and 5vol.%. A simulated input solution characterized by circumneutral pH and elevated concentrations of SO(4) and S(2)O(3) was passed through the columns for 540 days. The input solution contained low concentrations of metal(loid)s during the initial 300 days and elevated concentrations thereafter. Decreases in mass transport of S(2)O(3) were observed in all columns; with increased attenuation observed at 5 vol. % organic carbon content. Removal of Mn, Ni, Cu, Sb and Mo was observed in all columns during the initial 300 days. However, during this time, mobilization of Fe, As, Zn and Pb was observed, with the greatest increases in concentration observed at the higher organic carbon content. During the final 240 days, S(2)O(3) removal was enhanced in columns containing organic carbon, and Fe, Mn, Ni, Tl, As and Sb removal also was observed. This study demonstrates the influence of organic carbon amendments on metal(loid) mobility in mine tailings. Decreases in mass discharge of metal(loid)s may be achieved using this technique; however, site-specific geochemical conditions must be considered before field-scale implementation.     

Predictions of U.K. regulated power station contributions to regional air pollution and deposition: a model comparison exercise

Contributions of the emissions from a U.K. regulated fossil-fuel power station to regional air pollution and deposition are estimated using four air quality modeling systems for the year 2003. The modeling systems vary in complexity and emphasis in the way they treat atmospheric and chemical processes, and include the Community Multiscale Air Quality (CMAQ) modeling system in its versions 4.6 and 4.7, a nested modeling system that combines long- and short-range impacts (referred to as TRACK-ADMS [Trajectory Model with Atmospheric Chemical Kinetics-Atmospheric Dispersion Modelling System]), and the Fine Resolution Atmospheric Multi-pollutant Exchange (FRAME) model. An evaluation of the baseline calculations against U.K. monitoring network data is performed. The CMAQ modeling system version 4.6 data set is selected as the reference data set for the model footprint comparison. The annual mean air concentration and total deposition footprints are summarized for each modeling system. The footprints of the power station emissions can account for a significant fraction of the local impacts for some species (e.g., more than 50% for SO2 air concentration and non-sea-salt sulfur deposition close to the source) for 2003. The spatial correlation and the coefficient of variation of the root mean square error (CVRMSE) are calculated between each model footprint and that calculated by the CMAQ modeling system version 4.6. The correlation coefficient quantifies model agreement in terms of spatial patterns, and the CVRMSE measures the magnitude of the difference between model footprints. Possible reasons for the differences between model results are discussed. Finally, implications and recommendations for the regulatory assessment of the impact of major industrial sources using regional air quality modeling systems are discussed in the light of results from this case study.     

Dimensions and models of contemporary public space management in England

This article discusses the concept of public space management and its evolution in a context of wider changes to urban governance. Public space management is taken as a sphere of urban governance in which conflicting societal demands on, and aspirations for, public space are interpreted through a set of processes and practices. Four interlinked dimensions for public space management are proposed: the co-ordination of interventions; the regulation of uses and conflicts between uses; the definition and deployment of maintenance routines; and investment in public spaces and their services. Within this conceptual framework, the paper looks at recent changes in public space management in England to suggest the emergence of alternative models of management. These are based on the roles ascribed to the state, to private agents and to user organisations, and on different approaches to dealing with the four management dimensions. Although the discussion shows that these models are more than just abstract formulations, and have been used to deal with a variety of public space problems, an important purpose for the paper is to provide an analytical framework through which to examine emergent practices in the management of public space and their potential consequences.     

Organic aerosol source apportionment from highly time-resolved molecular composition measurements

Organic molecular composition measurements with 3.5 min time resolution were performed with the photoionization aerosol mass spectrometer (PIAMS) over an 18-day period in October–November 2007 in Wilmington, Delaware, USA. Mass spectra were obtained for a total of 6244 time periods, and the signal intensities of 60 specific m/z ratios corresponding to key organic molecular species were modeled by positive matrix factorization (PMF). Six factors were identified that could be tentatively linked to specific sources (diesel exhaust, car emissions/road dust, meat cooking) or types of compounds (alkanes/alkanoic acids, phthalates, PAHs). Owing to the inherent high time resolution of PIAMS, the temporal (diurnal) and wind direction dependencies of these factors could be examined in detail to assess the impacts of point sources and atmospheric processes. Time-resolved EC/OC and gas-phase data (O₃, NO_x, CO) were also obtained during the measurement period to help distinguish primary (POC) and secondary (SOC) organic carbon. The total organic carbon (TOC) concentration averaged 2.6 μg m^?3 during the measurement period and most (>90%) was classified as primary. Of this, approximately one-third could be assigned as combustion POC and the other two-thirds as non-combustion POC. The PMF results were combined with EC/OC data for source apportionment. The diesel and car/road dust factors together represented about two-thirds of TOC, while the alkane/alkanoic acid and meat cooking factors contributed most of the remaining one-third. The phthalate and PAH factors contributed very little, only a few percent of the total. The diesel factor correlated most strongly to combustion POC, while the sum of the remaining factors correlated well with non-combustion POC.     

Perceptions of climate change on the Island of Providencia

Climate change-related impacts have the capacity to substantially influence Small Island Developing States (SIDS) in the Caribbean. Currently, many SIDS are engaged in large-scale vulnerability assessments that aim to identify, analyse, and inform solutions to mitigate climate change-related impacts. Many of these assessments, while useful, place little emphasis on the local stakeholders' perceptions of climate change. One such Caribbean community impacted by climate-related change is Providence Island in Colombia. Using a vulnerability assessment framework (Marshall, P.A. et al. 2010. A framework for social adaptation to climate change: sustaining tropical coastal communities and industries. Gland: IUCN Publication Services), researchers interviewed island residents (N = 23) about their perceptions of climate change, impacts on the local environment, and how the island community may adapt. All interviews were transcribed and analysed using a priori and open coding to identify patterns of and relationships between stakeholders' responses. Results indicate that local perceptions of climate change are linked to (1) environmental knowledge, (2) environmental awareness, attitudes, and beliefs, and (3) perceptions of risk. Implications for local adaptive strategies, education, communication, and suggestions for engagement at the local level are discussed.     

Sea Cucumber Aquaculture in the Western Indian Ocean: Challenges for Sustainable Livelihood and Stock Improvement

The decline in sea cucumber fisheries that serve the Asian dried seafood market has prompted an increase in global sea cucumber aquaculture. The tropical sandfish (Holothuria scabra) has, in this context, been reared and produced with mixed success. In the Western Indian Ocean, villagers often participate in the export fishery for sea cucumbers as a source of income. However, with a growing concern of depleted stocks introduction of hatcheries to farm sandfish as a community livelihood and to replenish wild stocks is being promoted. This review identifies and discusses a number of aspects that constitute constraints or implications with regard to development of sandfish farming in the region. The conclusion is that for sandfish farming to live up to its expectations the possible impacts need to be further studied, and that improved evaluation of ongoing projects is required. In the interim, a precautionary approach toward new enterprise activities is suggested.