δ<Superscript>13</Superscript>C and δ<Superscript>15</Superscript>N values in reef corals <Emphasis Type="Italic">Porites lutea</Emphasis> and <Emphasis Type="Italic">P. cylindrica</Emphasis> and in their epilithic and endolithic algae

In summer 1998, shallow water corals at Sesoko Island, Japan (26°38′N, 127°52′E) were damaged by bleaching. In August 2003, partially damaged colonies of the massive Porites lutea and the branching P. cylindrica were collected at depths of 1.0–2.5 m. The species composition of epilithic algal communities on dead skeletal surfaces of the colonies (‘red turfs’, ‘green turfs’, ‘red crusts’) and the endolithic algae (living in coral skeletons) growing close to and away from living coral polyps was determined. Carbon and nitrogen stable isotope values of organic matter (δ¹³C and δ¹⁵N) from all six of these biological entities were determined. There were no significant differences in the isotope composition of coral tissues of the two corals, with P. lutea having δ¹³C of −15.3 to −9.6‰ and δ¹⁵N of 4.7–6.1‰ and P. cylindrica having similar values. Polyps in both species living close to an interface with epilithic algae had similar isotope values to polyps distant from such an interface. Despite differences in the relative abundance of the algal species in red turfs and crusts, their δ¹³C and δ¹⁵N values were not significantly different from each other (−18.2 to −13.9, −20.6 to −16.2, 1.1–4.3, and 3.3 to 4.9‰, respectively). The green algal turf had significantly higher δ¹³C values (−14.9 to −9.3‰) than that of red turfs and crusts but similar δ¹⁵N (1.2–4.1‰) to the red algae. The data do not suggest that adjoining associations of epilithic algae and coral polyps exchange carbon- and nitrogen-containing metabolites to a significant extent. The endolithic algae in the coral skeletons had δ¹³C values of −14.8 to −12.3‰ and δ¹⁵N of 4.0–5.4‰. Thus they did not differ significantly from the coral polyps in their carbon and nitrogen isotope values. The similarity in carbon isotope values between the coral polyps and endolithic algae may be attributed to a common source of CO₂ for zooxanthellae and endolithic algae, namely, from respiration by the coral host. While it is difficult to fully interpret similarity in the nitrogen isotope composition of coral tissue and of green endolithic algae and the difference in δ¹⁵N between green epilithic and endolithic algae, the data are consistent with nitrogen-containing metabolites from the scleractinian coral serving as a significant source of nitrogen for the endolithic algae.     

Reactive nitrogen and the world: 200 years of change

This paper examines the impact of food and energy production on the global N cycle by contrasting N flows in the late-19th century with those of the late-20th century. We have a good understanding of the amounts of reactive N created by humans, and the primary points of loss to the environment. However, we have a poor understanding of nitrogen's rate of accumulation in environmental reservoirs, which is problematic because of the cascading effects of accumulated N in the environment. The substantial regional variability in reactive nitrogen creation, its degree of distribution, and the likelihood of increased rates of reactive-N formation (especially in Asia) in the future creates a situation that calls for the development of a Total Reactive Nitrogen Approach that will optimize food and energy production and protect environmental systems.     

Source apportionment of polycyclic aromatic hydrocarbons in Lake Baikal water and adjacent air layer

The composition of polycyclic aromatic hydrocarbons (PAHs) in Lake Baikal water and adjacent air layer and PAH emission composition profiles of possible sources were investigated. Analysis of emission composition data showed that the source profiles could not be grouped by fuel type or pyrogenic/petrogenic origin. Because of the similarity of source PAH profiles, the drawing of 3D mixing diagrams was the only way to check whether some of the potential PAH sources were the true sources. The mixing diagrams showed that the sources of air pollution were paper mills and wood burning and that the sources of water pollution were coal-fired and oil-fired boilers. The common source for both air and water was only oil and petroleum products. To determine the locations of PAH sources, their contributions to air and water pollution were calculated and mapped. Based on the results, air and water were polluted from both local and regional sources. The location of the zone influenced by a particular source was conditioned by physical properties of source emission, direction of air/water flows that transfer PAHs and temperature differences between mixing air/water flows.     

Calcite precipitates in Slovenian bottled waters

Storage of bottled waters in varying ambient conditions affects its characteristics. Different storage conditions cause changes in the initial chemical composition of bottled water which lead to the occurrence of precipitates with various morphologies. In order to assess the relationship between water composition, storage conditions and precipitate morphology, a study of four brands of Slovenian bottled water stored in PET bottles was carried out. Chemical analyses of the main ions and measurements of the physical properties of water samples were performed before and after storage of water samples at different ambient conditions. SEM/EDS analysis of precipitates was performed after elapsed storage time. The results show that the presence of Mg²⁺, SO₄ ²⁻, SiO₂, Al, Mn and other impurities such as K⁺, Na⁺, Ba and Sr in the water controlled precipitate morphology by inhibiting crystal growth and leading to elongated rhombohedral calcite crystal forms which exhibit furrowed surfaces and calcite rosettes. Different storage conditions, however, affected the number of crystallization nuclei and size of calcite crystals. Hollow calcite spheres composed of cleavage rhombohedrons formed in the water with variable storage conditions by a combination of evaporation and precipitation of water droplets during high temperatures or by the bubble templating method.

     

Typologizing Stakeholder Information Use to Better Understand the Impacts of Collaborative Climate Science

There is increasing interest among scholars in producing information that is useful and usable to land and natural resource managers in a changing climate. This interest has prompted transitions from scientist- to stakeholder-driven or collaborative approaches to climate science. A common indicator of successful collaboration is whether stakeholders use the information resulting from the projects in which they are engaged. However, detailed examples of how stakeholders use climate information are relatively scarce in the literature, leading to a challenge in understanding what researchers can and should expect and plan for in terms of stakeholder use of research findings. Drawing on theoretical, typological, and evaluation insights from the field of information use, we examine stakeholder use of climate information emerging from 13 collaborative climate science projects conducted in the western United States between 2012 and 2016. Three primary types of use emerge from our findings—conceptual, instrumental, and justification—reflecting common typologization of information use. Conceptual use was the most predominant. We suggest that researcher awareness of this typology can enable more systematic understanding of what project outputs stakeholders use and impacts of those outputs, giving way to new areas of inquiry and aiding in the conceptualization and design of climate information products for land and natural resource managers.     

Silver nanoparticles: behaviour and effects in the aquatic environment

This review summarises and evaluates the present knowledge on the behaviour, the biological effects and the routes of uptake of silver nanoparticles (Ag NPs) to organisms, with considerations on the nanoparticle physicochemistry in the ecotoxicity testing systems used. Different types of Ag NP syntheses, characterisation techniques and predicted current and future concentrations in the environment are also outlined. Rapid progress in this area has been made over the last few years, but there is still a critical lack of understanding of the need for characterisation and synthesis in environmental and ecotoxicological studies. Concentration and form of nanomaterials in the environment are difficult to quantify and methodological progress is needed, although sophisticated exposure models show that predicted environmental concentrations (PECs) for Ag NPs in different environmental compartments are at the range of ng L(-1) to mg kg(-1). The ecotoxicological literature shows that concentrations of Ag NPs below the current and future PECs, as low as just a few ng L(-1), can affect prokaryotes, invertebrates and fish indicating a significant potential, though poorly characterised, risk to the environment. Mechanisms of toxicity are still poorly understood although it seems clear that in some cases nanoscale specific properties may cause biouptake and toxicity over and above that caused by the dissolved Ag ion. This review concludes with a set of recommendations for the advancement of understanding of the role of nanoscale silver in environmental and ecotoxicological research.     

Incorporating Bioavailability Considerations Into the Evaluation of Contaminated Sediment Sites

In March 2011, the Interstate Technology & Regulatory Council (ITRC) Contaminated Sediments Team published a web‐based Technical and Regulatory Guidance on the concepts, processes, and uses of bioavailability in a risk decision‐making framework at a contaminated sediment site. Bioavailability processes, as defined by the National Research Council (NRC; 2003), are the “individual physical, chemical, and biological interactions that determine the exposure of plants and animals to chemicals associated with soils and sediments.” Bioavailability assessment tools aid in the assessment of human and ecological exposure and development of site‐specific remedial objectives. The guidance provides information on the processes that may affect contaminant bioavailability within sediments to understand exposure within ecological and human receptors; supports the development of conceptual site models (CSMs); and describes available tools (biological, chemical, and physical) and models that are used to measure and characterize the fate and transport and potential bioavailability of contaminants. Case studies, referenced throughout the document, demonstrate the practical application of bioavailability measures. The guidance will describe the proper application of traditional and emerging sediment remediation technologies to support the selection of a remedy that is protective of human health and the environment. © 2013 Wiley Periodicals, Inc.     

GIS and the Analytic Hierarchy Process for Regional Landfill Site Selection in Transitional Countries: A Case Study From Serbia

The Serbian National Waste Management Strategy for the Period 2010–2019, harmonized with the European Union Directives, mandates new and very strict requirements for landfill sites. To enable analysis of a number of required qualitative and quantitative factors for landfill site selection, the traditional method of site selection must be replaced with a new approach. The combination of GIS and the Analytic Hierarchy Process (AHP) was selected to solve this complex problem. The Srem region in northern Serbia, being one of the most environmentally sensitive areas, was chosen as a case study. Seventeen factors selected as criteria/sub-criteria were recognized as most important, divided into geo-natural, environmental, social and techno-economic factors, and were evaluated by experts from different fields using an AHP extension in Arc GIS. Weighted spatial layers were combined into a landfill suitability map which was then overlapped with four restriction maps, resulting in a final suitability map. According to the results, 82.65% of the territory of Srem is unsuitable for regional landfill siting. The most suitable areas cover 9.14%, suitable areas 5.24%, while areas with low and very low suitability cover 2.21 and 0.76% of the territory, respectively. Based on these findings, five sites close to two large urban agglomerations were suggested as possible locations for a regional landfill site in Srem. However, the final decision will require further field investigation, a public acceptance survey, and consideration of ownership status and price of the land.     

Neural stem cell-based in vitro bioassay for the assessment of neurotoxic potential of water samples

Intensive agriculture activities, industrialization and growing numbers of wastewater treatment plants along river banks collectively contribute to the elevated levels of neurotoxic pollutants in natural water reservoirs across Europe. We established an in vitro bioassay based upon neural stem cells isolated from the subventricular zone of the postnatal mouse to evaluate the neurotoxic potential of raw wastewater, treated sewage effluent, groundwater and drinking water. The toxic potential of water samples was evaluated employing viability, proliferation, differentiation and migration assays. We found that raw wastewater could reduce the viability and proliferation of neural stem cells, and decreased the neuronal and astrocyte differentiation, neuronal neurite growth, astrocyte growth and cell migration. Treated sewage water also showed inhibitory effects on cell proliferation and migration. Our results indicated that relatively high concentrations of nitrogenous substances, pesticides, mercuric compounds, bisphenol-A, and phthalates, along with some other pollutants in raw wastewater and treated sewage water, might be the reason for the neuroinhibitory effects of these water samples. Our model successfully predicted the neurotoxicity of water samples collected from different sources and also revealed that the incomplete removal of contaminants from wastewater can be problematic for the developing nervous system. The presented data also provides strong evidence that more effective treatments should be used to minimize the contamination of water before release into major water bodies which may be considered as water reservoirs for human usage in the future.     

Effects of selected metal oxide nanoparticles on Artemia salina larvae: evaluation of mortality and behavioural and biochemical responses

The aim was to investigate the toxicity of selected metal oxide nanoparticles (MO-NPs) on the brine shrimp Artemia salina, by evaluating mortality and behavioural and biochemical responses. Larvae were exposed to tin(IV) oxide (stannic oxide (SnO₂)), cerium(IV) oxide (CeO₂) and iron(II, III) oxide (Fe₃O₄) NPs for 48 h in seawater, with MO-NP suspensions from 0.01 to 1.0 mg/mL. Mortality and behavioural responses (swimming speed alteration) and enzymatic activities of cholinesterase, glutathione-S-transferase and catalase were evaluated. Although the MO-NPs did not induce any mortality of the larvae, they caused changes in behavioural and biochemical responses. Swimming speed significantly decreased in larvae exposed to CeO₂ NPs. Cholinesterase and glutathione-S-transferase activities were significantly inhibited in larvae exposed to SnO₂ NPs, whereas cholinesterase activity significantly increased after CeO₂ NP and Fe₃O₄ NP exposure. Catalase activity significantly increased in larvae exposed to Fe₃O₄ NPs. In conclusion, swimming alteration and cholinesterase activity represent valid endpoints for MO-NP exposure, while glutathione-S-transferase and catalase activities appear to be NP-specific.