The Greater Yellowstone Ecosystem: Challenges for Regional Ecosystem Management

An adaptive management approach is necessary but not sufficient to address the long-term challenges of the Greater Yellowstone Ecosystem (GYE). Adaptive management, in turn, has its own particular challenges, of which we focus on two: science input, and stakeholder engagement. In order to frame our discussion and subsequent recommendations, we place the current management difficulties into their historical context, with special emphasis on the 1990 Vision document, which attempted a broad synthesis of management goals for the ecosystem. After examining these two key challenges in the context of the GYE, we make several recommendations that would allow for more effective ecosystem management in the long term. First, we recommend adoption of the GYE as a site for long-term science research and monitoring with an emphasis on integrative research, long-term federal funding, and public dissemination of data. Second, we conclude that a clearer prioritization of legislative mandates would allow for more flexible ecosystem management in the GYE, a region where conflicting mandates have historically led to litigation antithetical to effective ecosystem management. Finally, we recommend a renewed attempt at an updated Vision for the Future that engages stakeholders (including local landholders) substantively from the outset.     

Patterns and sources of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans in surficial sediments of Lakes Erie and Ontario

This study determines spatial trends and congener patterns of 2378-substituted polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in surficial sediments of Lakes Erie and Ontario. Sediments are enriched in 2378-PCDFs in Lake Ontario, and the PCDD/F concentrations increased from shallow near-shore sediments towards deep-water depositional zone sediments. In Lake Erie, sediments were dominated by octachlorodibenzo-p-dioxin, and the highest PCDD/F concentrations were observed in the western basin and the southern shoreline of the central basin with a decrease towards the eastern basin and the northern shoreline of the central basin. Principal components analysis revealed that chemical manufacture and disposal of chemical waste along the Niagara River has been a major PCDD/F source to Lake Ontario; while PCDD/Fs in Lake Erie are from multiple sources including industrial sources along the Detroit River, major tributaries along the southern shoreline of the lake, and atmospherically-derived material from the upper lakes and connecting channels.     

Traffic and meteorological impacts on near-road air quality: summary of methods and trends from the Raleigh Near-Road Study

A growing number of epidemiological studies conducted worldwide suggest an increase in the occurrence of adverse health effects in populations living, working, or going to school near major roadways. A study was designed to assess traffic emissions impacts on air quality and particle toxicity near a heavily traveled highway. In an attempt to describe the complex mixture of pollutants and atmospheric transport mechanisms affecting pollutant dispersion in this near-highway environment, several real-time and time-integrated sampling devices measured air quality concentrations at multiple distances and heights from the road. Pollutants analyzed included U.S. Environmental Protection Agency (EPA)-regulated gases, particulate matter (coarse, fine, and ultrafine), and air toxics. Pollutant measurements were synchronized with real-time traffic and meteorological monitoring devices to provide continuous and integrated assessments of the variation of near-road air pollutant concentrations and particle toxicity with changing traffic and environmental conditions, as well as distance from the road. Measurement results demonstrated the temporal and spatial impact of traffic emissions on near-road air quality. The distribution of mobile source emitted gas and particulate pollutants under all wind and traffic conditions indicated a higher proportion of elevated concentrations near the road, suggesting elevated exposures for populations spending significant amounts of time in this microenvironment. Diurnal variations in pollutant concentrations also demonstrated the impact of traffic activity and meteorology on near-road air quality. Time-resolved measurements of multiple pollutants demonstrated that traffic emissions produced a complex mixture of criteria and air toxic pollutants in this microenvironment. These results provide a foundation for future assessments of these data to identify the relationship of traffic activity and meteorology on air quality concentrations and population exposures.     

Indoor Air Quality at Rural and Urban Sites in Pakistan

In the developing world, the vast majority of people rely on solid biomass fuels for cooking and heating which results in poor indoor air quality. The present study determined indoor air quality in some rural and urban areas of Pakistan. Measurements were made of particulate mass (PM10, PM2.5 and PM1), number concentration and bioaerosols in different micro environments. PM10 concentrations of up to 8,555 μg/m³ were observed inside the kitchens where biofuels were used as energy source. Cleaning and smoking was identified as a major source of indoor particulate pollution and concentrations of more than more than 2,000 μg/m³ were recorded in the living room during these activities. Indoor number concentrations in Lahore were typically greater than those observed outdoors in European cites. At a rural site the highest Colony Forming Units (CFUs) were in the 0.5 μm–2 μm size fraction, while at the urban location CFUs were dominant for 2 μm–16 μm. It was observed that CFUs(Colony Forming Units) counts were higher inside living rooms than kitchens. It is important to note that women and children were exposed to extremely high levels of particulates during cooking. Overall, indoor air quality in Pakistan was poor and there is a dire need to take a serious step to combat with it.     

Impacts of Off-Road Vehicles (ORVs) on Macrobenthic Assemblages on Sandy Beaches

Sandy beaches are the prime sites for human recreation and underpin many coastal economies and developments. In many coastal areas worldwide, beach recreation relies on the use of off-road vehicles (ORVs) driven on the shore. Yet, the use of ORVs is not universally embraced due to social conflicts with other beach user groups and putative environmental consequences of vehicle traffic on sandy shores. Such ecological impacts of ORVs are, however, poorly understood for endobenthic invertebrates of the intertidal zone seawards of the dunes. Consequently, this study quantified the degree to which assemblages of intertidal beach invertebrates are affected by traffic. The study design comprised a series of temporally replicated spatial contrasts between two reference sites (no ORVs) and two beaches with heavy ORV traffic (in excess of 250,000 vehicles per year) located in South-East Queensland, Australia. Macrobenthic assemblages on ORV-impacted beaches had significantly fewer species at substantially reduced densities, resulting in marked shifts in community composition and structure. These shifts were particularly strong on the middle and upper shore where vehicle traffic was concentrated. Strong effects of ORVs were detectable in all seasons, but increased towards the summer months as a result of heavier traffic volumes. This study provides clear evidence that ORVs can have substantial impacts on sandy beach invertebrates that are manifested throughout the whole community. Demonstrating such an ecological impact caused by a single type of human use poses a formidable challenge to management, which needs to develop multi-faceted approaches to balance environmental, social, cultural, and economic arguments in the use of sandy shores, including management of “beach traffic.”     

Rapid quantification of polycyclic aromatic hydrocarbons in hydroxypropyl-beta-cyclodextrin (HPCD) soil extracts by synchronous fluorescence spectroscopy (SFS)

Synchronous fluorescence spectroscopy (SFS) was directly applied to rapidly quantify selected polycyclic aromatic hydrocarbons (PAHs: benzo[a]pyrene and pyrene) in aqueous hydroxypropyl-beta-cyclodextrin (HPCD) soil extract solutions from a variety of aged contaminated soils containing four different PAHs. The method was optimized and validated. The results show that SFS can be used to analyse benzo[a]pyrene and pyrene in HPCD based soil extracts with high sensitivity and selectivity. The linear calibration ranges were 4.0x10(-6)-1.0x10(-3)mM for benzo[a]pyrene and 6.0x10(-6)-1.2x10(-3)mM for pyrene in 10mM HPCD aqueous solution alone. The detection limits according to the error propagation theory for benzo[a]pyrene and pyrene were 3.9x10(-6) and 5.4x10(-6)mM, respectively. A good agreement between SFS and HPLC was reached for both determinations of PAHs in HPCD alone and in soil HPCD extracts. Hence, SFS is a potential means to simplify the present non-exhaustive hydroxypropyl-beta-cyclodextrin (HPCD)-based extraction technique for the evaluation of PAH bioavailability in soil.     

Efficiency of ASTM Method D4994-89 for Recovery of Enteric Viruses from Biosolids

The ASTM Method D4994-89 has been used in the United States for almost two decades to assess the virological quality of biosolids. However, the efficiency of this method for recovery of different enteric viruses has never been determined. The method was found to recover several different enteroviruses and adenovirus 2 with an efficiency ranging from 18.1 ± 5.5 to 24.6 ± 7.8%.     

Particulate pollution case studies which illustrate uses of individual particle analysis by scanning electron microscopy

Individual particle analysis by scanning electron microscopy is a high resolution analytical technique which can provide the detail necessary to solve many particulate pollution problems. In an electron microscope a beam of electrons is focused on a specimen resulting in a number of signals which are used to collect chemical and morphological information from individual features either manually or automatically. Case studies are presented which illustrate the applications of the technique to three paniculate pollution problems of differing complexity.     

Prenatal screening for Down syndrome in twin pregnancies: Estimates of screening performance based on 61 affected and 7302 unaffected twin pregnancies

The aims of this study were to determine whether assumptions used in prenatal screening for Down syndrome in twin pregnancies are valid and derive estimates of risk and screening performance in twin pregnancies using observed data. Data were collected on nuchal translucency, chorionicity, pregnancy associated plasma protein-A (PAPP-A), and free ß human chorionic gonadotrophin (free ß-hCG) from 61 twin pregnancies with Down syndrome and 7302 unaffected twin pregnancies. Distribution parameters were determined and used to estimate screening performance. The assumption that proportional differences in serum marker levels in affected and unaffected singleton pregnancies apply to twin pregnancies was not confirmed. Median free β-hCG value in monochorionic affected twin pregnancies (2.63 multiples of the median [MoM]; 95% CI, 1.79-3.22 MoM) was lower than that assuming proportionality (3.76 MoM), and the median PAPP-A value in dichorionic affected twin pregnancies (1.88 MoM; 95% CI, 1.60-2.17 MoM) was higher than that based on proportionality (1.33 MoM). The detection rate was 87% for a 3% false-positive rate in monochorionic twin pregnancies and 74% in dichorionic twin pregnancies compared with 86% in singleton pregnancies. Estimates of screening performance in Down syndrome twin pregnancies do not need to rely on assumptions and can take account of chorionicity and gestational age.