Cost-effective selection of sampling frequencies for regulatory water quality monitoring

A dynamic programming code was formulated for the purpose of assigning sampling frequencies throughout a regulatory water quality monitoring network in order to optimize the statistical performance of the network while operating within a fixed budgetary constraint. The statistical objective is to achieve the greatest possible station to station uniformity in confidence interval widths about annual geometric means of the measured water quality variables and to keep the average confidence width reasonably small. The objective function is the sum (over several selected variables and all stations) of the normalized positive deviations of the predicted confidence interval widths from preselected design confidence interval widths. The code was designed to account for the effects of deterministic seasonal variation and serial correlation of the water quality observations by incorporating the results of the time series analysis of historical quality data. The economic constraint ensures that the annual operating cost of the system, including direct costs of travel and laboratory analysis, will not exceed the allowable budget. As an example situation, the dynamic programming code was used to assign sampling frequencies to the nine stations in Illinois from which historical quality data had been obtained and analyzed. Using five design quality constituents and representative travel and laboratory costs, an “optimal” design was produced. The optimal design achieved a 10% improvement in uniformity (standard deviation) of confidence interval widths when compared to a more traditional design based on the same budget and using identical sampling frequencies at every station.     

Science in the public process of ecosystem management: lessons from Hawaii, Southeast Asia, Africa and the US Mainland

Partnerships and co-operative environmental management are increasing worldwide as is the call for scientific input in the public process of ecosystem management. In Hawaii, private landowners, non-governmental organizations, and state and federal agencies have formed watershed partnerships to conserve and better manage upland forested watersheds. In this paper, findings of an international workshop convened in Hawaii to explore the strengths of approaches used to assess stakeholder values of environmental resources and foster consensus in the public process of ecosystem management are presented. Authors draw upon field experience in projects throughout Hawaii, Southeast Asia, Africa and the US mainland to derive a set of lessons learned that can be applied to Hawaiian and other watershed partnerships in an effort to promote consensus and sustainable ecosystem management. Interdisciplinary science-based models can serve as effective tools to identify areas of potential consensus in the process of ecosystem management. Effective integration of scientific input in co-operative ecosystem management depends on the role of science, the stakeholders and decision-makers involved, and the common language utilized to compare tradeoffs. Trust is essential to consensus building and the integration of scientific input must be transparent and inclusive of public feedback. Consideration of all relevant stakeholders and the actual benefits and costs of management activities to each stakeholder is essential. Perceptions and intuitive responses of people can be as influential as analytical processes in decision-making and must be addressed. Deliberative, dynamic and iterative decision-making processes all influence the level of stakeholder achievement of consensus. In Hawaii, application of lessons learned can promote more informed and democratic decision processes, quality scientific analysis that is relevant, and legitimacy and public acceptance of ecosystem management.     

Phosphorus and nitrogen in rainfall simulation runoff after fresh and composted beef cattle manure application

Fresh beef cattle (Bos taurus) manure has traditionally been applied to cropland in southern Alberta, but there has been an increase in application of composted manure to cropland in this region. However, the quality of runoff under fresh manure (FM) versus composted manure (CM) has not been investigated. Our objective was to compare runoff quality under increasing rates (0, 13, 42, 83 Mg ha(-1) dry wt.) of FM and CM applied for two consecutive years to a clay loam soil cropped to irrigated barley (Hordeum vulgare L.). We determined total phosphorus (TP), particulate phosphorus (PP), dissolved reactive phosphorus (DRP), total nitrogen (TN), NH4-N, and NO3-N concentrations and loads in runoff after one (1999) and two (2000) applications of FM and CM. We found significantly (P < or = 0.05) higher TP, DRP, and NH4-N concentrations, and higher DRP and TN loads under FM than CM after 2 yr of manure application. The TP loads were also higher under FM than CM at the 83 Mg ha(-1) rate in 2000, and DRP loads were higher for FM than CM at this high rate when averaged over both years. Application rate had a significant effect on TP and DRP concentrations in runoff. In addition, the slope values of the regressions between TP and DRP in runoff versus application rate were considerably higher for FM in 2000 than for FM in 1999, and CM in both 1999 and 2000. Significant positive relationships were found for TP and DRP in runoff versus soil Kelowna-extractable P and soil water-extractable P for FM and CM in 2000, indicating that interaction of runoff with the soil controlled the release of P. Total P and DRP were the variables most affected by the treatments. Overall, our study found that application of CM rather than FM to cropland may lower certain forms of P and N in surface runoff, but this is dependent on the interaction with year, application rate, or both.     

Cobalt-based alumina pillared zirconium phosphate catalysts for the selective catalytic reduction of NO by propane

A series of cobalt containing alumina pillared zirconium phosphate materials have been prepared by ion exchange or by impregnation, and fully characterised. The catalytic behaviour of these materials in the selective catalytic reduction of NO by propane, in excess of oxygen, at temperatures ranging between 350 and 550 degrees C, has been also evaluated. A maximum NO conversion close to 14% is obtained on Co-impregnated catalysts heated at 600 degrees C. The NO reduction seems to be related to the presence of Co3+, thus the calcination temperature of samples influences the resulting activity much more than the cobalt content.     

Trends in environmental education for biodiversity conservation in Costa Rica

Costa Rica is internationally recognized for its abundant biodiversity and being a leader in the promotion of education strategies for biodiversity conservation. We interviewed staff from 16 institutions developing key environmental communication, education, and participation projects for biodiversity conservation in the country. Through content analysis, hierarchical cluster analysis and Chi-square tests, we examined the characteristics of the projects carried out by these institutions and developed a typology of four categories derived from six variables: primary audience, content, project purpose, location, scale, and facility. Then, we designed a conceptual model describing the integration of conservation and economic development in the educational projects. We found two key approaches related to this integration: vision of nature protection which aims to inform audiences of ecological concepts and focuses on schoolchildren and vision of sustainability which engages adult audiences and is management-oriented. Education for community-based environmental management may serve as a good example of educational projects which integrate conservation and economic development, implementing a vision of sustainability.     

Review and assessment of models for predicting the migration of radionuclides through rivers

The present paper summarises the results of the review and assessment of state-of-the-art models developed for predicting the migration of radionuclides through rivers. The different approaches of the models to predict the behaviour of radionuclides in lotic ecosystems are presented and compared. The models were classified and evaluated according to their main methodological approaches. The results of an exercise of model application to specific contamination scenarios aimed at assessing and comparing the model performances were described. A critical evaluation and analysis of the uncertainty of the models was carried out. The main factors influencing the inherent uncertainty of the models, such as the incompleteness of the actual knowledge and the intrinsic environmental and biological variability of the processes controlling the behaviour of radionuclides in rivers, are analysed.     

Removal of emerging pollutant dibutylhydroxytoluene from water with CNT/TiO2 catalysts in a visible LED photoreactor

Environmental Science and Pollution Research - For the photocatalytic degradation of antioxidant 2,6-di-tert-butyl-hydroxytoluene (BHT), several TiO2-based composites have been prepared in MWCNT...     

Genomic erosion in a demographically recovered bird species during conservation rescue

The pink pigeon (Nesoenas mayeri) is an endemic species of Mauritius that has made a remarkable recovery after a severe population bottleneck in the 1970s to early 1990s. Prior to this bottleneck, an ex situ population was established from which captive-bred individuals were released into free-living subpopulations to increase population size and genetic variation. This conservation rescue led to rapid population recovery to 400–480 individuals, and the species was twice downlisted on the International Union for the Conservation of Nature (IUCN) Red List. We analyzed the impacts of the bottleneck and genetic rescue on neutral genetic variation during and after population recovery (1993–2008) with restriction site-associated sequencing, microsatellite analyses, and quantitative genetic analysis of studbook data of 1112 birds from zoos in Europe and the United States. We used computer simulations to study the predicted changes in genetic variation and population viability from the past into the future. Genetic variation declined rapidly, despite the population rebound, and the effective population size was approximately an order of magnitude smaller than census size. The species carried a high genetic load of circa 15 lethal equivalents for longevity. Our computer simulations predicted continued inbreeding will likely result in increased expression of deleterious mutations (i.e., a high realized load) and severe inbreeding depression. Without continued conservation actions, it is likely that the pink pigeon will go extinct in the wild within 100 years. Conservation rescue of the pink pigeon has been instrumental in the recovery of the free-living population. However, further genetic rescue with captive-bred birds from zoos is required to recover lost variation, reduce expression of harmful deleterious variation, and prevent extinction. The use of genomics and modeling data can inform IUCN assessments of the viability and extinction risk of species, and it helps in assessments of the conservation dependency of populations.     

Spatial distribution of DDT in sediments from estuarine rivers of central Florida

Sediments may act as both a carrier for and a potential source of contaminants such as toxic organics in aquatic environments. This study investigated the spatial distribution of the pesticide DDT [1,1, 1-trichloro-2,2-bis(p-chlorophenyl)ethane] in sediments from the Cedar and Ortega Rivers located in the lower St. Johns River basin, Florida, USA, using field measurements and three-dimensional kriging analysis. High DDT concentrations were found near the junction of the Cedar and Ortega Rivers and at the north end of the Ortega River in the upper 0.5 m of the sediments, indicating that the sediment was enriched with DDT in the top layer although use of this chlorinated compound was banned in 1972. Further study revealed that the influence of sediment grain size or texture on DDT contamination was negligible in this river system and no linear correlations existed among DDT and its metabolites such as DDD [1,1-dichloro-2,2-bis(p-chlorophenyl)ethane] and DDE [1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene]. Comparison of three-dimensional distribution of DDT content to the Florida sediment quality assessment guideline or probable effect level (PEL) showed several "hot spots" in the Ortega River sediments, where DDT contents exceeded the PEL value of 4.78 microg kg(-1). Such contamination may pose a significant hazard to aquatic life.