Brood reduction in the American white pelican (Pelecanus erythrohynchos)

Summary American white pelicans (Pelecanus erythrorhynchos) breeding in colonies at East Shoal Lake, Manitoba, Canada exhibited a mean hatching asynchrony of 2.5 days in 2-egg clutches. This resulted in a size difference between chicks which facilitated sibling dominance, harassment and lack of food for the subordinate chick. Only one young survived per nest. In marked broods, the secondhatched chick survived in 20% of successful nests. Manipulated clutch sizes (1, 2 and 3 eggs or chicks per nest) revealed that the presence of a second chick contributes significantly to the reproductive success of the parents. Results support the hypothesis that the second egg functions as a form of insurance against early loss of the first egg or chick. The parents, by establishing hatching asynchrony, by nonintervention in sibling aggression, and by selectively feeding the dominant chick, maximize their chance of rearing the most viable young.     

Successful Deployment of an Innovative Environmental Technology: The Terra-Kleen Experience

The National Research Council's report, Innovations in Ground Water and Soil Cleanup: From Concept to Commercialization, reviewed the implementation of innovative remediation technologies and portrayed a bleak outlook for them. Conversely, Terra-Kleen has invented, patented, permitted, and profited through the use of an innovative technology in the current market. Terra-Kleen has implemented a solvent extraction technology for the removal of PCBs, PAHs, and chlorinated pesticides from soil, sediment, and debris. To date, Terra-Kleen has successfully processed over 23 million pounds of PCB-contaminated soil in Alaska, California, Florida, Ohio, and Oklahoma. The company has been profitable each year since its inception, and has averaged a revenue growth rate of 94 percent per year for the last four years. Corporate growth has been financed entirely through profits and conventional bank loans at favorable interest rates. This article reviews the factors that have led to Terra-Kleen's success, overviews the solvent extraction technology, and details specific projects that have implemented the technology.     

Development of a New Approach to Cumulative Effects Assessment: A Northern River Ecosystem Example

If sustainable development of Canadian waters is to be achieved, a realistic and manageable framework is required for assessing cumulative effects. The objective of this paper is to describe an approach for aquatic cumulative effects assessment that was developed under the Northern Rivers Ecosystem Initiative. The approach is based on a review of existing monitoring practices in Canada and the presence of existing thresholds for aquatic ecosystem health assessments. It suggests that a sustainable framework is possible for cumulative effects assessment of Canadian waters that would result in integration of national indicators of aquatic health, integration of national initiatives (e.g., water quality index, environmental effects monitoring), and provide an avenue where long-term monitoring programs could be integrated with baseline and follow-up monitoring conducted under the environmental assessment process.     

Gaseous and particulate emissions from a DC arc melter

Tests treating soils contaminated with metal compounds and radionuclide surrogates were conducted in a DC arc melter. The soil melted, and glassy or ceramic waste forms with a separate metal phase were produced. Tests were run in the melter plenum with either air or N2 purge gases. In addition to nitrogen, the primary emissions of gases were CO2, CO, oxygen, methane, and oxides of nitrogen (NO(x)). Although the gas flow through the melter was low, the particulate concentrations ranged from 32 to 145 g/m3. Cerium, a nonradioactive surrogate for plutonium and uranium, was not enriched in the particulate matter (PM). The PM was enriched in cesium and highly enriched in lead.     

Developmental stress impairs song complexity but not learning accuracy in non-domesticated zebra finches (<Emphasis Type="Italic">Taeniopygia guttata</Emphasis>)

Food restrictions early in life can have adverse effects on the development of adult avian song structure. Nutritional deficiencies during brain development are thought to impair the growth of neural circuits responsible for learning and production of song in adulthood. Thus, the quality of song may reflect the quality of the singer due to the costs associated with neural development early in life. Recent investigations have focused on domesticated laboratory strains of zebra finches where early dietary deficiencies have significantly reduced the complexity of song and its sexual attractiveness. Domesticated zebra finches may be more sensitive to the early effects of moderate under-nutrition on song complexity than their non-domesticated counterparts. In an aviary experiment with non-domesticated zebra finch stock, we found that song complexity when measured by a linear combination of six variables was reduced in food-restricted birds, with syllable rate and maximum syllable frequency as the principal variables affected. The restriction had no effect on learning accuracy when song phrases of experimental birds were compared to those of their fathers.This result demonstrates that early nutrition may differentially affect the development of neural processes that influence learning accuracy and song complexity. While the finding of negative effects of dietary restriction on song complexity is robust for zebra finches and is not an artefact of domestication, it does not explain why some nutritionally stressed populations of wild zebra finches have more complex songs than those from other regions of Australia characterised by greater food availability.     

Northern Rivers Ecosystem Initiative: Nutrients and Dissolved Oxygen – Issues and Impacts

Anthropogenic inputs of nitrogen (N), phosphorus (P) and oxygen-consuming material to aquatic ecosystems can change nutrient dynamics, deplete oxygen, and change abundance and diversity of aquatic plants and animals. The Northern Rivers Ecosystem Initiative required a research and assessment program to establish the contribution of pulp mill and sewage discharges to eutrophication and depressions in dissolved oxygen (DO) in the Athabasca and Wapiti rivers of northern Alberta, Canada and examine the adequacy of existing guidelines for protecting these systems. Analysis of long-term data showed that total N (TN) and total P (TP) concentrations in exposed river reaches exceeded concentrations in reference reaches by ≤ 2 times for the Athabasca River, and by 9.6 (TP) and 2.6 (TN) times for the Wapiti River. Results from nutrient limitation experiments conducted in situ and in mesocosms showed that benthic algal production was nutrient sufficient downstream of pulp mill discharges but constrained in upper river reaches by insufficient P (Athabasca River) or N + P (Wapiti River). Dissolved oxygen (DO) concentrations in both rivers declined during winter such that median concentrations in the Athabasca River 945 km downstream of the headwaters were approximately 8 mg L⁻¹ in mid-February. Although water column DO rarely approached the guideline of 6.5 mg L⁻¹, DO studies undertaken in the Wapiti River showed that pore water DO often failed to meet this guideline and could not be predicted from water column DO. Results from this integrated program of monitoring and experimentation have improved understanding of the interactions between nutrients, DO and aquatic ecosystem productivity and resulted in recommendations for revisions to nutrient and DO guidelines for these northern rivers.The Canadian Crown reserves the right to retain a non-exclusive, royalty free licence in and to any copyright.     

Corporate social responsibility and petroleum development in sub-Saharan Africa: The case of Chad

This paper contributes to the debate on governance, transparency and Corporate Social Responsibility (CSR) in oil-rich sub-Saharan Africa, focusing on the case of Chad. Over the past decade, Chad has gained international standing as an oil-producer on the back of the World Bank-catalyzed Chad–Cameroon pipeline project, which aims to develop the country's oil-rich Doba region. The analysis begins by examining at greater length the challenges to implementing a CSR agenda in fragile states such as Chad, highlighting, specifically, the barriers to facilitating development in environments exhibiting Dutch Disease-like symptoms. It subsequently critiques CSR programs in resource-rich developing countries, questioning the role of corporate intervention in such settings. The paper concludes by examining how CSR has been “operationalized” in Chad itself, where to ensure that the finances generated from the oil project are properly managed, the Bank instituted a comprehensive revenue management plan.