Social-ecological analysis of integrated agriculture-aquaculture systems in Dedza, Malawi

Through the case of integrated agriculture-aquaculture in rural Malawi, this paper argues that hybrid research can reveal new interactions in social-ecological systems not evident when studies by social or natural methods independently. While recent research acknowledges the social and natural dimensions of aquaculture systems, studies often create an artificial divide by attempting to address each aspect in isolation. Social science research has overlooked the biophysical aspects of aquaculture, while scientific research has uncritically accepted orthodox explanations of environmental outcomes without addressing the social contexts of such systems. The social component of this research reveals that fish farmers in Malawi are rejecting practices which do not work in the local context (fertilization with pond mud) and adopting strategies that do work (irrigation with pond water). The physical component of this research compliments the social by elucidating that irrigation with pond water resulted in higher soil nutrient and moisture content. The paper concludes that small-scale aquaculture can make significant contributions to rural household food and income security in Africa and that hybrid research methods can improve our abilities to investigate the complex, connected nature of social-ecological systems.     

Hydrologic monitoring tools for freshwater municipal planning in the Arctic: the case of Iqaluit,Nunavut, Canada

Freshwater and the services it provides are vital to both natural ecosystems and human needs; however, extreme climates and their influence on freshwater availability can be challenging for municipal planners and engineers to manage these resources effectively. In Arctic Canada, financial and human capital limitations have left a legacy of freshwater systems that underserve current communities and may be inadequate in the near future under a warming climate, growing population, and increasing demand. We address this challenge to community water resource planning by applying several novel water supply forecasting methods to evaluate the Apex River as an alternative freshwater source for Iqaluit, Nunavut (Canada). Surveys of water isotope composition of the Apex River and tributaries indicated that rainfall is the main source of water replenishment. This information was utilized to calibrate a water resource assessment that considered climate forecasting scenarios and their influence on supply, and alternative scenarios for freshwater management to better adapt to a changing climate. We found that under current climate and demand conditions, the freshwater supply of Iqaluit would be in a perpetual state of drawdown by 2024. Analysis of current infrastructure proposals revealed significant deficiencies in the supply extensions proposed whereby the Apex replenishment pipeline would only provide a 2-year extension to current municipal supply. Our heuristic supply forecast methods allowed for several alternative supply strategies to be rapidly evaluated, which will aid the community planning process by specifically quantifying the service life of the city’s current and future primary water supply.     

Evaluating impacts of forage fish abundance on marine predators

Forage fish—small, low trophic level, pelagic fish such as herrings, sardines, and anchovies—are important prey species in marine ecosystems and also support large commercial fisheries. In many parts of the world, forage fish fisheries are managed using precautionary principles that target catch limits below the maximum sustainable yield. However, there are increasing calls to further limit forage fish catch to safeguard their fish, seabird, and marine mammal predators. The effectiveness of these extra-precautionary regulations, which assume that increasing prey abundance increases predator productivity, are under debate. In this study, we used prey-linked population models to measure the influence of forage fish abundance on the population growth rates of 45 marine predator populations representing 32 fish, seabird, and mammal species from 5 regions around the world. We used simulated data to confirm the ability of the statistical model to accurately detect prey influences under varying levels of influence strength and process variability. Our results indicate that predator productivity was rarely influenced by the abundance of their forage fish prey. Only 6 predator populations (13% of the total) were positively influenced by increasing prey abundance and the model exhibited high power to detect prey influences when they existed. These results suggest that additional limitation of forage fish harvest to levels well below sustainable yields would rarely result in detectable increases in marine predator populations.     

Control of Environmental Noise

The article reviews the current state of knowledge of noise and how people respond to noise. Sources of community noise are discussed and existing federal legislation pertaining to noise is mentioned. Methods of reducing the noise impact on communities from aircraft, surface transportation, and industrial sites are presented. Interior noise in industry, OSHA noise standards and means of controlling the noise to minimize hearing impairment are emphasized.     

An Evaluation of Commercial Hazardous Waste Thermal Destruction Capacity

Thermal destruction capacity for commercial hazardous waste in the United States is examined to determine current and future capacity requirements. This study focuses on commercial incinerators and cement kilns burning conventional hazardous wastes. Aggregate maximum and available capacity estimates are derived using the most recent information. On a national basis, available capacity far exceeds present demand. On a regional basis, capacity appears sufficient with the exception of the California area. However, this shortfall appears insignificant given the overall capacity situation. While incineration demand may increase for solids and sludges as a consequence of Land Ban disposal restrictions and other reasons, capacity for these wastes again appears sufficient to meet current and projected demands. Thus, arguments that additional commercial incineration capacity will be needed to accommodate an expected increase in incinerable hazardous waste cannot be supported by the available information. The analysis raises concerns about the determination of realistic capacity estimates, and the lack of interaction between the capacity assurance process that documents the need for capacity and state siting processes for new waste management facilities. The excess incineration capacity shown in this paper will contribute to the successful implementation of EPA’s goal to reduce national capacity.