The overarching aim of the work presented here is to contribute to the development of a new interdisciplinary approach to fisheries economics for fisheries governance. it is geographically limited to West Africa but results can be used in other areas where small scale fisheries are active and governance rules are not fully implemented. The disciplinary orientations and conceptual frameworks applied in the research are institutional analysis and governance, as well as the assessment of key drivers of change. The new institutional economic theory provided a sound conceptual frame to analyse fisheries as it brings together economics (theory of the firm and social cost theory), law (convention, contracts, etc.) and sociology (sanctions, taboos, customs, traditions, and codes of conduct). Used on its own it provides a good framework for the analysis of the fish chain and relationships between stakeholders (wealth distribution and equity) and the whole governance of fisheries, coastal zones and oceans. Combined with neo-classical tools such as modelling of fishing activities, it provides a good analytical method to predict effects of management measures on fisher strategies. Furthermore, coupled with an ecological model such as ECOPATH or ECOSIM, its gives a holistic modelling tool (integrating ecology, economic and social dimensions) for the assessment of the full costs and benefits (private and public) of fishing practices and policy policies. The research suggests that the key drivers of change are often hidden and therefore not taken into account while designing management measures. Among shaping drivers, research in West Africa shows that international trade and its rules is shaping the orientation and the functioning of small scale fisheries. Fisher migration, which is directly linked to the trade driving effects, is currently one of the major drivers of change of West African fisheries and the most destabilizing factor. The main results, such as the identification of drivers of change (e.g. international trade, migration), and the integration of social, economic and ecological models are currently used by international institutions such as FAO, UNEP, UNDP and the Group of the ACP countries, regional organisations such as ATLFALCO (Ministerial conference of the African Atlantic countries), the Sub-regional Fishery Commission of seven West African countries and at national level by fishery ministries. The future of fisheries governance in West Africa is strongly linked to a better understanding of small scale fisher strategies and the way they react to fishery management. New research activities on co-management have to be developed in order to switch from a strong centralised fishery management process to a local one where fisher communities play a significant role. Aside from this, work has to be continued to implement the integrated approach into the fishery governance system in West Africa and in other world coastal countries.

<p> This dissertation links human and ecological systems research to analyze resource management decisions for elodea, Alaska&rsquo;s first submerged aquatic invasive plant. The plant likely made it to Alaska through the aquarium trade. It was first discovered in urban parts of the state but is being introduced to remote water bodies by floatplanes and other pathways. Once introduced, elodea changes freshwater systems in ways that can threaten salmon and make floatplane destinations inaccessible. The analysis integrates multiple social and ecological data to estimate the potential future economic loss associated with its introduction to salmon fisheries and floatplane pilots. For estimating the effects on commercial sockeye fisheries, multiple methods of expert elicitation are used to quantify and validate expert opinion about elodea&rsquo;s ecological effects on salmon. These effects are believed to most likely be negative, but can in some instances be positive. Combined with market-based economic valuation, the approach accounts for the full range of potential ecological and economic effects. For analyzing the lost trip values to floatplane pilots, the analysis uses contingent valuation to estimate recreation demand for landing spots. A spatially-explicit model consisting of seven regions simulates elodea&rsquo;s spread across Alaska and its erratic population dynamics. This simulation model accounts for the change in region-specific colonization rates as elodea populations are eradicated. The most probable economic loss to commercial fisheries and recreational floatplane pilots is $97 million per year, with a 5% chance that combined losses exceed $456 million annually. The analysis describes how loss varies among stakeholders and regions, with more than half of statewide loss accruing to commercial sockeye salmon fisheries in Bristol Bay. Upfront management of all existing invasions is found to be the optimal management strategy for minimizing long-term loss. Even though the range of future economic loss is large, the certainty of long-term damage favors investments to eradicate current invasions and prevent new arrivals. The study serves as a step toward risk management aimed at protecting productive ecosystems of national and global significance.</p>

<p> Waste disposal has always been one of the challenging aspects of human life mostly in populated areas. In every urban region, various factors can impact both amount and composition of the generated waste, and these factors might depend on a series of parameters. Therefore, developing a predictive model for waste generation has always been challenging. We believe that one main problem that city planners and policymakers face is a lack of an accurate yet easy-to-use predictive model for the waste production of a given municipality. It would be vital for them, especially during business downturns, to access a reliable predictive model that can be employed in planning resources and allocating budget. However, most developed models are complicated and extensive. The objective of this research is to study the trend of solid waste generation in Philadelphia with respect to business cycle indicators, population growth, current policies and environmental awareness, and to develop a satisfactory predictive model for waste generation. </p><p> Three predictive models were developed using time series analysis, stationary and nonstationary multiple linear regressions. The nonstationary OLS model was just used for comparison purposes and does not have any modeling value. Among the other two developed predictive models, the multiple linear regression model with stationary variables yielded the most accurate predictions for both total and municipal solid waste generation of Philadelphia. Despite its unsatisfactory statistics (R-square, p-value, and F-value), stationary OLS model could predict Philadelphia&rsquo;s waste generation with a low level of approximately 9% error. Although time series modeling demonstrated a less successful prediction comparing to the stationary OLS model (25% error for total solid waste, and 10.7% error for municipal waste predictions), it would be a more reliable method based on its model statistics. The common variable used in all three developed models which made our modeling different from the Streets Department&rsquo;s estimations was unemployment rate. Including an economic factor such as unemployment rate in modeling the waste generation could be helpful especially during economic downturns, in which economic factors can dominate the effects of population growth on waste generation. </p><p> A prediction of waste generation may not only help waste management sector in landfill and waste-to-energy facilities planning but it also provides the basis for a good estimation of its future environmental impacts. In future, we are hoping to predict related environmental trends such as greenhouse gas emissions using our predictive model.</p>