LCA has become an important method to study environmental impacts of human activities. Still, there are several methodological issues in LCA that can adversely affect the results reliability.... Show moreLCA has become an important method to study environmental impacts of human activities. Still, there are several methodological issues in LCA that can adversely affect the results reliability. Three of these issues relate to a) allocation, b) the representation of the time dimension and c) the interpretation of results in LCA. Uncertainties play a fundamental and underlying role for these issues. It is widely-agreed that correctly dealing with these different uncertainty sources is a vital step towards increasing the usefulness and reliability of LCA results. Practical ways to deal with uncertainty are needed. The aim of this thesis is to deepen the understanding of the uncertainty dimension of current LCA. By means of addressing different sources of uncertainty not yet addressed, with new methods, a clearer picture of the implications of different sources of uncertainty in LCA is provided. This thesis departed from broad domains of uncertainty including risk, uncertainty as conventionally described, ignorance and indeterminacies. The selected sources of uncertainty are in the domains of risk and conventional uncertainty i.e. those due to incomplete scientific knowledge and that are to some extent quantifiable. This does not mean that all can be known or quantified as ignorance and indeterminacies exist. Show less
Low-carbon (LE) technologies have a significant potential to reduce the total carbon emissions in China. Yet, in existing research, most authors analyzed such implications for China as a whole... Show moreLow-carbon (LE) technologies have a significant potential to reduce the total carbon emissions in China. Yet, in existing research, most authors analyzed such implications for China as a whole rather than the amount of carbon embodied in the products and services for China’s exports. We took a regional approach, since the implementation of LE and the production of products and services for China’s exports very heterogeneously distributed over the various Chinese regions. Current studies also tend to neglect the carbon emissions related to the investments in LE. Against this background, after providing an overview of China’s carbon emissions from a multi-sectoral perspective in Chapter 2, Chapter 3 analyzes the impact of LE development on carbon emissions embodied in the exports of China’s 30 provinces during 2002-2014. Moreover, Chapter 4 focuses on the carbon impact of LE infrastructure expansion using a demand-driven MRIO mode. Finally, Chapter 5 projects the carbon impact of LE investments during 2015-2040. The results show the patterns of carbon impacts of LE development across provinces and over the years, given the dynamic nature of China’s economic development and the heterogeneity of China’s regions. Show less
To limit the effects of climate change, global average temperature since pre-industrial measurements are to be kept well below 2 °C preferably even at 1.5 °C. The 2 °C limit and certainly the... Show moreTo limit the effects of climate change, global average temperature since pre-industrial measurements are to be kept well below 2 °C preferably even at 1.5 °C. The 2 °C limit and certainly the 1.5 °C target means that substantial GHG emission reductions should be realized already by 2050. How these emission reductions should be achieved is unclear. At least it is clear that the use of fossil fuels should be reduced. It is important to know if indeed the introduction of the renewable energy technologies can achieve the deep GHG emission reduction that are required in 30 years’ time against a backdrop of population growth and economic growth. Therefore we investigated the effects of the introduction of renewable technologies on GHG emissions and resource use until 2050. The principal global economy-environment model used in this investigation is based on a global multi-regional environmentally extended input-output framework which might be called a structural economic model. Because long-term socio-economic and technological developments cannot be predicted several scenarios with different penetration rates of low carbon and renewable energy technologies and resulting GHG emissions and resource use have been implemented in the structural economic model. Show less
Assessing the risks of engineered nanomaterials (ENMs) solely on the basis of experimental assays is time-consuming, resource intensive, and constrained by ethical considerations (such as the... Show moreAssessing the risks of engineered nanomaterials (ENMs) solely on the basis of experimental assays is time-consuming, resource intensive, and constrained by ethical considerations (such as the principles of the 3Rs of animal testing). The adoption of computational toxicology in this field is a high priority. Computational toxicology is able to contribute to the prediction of the extent of toxic effects of untested ENMs, to the hazard categorization and labeling of ENMs, and to the establishment of hazard threshold values that are sufficiently protecting the ecosystem with respect to the ENMs of concern. These three steps are listed by the European Chemicals Agency (ECHA) as the three elements in evaluating the hazards of ENMs. This study has expanded the use of computational toxicology in the hazard assessment with regard to the safe handling of ENMs. The results obtained contribute to the integration and evaluation of toxicity data, the identification of research gaps on ENM-related modeling, and the development of nano-SARs and SSDs for metallic ENMs. Despite the uncertainties that are associated with our results, as mainly due to limited data quality and availability, we managed to take this field one step forwards and contribute to better-informed regulatory decisions of ENMs. Show less
Fate and toxicity of copper nanoparticles was related to the water chemistry of the environment and pristine size. Connection between fate and toxicity of copper nanoparticles could be drawn. The... Show moreFate and toxicity of copper nanoparticles was related to the water chemistry of the environment and pristine size. Connection between fate and toxicity of copper nanoparticles could be drawn. The particle-specific toxicity of copper nanoparticles was dependent on water chemistry. Show less
Ethiopian wolves are endangered diurnal Afroalpine rodent hunters. I investigated the interaction between wolves, rodents and human land use in Borena Sayint National Park (BSNP), Abune Yosef and... Show moreEthiopian wolves are endangered diurnal Afroalpine rodent hunters. I investigated the interaction between wolves, rodents and human land use in Borena Sayint National Park (BSNP), Abune Yosef and Aboi Gara in Ethiopia. I applied scat analysis, interview, questionnaire and rodent-trapping survey methods. In BSNP 94.6% of wolf diet was made up of rodents, medium- sized mammals and others, while only 5.4% comprised livestock. Of all prey 79.2% were diurnal rodents. However, livestock presence indicated predation, which is damaging to livelihoods and perceptions to wolves. Rodent density across BSNP was higher in ungrazed land uses than grazed land and correlated positively to vegetation cover and negatively to livestock presence. In Abune Yosef 80% of local people benefited from natural resources but also suffered from predation by wolves and jackals. However, 66% reported positive attitude towards wolves and 71% recognised ecosystem protection. In Aboi Gara, I assessed extent of predation on small stock, its economic impact, and how it affects attitude towards wolf. Of 140 pastoralists, 70 losing 1.2 head of small stock to wolves and jackals over a year, this represents a loss of 10% herd size, or USD 92 per household. However, 62.1% of pastoralists had positive attitude towards wolves. Show less
Wetlands provide many ecosystem goods and services which include fish production. The sustainability of small-scale fisheries (SSF) has received considerable attention in recent years because fish... Show moreWetlands provide many ecosystem goods and services which include fish production. The sustainability of small-scale fisheries (SSF) has received considerable attention in recent years because fish is one of the major sources of animal protein to a considerable fraction of the global population which is estimated to increase to about 9.5 billion by 2050. Most of this attention has evolved around the pressures to which SSF are increasingly subjected, emanating particularly from population growth, rural poverty, weak institutional mechanisms, market forces, climate change among others. This thesis focuses on designing a sustainable management institution for the Elephant Marsh Fishery in Southern Malawi. With fieldwork which started in May 2011 to June 2013, this PhD study uses empirical data to understand the socio-ecological system of the Elephant Marsh Fishery and propose an actor-based institutional design which would achieve long-term sustainability of the fishery. After the introductory chapter 1, the second part of this thesis (Chapter 2) brings into perspective a clear understanding of the socio-ecological and land use setting of the Elephant Marsh as well as the ecosystem-based development potentials that exist at the wetland. The second chapter also highlights the actors and local institutions pertaining to the management of the wetland. Just like many similar ecosystems across the globe, the Elephant Marsh has come under increasing pressure in recent years which threatens the future of the wetland. Currently, Malawi does not have either a national wetland policy or a climate change policy and wetland issues are only marginally present in the National Parks and Wildlife Policy of 2000 and National Fisheries and Aquaculture Policy of 2001. As a result, the country lacks a framework that could be strong enough to achieve balanced and sustainable wetland management for multiple resource users. Chapter 2 of this study reveals that there are significant ecosystem-based development potentials at Elephant Marsh mainly in fisheries, recession agriculture, conservation, tourism and biomass for energy. Chapter 2 further shows that if these ecosystem-based development potentials are to be efficiently and effectively exploited at the Elephant Marsh, there is a need to rise above the institutional design principles of Ostrom which are based on nested enterprises and move towards real participatory approaches such as constitutionality (local people’s sense of ownership in bottom-up institution building). Certainly, as the present thesis suggests, there will be need to strike a balance between the local wetland management system, where pressure on the Elephant Marsh emanates mainly from poverty, and the national and international interests of biodiversity conservation as advocated by the Ramsar convention. Although enhanced production and maximum benefits from ecosystem good and services are central to any management system of the Elephant Marsh, it is important to realize that there are always limits to growth. Any management program for the Elephant Marsh should therefore strive towards sustainable exploitation of the opportunities that lie in the wetland’s goods and services. Globally, institutions that manage small-scale fisheries can be locally based, state controlled or of a mixed, cross-scale nature. The latter arrangement, widely known as co-management, is generally believed to be the preferred approach for fishery sustainability. In Africa, fisheries management faces many challenges due to unstable governance systems (weak states) whose role has evolved tremendously over the last century. The changes in the role of the state have mainly surfaced from a cautious realization that social actors (humans) respond to underlying incentives and are therefore central for any management system to work at all. With close reference to rich literature from across the globe, Chapter 3 of this thesis employs a crisp-set qualitative comparative analysis (csQCA) to examine cases of small-scale fisheries in several developing countries, in order to assess the degree of state involvement would be most relevant for designing a sustainable management for the Elephant Marsh Fishery. These degrees vary between: (a) strong top-down regulation irrespective of fishing community wishes, (b) a co-management mode of negotiation with fishing communities, (c) a merely supportive role of the state, or absence from the fishing scene. It was revealed that contrary to expectations, the sustainability of small-scale fisheries depended solely on the strength of collective social capital of the local communities at the resource scale. With weak local social capital, degrees of government involvement did not make any difference; the fisheries were unsustainable in all cases. The findings from this study have accentuated that the sustainability of SSF management in developing countries relies heavily on a strong collective social capital and a supportive government. Future practice and policy directions on fisheries management should understand the relevance of concrete community trust, networks, norms and values and strive to incorporate these in decision making and policy formulation. Governments, especially in developing countries, and their agents should realize the need to rise above the theoretical principles of “impose and control” and begin to take a more passive, non-conflictive position in designing working solutions for the sustainability of common pool resources such as small-scale fisheries. This can be done for example by encouraging civil engagement in transformative learning to reduce disadvantageous power differentials that exist in many fishing communities in developing countries. Chapter 4 uses the success and failure factors for SSF in developing countries which were identified in Chapter 3 to ascertain relevant factors for the sustainability of the Elephant Marsh Fishery. It is revealed that the Elephant Marsh Fishery sustainability depends on building strong local institutions with motivated leadership that can safeguard the interests of resource users. The present thesis therefore recommends that the government of Malawi should begin to take a more participatory position in designing locally crafted working institutions for the sustainability of common pool resources, such as small-scale fisheries at Elephant Marsh. In villages where fisheries fail due to weak local institutions or conflictive chiefs, the imposition of fishing rules is futile. The feasible government reaction then lies in (re)building collective social capital, especially the leadership of fisheries committees, and formally linking the established local institutions to the central government structure. In doing so an important inclusion would be the contextualization of key socio-causal dynamics of the management system at the Elephant Marsh. Cognizant of the importance of the socio-causal dynamics, Chapter 5 of this study used an actor-based framework (known as Action-in-Context) to unveil the issues that are crucial in devising a sustainable governance system for the Elephant Marsh Fishery. It was established that the key social variables for the designing a proposed three-pillared (locally based, weak and amorphous) resilient institution for sustainability of the Elephant Marsh Fishery are (i) the social reputation of the leaders of local fishery institutions and (ii) the power dynamics between traditional chiefs and these local fishery leaders. It is clearly evident from the present study that an actor-based multi-level analysis of rules and other mechanisms prevailing in a fishery can be instrumental in designing a cost-effective institution for the near future. For the design of longer-term institutional options, the assumptions underlying the actors-based method (Action-in-Context in our case) become weaker, e.g. because new types of actors may move in or because actor capacities and motivations may change or become more intertwined. This then necessitates a stronger reliance on both institutional theory and frameworks or (as has been my choice) the design of a flexible process of institutional development guided by an adaptive, learning organization. The last section of thesis (Chapter 6) synthesizes the main findings and proposes what needs to be done in designing a resilient management system for the Elephant Marsh Fishery. This PhD thesis ends by stimulating a style of thinking that may be fruitful for institutional science in general. Show less
My PhD covers the impact of land use changes on human-elephant conflicts (HECs), the feeding ecology and movements of the Bornean elephant (Elephas maximus borneensis) in North Kalimantan,... Show moreMy PhD covers the impact of land use changes on human-elephant conflicts (HECs), the feeding ecology and movements of the Bornean elephant (Elephas maximus borneensis) in North Kalimantan, Indonesia. I dentified two functional Bornean elephant dispersal corridors in the study area along the Agison River and the Upper Sibuda River which provide a connection between elephant core habitat in the Upper Apan of the Sebuku forest and the Bornean elephant population in Sabah, Malaysia. Although the population of elephants in the Sebuku forest is small, conservation efforts could secure its presence when important habitat of this forest keystone species is adequately protected. Although no retaliation in response to HEC has occurred in the study area, the frequency of crop-raiding incidents is increasing and the forest is being converted at an alarming rate. Current plans for the conversion of remaining forest into timber plantations or oil palm are posing a serious threat to the future of this small sub-population. Elephant movement patterns represent temporal patterns of site recursion amongst foraging sites. Recursion patterns showed via corridors suggest that it may be part of a foraging strategy to revisit areas of great nutritional value. Show less
The aim of my study was to analyze the impact of selective logging on plant and bird diversity in East Kalimantan. The impact of logging on plant communities was studied in a forest (in the... Show moreThe aim of my study was to analyze the impact of selective logging on plant and bird diversity in East Kalimantan. The impact of logging on plant communities was studied in a forest (in the process of FSC certification) that has been logged selectively 1, 5 and 10 years previously compared to a primary forest site. The stem densities of trees in the primary forest were significantly higher compared to the three selectively logged forest sites. Stem densities of saplings were equivalent in all four forest sites. Seedling stem densities were significantly higher in the forest site logged 10 years previously compared to the primary forest. The “heavy hardwood” class, represented by a certain abundance of stems and species richness, was significantly lower in the forest sites selectively logged 1 and 5 years ago compared to the primary forest site. Stems with a higher abundance in the selectively logged forest sites generally belonged to the “light wood” class. I also studied the impact of logging on bird communities in East Kalimantan. My study compared secondary forest sites with relatively undisturbed primary lowland dipterocarp rain forest sites of East Kalimantan. All birds were identified during point counts in all sites; in the selective logging concession in a primary site and in selectively logged forest sites in the Berau district, a primary site in Sungai Wain and a disturbed site in Pusrehut Kutai Kartanegara. I found a significantly higher abundance of birds in the terrestrial foraging layer in primary forests as compared to secondary forests. I also found a significantly higher abundance of birds of the frugivorous/insectivorous guild and of endemic insectivorous birds in the primary forest. Show less
Economic valuation of ecosystem services is a popular yet troubled approach in modern nature conservation. It's effectiveness remains unknown while a lot of criticism is noted in the... Show more Economic valuation of ecosystem services is a popular yet troubled approach in modern nature conservation. It's effectiveness remains unknown while a lot of criticism is noted in the literature about potential consequences of this approach. This thesis first clarifies the various discourses extant about the topic. Then, it shows how the topic of ecosystem services is replacing calls for nature conservation in policy documents. It investigates two different ways to give ecological knowledge a strong influence in market-based approaches. The first way being the use of portfolio theory and the second way being the use of indicators for conservation success based on ecological science. The thesis finally turns towards the greater challenge of motivating people to protect nature, and argues that economic valuation has only a limited role to play in this endeavor. Show less
This dissertation is the culmination of over four years research on the rare earth element neodymium in the context of the 2010 REE crisis. Neodymium is a generally recognized ‘critical’... Show more This dissertation is the culmination of over four years research on the rare earth element neodymium in the context of the 2010 REE crisis. Neodymium is a generally recognized ‘critical’ material with a relevant application in the form of NdFeB magnets, both for sustainable energy technologies as well as the wider economy. This dissertation answers four main research questions: 1. What are the material flows of neodymium for NdFeB magnets, and how much can be made available for recycling? 2. What are the environmental burdens of NdFeB production, and how does recycling alleviate this burden? 3. What type of mechanisms along the NdFeB supply chain provide resilience in response to supply constraints and disruptions 4. Of all the possible resilience mechanisms, which played the largest role in the aftermath of the 2010 REE crisis? Besides directly answering the research question, this dissertation also reflects on the broader question of how actors in the NdFeB supply chain can change their behavior to limit their exposure to an unforeseen yet inevitable future crisis. Show less
Eco-innovation often underperforms due to behavioral and systemic responses to technical change leading to additional demand and environmental damage. This paradox, also known as the rebound... Show moreEco-innovation often underperforms due to behavioral and systemic responses to technical change leading to additional demand and environmental damage. This paradox, also known as the rebound effect, has puzzled for decades scholars from a myriad of disciplines, mostly due to the profound implications for achieving environmental targets. Within the different disciplinary understandings, concepts and methods from the industrial ecology domain offer unexplored potential for the study of the rebound effect. The transport sector, a vital engine of social progress and historically at the spotlight of environmental policy, is a perfect case study to unveil such potential. The aim of this dissertation is to investigate the role of rebound effects in shaping the environmental performance of transport eco-innovation, and to investigate the value of applying concepts and methods from the realm of industrial ecology and other sustainability sciences. Through case studies, the value of this renewed perspective – the environmental rebound effect– is confirmed in the context of complex sustainability issues. Show less
The aims of this thesis are to conduct a comprehensive investigation into the theoretical and methodological aspects of environmental footprints and into the disciplinary relationship with the... Show moreThe aims of this thesis are to conduct a comprehensive investigation into the theoretical and methodological aspects of environmental footprints and into the disciplinary relationship with the latest science in defining planetary boundaries for human activities. Main conclusions are as follows: (1) environmental footprints are measures of anthropogenic pressure or impact on the planet's environment irrespective of their precise units and dimensions; (2) environmental footprints are classified into the inventory-oriented footprints and impact-oriented footprints, which offer two competing paradigms for footprint indicators; (3) integrating the impact-oriented footprints provides policy makers with a unified approach to assessing overall environmental impacts and has a broader scope of applicability than life cycle assessment; (4) life cycle assessment cannot be interpreted as a versatile tool for accounting for all possible environmental footprints, although the footprint community has indeed learned and borrowed much from it; (5) latest science in planetary boundaries is found to complement environmental footprints in assessing environmental sustainability that is a critical prerequisite for the economic and social pillars of sustainable development; and (6) the sustainability gap between the converted footprint and boundary metrics plays a central role in understanding the national performance on individual and collective environmental issues. Show less
Carnivores are an important component of many ecological systems and they play a vital role in maintaining ecosystem health (Terborgh et al., 1999; Terborgh et al., 2002; Ray et al., 2005). Being... Show moreCarnivores are an important component of many ecological systems and they play a vital role in maintaining ecosystem health (Terborgh et al., 1999; Terborgh et al., 2002; Ray et al., 2005). Being at the top of the food chain, carnivores have important ecological impacts, such as the regulation of mesopredators and prey numbers present in an area (Terborgh et al., 1999). Important cascading trophic effects, caused by population changes of their prey or of sympatric mesopredators, may result when some of these large carnivores are extirpated from ecosystems. Unexpected effects of trophic cascades on various taxa and processes include changes to other vertebrates and herpetofaunal abundance or diversity. It could also have indirect effects and altered disease dynamics; carbon sequestration; modified stream morphology; and crop damage (Ray, 2005). Therefore, promoting tolerance and coexistence with large carnivores is a more crucial societal challenge now than ever before. The removal of top predators from ecosystems commonly results in dramatic changes in biodiversity and community structure, and as a result these areas can have severe consequences for the functioning of ecosystems (Berger et al., 2001; Terborgh et al., 1999). Show less
This thesis aims to evaluate the environmental sustainability of European imports of farmed aquatic food products from Asia, using life cycle assessment (LCA). Farming of Asian tiger prawn,... Show moreThis thesis aims to evaluate the environmental sustainability of European imports of farmed aquatic food products from Asia, using life cycle assessment (LCA). Farming of Asian tiger prawn, whiteleg shrimp, freshwater prawn, tilapia and pangasius catfish in Bangladesh, China, Thailand and Vietnam were chosen as representatives of the Asian aquaculture industry. Initial research revealed large discrepancies among LCA results driven by methodological choices and data sourcing. A protocol for quantifying dispersions around unit process data was therefore developed, characterising inherent uncertainty, spread (variability) and unrepresentativeness as the three major sources driving overall discrepancies. Results, propagated using Monte Carlo simulations, highlighted that the uncertainty related to LCA results could range with over an order of magnitude. For comparative purposes, however, only relative uncertainties are of relevance. Defining a hypothesis and using dependent sampling therefore allowed for several significant conclusions to be identified. Among these were significantly lower environmental impacts of Asian tiger shrimp farming in western Bangladesh, tilapia in Guangdong and pangasius in large-scale farms. Common environmental hot-spots included aqua-feeds, eutrophying effluents from farms, the use of benzalkonium chloride and other chlorine releasing compounds as disinfectants, and extensive use of paddle-wheels on shrimp farms. The research identified discrepancies Show less
The overall framework of the thesis is to develop an approach to compare the impacts between leaving biomass residues in fields and utilizing them for bioenergy. In this regard, residue-based... Show moreThe overall framework of the thesis is to develop an approach to compare the impacts between leaving biomass residues in fields and utilizing them for bioenergy. In this regard, residue-based bioenergy should be managed differently from product-based bioenergy. The objectives of this thesis are to identify the key issues when conducting a life cycle assessment (LCA) of residue-based bioenergy and to propose improvement in LCA procedures, specifically in the areas of life cycle inventory (LCI), life cycle impact assessment (LCIA), and methodological choices in the comparative LCA. It was discovered that the key issues associated with residue-based bioenergy relate to four primary characteristics with respect to its raw materials (biomass residues), i.e., excessive removal from plantation fields which can affect soil fertility; valuation (relative to biomass products); competing uses (bioenergy, feed, fiber, fertilizers); and treatment of biogenic carbon (assumptions of carbon neutrality vs. complete inventory). These unique features require specific LCA approaches which vary from those of conventional product-based bioenergy. These approaches include: [1] solutions to the existing dissimilar practices in the LCI of biogenic carbon; [2] an LCIA method of removing biomass residues from soil on biomass productivity; and [3] methodological choices in comparative LCA of biomass residues utilization. Show less
Our study emphasizes the importance of two toxicity-modifying factors (the composition of the surrounding exposure media and mixture effects) in the assessment of toxic effects of metals and... Show more Our study emphasizes the importance of two toxicity-modifying factors (the composition of the surrounding exposure media and mixture effects) in the assessment of toxic effects of metals and metal-based NPs on higher plants. Based on the affinity of metals for binding sites on the biotic ligand at the water-organism interface, the mechanistic models we developed provide better links with the toxicity of metal mixtures. We also recommend that finding a statistically significant deviation from additivity can be the starting point for further mechanistic research concerning toxicologically relevant interactions between substances, instead of the endpoint of research used so far. As an extension of the research discussed in the third chapter of this thesis, the commonly known model for the toxicity of mixtures was proven to be suitable for preliminarily assessing the effects of metal-based NPs on terrestrial organisms. The experimental design of nested combinations helps establish a more realistic exposure scenario for the environment and makes it possible to identify where and how chemical-chemical interactions occur with metal-based NPs. Consequently, our findings enrich the rapidly evolving field of toxicology regarding metals and metal-based NPs. Show less
Nanoparticles (NPs) exhibit special physicochemical properties compared to bulk particles. The difference in properties could, in principle, produce different effects on organisms. It is therefore... Show moreNanoparticles (NPs) exhibit special physicochemical properties compared to bulk particles. The difference in properties could, in principle, produce different effects on organisms. It is therefore important to determine the relationship between the physicochemical characteristics of NPs and their toxicity profile, by means of experimental testing. Experimental toxicity testing data can also be used to find the best dose metric for the responses induced by NPs, which was the purpose of the research presented in this thesis. Furthermore, this thesis aims to move forward from toxicity testing primarily in animal models to computational dose metric modeling. Show less
The aim of this PhD was to identify important factors that affect toxicity of copper nanoparticles (NPs), and to explore suited evaluation strategies to better understand the risk of metallic NPs... Show moreThe aim of this PhD was to identify important factors that affect toxicity of copper nanoparticles (NPs), and to explore suited evaluation strategies to better understand the risk of metallic NPs to organisms from different trophic levels. Based on this aim, the specific objectives of this PhD-thesis were: [1] To develop a framework for nanotoxicity testing to better understand the toxicity of NPs across species. [2] To apply the proposed testing framework to evaluate the toxicity of NPs, using species from different trophic levels. [3] To assess the risk of NPs by comparing the toxicity of NPs at different trophic levels. Three spherical copper NPs (CuNPs) with different diameters (25, 50 and 100 nm), one type of rod shaped CuNP (78 nm) and one type of micro copper particle (500 nm) were used in this thesis. Two types of mammalian cell lines and two types of piscine cell lines (Chapter 3), five cladoceran species (Chapter 4), three Lemnaceae species (Chapter 5) and three fish species (Chapter 6) were used to determine the toxicity of CuNPs. The species used covered different trophic levels and hence can provide systematic information for the risk assessment of CuNPs in the environment. Show less
In Dutch waters, two seal species occur namely common seals (Phoca vitulina vitulina) and grey seals (Halichoerus grypus). In the 1970s, the common seal population reached a historical low point... Show moreIn Dutch waters, two seal species occur namely common seals (Phoca vitulina vitulina) and grey seals (Halichoerus grypus). In the 1970s, the common seal population reached a historical low point after centuries of hunting, followed by exposure to pollution. Grey seals had already disappeared from Dutch waters in the preceding centuries, probably due to hunting. In this thesis, seals were studied over a period of four decades (1971-2013) in which the common seals have shown a recovery and the grey seals successfully recolonised Dutch waters. The research is conducted in the period 2006-2013 at the Seal Rehabilitation and Research Centre (Pieterburen) in collaboration with several universities. A multidisciplinary approach has been applied to learn more about the biology and pathology of seals and to obtain a comprehensive view on their status in Dutch waters. The patterns and trends in stranding were studied for both seal species, followed by a study of their current genetic status. Based on the analysis of stranding data, parasitic pneumonia (common seals only) and orphanage (both species) were found to be the main causes of stranding. Therefore, the occurrence of parasitic infections and the breeding biology of seals were studied in the following chapters. Show less
