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Aanestad, Sigurd (Doctoral thesis; Doktorgradsavhandling, 18-Sep-2009)[+][-]
URI: http://hdl.handle.net/10037/2588 File(s) in this item: 7
appendices.pdf (130.5Kb)paper_1.pdf (210.6Kb)paper_2.pdf (1.341Mb)paper_3.pdf (2.940Mb)(more files) -
Andersen, Magnus (Doctoral thesis; Doktorgradsavhandling, 16-Mar-2013)[+][-]
Abstract: Polar bears in the Barents Sea population have been protected from hunting in Russia since 1956 and following the signing of the international Polar Bear Agreement in 1973 in Norway. This thesis seeks to summarise current knowledge on key population biology issues four decades after the Norwegian protection and almost six after the Russian. Further, it discusses threats that have developed in the decades following protection against human harvesting. It concludes with a discussion of the effect of multiple stressors on the population, and some thoughts on future research, monitoring and management. Polar bears in Svalbard and the Barents Sea area have been studied during the last 40 years with the aim of gaining knowledge regarding population biology and to evaluate potential sources of impact on the population from anthropogenic activity and changes to their habitat. The initial threat to polar bears in the region was unquestionably overharvest. Polar bear numbers were reduced quite drastically and hunting was clearly not sustainable. After the harvesting was stopped, the population grew in size to an estimated 2650 (1900-3600) in 2004. We believe that population recovery led to a wider distribution of maternity denning in the Svalbard Archipelago, compared to the period just after the protection of the population in 1973. However, during recent decades, the population has faced challenges from a variety of new anthropogenic impacts. The population has been exposed to a range of pollutants and an increasing level of human presence and activity within their range. Contaminants are bioaccumulated through the trophic levels in the marine food web, culminating in this top predator that consumes primarily ringed, bearded and harp seals. Females with small cubs use the land-fast sea ice for hunting, and are vulnerable to human disturbance. Changes in sea ice conditions also affect polar bears in the region, and reduced access to denning areas on the eastern islands of Svalbard is currently a concern. A decrease in spring land-fast ice close to important denning areas could negatively affect the survival of cubs. Research and monitoring provides advice to management bodies both locally and globally. Information on the presence of toxic compounds in High Arctic systems has resulted in progress in recent decades in having better control of harmful substances and in some cases international bans on their production and use. This has resulted in declining contaminant burdens in polar bears. Unfortunately, new harmful substances are finding their way to the Arctic, while others, such as radionuclides, are stored locally (within Russian Territories) in large quantities, representing potential sources of pollution. The protection of important habitats locally with restrictions on motorized traffic may help reduce negative impacts from human activity on polar bears in the region. The fate of polar bears with regard to climate change is uncertain, but significant negative effects have been documented and these impacts are expected to increase in the coming decades. Relevant research and monitoring of polar bears is essential for future management of the species. The arctic environment should be managed in such a way that the combined effects of stressors on polar bear populations are minimized. Description: All but paper 5 of this thesis are not available in Munin:
1. Aars J, Marques T A, Buckland ST, Andersen M, Belikov S, Boltunov A & Wiig Ø.: 'Estimating the Barents Sea polar bear subpopulation size', Marine Mammal Science (2009), vol. 25(1):35-52. Available at http://dx.doi.org/10.1111/j.1748-7692.2008.00228.x
2. Andersen M, Derocher AE, Wiig Ø & Aars J.: 'Movements of two Svalbard polar bears recorded using geographical positioning system satellite transmitters', Polar Biology (2008), vol. 31:501-507. Available at http://dx.doi.org/10.1007/s00300-008-0428-x
3. Freitas C, Kovacs KM, Andersen M, Aars J, Sandven S, Mauritzen M, Pavlova O & Lydersen C.: 'Importance of fast ice and glacier fronts for female polar bears and their cubs during spring in Svalbard, Norway', Marine Ecology Progress Series (2012), 447:289-304. Available at http://dx.doi.org/10.3354/meps09516
4. Andersen M, Derocher AE, Wiig Ø & Aars J.: 'Polar bear (Ursus maritimus) maternity den distribution in Svalbard, Norway', Polar Biology (2012), vol.35:499-508. Available at http://dx.doi.org/10.1007/s00300-011-1094-y
6. Andersen M and Aars J.: 'Short-term behavioural responses of polar bears to disturbance by snowmobiles', Polar Biology (2008), vol.31:501-507. Available at http://dx.doi.org/10.1007/s00300-007-0376-x
7. Derocher AE, Wiig Ø & Andersen M.: 'Diet composition of polar bears in Svalbard and the western Barents Sea', Polar Biology (2002), vol.25:448-452. Available at http://dx.doi.org/10.1007/s00300-002-0364-0
8. Andersen M, Lie E, Derocher AE, Belikov SE, Bernhoft A, Boltunov AN, Garner GW, Skaare JU & Wiig Ø.: 'Geographic variation of PCB congeners in polar bears (Ursus maritimus), from Svalbard to the Chukchi Sea', Polar Biology (2001), vol. 24:231-238. Available at http://dx.doi.org/10.1007/s003000000201
9. Andersen M, Gwynn JP, Dowdall M, Lydersen C & Kovacs KM.: 'Radiocaesium in marine mammals from Svalbard, the Barents Sea and the North Greenland Sea', Science of the Total Environment (2006), vol. 363:87-94. Available at http://dx.doi.org/10.1016/j.scitotenv.2005.06.019URI: http://hdl.handle.net/10037/5069 File(s) in this item: 2
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Asmyhr, Lasse (Doctoral thesis; Doktorgradsavhandling, 19-Dec-2012)[+][-]
Abstract: An important aspect of ecological research is to provide guidelines and tools to wildlife managers. The ecological feature of density dependence which shapes population responses to harvest are important for wildlife management, but monitoring practices and exploiter dynamics to the changing resources and management regimes should also be included. Bag records are often collected by wildlife managers as part of their management regime, in which monitoring of the harvest is crucial. However, bag records are also commonly used as an index for population abundance and reproductive success. Bag records are valuable for their accessibility at a low cost and are used by researchers to parameterize harvest models and in studying population dynamics. However, seldom are bag records utilised as an index for abundance and reproduction, properly evaluated against abundance estimates based on count data. Moreover, which factors influence hunters’ effort and success (and hence bag size), are not well explored for many game species. In this thesis I present my aims, by means of long-term monitoring records and more short-term experimental data, are (1) to evaluate bag records of willow grouse (Lagopus lagopus) as indices for willow grouse abundance and breeding success and (2) to provide advancement in understanding of the underlying mechanisms determining the harvest rates; the hunters and their behavioural responses to willow grouse and (3) to derive implications for rational management of willow grouse populations. I found the bag size and harvest rate to be more dependent on hunter effort than on willow grouse density and breeding success. The vulnerability of grouse to harvest was different for young and adult birds; young were most vulnerable. Among adults vulnerability depended on whether they had bred successfully or not; reproductively successful adults were most vulnerable. The sex ratio of the adult grouse in the harvest tended to be male-biased, in accordance with what has been found earlier, and independent of willow grouse density and breeding success. Hunter’s daily bag size was at best weakly density dependent. The number of grouse encounters, which was independent of willow grouse density, and gender of the hunter were the two strongest determinants for daily bag size. Hunters general experience in willow grouse hunting seems highly variable and of great importance for their success in bagging grouse. Still, hunters with several years of local knowledge from the hunting area were equally efficient in bagging grouse as hunters with equal experience, but from other hunting areas. Hunters considered less experienced in grouse hunting managed to increase their Catch Per Unit Effort (CPUE) in an area from one year to the next. Less than one third of the hunters return to the same area from one year to the next and the return rate was dependent of their previous CPUE, contrary to what hunters express is important for their satisfaction. In conclusion, I urge caution in relying on bag size and harvest age ratios as indexes for willow grouse abundance and breeding success. The harvest rate was mostly determined by hunter effort and implies a potential for the regulation of hunter effort to maintain sustainable harvest rates. The finding that hunters appear to be selective towards key demographic components of willow grouse populations, such as adults with high reproductive success, suggests that this aspect of hunters’ behaviour should be taken into account when deciding on sustainable harvest levels for willow grouse populations. Description: The papers of this thesis are not available in Munin:
1. Willebrand, T., Hörnell-Willebrand, M. and Asmyhr, L.: 'Willow grouse bag size is more sensitive to variation in hunter effort than to variation in willow grouse density', Oikos (2011), vol.120, no.11:1667-1673. Available at http://dx.doi.org/10.1111/j.1600-0706.2011.19204.x
2. Asmyhr, L., Willebrand, T. and Hörnell-Willebrand, M.: 'General experience rather than of local knowledge is important for grouse hunters bag size', (forthcomming manuscript in Human Dimension of Wildlife).
3. Asmyhr, L., Willebrand, T. and Hörnell-Willebrand, M.: 'Successful adult willow grouse are exposed to increased harvest risk', Journal of Wildlife Management (2012), vol.76, no.5:940-943. Available at http://dx.doi.org/10.1002/jwmg.340
4. Asmyhr, L., Willebrand, T. and Hörnell-Willebrand, M.: 'Previous catch per unit effort (CPUE) increases rate of subsequent return and CPUE of willow grouse hunters' (manuscript).URI: http://hdl.handle.net/10037/4663 File(s) in this item: 1
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Aubert, Anaïs (Doctoral thesis; Doktorgradsavhandling, 12-Dec-2012)[+][-]
Abstract: Calanoid copepods, Calanus finmarchicus, C. glacialis and C. hyperboreus, are key species in Arctic and sub-Arctic marine ecosystems. They represent important prey for a number of species such as juvenile herring and cod because of their high but seasonally variable calorific value: they synthesize and store lipids as part of their survival strategy. Limitations in food quantity and quality can have strong impact on the copepods’ lipid synthesis and development, with implications for their predators and thus for the lipid-driven Arctic marine food web. Ecological stoichiometry, i.e. the study of the relative abundance of elements (most commonly carbon, nitrogen, and phosphorus) in biological entities, is a powerful tool to study potential limitation of aquatic organisms, particularly in primary producers and in omnivorous and herbivorous zooplankton grazers. However, studies that apply a stoichiometric approach to the high-latitude marine regions are extremely rare. The main aim of this thesis is to reveal the elemental requirements and potential limitation of high-latitude calanoid copepods by investigating their C:N:P composition in combination with information on other biochemical compounds. The impact of copepods on nutrient recycling and C:N:P export through fecal pellets is also investigated. The study was conducted in a sub-Arctic north-Norwegian fjord, and in the western part of the European Arctic Ocean, focusing on the period of intense primary production during spring. Somatic stoichiometric ratios in copepods were calculated by subtracting C in the lipid sac from the total body C. Due to the strong influence of lipid storage on total body stoichiometry, high-latitude calanoid copepods, and by implication lipid-synthesizing zooplankton in general, should be treated through a two-compartment stoichiometric approach, with lipid storage and somatic tissues separated. Both season and development stage influence the somatic elemental ratios. The somatic C:P ratios of high-latitude calanoid copepods are somewhat lower than those reported in marine copepods from other areas, suggesting that they have higher growth rates than temperate and tropical copepods. Seston C:N:P stoichiometry is used as a proxy for food quality in the calculation of copepod elemental limitation. The seston C:P and N:P ratios are among the first to be reported for the Arctic Ocean and indicate a higher relative proportion of nutrients (N and P) compared to published seston values from other marine regions. Seston C:N:P ratios varied according to bloom stage, which therefore also impacts the potential C, N or P limitation of copepods. Unless they have high assimilation efficiency for C, calanoid copepods are shown to be most likely subject to C limitation. However, variable requirements during ontogeny make specific stages, such as copepodite IV, and females more sensitive to nutrient limitation (N or P). This study is the first to present data on stoichiometric ratios including P for copepod fecal pellets in the Arctic, and shows their high potential not only to vertically export P at depth but also to provide a source of P in the upper layers during the productive season if degraded. The Arctic marine regions are experiencing the greatest climate change, and the potential future stoichiometric changes in the Arctic and how climate change affects copepod-seston interaction are discussed. Description: The papers of this thesis are not available in Munin:
1. Aubert, A.B., Svensen, C., Hessen, D., Tamelander, T.: 'CNP stoichiometry of a lipid-synthesising calanoid copepod, Calanus finmarchicus, from winter to spring bloom in a sub-Arctic sound', Journal of Marine Systems (2012), Volumes 111–112, pp.19–28. Available at http://dx.doi.org/10.1016/j.jmarsys.2012.09.004
2. Aubert, A.B., Tamelander, T.: 'Stoichiometric approach to elemental limitation of pelagic producers and grazers during the Arctic summer' (manuscript).
3. Tamelander, T., Aubert, A. B., Wexels Riser, C.: 'Export stoichiometry and contribution of copepod faecal pellets to vertical flux of particulate carbon, nitrogen and phosphorus', Marine Ecology Progress Series (2012), vol.459, pp.17-28. Available at http://dx.doi.org/10.3354/meps09733URI: http://hdl.handle.net/10037/4768 File(s) in this item: 1
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Bay-Larsen, Ingrid Agathe (Doctoral thesis; Doktorgradsavhandling, 08-Mar-2013)[+][-]
Abstract: Loss of biodiversity and fragmentation of habitats are two of the world’s persistent environmental problems. This is due to the emerging complexities, uncertainties and questions of societal scale in both defining and resolving the problems. One of the challenges connected to resolving these problems pertains to the divide between the local level, which carries the costs of restrictions and regulations of use and resource extraction, and the national and global levels, where benefits are realized in terms of multiple ecosystem services (also for future generations). Another salient challenge pertains to the divide between the aggregate level of scientific expertise about the environment and the concepts and capacities of stakeholders and their resource use. These are well-known divides that typically emerge in analyses of coupled social-ecological systems. Resolving environmental problems therefore takes place in the intersection between multiple scales, actors, agencies and competencies. The local and national/international levels are likely to differ in their perceptions of environmental problems and in their perceived needs and strategies for environmental protection. Deliberative environmental governance is increasingly a focus of the international environmental agenda, and a wide range of political programs and efforts have been launched to implement and increase the efficacy and legitimacy of environmental protection. The shift from environmental governing to governance is placing more emphasis on sectors, stakeholders and knowledge across multiple scales in environmental and other policy areas. This has added the dimension of vertical divides to persistent environmental problems in addition to the horizontal ones described above. The integration of actors, agencies and competencies across both the horizontal and vertical divides influences decision-making processes and the role and position of the environmental administration. Compared with environmental governing, deliberative environmental governance places less importance on legal instruments and formal rules, new roles for civil society, as well as trust in other institutions' expert knowledge. These shifts have implications for how the environmental administration maintains power and legitimacy for their decisions and programs. This thesis asks how Norwegian environmental administration responds to such a shift from governing to governance, in particular with respect to the empowerment of local user interests and the implementation of expert knowledge in the protection of areas and biodiversity. It also addresses how the administration utilizes the potential for combining national and local ambitions and perceptions of environmental policy. The overall research question is examined in three published articles, each answering one sub-question. Findings from these articles show that: 1) there are differing responses at the regional and national administrative levels to challenges of accountability and competence resulting from the decentralization of power; 2) the environmental administration struggles to address the inherent limitations in expert knowledge applied in environmental planning, particularly with respect to the complexities of environmental problems and how to handle scientific uncertainties; and 3) the contesters of environmental protection apply various power resources to challenge the comprehension of environmental problems upon which environmental policy rests. This thesis clearly shows how the ideals embedded in deliberative environmental governance are quickly faced with political, juridical and scientific complexities in the administrative reality. A paradox evolves as diverging strategies at administrative levels, and the lack of strategies to cope with the limitations of science, may weaken their power and position. Instead of protecting their role and the mandate of environmental programs, a further marginalizing of environmental protection may be the consequence. This thesis suggests that administrative strategies and guidelines also need to be amended in order to solve persistent environmental problems. Lessons learned from this thesis include the need to harmonize strategies across administrative levels and to develop guidelines to differentiate between users that are potential allies for nature protection (as embedded in international environmental conventions), versus the users that are capable of marginalizing the environmental administration and their legitimacy and efficiency. Environmental administration at both levels also needs to develop strategies to manage the limitations of scientific expertise (complexities and uncertainties) so that these are not used strategically to contest environmental programs. Finally, this thesis shows how the environmental administration not only deals with the protection of areas and nature, but also with the protection of discourses that regulate the administrative power, the boundaries between science and policy and the comprehension of coupled social-ecological systems. Description: The papers of this thesis are not available in Munin:
1. Ingrid Bay-Larsen: 'The conservationists’ concerns: on national administration response to integrated use and protection planning', Local Environment (2010), vol.15(4):357-371. Available at http://dx.doi.org/10.1080/13549831003677688>
2. Ingrid Bay-Larsen: 'The Premises and Promises of Trolls in Norwegian Biodiversity Preservation', Environmental Management (2012), vol. 49(5):942-953 . Available at http://dx.doi.org/10.1007/s00267-012-9837-2
3. Ingrid Bay-Larsen: 'The constitution of power in Norway’s protected areas: on shore and in the sea', Local Environment (2012), vol. 17(3):331–347. Available at http://dx.doi.org/10.1080/13549839.2012.665862URI: http://hdl.handle.net/10037/5071 File(s) in this item: 1
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Bjørkan, Maiken (Doctoral thesis; Doktorgradsavhandling, 15-Dec-2011)[+][-]
Abstract: This dissertation is about the changing relationship between science and society and the attempt to organize knowledge production and advisory processes in new ways: How can the relations between science and society be organized in a way that ensures sound advice as well as democratic ideals such as transparency and inclusion? Is it possible to relax the boundary between science and society without making it too blurry? How can arenas be built where scientists and stakeholders can cooperate effectively in knowledge production? How can lay people and their knowledge be included in advisory processes? To include stakeholders and at the same provide sound scientific advice, new solutions that require more openness in scientific processes are called for. In order to explore such solutions, the dissertation turn to the fisheries sector, where the top-down, traditional divide between science and other forms of knowledge is obvious: scientists are the experts with relevant and reliable knowledge for fisheries management. In recent decades, however, fisher stakeholders are identified as having valuable knowledge based on their experiences. Some also argue that fishers are experience based experts. But how to include them in a meaningful way, and how they are experts, are issues that are still open for debate. In Norway, the Institute of Marine Research runs a project called the Norwegian Reference Fleet, where fishers are invited to participate in knowledge production for advice. The Reference Fleet project provides a relevant framework to investigate empirically how to solve dilemmas related to the organization of knowledge production and advisory processes in more open, yet effective ways. The thesis makes a detailed account of how fishers are included by describing the knowledge chains in which they participate, and what happens to the knowledge as it is made to circulate and used for advice in fisheries management issues. Based on ethnographic methods, the Reference Fleets’ knowledge production has been followed wherever it has taken place: in laboratories and at sea; and in formal and informal settings. Theoretically, this thesis is supported by Science and Technology Studies, and Actor Network Theory in particular. The thesis aims to contribute to the on-going discourses on the 'lay expert' and how to open up science for stakeholders. It demonstrates that it is possible to include stakeholders in knowledge production for advice, and that lay people can become experts. However, it also argues that this hinges on participation at appropriate stages in the process, and that lay people, like scientists, needs access to both laboratories and authorization mechanisms in order to be included or be part of the expertise. URI: http://hdl.handle.net/10037/3770 File(s) in this item: 1
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Brattland, Camilla (Doctoral thesis; Doktorgradsavhandling, 22-Jun-2012)[+][-]
Abstract: This thesis addresses the lack of knowledge production on impacts of new marine industries on coastal Sami culture in the Norwegian coastal zone. It asks how Sami culture matters in contemporary Norwegian marine governance, and discusses how ecosystem mapping practices facilitate knowledge production on Sami relations and use of the marine environment. This is done through five papers and a film, focusing on the Porsanger and Lyngen fjords in northern Norway, analyzing 1) the characteristics of Sami fisheries and seascapes, 2) how Sami fisheries are enacted through fisheries management and Sami rights mapping practices, and 3) how knowledge is produced about Sami culture and how it is represented in ecosystem governance. What can be observed in the period since 1989 is a diversification and polarization of the coastal small-scale fishing fleet ranging from the very small-scale to the full-fledged industrial coastal fishing vessel. Fisheries governance practices as well as Sami rights mapping practices however tend to enact an image of Sami culture as uniform and having the same needs and challenges independent of social and ecological contexts, which is materialized in universal solutions to the whole population in the Sami settlement area. Current ethno-ecological governance mapping practices offer an image of Sami culture as connected to vulnerable and valuable ethno-ecological spaces to be protected from environmental threats. This materializes ethno-ecological seascapes, but it does little to materialize cultural diversity and multiple knowledge products in the coastal zone. These are mainly the Marine Resource Act (2009), the Nature Diversity Act (2009) and the Planning and Building Act (2008), following the increased political influence of the Sami Parliament through the Consultation Agreement (2005). The thesis identifies alternative local knowledge production practices as remedial actions for increasing the knowledge base on how culture and coastal societies are impacted by new industries in the coastal zone. Description: The papers and the film of this thesis are not available in Munin:
1. Brattland, Camilla and Nilsen, Steinar: 'Reclaiming indigenous seascapes. Sami place names in Norwegian sea charts', Polar Geography (2011), vol. 34, no. 4:275-297. Available at http://dx.doi.org/10.1080/1088937X.2011.644871
2. Brattland, Camilla: 'Overfishing and cyborgization in Sami fisheries. A case study of the use of traditional knowledge in small-scale fisheries in Porsanger, Norway', (submitted manuscript to Maritime Studies (MAST)).
3. Brattland, Camilla: 'Mapping rights in coastal Sami seascapes', in Arctic Review of Law and Politics (2010) vol. 1 no. 1:28-53. Available at http://lawlib.wlu.edu/CLJC/index.aspx?mainid=1724&issuedate=2011-05-09
4. Brattland, Camilla: 'Fish farming, politics and monster cod. The production of fishers‘ knowledge in the coastal zone', (forthcomming manuscript in Acta Borealia).
5. Brattland, Camilla: 'Sami fishing grounds and the missing layers of the marine environment', (manuscript submitted to Norsk Geografisk Tidsskrift – Norwegian Journal of Geography).
Ethnographic film: Wright, Reni and Brattland, Camilla: 'Learning hoavda‘s seascape' (2012), (10:36 min). Norwegian title: 'Hoavda og skårungene'. Wright kunnskapsformidling and Visual Cultural Studies, Department of Archaeology and Social Anthropology, University of Tromsø. Available at the University Library of Tromsø and Center for Sami Studies, University of Tromsø.URI: http://hdl.handle.net/10037/4267 File(s) in this item: 1
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Bårdsen, Bård-Jørgen (Doctoral thesis; Doktorgradsavhandling, 13-Feb-2009)[+][-]
Abstract: A crucial task in ecology is to quantify trade offs between competing demographic processes for experienced by individuals that inhabit unpredictable environments. Perhaps the most widely studied trade off is that between current reproduction and future survival (‘the cost of reproduction’). While experimental studies have been widely used to quantify life history strategies in birds, virtually no experimental studies have been carried out on large and free ranging mammals. This thesis quantifies how female reindeer Rangifer tarandus subject to variability in food availability, trade their resources between reproduction and body mass to ensure own survival. By combining two experiments, one observational study and one theoretical model, this thesis show that: (1) Individuals subject to reduced food availability in one winter feeding promptly reduced their reproductive allocation the following summer to increased their autumn body mass. On the other hand, short-term improved conditions did not result in increased reproductive allocation. (2) Long-term improved winter feeding conditions did, however, result in increased reproductive allocation. (3) Reproduction was costly, especially for smaller females, as occasional harsh winters and high population density resulted in reduced reproduction and lowered female body mass. Moreover, a successfully reproducing female produced a smaller offspring in the coming year relative to a barren one. Reindeer also differ in their intrinsic quality as successfully reproducing females’ showed an increased probability of reproducing also in the following year. (4) In harsh and unpredictable winter conditions, the optimal reproductive strategy involved a low reproductive allocation per unit female spring body mass. Under such conditions females increased their autumn body mass to enhance their own survival. Conversely, the optimal reproductive strategy in benign and predictable conditions involved a higher reproductive allocation. (5) Reproductive strategies and environmental conditions had significant effects on population dynamics. Female reindeer do not to jeopardize their own survival and adjust their reproductive allocation in order to buffer periods of low food availability in a risk sensitive manner. Description: Papers number 1 and 2 of the thesis are not available in Munin, due to publishers' restrictions:
1. Bårdsen, B.-J., P. Fauchald, T. Tveraa, K. Langeland, N. G. Yoccoz, and R. A. Ims: "Experimental evidence for a risk sensitive reproductive allocation in a long-lived mammal", Ecology (2008)89:829-837 (Ecological Society of America). Available at http://dx.doi.org/10.1890/07-0414.1
2. Bårdsen, B.-J., P. Fauchald, T. Tveraa, K. Langeland, and M. Nieminen: "Experimental evidence of cost of lactation in a low risk environment for a long-lived mammal", Oikos (2009)118:837-852. Available at http://dx.doi.org/10.1111/j.1600-0706.2008.17414.xURI: http://hdl.handle.net/10037/2807 File(s) in this item: 3
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Davidsen, Jan Grimsrud (Doctoral thesis; Doktorgradsavhandling, 04-Jun-2010)[+][-]
Abstract: Over the last decades, the abundances of many Atlantic salmon populations have declined drastically both due to anthropogenic and natural factors. The period when salmon enter the sea for the first time, starting as smolts in the river and subsequently as post-smolts in the fjord, is regarded as one of most critical periods in the salmon life history. In addition, salmon can also suffer from high mortality during their return migration through fjords and estuaries both due to predation and coastal fisheries. Despite an increasing number of recent Atlantic salmon migration studies, few have been conducted in northern areas which host some of the largest and most productive salmon populations in the world.
The main aim of this thesis was therefore by use of electronic acoustic tracking and video observation to study how the environment influence on the behaviour patterns of northern Atlantic salmon during their smolt migration in rivers (Tana and Alta), and as post-smolts and homing salmon during their estuary and fjord migration (Alta). Since northern areas have 24 h daylight during summer, special attention was given to the impact of light intensity on salmon migratory behaviour. This also includes a study of direct impact from light intensities on post-smolt swimming behaviour in a south-west Norwegian fjord (Hardanger Fjord) with distinctive day and night periods. Secondly, the observed behaviour of the northern Atlantic salmon was related to other important environmental factors like temperature, river flow, current, tides and wind. Finally, the survival rate of post-smolt during fjord migration, as well as the fjord residency and migratory speeds of both northern post-smolts and homing salmon, were studied for the first time for a northern salmon population. The results were compared with earlier reported findings from southern populations.
The results showed that the northern smolts, post-smolts and homing salmon migrated during both day and night in both the river and fjord. In contrast, the post-smolts in the south-western Hardanger Fjord showed distinctive changes in day and night behaviour by swimming deeper in the water column during the day than during the night. However, the northern smolt behaviour was affected by river flow and water temperature, and the post-smolts in the estuary and fjord seemed to be affected by the tidal cycle and wind-induced currents. The homing salmon were also periodically affected by wind-induced currents, and similar to the post-smolts, they migrated mainly close to the surface. Further, the homing salmon generally followed the coastline towards the river mouth, and as they approached the estuary, migratory speed was reduced by 75% and the average swimming depth reduced from 2.5 m to 0.5 m. There was no evidence that river entry of these fish was affected by tidal cycles or river flow. The post-smolts used on average only 0.8 days to migrate the first 17 km outward through the fjord (20.5 km day-1). In contrast, the homing adult salmon used 20% more time over the same distance (16.5 km day-1). Finally, the post-smolt survival rate was estimated to be 75% from the estuary and through the first 17 km of the fjord.
The findings of seemingly no difference between day and night migratory behaviour for the northern smolts and post-smolts in the present thesis may be due to the fact that nocturnal migration, as often observed for southern populations, does not provide the northern fish any benefit in regard to sight feeding predators due to the 24 h of daylight. The observed change in day and night swimming depth in the Hardanger Fjord indicated that light intensity may also affect the swimming depth of post-smolts. The relationships between migratory behaviour of northern smolts and post-smolt and water temperature, river flow and tidal cycles found in this thesis, could, as well as the adaptation to the light intensities, be antipredatory strategies.
In total, it seemed like the first-time migrants were more influenced by light, river flow, tidal cycle and fjord currents than the homing salmon. This may be due to their smaller size and higher vulnerability to predation, supported by the fact that 25% of the tagged post-smolts did probably not survive the first 17 km of the fjord migration. The high mortality rate was similar to earlier findings in southern populations during the first few days after sea entry. However, the finding that the homing salmon migrated close to the surface and shoreline, combined with their longer residency in the inner fjord, may greatly have increased their risk of being caught by net fishing targeting salmon along the shoreline in this area.
In conclusion, this thesis indicates that the migration behaviour of northern and southern salmon differ somewhat, and that this is related to local adjustments to the existing abiotic environmental factors typically for the different latitudes, in particular the light regimes. These local adaptations may be due to phenotypic plasticity and/or different genotypes. The study also highlight the post-smolts and homing salmon phases in fjords and estuaries as important bottlenecks of survival in the Atlantic salmon life cycle, and that variation in both natural and anthropogenic factors during these phases may have large impacts on their migration behaviour, performance and subsequently the total return rate of salmon to their home rivers. An evaluation of the impact from subsequent effects of interventions along the coastline in areas with migratory Atlantic salmon is highly recommended in order to avoid any negative effects on the seaward and homing migration.Description: The papers of the thesis are not available in Munin:
1. Davidsen, J., Svenning, M. A., Orell, P., Yoccoz, N., Dempson, J. B., Niemelä, E., Klemetsen, A., Lamberg, A. & Erkinaro, J.: «Spatial and temporal migration of wild Atlantic salmon smolts determined from a video camera array in the sub-Arctic River Tana», Fisheries Research 74(2005), 210-222 (Elsevier - publisher's restriction). Available at http://dx.doi.org/10.1016/j.fishres.2005.02.005.
2. Davidsen, J. G., Plantalech Manel-la, N., Økland, F., Diserud, O. H., Thorstad, E. B., Finstad, B., Sivertsgård, R., McKinley, R. S. & Rikardsen, A. H.: «Changes in swimming depths of Atlantic salmon Salmo salar post-smolts relative to light intensity», Journal of Fish Biology 73(2008), 1065-1074 (Wiley - publisher's restriction). Available at http://dx.doi.org/10.1111/j.1095-8649.2008.02004.x. Accepted version of this paper is available in Munin: http://hdl.handle.net/10037/2227
3. Davidsen, J. G., Rikardsen, A. H., Halttunen, E., Thorstad, E. B., Økland, F., Letcher, B. H., Skarðhamar, J. & Næsje, T. F.: «Migratory behaviour and survival rates of wild northern Atlantic salmon (Salmo salar) post-smolts: effects of environmental factors», Journal of Fish Biology 75(2009), 1700-1718 (Wiley - publisher's restriction). Available at http://dx.doi.org/10.1111/j.1095-8649.2009.02423.x. Accepted version of this paper is available in Munin: http://hdl.handle.net/10037/2431.
4. Davidsen, J. G., Rikardsen, A. H., Halttunen, E., Mitamura, H., Thorstad, E. B., Præbel, K., Skarðhamar, J. & Næsje, T. F.: «Homing behaviour of Atlantic salmon during final marine phase and river entry» (manuscript).URI: http://hdl.handle.net/10037/2480 File(s) in this item: 1
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Degerlund, Maria (Doctoral thesis; Doktorgradsavhandling, 18-Oct-2011)[+][-]
Abstract: The choice of species concept when delineating phytoplankton species is decisive for our knowledge of species diversity and distribution, but will also affect our understanding of the functioning of marine ecosystems. This is particularly true for so-called cryptic species, which may show high degree of genetic and physiological heterogeneity although being morphologically similar. A precise species delimitation procedure appreciating the value of genotypic as well as phenotypic traits is therefore important. In this thesis, species concepts and functional aspects in abundant cold-water diatoms were investigated using biogeographic (species presence and abundance), taxonomic (morphological and molecular data), and functional (experimental physiological and metabolomics data) tools. A compilation of multiannual phytoplankton species abundance data gathered during the spring bloom period from north-east Atlantic and Arctic waters (68-80oN) revealed high similarities in associations of the most abundant species. Spring associations were dominated by the diatom Chaetoceros socialis and the prymnesiophyte Phaeocystis pouchetii. A corresponding investigation of the winter period in this area could not identify associations of actively growing, autotrophic phytoplankton species. Change in species composition and abundance in time could not be assessed due to lack of consistency and regularity in sampling. A high-resolution time series of phytoplankton distribution is therefore needed in this area. A case study of the so-called cosmopolitan diatom C. socialis was performed using strains from north-east Atlantic/Arctic and from Mediterranean waters. By applying a phylo-phenetic species concept the two geographical populations were found to be pseudo-cryptic. They were genetically distinct, but only slight morphological differences were observed, in this case in resting spore morphology. Furthermore, when cultivated at 2.5, 8 and 13oC, the two groups of strains were functionally different in terms of growth rates (doublings day-1), photosynthetic efficiency (maximum quantum yield), and metabolic profiles. Our results do not support the assumed cosmopolitan distribution of C. socialis and therefore the present taxonomy of this species will need revision. A taxonomic update of the pseudo-cryptic diatom formerly known as Skeletonema costatum indicated that the species present in northern Norwegian and Barents Sea waters is identical to S. marinoi. Due to reports of high genetic, metabolic, and physiological diversity within this species, a functional approach would be valuable for understanding the ecology of S. marinoi in this area. Integrated approaches combining taxonomic and functional variables are recommended for future taxonomic work on phytoplankton species. Similarly, phytoplankton ecologists are urged to acknowledge the high degree of hidden taxonomic and functional diversity present in several phytoplankton species. Functional diversity studies are suggested to be a useful spot for integration and eventual modelling phenotypic, genotypic and ecological species data. Ultimately, such an approach should be beneficial also at the ecosystem level. Description: The papers of this thesis are not available in Munin:
1. Degerlund M and Eilertsen HC: 'Main species characteristics of phytoplankton spring blooms in NE Atlantic and Arctic waters(68–80°N)', Estuaries and Coasts (2010) 33: 242-269. Available at http://dx.doi.org/10.1007/s12237-009-9167-7
2. Eilertsen HC and Degerlund M: 'Phytoplankton and light during the northern high-latitude winter', Journal of Plankton Research (2010) 32: 899-912. Available at http://dx.doi.org/10.1093/plankt/fbq017
3. Degerlund M, Huseby S, Zingone A, Sarno D and Landfald B: 'Functional diversity in cryptic species of Chaetoceros socialis Lauder (Bacillariophyceae)' (submitted paper to Journal of Plankton Research).
4. Huseby S, Degerlund M, Zingone A and Hansen, E: 'Metabolite fingerprinting and physiology of the cryptic diatom Chaetoceros socialis Lauder' (manuscript)URI: http://hdl.handle.net/10037/3679 File(s) in this item: 1
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Donnelly, Kathryn Anne-Marie (Doctoral thesis; Doktorgradsavhandling, 04-Nov-2010)[+][-]
Abstract: The globalisation and intensification of food production has led to food related health incidents. These incidents range from BSE in cattle to illegally high levels of dioxins in chicken feed (Carriquiry and Babcock, 2007, Caswell, 2000, Elbers et al., 2001, Fallon, 2001, Hobbs, 2004, Madec et al., 2001, Ozawa et al., 2001, Sporleder and Goldsmith, 2001). The modern consumer is increasingly concerned with quality, sustainability and the possible health benefits related to the food that they eat (Chryssochoidis et al., 2008, Gellynck and Verbeke, 2001, Kehagia et al., 2007, van Rijswijk and Frewer, 2008). There is an increasing need for information when consumers are no longer familiar with the production attributes of their food (Carriquiry and Babcock, 2007, Kiesel et al., 2005, Pettitt, 2001). In this research features such as systematic information loss and lack of unique identification were identified as inhibitors of traceability. Standardisation of data elements for electronic information exchange and the identification of critical traceability points were identified as important activators. Description: Papers 2-7 are not available in Munin, due to publishers' restrictions:
2. Donnelly, K.A-M., Karlsen, K.M. and Olsen, P. (2009) 'The importance of transformations for traceability', Meat Science, 83 pp 68-73.
3. Karlsen, K.M:, Olsen, P. and Donnelly K. A-M., (2009) 'Implementing traceability: Practical challenges at a mineral water bottling plant', British Food Journal 112 (2) pp 187-197.
4. Donnelly, K.A-M. and Karlsen, K.M. (2010) 'Lessons from two case studies in implementing traceability in the dried salted fish industry'. Journal of Aquatic Food Product Technology, 19 (10) pp 38-47.
5. Donnelly, K.A‐M., Karlsen, K.M., Olsen, P. and van der Roest, J. (2008) 'Creating standardised data lists for traceability: a study of honey processing', Int. J. Metadata, Semantics and Ontologies, Vol. 3 (4) pp 283–291.
6. Donnelly, K.A‐M., Roest, J. V. D., Hoskuldsson, S. T., Olsen P. and Karlsen K.M., (2009) 'Improving information exchange in the chicken processing sector using standardised data lists'. Communications in Computer and Information Science, 46, pp 312‐321.
7. Thakur, M, and Donnelly, K.A‐M, (2010) 'Modelling traceability information in soyabean value chains', Journal of Food Engineering, 99(1) pp 98-65.URI: http://hdl.handle.net/10037/2891 File(s) in this item: 3
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Eide, Arne (Doctoral thesis; Doktorgradsavhandling, 14-Nov-2008)[+][-]
Description: This is a Dr. philos. thesis.
Papers number 1, 2, 4 and 7 of the thesis are not available in Munin:
1. Arne Eide, Frode Skjold, Frank Olsen and Ola Flaaten: 'Harvest Functions: The Norwegian Bottom Trawl Cod Fisheries', Marine Resource Economics, Volume 18, pp. 81–93 (MRE Foundation - publisher's restrictions). Available at http://purl.umn.edu/28294
2. Arne Eide and Knut Heen: 'Economic impacts of global warming. A study of the fishing industry in North Norway', Fisheries Research 56 (2002) 261–274 (Elsevier - publisher's restrictions). Available at http://dx.doi.org/10.1016/S0165-7836(01)00324-1
4. Arne Eide: 'An integrated study of economic effects of and vulnerabilities to global warming on the Barents Sea cod fisheries', Climatic Change (2008) 87:251–262 (Springer - publisher's restrictions). Available at http://dx.doi.org/10.1007/s10584-007-9338-0
7. Arne Eide & Arild Wikan: 'An Analysis of a Nonlinear Stage-Structured Cannibalism Model with Application to the Northeast Arctic Cod Stock', Bulletin of Mathematical Biology (2004) 66, 1685–1704 (Elsevier - publisher's restrictions). Available at http://dx.doi.org/10.1016/j.bulm.2004.03.005URI: http://hdl.handle.net/10037/2399 File(s) in this item: 4
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Elverland, Ellen (Doctoral thesis; Doktorgradsavhandling, 26-Oct-2012)[+][-]
Abstract: This thesis shows that Late Weichselian vegetation on Andøya may have been more diverse than previous studies have revealed. The thorough investigation of macrofossils in four parallel cores provides more reliable evidence for interpreting changes in vegetation cover than reconstructions based on a single core. The botanical macrofossils retrieved in this study largely support previous studies at the northern tip of Andøya. Arctic plant communities, probably dominated by Papaver and several species of Poaceae and Brassicaceae characterized the area. Climatic ameliorations occurred at c. 22 000 – 20 100, 20 100 – 19 500, 19 500 – 19 200, 18 800 – 18 100, 17 500 – 16 800 and 15 100 – 14 500 cal. yr BP, and during these ameliorations, the vegetation may have been more diverse than recorded both in the pollen- and macrofossil material. Macrofossils (bones) of little auk (Alle alle), coupled with other evidence, suggest a longlasting presence of sea birds in the area. Manuring by birds made a considerable impact on the local terrestrial environment, and during the ameliorations in particular, these favorable local habitats may have supported species not found in the present-day Arctic, e.g. Urtica dioica. Sedimentary ancient DNA (sedaDNA) provides evidence that during the ameliorations, Andøya may have hosted small enclaves of boreal conifer trees. Their presence on Andøya has yet to be detected by macrofossil- or pollen analyses, but the DNA evidence provides an important contribution to the debate concerning glacial survival of boreal trees within Scandinavia. Description: The papers of this thesis are not available in Munin:
1. Elverland, E. & Alm, T.: 'High resolution macrofossil analysis of Late Weichselian Arctic lacustrine sediments on Andøya, northern Norway' (manuscript)
2. Elverland, E., Bjerke, J.W. & Alm, T.: 'Is one core enough? A study of the intrasite macrofossil variability of a Late Weichselian lacustrine record on Andøya, North Norway' (manuscript)
3. Alm, T. & Elverland, E.: 'A Late Weichselian Alle alle colony on Andøya, northern Norway : a contribution to the history of an important Arctic environment' (manuscript)
4. Parducci, L., Jørgensen, T., Tollefsrud. M.M., Elverland, E., Alm, T., Fontana, S.L., Bennett, K.D., Haile, J., Matetovici, I., Suyama, Y., Edwards, M.E., Andersen, K., Rasmussen, M., Boessenkool, S., Coissac, E., Brochmann, C., Taberlet, T., Houmark-Nielsen, M., Krog-Larsen, N.,Orlando, L., Gilbert, M.T.P., Kjær, K.H., Alsos, I.G. & Willerslev: 'Glacial Survival of Boreal trees in Northern Scandinavia', Science (2012) vol.335 no.6072:1083-1086. Available at http://dx.doi.org/10.1126/science.1216043URI: http://hdl.handle.net/10037/4565 File(s) in this item: 1
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Falk-Petersen, Jannike (Doctoral thesis; Doktorgradsavhandling, 12-Jun-2012)[+][-]
Abstract: The red king crab (Paralithodes camtschaticus) is a highly valuable resource that also represents a potential threat since it is an alien invasive species in the Barents Sea ecosystem. This thesis explores the use of different interdisciplinary frameworks to analyse how ecological, social and economic concerns could be accounted for in deciding on how the king crab should be managed in the Norwegian part of the Barents Sea. Clarification of terminology used in invasion biology and systematisation of ecological information in order to establish the ecological knowledge base for management forms the basis for further analysis. Bio-economic modelling and discourse analysis are used to explore how uncertainty and the range of services the ecosystem provides can be incorporated in management. Finally the use of ecosystem service frameworks to integrate ecosystem and social science research in ecosystem based management is discussed. The ecological review revealed numerous knowledge gaps in our understanding of how the king crab interacts with native biota. It also identified negative impacts on benthic ecosystems that provide supporting services, and on provisioning services through predation on eggs of commercial fish. Bio-economic analysis illustrated the need to identify the correct relationship between crab stock size and ecosystem damage. It also showed that optimal harvest of king crab cannot be reconciled with the Barents Sea management goal of securing the ecosystem structure. The discourse analysis showed that people recognise both positive and negative impacts of the crab on supporting, provisioning and cultural services. In addition the impacts on ecosystem services we do not have the knowledge to value today, or option values, were important in forming people’s perception on how the crab should be managed. This thesis demonstrates that while the natural sciences have a clear role to play in establishing the ecological knowledge base, uncertainty and the need to account for stakeholder concerns calls for integration of social science research in the management process. Ecosystem service frameworks can be useful tools for identification, integration and evaluation of such information. Description: The papers of this thesis are not available in Munin:
1. Falk-Petersen, J, Bøhn, T. and Sandlund, O.T.: 'On the numerous concepts in invasion biology', Biological Invasions (2006), 8: 1409-1424. Available at http://dx.doi.org/10.1007/s10530-005-0710-6
2. Armstrong, C.W. and Falk-Petersen, J.: Habitat-fisheries interactions : a missing link?', ICES Journal of Marine Science (2008), 65: 817-821. Available at http://dx.doi.org/10.1093/icesjms/fsn092
3. Falk-Petersen, J., Renaud, P. and Anisimova, N.: 'Establishment and ecosystem effects of the alien invasive red king crab in the Barents Sea', ICES Journal of Marine Science (2011), 68 (3): 479-488. Available at http://dx.doi.org/10.1093/icesjms/fsq192
4. Falk-Petersen, J. and Armstrong, C.: 'To have one’s cake and eat it : managing the alien invasive red king crab stock' (submitted manuscript).
5. Falk-Petersen, J.: 'Option lost or opportunity gained? Perceptions on the Barents Sea red king crab invasion', (submitted manuscript).URI: http://hdl.handle.net/10037/4236 File(s) in this item: 1
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Figenschou, Lars (Doctoral thesis; Doktorgradsavhandling, 12-May-2010)[+][-]
Abstract: This thesis illuminates several aspects of mate choice and sexual selection in a species with external fertilization and no parental care. At a general level we have contributed to the basic framework within evolutionary biology and ecology and at a more specific level, as the proximate mechanisms controlling the associations between immune response, parasite intensities and traits indicative of sperm quality are not straightforward, we examined the effect of increased immunological activity on sperm traits. Our results have established the significance of male social status, and in the two inter-disciplinary studies, showed that parasitized and infected males seem to invest more in sperm quality, less in ornamental development and adapt to sperm competition (i.e., subordinate mating tactic). Thus, as reproductive decisions in charr seem to be strongly influenced by parasites and antigens, host parasite co-evolution may have been a significant mechanism in the maintenance and evolution of both male sexual behaviour and ornamentation. Description: Papers number 1, 3, 4, 5 and 6 of the thesis are not available in Munin:
1. Figenschou, L., Folstad, I. & Liljedal, S.: «Lek fidelity of male Arctic charr», Canadian Journal of Zoology, 82(2004): 1278-1284 (National Research Council Canada - publisher's restrictions). Available at http://dx.doi.org/10.1139/z04-106
3. Rudolfsen, G., Figenschou, L., Folstad, I., Tveiten, H. & Figenschou, M.: «Rapid adjustments of sperm characteristic in relation to social status», Proceedings of the Royal Society of London, Series B-Biological Sciences, 273(2006): 325-332 (publisher's restrictions). Available at http://dx.doi.org/10.1098/rspb.2005.3305
4. Figenschou, L., Rudolfsen, G., & Folstad, I.: «Female Arctic charr do not show apparent benefits from exposing their eggs to sperm from dominant males», Journal of Fish Biology, 71(2007): 284–289 (Wiley - publisher's restrictions). Available at http://dx.doi.org/10.1111/j.1095-8649.2007.01477.x
5. Figenschou, L., Skau, P.A., Folstad, I., Rudolfsen, G., Hanssen, S.A., Kortet, R., Killie, J.E., Oskam, I. & Strand, H.: «Parasite intensities and male social status as modifiers of sperm production and sperm swimming speed in the Arctic charr (Salvelinus alpinus)» (manuscript)
6. Figenschou, L., Skau, P.A., Folstad, I., Rudolfsen, G., Hanssen, S.A., Kortet, R., Killie, J.E. & Strand, H.: «Immune activation leads to reproductive compensation in Arctic charr (Salvelinus alpinus)» (manuscript)URI: http://hdl.handle.net/10037/2639 File(s) in this item: 2
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Flåten, Ola (Doctoral thesis; Doktorgradsavhandling, 1990)[+][-]
Abstract: This is a thesis on the utilization of renewable resources with species interactions, within the field of natural resource economics. It comprises theoretical analysis as well as empirical application of the theory to the fisheries of the Barents Sea and adjacent areas. URI: http://hdl.handle.net/10037/1659 File(s) in this item: 5
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Fredriksen, Børge Nilsen (Doctoral thesis; Doktorgradsavhandling, 07-Jun-2012)[+][-]
Abstract: Vaccines are regarded as the safest and most cost-effective strategy to prevent infectious diseases. For some diseases, vaccine improvements are required as protection levels are still inadequate. The key to solving this challenge might lie in the development of more efficacious vaccine delivery systems and adjuvants. Poly (lactide-co-glycolide) (PLGA) is a biodegradable polymer which has an extensive safety record in biological systems and possesses immunological adjuvant properties as injectable particles. In the present work, micro- and nanoparticles of PLGA and PLA were explored as a vaccine delivery system in Atlantic salmon (Salmo salar). The overall objectives were to investigate their adjuvant abilities in provoking innate and adaptive immune responses, forming antigen depots and inducing protective immunity in a challenge test with infectious pancreatic necrosis virus (IPNV). Formulation parameters in preparation of polymeric particles were systematically optimized (paper IV) to achieve stable PLGA particle products containing co-entrapped model antigens and β-glucan (paper I and II), or virus particles of infectious pancreatic necrosis virus (IPNV) (paper III). Post immunization potency of nanoparticles (300-400 nm) was demonstrated by their ability to induce early innate responses (day 2, 4 and 8) at transcription levels equal to or higher than the oil-adjuvanted formulation (paper I). Temporal differences in expression levels of innate markers were observed, suggesting rapid systemic distribution of particles (paper I). By tracing of isotope labelled proteins, nanoparticles (˂ 1000 nm) were found to localize antigens in the head kidney while micro-sized (~ 8 µm) particles generally retained antigen at the injection site. Irrespective of size, particles made of polymers with high molecular weight (MW) generally had superior depot capabilities compared to their low MW counterparts (paper II). Adaptive immune responses to immunization were assessed by QPCR and ELISA. T cell markers were not differentially expressed at the selected early time points (paper I), but at day 60 and 75 antibody responses were found to be elevated (paper II and III). In a dose-response study, micro- but not nanoparticles were demonstrated to be equally potent compared to the oil-adjuvanted control group with regard to induction of antibody responses. Long-term antibody responses induced by particles were generally less robust and therefore declined towards the end of the experimental period (120 days), while responses induced by the oil-adjuvanted formulation progressively increased. Following immunization, antibody responses were not related to polymer qualities or the ability of particles to depot or distribute antigens. Scoring of side effects demonstrated excellent safety profiles for the particle formulations (paper II and discussed in paper V). In paper III, vaccine efficacy was tested in a cohabitation challenge with IPN. Survival rates for the nanoparticle vaccinated groups were comparable to the non-vaccinated control fish and demonstrated that their ability to induce protection against IPN was inferior to the oil-adjuvanted vaccines. Virus re-isolation from head kidney and blood during the challenge period did however demonstrate some level of protection as the nanoparticle vaccinated groups were able to delay the IPNV infection. In the presented studies, the principal adjuvant properties of PLGA particles in Atlantic salmon have been demonstrated to include their capacity to induce strong innate responses and provide antigen depots for long-term delivery of antigens. In addition, indication of particle presence in lymphoid organs was an interesting finding that could suggest a certain targeting effect to phagocytic cells. To achieve a better understanding of how PLGA particles may be used to direct immune responses in salmon, more detailed studies on particle qualities-cell interactions/responses are required. Description: Papers 1-4 of this thesis are not available in Munin:
1. B.N. Fredriksen, K. Sævareid, L. McAuley, M.E. Lane, J. Bøgwald and R.A. Dalmo.: 'Early immune responses in Atlantic salmon (Salmo salar L) after immunization with PLGA nanoparticles loaded with a model antigen and β-glucan', Vaccine (2011) 29(46):8338-8349. Available at http://dx.doi.org/10.1016/j.vaccine.2011.08.087
2. B.N. Fredriksen and J. Grip.: 'PLGA/PLA micro- and nanoparticle formulations serve as antigen depots and induce elevated humoral responses after immunization of Atlantic salmon (Salmo salar L)', Vaccine (2012) 30(3):656-667. Available at http://dx.doi.org/10.1016/j.vaccine.2011.10.105
3. H.M. Munang‟andu, B. N. Fredriksen, S. Mutoloki, B. Brudeseth, T.Y. Kuo, I. S. Marjara, R.A. Dalmo and Ø. Evensen.: 'Comparison of vaccine efficacy for different antigen delivery systems for infectious pancreatic necrosis virus vaccines in Atlantic salmon (Salmo salar L)' (submitted manuscript).
4. B.N. Fredriksen, L.B. Hølvold, J.Bøgwald and R.A. Dalmo.: 'Optimization of formulation variables to increase antigen entrapment in PLGA particles' (submitted manuscript).URI: http://hdl.handle.net/10037/4153 File(s) in this item: 2
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Fuss, Janina (Doctoral thesis; Doktorgradsavhandling, 11-May-2012)[+][-]
Abstract: The endosymbiosis-derived organelles within a plant cell, plastids and mitochondria, have to be equipped with a certain set of proteins to be fully functional. This set of proteins is encoded by different genomes: the organellar genomes and the nuclear genomes. This setup poses some interesting challenges for the regulation of gene expression and protein transport. On the one hand, the targeting signals that transport proteins to the organelles have to be highly specific and on the other hand, the communication between the DNA containing compartments to coordinate their gene expression has to be transmitted somehow, not only from the nucleus but also from the organelles back to the nucleus. In this thesis, two prediction programs are introduced. One of them can predict dual targeted proteins to both organelles (ATP, ambiguous targeting predictor) and the other one is species- specific for Physcomitrella patens (GTP_Pp; green targeting predictor – P. patens-specific). The first predictor can help to gain a more complete picture of the proteins potentially present in the organelles. With the help of that predictor, we predicted that the amount of proteins with dual targeting signals is higher than anticipated and that we to date know only a minor part of actually dual targeted proteins. The second predictor can help to answer the question on the evolutionary consistency of targeting signals within the plant kingdom and the importance of having species-specific approaches in analyzing protein targeting. We actually observed a surprisingly big difference in composition and recognition of mitochondrial and dual-targeting protein signals, which led to the conclusion, that species-specific approaches always should be considered as the optimal option for both, in silico and in vivo experiments. The second part of this thesis focuses the mechanisms of communication between nucleus and the organelles, especially the plastid possibly mediated by dual targeting. We chose several plastid RNA-/DNA-binding proteins to analyze their sub-plastidic localization and their potential additional nuclear localization. Those candidates were AtWHY1 (Arabidopsis thaliana Whirly1), four members of the AtcpRNP (chloroplast ribonucleoprotein) family and AtEF-Tu (elongation factor thermo-unstable). The analyzed members of the AtcpRNP family reflect their described multiple functions within the plastid also in a multiple localization pattern. Furthermore, we were able to show interactions of different members of the AtcpRNP family by yeast-two-hybrid interaction assays. The localization pattern of AtEF-Tu was very similar to the one observed for the AtcpRNPs, which indicated, together with a confirmed localization within the transcriptionally active chromosome, a multiple function for AtEF-Tu. The sub-plastidic localization data suggest overlapping networks of activity for the proteins by observed co-localizations. This was also shown with respect to several marker proteins for plastid functions. For AtEF-Tu and the AtcpRNPs, we also showed experimentally that a second localization in the nucleus is possible for the mature protein, which makes them interesting candidates for a possible mediation of plastid signals to the nucleus next to AtWHY1. For AtWHY1, we were able to show an effect of the DNA binding domain on the known localization pattern which seemed to reflect an aberration in transport processes through the envelope. This offers a potential regulatory mechanism that needs to be explored in detail in the future. Description: Papers 1, 3, 4 and 5 are not available in Munin:
1. Mitschke J, Fuss J, Blum T, Hoglund A, Reski R, Kohlbacher O and Rensing SA.: 'Prediction of dual protein targeting to plant organelles', New Phytologist (2009), 183(1): 224-235. Available at http://dx.doi.org/10.1111/j.1469-8137.2009.02832.x
3. Herrmann U, Fuss J, Krupinska K and Krause K.: 'Moonlighting in plastids : translation elongation factor EF-Tu is a component of chloroplast transcriptionally active chromosomes' (manuscript I submitted to Current Genetics).
4. Fuss J, Krause K.: 'Co-Localization and interaction of ribonucleoproteins in chloroplasts of Arabidopsis thaliana' (manuscript II).
5. Fuss J, Liegmann O, Krause K and Rensing SA.: 'Can Arabidopsis thaliana read the messages from Physcomitrella patens and vice versa? : an analysis on the conservation of targeting signals' (manuscript III submitted to New Phytologist).
6. Fuss J, Krause K.: 'The DNA binding domain of a Whirly protein from Arabidopsis thaliana is engaged in protein translocation across the plastid envelope membrane' (manuscript IV).URI: http://hdl.handle.net/10037/4154 File(s) in this item: 2
paper_2.pdf (541.8Kb)thesis.pdf (1.509Mb) -
Glorvigen, Petter (Doctoral thesis; Doktorgradsavhandling, 06-Dec-2012)[+][-]
Abstract: The multiannual population cycles in small rodents have triggered an intense debate between proponents of population-intrinsic and community-extrinsic factors as the cycle generating mechanisms. A well-known challenge is the apparent absence of vole individuals during the low phase of the population cycle and the fact that most studies addressing vole and lemming behaviour and demography are conducted at high to moderate population densities. Overall this thesis aim to (1) present new insight for the least studied phase(s)of the vole population cycles: specifically the role of colonisation processes in the transition from small isolated populations in the low-phase to the spatially extensively distributed populations in the peak phase of the cycle, and (2) provide an updated view on how population-intrinsic and community-extrinsic processes may interact during the vole population cycles. The first experiment documented that colonisation is a beneficial strategy in female bank voles (Myodes glareolus) compared to immigration. The second experiment demonstrated that the first born cohort of root voles (Microtus oeconomus) emigrating in early summer have large capacity for colonising spatially scattered habitat patches – a capacity that explains the fast recolonistation of empty habitat space following crashes in cyclic populations. These experimental results also gave evidence for presence of social fences around high quality habitats at low population density. Hence, in the increase phase voles seem to actively search for vacant habitats and settle in them conditional on habitat quality and population density. An observational study of a riparian mainland-island root vole metapopulation confirmed that such patchy populations with cyclic dynamics may be subject to extensive occupancy dynamics. However, owing to high capacities for dispersal and habitat tracking, voles rapidly colonised the high quality islands across the entire metapopulation landscape that previously had gone extinct due to demographic (small population size) and environmental (high water levels) stochasticity. In total, the experimental and observational studies show that spatially scattered (sub)populations that have survived the crash phase are able to provide colonists to remote habitat patches embedded in hostile matrix and thus pave the way to a new increase and peak phase. The updated view on the causes of population cycles in voles emphasises the important role of dispersal (colonisation) and sociality in all phases of the cycle. It is not claimed that intrinsic mechanisms, either alone or in interactions with extrinsic factors, are necessary for generating multiannual cycles. Rather that the interaction between extrinsic and intrinsic factors likely contribute to shape rodent population dynamics, and that different innate propensities for sociality and dispersal among different rodent species may be related to interspecific variation in topology of the cycles (i.e. cycle shape and amplitude) and degree of spatial population synchrony. Description: The papers of this thesis are not available in Munin:
1. Glorvigen, P., Bjørnstad O.N., Andreassen, H.P. and Ims, R.A.: 'Settlement in empty versus occupied habitats : an experimental study on bank voles', Population Ecology (2012), vol. 54:55-63. Available at http://dx.doi.org/10.1007/s10144-011-0295-0
2. Glorvigen, P., Gundersen, G., Andreassen, H.P. and Ims, R.A.: 'The role of colonization in patchy population dynamics of a cyclic vole species' (manuscript).
3. Glorvigen, P., Andreassen, H.P. and Ims, R.A.: 'Relative importance of habitat geometry, habitat quality, population size and environmental stochasticity on occupancy dynamics in a riparian mainland-island root vole metapopulation', (manuscript).
4. Andreassen, H.P., Glorvigen, P., Rémy, A. and Ims, R. A.: 'New views on how population-intrinsic and community-extrinsic processes interact during the vole population cycles' (manuscript)URI: http://hdl.handle.net/10037/4655 File(s) in this item: 1
thesis.pdf (2.547Mb) -
Halttunen, Elina (Doctoral thesis; Doktorgradsavhandling, 19-Aug-2011)[+][-]
Abstract: Summary Atlantic salmon (Salmo salar L.) repeat-spawners might play an important role in population persistence by increasing both total recruitment and long-term stability of a population. This is because repeat spawners return at larger sizes and with greater fecundity than first time spawners, and the large majority of repeat-spawners are females. Nevertheless, little knowledge exists of this potentially significant population sub-unit. We conducted a four-year field study in the River Alta, Northern Norway, using acoustic and radio telemetry combined with scale sample analysis and mark recapture, with the aim of 1) assessing the survival and migration patterns after spawning, 2) assessing the post and repeat-spawner mortality in the fisheries, and 3) quantifying the returning rate of post spawning females. These results were further used in combination with historical catch-records from both sea and in-river fisheries to 4) model the repeat spawning rate in the female population and the significance of repeat spawning for egg production during fluctuating maiden runs. We found that 1) survival after spawning and early marine migration was high (63-80% and 96%, respectively), and that the post-spawners (kelts) in best condition waited longest in the river before migrating. 2) The fisheries mortality was low (4%) when exiting the river and fjord, and moderate (11 %) when re-entering the fjord and river upon return. 3) Female survival until spawning was on average 32 %, and 4) according to model simulations, on average 20% of the female population consisted of repeat-spawners, which might have an important stabilizing function reducing fluctuations in a population by contributing an average of 27% (2%-59%) of all the eggs spawned in the river. We conclude that the post-spawners have high survival both in the river and the sea despite their weakened condition after spawning and overwintering in the river, and that repeat-spawners might contribute significantly to Atlantic salmon production. Their numeric and genetic contribution might be especially important during declining and fluctuating populations as a buffer against poor maiden recruitment years. Therefore post- and repeat-spawners are worthy of special conservational attention and management measures. Description: The papers of this thesis are not available in Munin:
1. Elina Halttunen, Audun H. Rikardsen, Jan G. Davidsen, Eva B. Thorstad and J. Brian Dempson: 'Survival, migration speed and swimming depth of Atlantic Salmon Kelts during sea entry and fjord migration', Reviews: Methods and Technologies in Fish Biology and Fisheries (2009) Volume 9, Part I, Part 1, 35-49. Available at http://dx.doi.org/10.1007/978-1-4020-9640-2_3
2. Elina Halttunena, Audun H. Rikardsen, Eva B. Thorstad, Tor F. Næsje, Jenny L.A. Jensen and Øystein Aas: 'Impact of catch-and-release practices on behavior and mortality of Atlantic salmon (Salmo salar L.) kelts', Fisheries Research (2010) vol 105, 141–147. Available at http://dx.doi.org/10.1016/j.fishres.2010.03.017
3. Elina Halttunen, Jenny Lovisa Alexandra Jensen, Tor Fredrik Næsje, Jan Grimsrud Davidsen, Eva Bonsak Thorstad, Cedar Marget Chittenden, Sandra Hamel, Raul Primicerio and Audun Håvard Rikardsen: 'State-dependent migratory behaviour of post-spawned Atlantic salmon (Salmo salar)' (unpublished paper).
4. Elina Halttunen, Audun Håvard Rikardsen, Ola Ugedal, Eva Bonsak Thorstad, Jenny Lovisa Alexandra Jensen and Tor Fredrik Næsje: 'The significance of repeat spawning for the production of Atlantic salmon (Salmo salar)' (unpublished paper).URI: http://hdl.handle.net/10037/3536 File(s) in this item: 1
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