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This thesis describes the seasonality of the mesozooplankton community in Ramfjord, a shallow high-latitude fjord, in terms of diversity and behavior, using a combination of new and traditional methods. The approach aimed to gain insight into how environmental drivers such as photoperiod and food availability shape seasonal changes in mesozooplankton community structure and Calanus spp. behavior. Seasonal changes in diel vertical migration (DVM) were closely linked to the seasonal changes in day length. Monthly sampling over an entire annual cycle revealed that Ramfjord has particular characteristics such as the dominance of small copepods year-round in terms of abundance and biomass and a population of Calanus finmarchicus that enters a winter resting state rather than a diapause stage. This investigation also used metabarcoding as a quantitative tool for the first time, demonstrating the usefulness of this method in establishing the mesozooplankton community structure. Monthly monitoring of Calanus spp. swimming activity with the locomotor activity method confirmed the efficiency of this method in detecting overwintering in the Calanus population and determined that swimming activity can be used as a proxy for DVM behavior. This thesis demonstrates that the combination of newly developed methods (locomotor activity monitor and metabarcoding as a quantitative tool) with more traditional methods, such as visual identification and active acoustics, can provide new understanding of seasonal changes in the mesozooplankton community structure and behavior.

Small copepods (≤ 2 mm) are highly abundant mesozooplankton in Arctic and sub-Arctic marine ecosystems. However, small copepods are generally underestimated in zooplankton studies because of the use of large-meshed nets (≥ 180-µm mesh size) and are relatively poorly studied compared to large copepods. This thesis investigates the egg hatching rates, population dynamics and production rates of three abundant small copepod species in high-latitude ecosystems: Oithona similis, Microsetella norvegica, and Microcalanus pusillus. The egg hatching rates were investigated at between 1.3°C and 13.2°C by incubating ovigerous females. Field work was conducted in three sub-Arctic fjords and around Svalbard to obtain the biomass, age structure, and production of the populations sampled with a 64-µm mesh net. The egg hatching rates had various species-specific temperature response, which suggested different thermal plasticity among the three similar-sized species. The population dynamics of the three studied species also showed different patterns. M. norvegica has a time-limited reproduction resulting in a short but intense reproductive season and overwintering as adults. In contrast, O. similis and M. pusillus have continuous reproduction, where winter is used as recruitment period for a second generation. The most important findings of this thesis is the high biomass and production revealed by the quantitative sampling of small copepods. The biomass and production of small copepods could be equal to or even higher than that of large copepods, regardless of the season but with large spatial and interannual variations. In Balsfjord, the total production of the three small copepods could equal 0.3 to 27% of the primary production, meaning that small copepods have a significant role in the food web and carbon cycling of high-latitude ecosystems.

This thesis examines efficiency in the retail industry in two different directions. In the first setting, the link between inventory efficiency and performance is examined in relation to firm characteristics and exogenous explanatory variables. More specifically, in addition to general firm-specific characteristics, the effects of chain affiliation and time trends within retail chains is examined. The effects of business environment factors on inventory turnover are examined on the basis of geographic location and market conditions. In the customer efficiency setting, efficiency is studied by observing customers’ in-store behaviours to identify how specific customer characteristics in general, and the use of in-store carrying equipment in particular, are associated with shopper efficiency. These two avenues for detecting important retail efficiency metrics are examined in three individual research papers. The papers empirically demonstrate two different perspectives on efficiency that are important for retailers to be aware of. From this customer and retailer perspective, several dilemmas exist that have been only partly covered in the three papers. This dissertation aims to discuss some of these dilemmas and to demonstrate some of the dualities that exist in the intricate interconnection between the customer and the retailer in the pursuit of efficiency. Overall, the thesis offers new insights, makes significant contributions to the literature and to retail practice in terms of the complex topic of retailer logistical performance and customer efficiency and develops a better understanding of some tenets of eminent and sustainable brick and mortar retailing.

We focused on the responses of two arms of the Atlantic salmon immune system against intracellular pathogens: the antibody (Ab) production by B cells after challenge with the facultative intracellular bacterium Pisciricketsia salmonis and the interferon (IFN) responses in a salmonid cell line against salmon alphavirus (SAV), infectious necrotic pancreas virus (IPNV), and P. salmonis. We developed tools and generated knowledge on these immune responses to contribute to the development of effective vaccines against intracellular pathogens, focusing on P. salmonis. We induced CRISPR-Cas knock outs (KOs) in the salmonid cell line CHSE-214 for IRF3, IRF7, and MAVS. The induction of IFN responses was disrupted in the IRF3 and MAVS KOs, while we did not observe effects of similar magnitude in the IRF7 KO. Although replication of SAV was positively affected in the KOs with disrupted IFN induction, IPNV replication and P. salmonis growth were negatively affected by these KOs. To investigate Ab production after P. salmonis infection of Atlantic salmon, we developed two intraperitoneal challenge models. In the first study, we observed a significant increase in anti-P. salmonis serum Abs at 14 weeks post challenge (wpc), but not at 18 wpc. The fish were protected against a secondary challenge at 14 wpc, while the protection might have been reduced at 18 wpc. In the second in vivo study, we investigated the origin and specificity of early Ab responses using ELISpot and ELISA assays. The intraperitoneal challenge resulted in a major increase of leukocytes, total IgM Ab secreting cells (ASC), and anti-P. salmonis ASC in the peritoneal cavity (PerC), compared to the head kidney and spleen. Furthermore, we observed an early increase of non-specific Ab production, while specific Abs dominated the later time point. We discuss how our findings fit together in a model of specific and non-specific activation of B cells through B cell receptors and pattern recognition receptors, respectively, which could explain the early presence of non-specific Abs. Our model addresses the location of early Ab production, the transition to a more specific Ab response, and the possible functions of the PerC and its adipose tissue in this. Finally, we address the duration of Ab responses against P. salmonis, how our findings can contribute to the development of vaccine strategies with long term protection, and possible avenues for future research.

Planktonic early life stages of marine benthic invertebrates play an important role in dispersal and at times represent a substantial proportion of the zooplankton. Information about the larval communities present on the Arctic inflow shelves of the Barents and Chukchi Seas, however, is incomplete and limited because of infrequent sampling and low resolution of identification. The aims of the work described in this thesis were to characterize the meroplanktonic communities of the Barents and Chukchi Sea shelves in greater taxonomic (using DNA barcoding), spatial and temporal resolution than previously achieved, and to investigate the possible origins of the identified larvae. Key findings from this thesis include 1) much higher diversity of invertebrate larvae was found on the Arctic inflow shelves than previously, 2) larvae are present on the shelves year-round but their abundances peak in late summer and fall, 3) the larval community is composed mainly of taxa known to the region but there is evidence of some species drifting in from further south. Findings from this thesis highlight the immense potential gained from species-level identification and shine a light on critical yet poorly-known life stages of the rich Arctic shelf benthic communities in a time of rapid climate change.

Climate change is a major concern in the Arctic region, as large amounts of organic carbon (C) are stored in permafrost soils and sediments. Increasing average temperatures have the potential to release that C and making it available to biologic activity. Carbon-rich, anoxic soils such as peatlands are inhabited by methanogenic archaea that can metabolize by-products of microbial C decomposition and consequently release methane (CH4). Methane oxidizing bacteria (MOB) comprise a major biological filter for CH4 in terrestrial and aquatic ecosystems and thereby regulate CH4 emissions to the atmosphere. The genus Methylobacter has been detected in many CH4 rich ecosystems and several circumpolar locations. Climate change in the Arctic includes changes in both temperature and precipitation as well as ecosystem changes related to plant cover and herbivory. All of these changes have the potential to influence soil structure and soil biological processes. Thus, they are important factors controlling the soil C cycle and eventually the activity of MOB. The aim of this thesis was to investigate the ability of the Arctic biological CH4 filter to adapt to changes in vegetation, CH4 concentrations and temperature. Further, to gain insights in the resilience and resistance of the MOB community to environmental changes. We have shown that herbivory by geese changes the soil structure and thus the vertical distribution of CH4 and oxygen (O2) concentrations in a high Arctic peatland. These differences are accompanied by changes in the potential rates of CH4 oxidation. The highest activity was detected in shallower parts of the peatland in grazed sites compared to sites protected from grazing. Different MOB communities are responsible for the CH4 oxidation, depending on the above ground grazing and these communities are composed of closely related Methylobacter OTUs. Exposing peat soils from both grazed and protected sites to increased CH4 concentrations and temperature revealed that MOB respond strongly to changing CH4 concentrations, but apparently not to temperature. The response to changing CH4 concentrations involved different members of the Methylobacter community depending on the CH4 concentration and their previous exposure to herbivory. Temperature had minor effects on the CH4 oxidation activity and the MOB community pmoA transcription in the soils. However, temperature clearly influences growth, CH4 oxidation and CO2 production in the native peat soil isolate Methylobacter tundripaludum SV96. The temperature adaptation of M. tundripaludum SV96 is modulated by fine tuning transcription and translation to achieve the optimal balance between substrate availability, growth, and energy generation at different temperatures. These findings show that identical CH4 oxidation rates can be produced from very different physiological states. This also explains how the apparent lack of temperature responses in soil MOB communities is a result of physiological acclimation. Our results show that MOB in high Arctic peatlands and particular the genus Methylobacter is both physiologically and ecologically flexible in adapting to changes in plant cover, O2 distribution, CH4 concentrations and temperature. Thus, the MOB community comprises an efficient and resilient CH4 filter in high Arctic peat soils.

The rise in frequency of antibiotic resistant pathogenic bacteria makes the need for new treatment options for previously curable bacterial infections ever more important. In the process of discovering and developing antibacterial agents, one powerful approach has been borrowing wisdom from nature. Antimicrobial peptides (AMPs) are critical components of the innate immune systems found in almost all eukaryotic life forms. Their mode of action includes disruption of the bacterial membrane and to trigger supporting immune responses. Due to these properties, AMPs are considered promising lead structures that can be further developed into commercially available antibiotics to treat or prevent human diseases caused by bacteria. The work conducted in this thesis aims to discover and characterize novel antimicrobial peptides from the Arctic marine ascidian Synoicum turgens by using a marine bioprospecting approach. This includes collection, extraction and fractionation of biomass, antibacterial bioactivity testing and AMP isolation followed by chemical and biological characterization. For one isolated peptide class, truncated versions were prepared, aiming to produce shorter, linear variants with retained antimicrobial activity. In paper I, turgencin A and B and their oxidized derivatives were discovered through bioassay-guided purification. These peptides had an unusual disulfide connectivity, rarely seen in marine AMPs. Both turgencin A and B were potently active against all assayed bacterial strains. Membrane assays showed that the peptides cause bacterial membrane disruption within a few seconds. Turgencin A and B also displayed some cytotoxic activity against two human cell lines. Oxidation of the methionine present in both peptides decreased the bioactivities in all assays. Turgencin A, being the most potent AMP, was subject for sequence analysis and prediction of antimicrobial potential of different regions in paper II. Truncated and modified variants of turgencin A were synthetically produced to make smaller AMPs with the potential of being developed into antimicrobial drug leads. These 10-mer peptides, named StAMP-1–11, were made using an amino acid replacement strategy. Some of the Trp enriched peptides had similar bactericidal activity as the parent peptide turgencin A, and no cytotoxic activity against the mammalian cell lines. During turgencin isolation, a series of other smaller peptides were discovered in the same extracts presumably with antimicrobial activity. These isolated and characterized ~2 kDa, cysteine-rich peptides (CRPs) (described in paper III), were named St-CRP-1 and St-CRP-2 and contained 18-19 amino acids. The St-CRPs shared a disulfide connectivity pattern with alpha-defensins, had a neutral net charge, moderate antibacterial activity and showed no cytotoxicity. In addition, the introduction section provides background information on topics related to the thematic of the articles. This includes an introduction to bacteria, antibiotics and antibiotic resistance, AMPs, ascidians, and the marine environment.

Regarding the growing population and escalated development on the coasts, the environmental policymakers often face the dilemma of exploiting or protecting marine and coastal ecosystem services (ES). Therefore, the non-market valuation has become an essential instrument for supporting policymakers in eliciting preferences and welfare estimates regarding various ES, which further feed into the cost-benefit analyses (CBA). Among various non-market valuation techniques, the discrete choice experiment (DCE) methodology has gained ground in recent years for its advantages for capturing several trade- offs across multiple policy scenario alternatives and attributes. This thesis examines methodological issues regarding DCE applications on marine and coastal ES valuation and the further utilization of obtained non-market values in bio-economic models. Across three research papers utilizing DCE data collected in Arctic Norway, the results present implications for non-market valuation research and policymakers. The first paper studies the impact of including a socio-economic attribute in environmental policy DCE studies on the attendance paid to the other attributes. We utilize split sample DCE data to elicit preferences regarding coastal development on the Arctic coast, where we present an additional socio-economic attribute indicating the number of jobs created in the region in one version. The analysis suggests that a socio-economic attribute does not significantly alter the attention dedicated to other attributes. However, the obtained willingness-to-pay (WTP) measures significantly fluctuate across two samples, which can have important implications for the subsequent CBA. The second paper focuses on choice architecture interventions in DCE design. The study employs a three-way split sample for studying value activation through environmental and socio-economic signposts. Employing the case of coastal cod regulations and the controversial expansion of fishing tourism in Arctic Norway, the base DCE involves the attributes of coastal cod spawning stock biomass (SSB), stricter regulated user group, and cost. However, the other two versions include additional attributes of catch by fishing tourists (Treatment 1) and jobs created by fishing tourism (Treatment 2), which serve as decision signposts for value activation. The results indicate rather weak evidence for activating pre-existing pro-environmental and pro- development values through the adoption of signposts in DCE design. Nonetheless, we observe statistically significant differences in WTPs, supporting the results obtained in paper I. Finally, the third paper expands the standard bioeconomic models to incorporate non-use values and locals’ prioritization of ES uses. We gradually extend the bioeconomic model to involve the commercial fishing benefits, recreational fishing benefits, non-use benefits, and prioritization weights attached to these by the local population for optimizing the coastal cod biomass. Overall, the bioeconomic dynamic optimization results suggest that disregarding the non-use benefits attached to coastal cod results in the undervaluation of stock, which can lead to significant overexploitation and degradation.

The research presented in this thesis has focused on the economic valuation of climate change impacts on ecotourism in a coastal wetland using three different methods of stated-preference techniques to provide answers to different research questions related to coastal tourism and climate change. Rekawa coastal wetland in Southern Sri Lanka was taken as the empirical context to examine the identified research questions. The first issue studied in this thesis concerns the balance between conservation goals and the development of ecotourism in coastal wetland management. Our findings provide empirical evidence suggesting that ecotourism is not only an economically viable industry but also a good ecological policy instrument. This since economic benefits arising from ecotourism can be used for environmental protection and biodiversity conservation by ensuring habitat protection for a broad set of species. We have proved that well-managed sustainable tourism in and around coastal wetlands can bring important economic and ecological benefits. The second research question attempts to provide a regional perspective on intended future visitation behavior of both domestic and foreign tourists to a coastal wetland under climate change impacts explained by a climate change induced environmental index based on IPCC scenarios. The climate change induced environmental index that we developed, was found to be a significant determinant of intended visitation behavior of tourists. The final part of the research refers to tourists’ preferences and willingness to pay for restoration of mangroves to reduce the climate change impacts on ecotourism. Our findings highlight the importance of mangrove protection as an adaptation strategy to minimize the climate change impacts. Tourists’ preferences and willingness to pay for mangrove protection support the formation of an environmental protection fund and use of it in different mangrove protection measures. If increasing impacts of climate change are unattended in a timely fashion with site-specific adaptation measures, future ecotourism in coastal wetlands could be at risk.

This thesis is published on Munin with a CC BY license. Cuscuta is a genus of parasitic plants that form cross-species bridges and connect to the xylem and phloem of a wide variety of host plants. Because of their unique lifestyle, research into processes like the formation of connections in between plant cells and plant immunity would benefit from Cuscuta as a model system. However, a method to study gene functions in a Cuscuta species is still missing. Its development was therefore chosen as the goal of this thesis. In vitro culture techniques for Cuscuta campestris were developed and Agrobacterium transformation of Cuscuta tissue was successfully performed in two different systems, the adhesive disk area close to the parasitic infection organ, and seedlings of C. campestris. As an alternative method for gene function studies in Cuscuta, virus induced gene silencing was tested in C. campestris. Mineral transport across the host-parasite border was studied and the potential use of interspecies plasmodesmata between Cuscuta and its hosts was investigated. The results presented in this thesis allow for first gene function studies in Cuscuta and are good foundations for the development of pipelines for transgenic plant production and gene silencing techniques. Challenges and opportunities with this system are outlined. The conclusions of this thesis will help to “tame” Cuscuta and use its unique physique and strategies for host plant infection to establish a model species for studying plant-cell connections, transport processes and plant immunity.

Infectious diseases have been a problem for humans since the beginning of human existence. The “golden age” of antibiotics started at the end of the 1920s, with the discovery of penicillin by Sir Alexander Fleming. This was followed by the discovery of several life-saving antibiotics. The number of new marketed antibiotics has declined, and most pharmaceutical companies are no longer working in antibiotic development. This in itself would be unproblematic, had it not been for the rapid ability of bacteria to become resistant towards previously debilitating agents. The need for new antibiotics is therefore eminent. Natural products have been important contributors for antibiotic drug discovery and development. Microorganisms have been a particularly proliferative source of antibiotics, providing us with among others the penicillins, aminoglycosides, tetracyclines and polymyxins. Most naturally derived pharmaceuticals, including antibiotics, originate from terrestrial organisms. This is mainly because the terrestrial environment historically has been easier to access compared to the marine environment below the intertidal zone. The marine environment is highly diverse, and there is still a huge biodiversity that is yet to be explored. In this project, Arctic and sub-Arctic marine bacteria and fungi were cultivated and studied for their production of natural products. The cultures were extracted and fractionated, and the fractions were tested for bioactivity, mainly focusing on antibacterial activity. Using bioactivity-guided isolation, compounds were isolated and structurally characterized. Finally, the bioactivity of the isolated compounds was broadly evaluated. In paper I, a known siderophore, serratiochelin A, was isolated from a co-culture of two bacteria, Serratia sp. and Shewanella sp. The compound was not detected in axenic cultures, indicating that cocultivation triggered production. The acid-catalyzed degradation of serratiochelin A into serratiochelin C was also observed. Serratiochelin A had weak activity against Staphylococcus aureus, melanoma cells and non-malignant lung fibroblasts. No activity was observed for the degradation product serratiochelin C, indicating that the oxazoline moiety in the original compound is essential for the bioactivity. In paper II, a marine bacterium Lacinutrix sp. was cultivated and studied for its ability to produce bioactive natural products. Through bioactivity-guided isolation, two new lyso-ornithine lipids were isolated, and their structures elucidated, showing that they only differed by the length of the hydrocarbon tail. Analysis by UHPLC-HR-MS indicate that the purified solutions are mixtures of isomers, but these were not possible to separate by preparative HPLC-MS. The compounds were evaluated for antibacterial activity and antiproliferative activity against human cells. Compound 1 displayed weak activity against Streptococcus agalactiae, while compound 2 had weak activity against melanoma cells. In paper III, a new dimeric naphthopyrone substituted with a sulphate group was isolated in high yields from cultures of an obligate marine fungus in the family Lulworthiaceae. The compound was tested against an extended panel of clinical bacterial isolates and showed potent antibacterial activity against several clinical methicillin-resistant Staphylococcus aureus isolates, with MICs down to 1.56 μg/mL. Acid-catalyzed degradation was also observed. The compound also displayed moderate activities against three human cell lines: melanoma, hepatocellular carcinoma, and non-malignant lung fibroblast. In paper IV, a new chlovalicin variant, chlovalicin B, was isolated from cultures of the obligate marine fungus Digitatispora marina. The fungus has previously been studied for its distribution in the marine environment but has not been extensively studied for its biosynthetic potential. The compound was isolated in low yields, and the structure was elucidated by NMR and HRMS experiments. The compound was assessed for a range of bioactivities and had weak antiproliferative activity against human melanoma cells.

Marine ecosystems are under pressures of human activities that have altered their dynamics and structure during the last five decades, but there can also vary due to internal dynamics or chance. Managers focus on human activities and often ignore the contribution of internal dynamics and chance to ecosystem dynamics in the decision-making process. In this thesis, I use food-web modelling based on the principles of Chance and Necessity to explore the possible variability of the Nordic Seas’ food-web. I show that internal dynamics and randomness have a key role in the variability of marine food-webs. I also show that climate change and fisheries affect the variability of the Nordic Seas in a combined manner, which suggest that both stressors should not be considered separately for management. I suggest that Chance and Necessity can used a tool to inform adaptive management, ecosystem-based management, and integrated ecosystem assessment.

This thesis addressed phenotypic and genetic variation in seasonal time keeping mechanisms of the tundra vole (Microtus oeconomus) and the common vole (Microtus arvalis). Voles (Microtus) are short-lived, non-hibernating and seasonally breeding rodents. The genus has rapidly evolved (< 2 million years) into one of the most speciose mammalian genera (Sitnikova et al. 2007; Triant and DeWoody 2006) and occupies a wide range of latitudes (14-78°N) with the tundra vole being the most wide spread species. Seasonality is strong at high latitudes with lower and more seasonally fluctuating ambient temperatures (Hut et al. 2013). Therefore, animals have evolved mechanisms to time their life cycles with the strongly cyclical environment. The annual day length cycle is the most reliable cue to predict upcoming changes and prepare accordingly. This information is integrated by the photoneuroendocrine system (PNES) that coordinates phenotypic changes such as seasonal molt and reproduction (D. Hazlerigg and Simonneaux 2015). In paper I, we showed that under laboratory conditions, short winter photoperiods alone reduced somatic growth (body mass) in tundra voles and gonadal growth (reproduction) in common voles. Since both vole species were caught at the same location (the Netherlands, 53°N), the different response can be ascribed to genetic variation between the species. This was possibly shaped by different selection pressures occurring during the more northern (tundra vole) and southern (common vole) paleogeographic history of the two species. Within and among vole species, the timing of breeding shows great year-to-year variation (Tast 1966; T. Ergon et al. 2001), which is apparently influenced by environmental conditions such as ambient temperature (Kriegsfeld, Trasy, and Nelson 2000). The breeding season starts in spring with the overwintering individuals producing the first spring-born cohort of pups. The short gestation and development times allow these spring-born cohorts to reproduce during the same breeding season as their parents and produce several subsequent cohorts until the end of the breeding season in autumn (Horton 1984a; Gliwicz 1996). In papers II and III, we investigated the critical photoperiod thresholds for initiation of accelerated reproductive maturation in voles on a spring developmental program and for the deceleration of development in voles on an autumn program. Further, we assessed the influence of ambient temperature (10°C or 21°C) on the response parameters. Seasonal gene expression, hormone levels, downstream body-mass and gonadal mass had different species-specific response thresholds to photoperiod and temperature. This indicates that the system has a hierarchical organization that allowed for independent modulation at various levels. The results of these experiments also emphasise the importance of the direction of day length change in setting maturation trajectories. In Paper IV we searched for signatures of selection across the genomes of tundra voles from a northern (70°N) and southern (53°N) population. A signature of selection is a reduction in population diversity at a certain genomic position because of positive selection on a favoured allele. We found selection on a paralogue of the Aldh1a1 gene located between the Aldh1a1 and Aldh1a7 genes. We found two additional Aldh1a1-like paralogues on the same locus. Other voles investigated also had two or three paralogues, which are not present in mouse and rat genomes. Aldh1a1 has a central role in photoperiodic retinoic acid signaling in the rodent hypothalamus, which may be involved in seasonal body mass regulation (Helfer, Barrett, and Morgan 2019; Shearer, Stoney, Nanescu, et al. 2012). Aldh1a7 is also considered as a paralogue of Aldh1a1 (90% amino acid sequence homology in the mouse) but it is not involved in retinoic acid signaling (Hsu et al. 1999). The paralogues found in the vole had the highest sequence homology with Aldh1a7. Future research has to clarify the function of this gene and whether this selection pressure is associated with latitude. Taken together we found various levels of flexibility within the vole PNES where ambient temperature and photoperiodic history can modulate the seasonal response which is possibly affected by evolution at different latitudes. Reproductive opportunism and an ability to override photoperiodic information may be favoured in voles living at higher latitudes which may lead to genetic differences between and within species.

Population cycles in small rodents have attracted attention from ecologists for more than a century. This spectacular phenomenon is crucial for the functioning of many northern food-webs and has intrigued ecologist because of its lessons for general ecology. Knowledge about the rodent cycle has, however, been hampered by the lack of reliable monitoring methods both for rodents and some of their assumed interactants (e.g. the small mustelids). In resent decades, camera traps have become widely used in ecology as they provide a cost-efficient and non-invasive method for wildlife monitoring. In this thesis, consisting of four studies, I will investigate how camera trap tunnels tailored for small mammals can enhance rodent monitoring. First, in study I, I together with colleagues conducted the first large scale assessment of the applicability of tunnel-based camera traps to estimate population parameters in a small mammal community, including during a long Arctic winter. We showed that the camera trap provide estimates of rodent occupancy also under the snow during winter. Further we give recommendation on micro-scale placement of the traps to maximize technical functionality in order to avoid loss of data. Then, in study II, we expand on dynamic occupancy models for interacting species by including two nested spatial scales. This allows for camera trap-based investigation of the rodent-mustelid interaction on both a local and a landscape scale. Features of this interaction are assumed to be a key to understand the cause(s) of the rodent population cycles. In study III, we apply the statistical framework developed in study II to a dataset derived from the long-term monitoring program Climate-ecological Observatory for Arctic Tundra (COAT). Our results show that presence of mustelids increased the extinction probability of rodents on both a local and a landscape scale. Furthermore, we demonstrate a clear habitat dependence and indications of a season-dependency in the rodent-mustelid interaction strength. Finally, in study IV, we assess whether camera trap-based abundance indices can be used to study population dynamics of two rodent species (gray-sided vole (Myodes rufocanus) and tundra vole (Microtus oeconomus)). This was done by comparing camera trap-based abundance indices to abundance estimated from capture-mark-recapture (CMR). For gray-sided voles a single camera trap provided reliable abundance indices with camera trap counts aggregated over 5-days. For tundra voles counts from four spatially replicated camera traps from a single day within the same local population needed to be aggregated to obtain a good correspondence to the abundance estimated from CMR. Such species-differences imply that the design of camera trap studies should be adapted to the species in focus. This study further highlight that camera traps yield much more temporally resolved abundance metrics than alternative methods. To conclude, the work presented in this thesis demonstrates how camera trap-based rodent monitoring provides multiple improvements compared to previous methods. Camera traps are non-invasive avoiding the ethical issues kill-trapping are fraught with. Further, camera traps provide data year round - including from under the snow- on a fine temporal scale. In addition camera traps are not species specific and provide data on the whole small mammals community including small rodents, shrews and small mustelids. In addition, camera traps provide a reliable abundance index at least for two of the most ecologically important rodents species in northern Fennoscandia. Furthermore, this thesis present a statistical framework for investigating mustelid-rodent interactions based camera trap data and exemplify how this framework can improve on the knowledge on one of the longest standing mysteries in ecology.

This thesis presents a study of the impact of climate warming on deep demersal fish communities East of Greenland, in a transition zone between Atlantic and Arctic waters. Climate change was expected to affect fish community composition and functional characterization via poleward distributional shifts and changes in abundance. To assess the climate driven effects on fish communities, I used long term survey data (1998 – 2016) covering a depth range of nearly 1500m. Data on taxonomic composition and abundance were combined with functional traits information to address temporal changes in diversity, community structure and functional characterization at different depths. The rapid warming registered during the study period was associated with a decline in both taxonomic and functional diversity, with the sharpest negative trends at depths between 300 and 1000m. Overall, the abundance of boreal species with a generalist diet, like greater argentine (Argentina silus) and Tusk (Brosme brosme) increased, whereas the abundance of Arctic fish benthivores like Lycodes spp. and northern wolffish (Anarhichas denticulatus) decreased. Functional reorganization was most pronounced at depths from 300 to 750m. Species living at great depths down to 1000m were affected by climate events detected at the surface, displaying rapid responses that were likely mediated by behaviour. These findings suggest that deep sea demersal species can respond just as fast to environmental change as species living in the shallower waters of shelf seas. The diversity loss was not consistent with the general expectations of a climate driven increase in Arctic marine biodiversity, observed in other high latitude ecosystems. Clearly, regional conditions may decide the climate driven effects on diversity, as the combination of currents and topography East of Greenland seems to inhibit colonization by boreal species. The documented taxonomic and functional reorganization of the fish communities east of Greenland are likely to affect ecosystem functioning and vulnerability. The increasing importance of generalist species, also feeding in the pelagic food web compartment, changes the main pathways of energy and material flow, and tends to connect more tightly the food web. The increased connectivity of the food web may promote the spread of perturbations within an ecosystem that is losing adaptive capacity due to a decline in diversity. Since the East Greenland Ecosystem seems to be highly vulnerable to environmental change, future monitoring and a precautionary approach to fisheries and ecosystem management is suggested.

Long-term temperature increases, higher frequencies of extreme weather events and changes in food web structures will all affect the state of Arctic tundra ecosystems at different temporal and spatial scales. Ecologists are tasked with understanding these biotic and abiotic interactions and finding methods to measure them. This thesis applies new technology and methods within the principles of adaptive monitoring to achieve four overarching goals: 1) Design a conceptual model for Svalbard’s moss tundra ecosystem and define the vegetation monitoring needs of high Arctic tundra systems in the context of climate change and herbivore management. 2) Design new monitoring approaches that help quantify habitat types and drivers of future vegetation state changes. 3) Evaluate the practical implications of using drone imagery, photogrammetry, and image classification-based approaches for monitoring. 4) Assess how the findings of the thesis can contribute to future adaptive monitoring of moss tundra. Drone images and random forest classifiers were reliably able to distinguish up to 15 different tundra ground cover classes, including those that represent disturbances such as winter damage from extreme weather events, pink-footed goose grubbing and bare ground. Snowmelt progression was mapped using drone and satellite images and combined with telemetry data to enable analysis of pink-footed goose behavior. This revealed a consistent correspondence, driven by vegetation class and snowmelt date, of habitat use and vegetation disturbance across spatial scales. Collecting ground truthing data in the field requires a good understanding of focal ecosystem components and their interactions with both abiotic and biotic factors, to not only detect visually distinctive, but also ecologically relevant ground cover classes. A close integration of detailed field-based assessments and drone images can elevate studies of causal ecological relationships into a spatial context. In addition, drone images will continue to improve the quality of information gained from satellite-based remote sensing.

The European Arctic is characterized by large surface areas of coastal seas and long coastlines where important ecosystem processes are regulated by marine microbiomes that contribute to global carbon cycling via primary productivity and atmospheric CO2 drawdown. In addition to biogeochemical cycling, these complex microbial ecosystems also support major marine food webs and lend themselves to marine bioprospecting for novel biotechnologies. However, they are not well understood and remain unpredictable. For example, northern coastal Norway is periodically affected by unwanted ecosystem functions such as sporadic harmful algae blooms that are detrimental to local aquaculture industry. These cold adapted marine microbiomes perform ecological processes that are often driven by phytoplankton and their associated heterotrophic communities which undergo strong seasonal variation within complex and variable oceanographical and biogeochemical conditions. Climate change driven temperature increases with resulting direct and undirect changes on environmental conditions have been reported to alter microbial community structures of surface microbiomes. Hence, these important microbial ecosystems are in transition, and it is difficult to predict the trajectory of how specific ecosystem functions may be changing. This thesis is centered around cold-water communities of phytoplankton and bacterioplankton with the aim to enhance our contemporary understanding on surface microbial ecosystems and their function with respect to carbon cycling, community dynamics and community selection. Paper I and Paper II took place in northern Norwegian fjords and costal systems where spatial variation and magnitude of atmospheric CO2 uptake were investigated and the main physical and biological factors driving surface partial pressure of CO2 with respect to atmospheric CO2 were assessed in four fjords and a coastal bay through seasonal changes. The results indicate that northern Norwegian fjords free of sea-ice act as a sink for atmospheric CO2, although the magnitude of air-to-sea CO2 flux showed fjord-specific variation, and the biological fixation of CO2 is a strong driver of CO2 undersaturation. In addition, the temporal and spatial dynamics of early summer microeukaryotes with co-blooming bacteria were examined during a destructive haptophyte Chrysochromulina leadbeateri-associated harmful algae bloom. The coastal habitats harbor highly localized phytoplankton microbial communities which succession dynamics of blooming populations (including C. leadbeateri) undergo strong temporal variability. Paper III took place across a long transect from Atlantic water influenced Barents Sea to less influenced Nansen Basin in the high Arctic with the aim to understand more about the influence of ecological community processes on the distribution of phytoplankton and microbial taxa. Inferences based on phylogenetic turnover, generated through null modeling randomization of phylogenetic relatedness, indicates that the dominant selective force is homogeneous across the studied transect despite differences regarding temperature, sea-ice conditions, and origin of a water mass. Our findings highlight that both large scale and local studies are important to form the needed comprehensive understanding of these microbial ecosystems as the regional taxonomic pool is determined by fundamental ecological processes but community structure influencing ecosystem function is instead subjected to more localized variation of abiotic and biotic factors.

Climate warming in the Arctic has resulted in widespread changes in the physical oceanographic characteristics of the Arctic Ocean. One particularly visible change is the loss of sea ice both within the Arctic Ocean and in the surrounding shelf seas. Compared to the other shelf seas, the Barents Sea has experienced the largest declines in sea ice extent, with much of this loss occurring during winter. In response to these changes, a range of biological responses have already begun–from population declines to changes in community compositions. This thesis explored sea ice dependencies of various Arctic marine organisms. Paper 1 explored if a pelagic phase could be party of the life cycle of a so-far presumed fully sea ice-associated amphipod. Paper 2 investigated seasonal (rarely studied polar night versus commonly studied polar day) diet changes in three zooplankton and two sea ice-associated amphipod species. Paper 3 quantified the contributions of sea ice-associated and pelagic (open water) carbon sources to diets of two different Arctic seal species: the harp and ringed seals. The main findings of this thesis demonstrate that in this time of transition–where Arctic sea ice is still present but receding–the studied Arctic marine organisms exhibit a wide range of sea ice dependence. While the seal species displayed strong seasonal associations to the sea ice habitat (in terms of energetic sources), zooplankton and sea ice amphipod species had varying degrees of trophic plasticity (for example, polar night feeding activity and being supported by pelagic carbon). This thesis research increases the knowledge of potential biological response to the current state of the Arctic.

The focus of this thesis is on the economic performance and technical efficiency of a Vietnamese fishing fleet by the use of data envelopment analysis (DEA). The double bootstrap method has been used to overcome some of the limitations of DEA. In addition, the dissertation evaluates fishers’ perceptions of negative events affecting the fishing activities. The first of three papers presents the investigated fleet and the economic performance in 2016 under open access conditions. Fixed and variable costs, and revenue have been used for estimating the technical efficiency. By adopting double bootstrap DEA under the hypothesis of variable returns to scale, the average technical efficiency of the fleet is found to be relatively high. Nevertheless, the DEA calculations showed that the current catch level could be obtained by a fishing effort 24–35% lower than the actual vessel activity. Vessel size and fishing experience are all factors affecting the technical efficiency. The second paper measures and compares the technical efficiency using physical vs. economic measures. The study focuses on the same 52 Nha Trang purse seiners as in the first paper. Adopting the double bootstrap DEA method, the findings show that economic measures give a lower level of technical efficiency than that which is obtained by physical measures. However, there is significant difference in the technical efficiency between these two measures. The skipper’s experience and interest payment significantly affects the physically based technical efficiency at the 5% level. This study concludes that physical variables, which are often more accessible, are capable of capturing essential economic differences between vessels. The third paper studies the same purse seine fishers’ perceptions of how environmental and socio-economic factors influence their life and fishing activities. The findings are that storms/cyclones, severe floods, heavy rains, high temperature, big waves and bad weather reduce fish density, and the poor availability of capital, health conditions and crew access all negatively affect fishing activities. The fishers’ perceptions of the increased temperature and declining fish stocks over time are in line with available data, whereas their perceptions of the frequencies of storms, floods and heavy rains differ from the observations. Despite increasing frequencies of storms and precipitation not actually observed, the fishers perceive such factors as creating problems for their current fishing activities. Almost all the fishers in the sample expected the frequency and severity of rainfalls and the average temperature to increase in the future, while fish stock availability will decline. However, climate change is not expected to be among the most important negative factors in the future. Cost of fishing, health conditions, efficient fishing gear and boats, as well as the resource situation, represent important factors causing greater concern among fishers regarding future fishing activities.

We took an experimental approach to study what may contribute to such behavior, and what effect these choices have on individual wellbeing. We used three independent surveys to analyze this, all three measuring positional preferences in a broad spectrum of domains. If left uncorrected, there might be large unintended external effects from positional preferences, which is why this research is necessary. On a greater scale, we can use this understanding as a tool to design a policy instrument correcting for the suboptimal behavior when people are concerned with relative performance. Our first study focused on the effect of gender, closeness, and relevance of the reference group (with whom we compare) on positional preferences and we explored how social identification in the relevant domains contributes to such behavior. The focus of our second study was to test if the instruments commonly used in this research are robust to a variation in levels (endowment) or subject (deciding for the self or deciding for a grandchild). Finally, our third study focused on the effects of positional preferences on life satisfaction. To test our hypotheses we ran a set of logistic regressions, controlling for a variety of social-demographic indicators. Our findings suggest that comparing with an average in society elicits a higher share of positional preferences than comparing with someone close and relevant, and we found that social identification with a domain correlates with positional preferences in the same domain. We also found that gender of the individual, and the reference group matter for positional preferences in some domains, but not all domains are gendered. When we tested the robustness of these instruments, we found that they are relatively insensitive to a variation in levels and in the targeted subject, which is reassuring as it validates earlier findings and makes them replicable. Finally, our third study suggests that positionality in all the included domains has negative and significant effects on how we feel about ourselves.

Thinking of fisheries as a system is a relatively new approach in fisheries science and management. As part of my contribution to this perspective, this thesis uses mental models as a new approach to gain insights into how individuals conceptualize fisheries. Mental models are internal representations of the surrounding world (e.g., phenomena, processes, problems) and they are important because these representations shape how individuals solve problems, take decisions, and communicate. Following an established methodology for analyzing mental models, this thesis begins with establishing a reference model of fishery systems. This reference model is then compared with: 1) the conceptualization extracted from 18 definitions of fisheries formulated by various organizations involved in fisheries management and reference materials; 2) the conceptualization extracted from South African learning material (textbooks used in Grade 9, last compulsory grade, and textbooks used in the only BSc with a major in fisheries offered in the country). The analysis indicates that neither the definitions nor the textbooks manage to provide a comprehensive and balanced understanding of fisheries as systems. Shifting the focus from artefacts (i.e., definitions, textbooks) to human subjects, this thesis developed and tested a novel instrument for eliciting mental models about fisheries. This instrument can be used to elicit the mental models that various stakeholders have about fisheries and the analysis of these representations can guide targeted raising awareness efforts so that gaps or misunderstandings are addressed. The mental models elicited through the three studies are then compared. This thesis introduces the mental models approach as a new method that has the potential to push research further on the path of conceptualizing fishery as a system from a holistic approach.

Climate change driven increases in temperature are enhancing land-ocean connectivity in the coastal Arctic, with a range of implications for coastal food-webs and contaminant cycling. Terrestrial inputs are a direct source of carbon and legacy contaminants to coastal areas, but as a source of freshwater, nutrients and suspended inorganic sediments, they can also affect coastal food-webs and contaminant cycling indirectly through impacts on phytoplankton community structure and contaminant removal and burial. To investigate coastal responses to terrestrial inputs, we conducted a field study in a river- and glacier- influenced Arctic fjord system (Isfjorden, Svalbard), in May, June and August, 2018 with a follow-up study in 2019. Environmental data, zooplankton and benthos were collected from 17 fjord stations along transects from river estuaries and glacier fronts to the outer fjord. Fauna were analyzed for persistent organic pollutants and dietary carbon sources were assessed using a variety of biogeochemical tracer techniques, including fatty acid trophic markers and bulk stable isotopes. Our observations revealed a pervasive freshwater footprint in the inner fjord arms, the geochemical properties of which varied spatially and seasonally as the melt season progressed from snowmelt in June to glacial melt and permafrost runoff in August. Zooplankton fatty acid profiles were strongly coupled to fatty acid profiles of water column particulate organic matter, reflecting seasonal and spatial shifts in phytoplankton community structure, with elevated contributions of diatom fatty acids in May following the spring phytoplankton bloom, to dinoflagellate and terrestrial fatty acids in June and August when high sediment loads attenuate light in the nearshore. Persistent organic pollutant concentrations in coastal fauna were inversely related to terrestrial inputs spatially and seasonally, suggesting that freshwater and associated high rates of inorganic sedimentation act to dilute, bind and bury persistent organic pollutants in the inner fjord arms of Isfjorden. Our results highlight the physical, chemical and biological impact of terrestrial inputs on downstream coastal ecosystems in a rapidly changing Arctic environment.

Understanding Arctic deep-sea ecosystem structure and functioning is an urgent task because ongoing sea-ice reduction modifies and opens up these regions for resource exploitation. This thesis aims to increase knowledge on epibenthos in the Chukchi Borderland (deep Arctic Ocean). Paper I documents low epifaunal densities and biomass, a total of 152 taxa, and dominance of Echinodermata, Arthropoda and Cnidaria for taxon richness and/or abundance/biomass. Most taxa had Atlantic biogeographic affinity. Ridge and plateau community structure did not differ but western and eastern communities did, linked to food input and drop-stone availability. Paper II findings generally support the current view of common trait modalities in deep-sea epibenthos. Higher functional diversity at mid-depth than deep stations indicated more variable resource use, while higher functional redundancy in basin communities suggested adaptation to more homogeneous environments by fewer, shared traits. Paper III suggests tighter pelagic-benthic coupling in 2005 (high sea-ice cover) than 2016 (low sea-ice cover), reflected in higher isotopic-niche overlap and shorter isotopic-distances between pelagic and benthic systems in 2005. Isotope values suggest higher ice algal contribution in 2005 and more refractory food consumed by benthos in 2016. This study adds much-needed biological and ecological knowledge with implications for vulnerability and resilience and highlights the need for deep-sea monitoring.

Consumers’ perception of seafood products plays a critical role in determining their consumption behaviour. As a great quantity of seafood is produced by aquaculture, specifically farmed fish, consumers’ perception of farmed fish is crucial. In recent years, consumers in developing and emerging countries have increased their concern about seafood safety. This thesis investigates consumers’ perception of seafood in an emerging market such as Bangladesh and their willingness to pay (WTP) for fish attributes such as safety and green labels. The thesis contributes to the literature by adding value to the empirical knowledge of consumers’ perceptions and attitudes and the discrepancy of knowledge in emerging markets, especially about sustainable and organic farmed fish. The thesis comprises an independent introductory section and four individual papers.

The dissertation includes four papers altogether. Three papers examine mechanisms for price transmission between markets. Among them, one deals with price transmission along the supply chain, and the other two deal with price transmission across spatially distinct markets. The fourth paper measures the effects of demand shifts on the market price equilibrium. Paper 1 investigates price transmission relationships in the salmon value chain between the export market of Norway and retail markets of France and Spain. We assume processing costs have a significant impact on a vertical price linkage along the supply chain. Specifically, asymmetric price transmission is investigated along the supply chain of two salmon products, a relatively unprocessed product (fresh salmon) and a more processed product (smoked salmon). The threshold cointegration and the asymmetric error correction models are estimated to examine the patterns of price adjustment. Results indicate a price transmission relationship in both markets along the fresh salmon supply chain but not along the smoked salmon chain in either market. Furthermore, for the fresh salmon supply chain, asymmetric adjustment is observed in both markets. Processing salmon into value-added consumer products involves additional inputs, including labor, capital, marketing, and packaging costs and time. The greater the share of these non-raw materials costs in the final consumer prices, the less the price influence of farmed fish on the final product price. Hence, we can argue that price transmission between the export and retail salmon markets decreases as more processing is involved. The second paper explores market integration and spatial price transmission in the regional grain markets in Ethiopia. Since mid-2006, prices of basic food crops (such as wheat and maize) have persistently increased and have become a critical challenge in Ethiopia. The literature indicates that food prices in any market may change as a result of several factors, including price shock diffusion from international markets (Baquedano & Liefert, 2014; Ceballos et al., 2017), changes in the exchange rate (Hazel et al., 1990; Dawe, 2008), changes in domestic demand and supply conditions (Brækkan et al., 2018), and in the market structure (Abdulai, 2000). In this paper, the objective was to investigate whether the Ethiopian grain market structure has contributed to price increases in the Ethiopian grain market. The study uses monthly wholesale prices of wheat, maize, and teff from major regional grain markets in Ethiopia. The Engle-Granger and threshold cointegration models were the main methods employed to investigate the extent, speed, and nature of price signal transmission between the central and major regional grain markets. The estimated results given by both models suggest the presence of long-run relationships between the central and major regional grain markets for each commodity. Moreover, the results obtained from the threshold cointegration model indicate the general absence of asymmetric price adjustment in each of the markets. This might imply the presence of efficient price transmission in the Ethiopian grain market. Hence, I argue that this study provides insufficient evidence to support the hypothesis that the price adjustment behavior of grain traders (or market structure) leads to sustained grain-price increases in Ethiopia. The third paper investigate price transmission in EU pork markets. The pork market in the EU has undergone important changes in recent years, such as the growing concentration of power in both producing and consuming countries, which might impact the price transmission process between markets. This study therefore investigated price transmission between major EU spatial pork markets. Two different techniques, namely threshold autoregressive and local polynomial techniques, were applied to obtain reliable results. The results suggest that price transmission mechanisms vary significantly between different EU markets. However, the transmission speeds between the markets are overall small, indicating that price adjustments take a long time in each market. Furthermore, the estimated results provide some evidence of asymmetric adjustment within the EU pork markets. The fourth paper takes a different approach by studying market price formation. Growing global demand for seafood has shifted the demand curves in the world seafood markets upward. In this paper, we use the demand index approach of Marsh (2003) to measure the growth in seafood demand of 107 countries between 1984 and 2013. The estimated results are then used to calculate aggregate demand growth by income level, regionally, and over time. Results indicate that demand growth varies considerably across countries, regions, income groups, and over time. Furthermore, while the literature show seafood production has more than doubled since the mid-1980s, our results indicate that global demand for seafood has exceeded the global seafood supply, which explains the increasing global seafood prices.

The manuscripts of the dissertation presented here encompass several aspects of adaptations in ice-associated amphipods, focussing mainly on their ability to cope with increased light levels, including the ultraviolet radiation (UVR), under thinner or more dispersed sea ice. A decrease in multi-year ice (MYI) in the Arctic, and a concurrent reduction in stable habitat for ice-associated species, is a substantial threat to the ecosystem in the Arctic Ocean, as these amphipods act as a key trophic link between primary production inside and under sea ice, and higher trophic levels. In a shift from thicker multi-year ice to thinner and less coherent first-year ice, the changes in under-ice light levels may be considered as the second-most significant factor, after the loss of the habitat itself. This thesis has as its overarching ambition to contribute to our understanding of how this change may affect the organisms living in association with the Arctic sea ice. While the reduction in stratospheric ozone and the resulting seasonal increases in ultraviolet radiation (UVR) have been halted and to some extent reversed, the recovery period is calculated to be protracted, and might even be affected negatively by the ongoing warming of the troposphere through the ongoing emission of greenhouse gases. So both the direct and indirect effects of UVR on sea ice-associated amphipods have been proven to be a significant factor, especially in the context of a reduction in both thickness and extent of the Arctic sea ice cover. The effects of pigment ingestion and accumulation have also been of particular interest, as well as the capacity of organisms to cope with and adapt to elevated, radiation-induced oxidative stress. Another aspect of this thesis has been to investigate hitherto and potentially overlooked aspects of the distribution and occurrence of ice-associated amphipods in the Antarctic. This study contributed to altering the previously held assumption that ice-associated amphipods in Antarctic waters were predominantly originating from the shallow benthos and were thus able to interact with sea ice only when it is over relatively shallow depths. One of the papers presented in this thesis documents several pelagic amphipod species living in close association with sea ice. Hence, an important conclusion from this is that there is a pelago-sympagic component of Antarctic amphipods in the Weddell Sea.

The overall aim of this dissertation is to improve the theoretical and empirical understanding of consumers’ behavioral tendencies toward functional food consumption. The main purpose is to provide a deeper understanding of antecedents that are relevant for explaining consumer evaluation of functional food and consumption behavior. Functional foods are food products that have been enriched to make them healthier or to prevent diseases. This thesis contributes to the existing literature on the explanation and understanding of individual differences in the evaluation and consumption of functional food by combining a variable- or construct-centered approach (SEM) with a person-centered approach (clustering technique). The present research enhances the understanding of the underlying motivations behind consumers’ evaluation of and behavior toward functional foods. Key findings include (a) the differential influence that hedonic and utilitarian eating values exert on attitude toward consuming functional food, (b) the differential effect of future- and immediate time perspectives on consumption of functional food, (c) the nature of the personality trait–time perspective–behavior relationship, and (d) how consumer profiles differ in their evaluations of and propensities to consume functional food. The results should be useful to better target functional food according to consumers’ motivational antecedents and personal features.

Berries are abundant in bioactive compounds. Bilberry or European blueberry (Vaccinium myrtillus L.) is in particular gaining worldwide attention being one of the best natural sources of antioxidant rich phenolics that accumulate in both skin and flesh during fruit ripening. Alongside, the ubiquitous presence of anthocyanins and related flavonoids, it also contains other compounds such as carotenoids, stilbenes, terpenoids, vitamins and sugars. Especially flavonoids and sugars have major effect of fruit quality. Beside the genetic adaptation by the latitude-based cultivars and ecotypes, altering environmental conditions play a major role in determining the bioavailability of these compounds. Especially, the light quality impacts several secondary metabolic processes, thus by interacting with the number of known positive regulators and repressors of light signaling. The thesis is focused on understanding the biosynthesis and regulatory mechanisms of the key quality compounds, flavonoids and sugars, in bilberry in response to different light qualities from the photosynthetically active radiation (PAR) spectrum. The light quality experiments were carried out in controlled conditions by mimicking single wavelength light spectra of red, blue and far-red using LED-light systems. The promising results showed that indeed supplemental light wavelengths have a positive effect on anthocyanin and sugar biosynthesis in bilberries. Especially, delphinidins were found to be the most reactive class of anthocyanins in response to red light treatments, which increased the concentration several fold in fully ripe berries. The transcriptomic data revealed that the abscisic acid (ABA) biosynthesis and signaling was found to regulate the anthocyanin accumulation, where even the ABA degrading enzyme, ABA-8'-hydroxylase, acted as positive signaling factor. However, the results showed a differential effect or opposite response pattern towards red and blue light in berries which are ripening independently of mother plant to that of naturally attached ripening berries. Interestingly, the blue light influenced the anthocyanin biosynthesis in detached berries to the most, and resulted in highest anthocyanin levels quantified in fully ripe bilberries. The study also showed the effect of light quality on sugar metabolism from the differentially expressed genes (DEGs) data, where both red and blue light influenced the starch and sucrose metabolism. Supplemental red light also increased the amount of sugars in ripe bilberry. The findings of this study will drive-forward the plant research communities towards better understanding on the effect of light on fruit ripening and improving quality. The results can also be further utilized in future commercial breeding programs or cultivation practices of wild Vaccinium berries with improved value-added properties.

Cold seeps are locations on the seafloor where CH4 migrates from reservoirs below sediments towards the atmosphere, sustaining thereby a high microbial and macrofaunal biomass and a diversity contrasting from the surrounding seafloor. The oxidation of methane and sulphide are typically the main sources of primary productivity of these ecosystems and have therefore gained a particular attention in the global oceans. Yet, despite the ubiquitous presence of these seeping sites and the presence of gas hydrates in the Arctic Ocean and its adjacent shelves, the impact of methane on benthic and pelagic microbial communities in this region have remained limited. Recently, five gas hydrate bearing mounds with ongoing methane seeping activity were discovered south of Svalbard, in the northern Barents Sea. In this PhD project, I studied changes in the structure of microbial communities, including both prokaryotes and eukaryotes, and geochemical profiles at these mounds to highlight key microbial groups and to provide insights on their ecological roles. Different niches were addressed, including: deep anaerobic sediments (Paper I and II); niches at the sediment surface at gas flare locations and within bacterial mats and siboglinid fields (Paper III); and above gas flares in the shallow shelf water column (Paper IV). The microbial biodiversity and the structure of communities were successfully identified for each of the habitats listed above. Our investigations revealed a microbial composition similar to other cold seeps: a predominance of archaeal anaerobic methanotrophs (ANME) and sulphate-reducing bacteria (SRB) in CH4-rich sediments, a higher abundance of methane oxidizing bacteria associated to the Methylococcales in the surface sediments and water column; and a co-occurrence of other commonly found prokaryotic groups. Yet, uncommon biological traits were also uncovered at these methane seeping sites: the anaerobic oxidation of methane was merely only driven by ANME-1 without the co-occurrence of a specific SRB clade; an abundant methanotroph with little genetic similarity in databases was detected; and a strong niche differentiation of sulphide-oxidizing bacteria within the different bacterial mats. This project has thereby extended our knowledge on the microbial biodiversity at Arctic cold seeps and opened further future research perspective toward microbial activity and metabolism at these high latitudes.

Climate change is one of the greatest threats to animal wildlife in high latitude freshwater ecosystems. Climate warming is rapidly increasing water temperatures in these areas, affecting biological processes of ectotherms such as growth, maturation and reproduction, which in turn trigger population responses. The magnitude of the effects of climate warming will vary depending on the thermal niche and phenotype of species. Climate change will continue to redistribute species, and fish species from warmer temperature guilds will invade and possibly take over areas where cold water fish currently dominate. Hence, it is important to establish the performance of cold vs warmer water species in a warming Arctic. The aim of this thesis is therefore to provide novel insights and predictions on population level implications of climate change for both cold- and cool water fish at high latitudes. The primary focus is on climate effects mediated by direct and indirect individual-level responses to increasing water temperatures, addressed using long-term empirical investigations and modelling in retrospective and prospective studies. In addition, the thesis addresses interactions between climate change and size-selective harvesting, a main pressure on high latitude fish populations, by modelling their cumulative effects to evaluate risks and reveal potential synergistic threats. The thesis documents how both cold- and cool water fish at their northern range edge have increased their somatic growth rates during the last three decades of warming. However, the cool-water adapted vendace and perch displayed a higher increase in juvenile somatic growth with warming compared to cold-water Arctic charr and whitefish, stressing how the thermal niche modulates the magnitude of warming effects. The individual based models developed for this thesis predict a further increase in somatic growth towards year 2100 under warming scenarios (RCP-4.5, -8.5), with cool water fish displaying a greater increase in somatic growth rate than cold water fish. The documented and projected climate driven increase in somatic growth rate mediates changes in survival rates and life history, including a likely increase in juvenile survival, and earlier maturation, the latter being contingent on species’ maturation reaction norm. The demographic implications of these individual effects were investigated via modelling and long-term empirical studies. The population level response to climate warming, mediated by individual effects, was evident in the cool water adapted perch, which experienced a substantial increase in density and importance relative to the cold-water adapted whitefish, which is dominant in the investigated lakes. The population response of this cool water fish was mediated by an increase in juvenile growth rate which resulted in larger size at age and earlier maturation, but also a likely increase in survival through the first critical winter. The modelled populations displayed higher biomass and yield as size at age increased with warming, but this effect was larger in the cool water specie than in the cold water species. In sum, cool water fish will benefit more from climate warming than cold water fish at high latitudes, and where they coexist, cool water fish may become the dominant player in the fish community. The climate driven increase in size at age affects the age-specific exposure to size-selective harvesting, increasing the risk of younger individuals being caught by gillnets. The population level effect of earlier gillnet exposure is an increased age truncation, as illustrated by individual based model outcomes. Also, larger size at age increased the proportion of immature individuals being caught, with the magnitude of the effect being contingent on growth trajectories, their temperature dependence, and orientation of the maturation reaction norm. The increased juvenile mortality and more pronounced age truncation reduce recruitment, increasing the vulnerability of exploited populations to environmental stressors. Fish species with large size, slow growth, and late maturation like Arctic charr were more vulnerable to warming and harvesting than species with a faster life history, like vendace. In conclusion, the stronger positive effects of warming on the performance of cool-water adapted species relative to cold-water salmonids, and the greater vulnerability of the latter when exposed to size-selective harvesting, warn of incipient reorganizations of Arctic fish communities, and invite climate adaptation in the management of high latitude populations.

The diatoms make up the largest and most important group of marine microalgae. They are responsible for a quarter of all inorganic carbon fixation in the ocean and are thus of immense importance for global CO2 sequestration. This makes them good candidates for biological carbon capture and utilization (CCU) by mass cultivation using CO2 emissions from industrial point sources. Large scale cultivation of marine diatoms will produce valuable biomass containing marine lipids and proteins with possible commercial application. Commercial production of biomass requires extensive knowledge on the species to be cultivated in terms of optimal cultivation conditions, but also on the bioactivity, cytotoxicity and how the species responds to changing cultivation conditions. Most studies on the bioactivity and biochemistry of marine diatoms have been performed on species cultivated in the laboratory. Cultivation conditions are known to affect the biochemistry of diatoms, and large-scale cultivation will inevitably lead to a change in the environmental conditions. The present study was therefore designed to investigate how Porosira glacialis cultivated in large scale responds to changes in abiotic and biotic cultivation conditions. The first study was designed to investigate whether the direct addition of factory smoke as a source of CO2 would trigger production of bioactive or cytotoxic compounds in P. glacialis. Bioactivity testing revealed activity in anticancer, antibacterial and antibiofilm assays, in addition to cytotoxicity against human lung fibroblasts and effect on the development of sea urchin larvae. Nonetheless, the addition of factory smoke did not increase the cytotoxicity of P. glacialis, nor did it change the beneficial antibacterial and antibiofilm activity. These results are favourable for further development of large-scale production of diatom biomass. P. glacialis was co-cultivated with zooplankton to investigate whether the bioactivity and metabolic expression of the diatom would change when exposed to grazing pressure. The bioactivity testing revealed that the presence of zooplankton increased the cytotoxicity of P. glacialis towards human normal lung fibroblasts. Investigation of active compounds and metabolomic analysis showed that the grazing pressure possibly influence the carotenoid concentration in P. glacialis. It was also found that the bioactivity might be traced to primary metabolites such as chlorophyll derived compounds. The study also showed that the use of OSMAC (one strain many compounds) could be a useful method for further investigation of the bioactivity of diatoms. Investigation of the antibiofilm activity of P. glacialis resulted in isolation of two compounds showing inhibition of biofilm formation by Staphylococcus epidermidis. The compounds isolated were methyl 3-hydroxyoctadecanoate and a pheophorbide-like compound. This is the first time compounds with antibiofilm activity have been isolated from P. glacialis as well as the first evidence of such activity from both the isolated compounds. Kiselalgene utgjør den største og viktigste gruppen av marine mikroalger. De er ansvarlige for en fjerdedel av all uorganisk karbonfiksering i havet og er dermed av enorm betydning for det globale CO2 opptaket. Dette gjør dem til gode kandidater for biologisk karbonfangst og -utnyttelse (CCU) i massedyrking ved bruk av CO2 fra industrielle punktutslipp. Storskala dyrking av marine kiselalger vil produsere verdifull biomasse som inneholder marine lipider og proteiner med mulig kommersiell anvendelse. Kommersiell produksjon av biomasse krever stor kunnskap om arten som skal dyrkes med tanke på best mulige dyrkingsforhold, men også om bioaktivitet, toksisitet og hvordan arten reagerer på endrede dyrkingsforhold. De fleste studier på bioaktivitet og biokjemi av marine kiselalger er utført på arter dyrket i laboratoriet. Det er kjent at dyrkingsforhold påvirker biokjemien til kiselalger, og dyrking i stor skala vil uunngåelig føre til en endring i miljøforholdene. Denne studien ble derfor designet for å undersøke hvordan Porosira glacialis dyrket i stor skala reagerer på endringer i abiotiske og biotiske dyrkingsforhold. Den første studien undersøkte om direkte tilsetning av fabrikkrøyk som kilde til CO2 ville endre produksjon av bioaktive eller toksiske forbindelser i P. glacialis. Bioaktivitetstesting avdekket aktivitet i alle tester: anticancer, antibakteriell og anti-biofilm. I tillegg viste resultatene toksisitet som hemmet utvikling av kråkebolle-larver og humane lungefibroblaster. Likevel økte ikke tilsetting av fabrikkrøyk toksisiteten til P. glacialis, og den hemmet heller ikke den gunstige antibakterielle og anti-biofilm-aktiviteten til algene. Disse resultatene er svært positive for videre utvikling av storskala produksjon av kiselalger. P. glacialis ble dyrket sammen med dyreplankton for å undersøke om bioaktiviteten og utrykket av metabolitter ville endre seg når de ble utsatt for stress i form av beitetrykk. Testing av bioaktivitet avslørte at tilstedeværelsen av zooplankton økte toksisiteten til P. glacialis mot humane normale lungefibroblaster. Undersøkelse av aktive forbindelser og metabolittprofiler viste at beitetrykket muligens påvirker konsentrasjonen av karotenoider i P. glacialis, og at bioaktiviteten muligens kan spores til primære metabolitter som klorofyllderivater. Studien viste også at bruk av OSMAC (one strain many compounds) kunne være en nyttig metode for videre undersøkelse av bioaktiviteten til kiselalger. Undersøkelse av anti-biofilm-aktiviteten til P. glacialis resulterte i isolasjon av to forbindelser som viser inhibering av biofilmdannelse av bakterien Staphylococcus epidermidis. De isolerte forbindelsene var metyl-3-hydroksyoktadekanoat og en pheophorbid-lignende struktur. Dette er første gang en forbindelse med anti-biofilm-aktivitet er blitt isolert fra P. glacialis, og det første beviset på slik aktivitet fra begge de isolerte forbindelsene.

The empirical investigation of fishers’ harvest behavior is an important but neglected strand of fishery science. In this thesis, we fill some of this gap by developing empirical models to investigate trawlers’ harvest behavior over time and space in codfish fisheries, managed using individual vessel quotas (IVQs). Fishers’ harvest behavior is reflected in the decision-making processes underlying effort allocation: when and where to fish, what species to target, and how much to fish in each haul to avoid over- and underutilization of quotas. Effort allocation is a challenging task, especially in multi-species fisheries as the fish stocks in the fishing portfolio may differ in feeding, breeding, and migration patterns. This biological heterogeneity together with constant movement of different fish stocks across various locations influences economic conditions such as market prices and operation costs. What adds more complication to optimal allocation of fishing effort is the constantly changing environmental conditions such as food availability and sea temperature, which influence fish behavior. Another complication arises from the inherent uncertainties and external disturbances such as abrupt oceanographic changes, which affect the catch size and profitability. On top of what has been mentioned, institutional regulations such as quota restrictions further complicate the decisions underlying effort allocation. Understanding how trawlers behave and why they behave the way they do reveals valuable information about marine resource status, as well as evaluating fisheries management options to anticipate the possible responses of fishers to changing regulatory schemes. Moreover, recognition of the fishing effort allocation of the trawl fleet enables fisheries managers to evaluate the status of the benthos and seafloor as dragging heavy nets across the ocean can be environmentally destructive. This thesis focuses on codfish; that is, cod, saithe, and haddock fisheries as this portfolio includes economically important species in terms of volume and total revenue. These fish species are seasonally migratory and constantly swim over a vast geographical area to spawn and/or feed. The thesis aims to empirically investigate the fishing behavior of Norwegian trawlers in response to the economic changes stemming from the migratory behavior of these fish stocks, and to show how this could affect harvest attributes such as location choice, timing of production, preference in target species, and quota utilization. This study employs and combines multiple data sources for the empirical analysis of spatiotemporal allocation of fishing effort in trawl fishery. Our comprehensive data set covers the relevant information of trawl fishery during 2011–2016 to conduct empirical investigations of trawlers’ adopted harvest strategy and explain the drivers behind the chosen harvest strategy. The outcomes of this thesis are believed to be useful to fisheries managers in the policy-making process as well as for fishers’ communities to enhance the efficiency of their fishing activities.

Det er et stort behov for marine langkjedede omega-3 fettsyrer både til humant konsum og til fiskefôr. De langkjedede omega-3 fettsyrene EPA og DHA har gunstige helseeffekter for både mennesker og fisk. Mengden villfanget fisk har de siste 40 årene nådd maksimal utnyttelse mens volumet av oppdrettsfisk har økt betraktelig. Mangelen på marint råstoff har ført til en økt andel terrestrisk råstoff i fiskefôret, noe som påvirker næringssammensetningen i oppdrettsfisken. Dyrking av marine mikroalger kan være med på å løse utfordringene knyttet til mangel på marine langkjedede omega-3 fettsyrer, da de er havets primærprodusenter av EPA og DHA. Mikroalger dyrkes i vann og trenger CO2, lys og uorganiske næringsstoffer for å vokse. Mikroalger kan også være med på å redusere direkte utslipp av CO2 fra store utslippspunkter ved å benytte denne gassen til slik dyrking. I dette prosjektet ble den kaldtvannstilpassede kiselalgen Porosira glacialis dyrket for å undersøke om lipidfraksjonen er egnet som tilskudd i fiskefôr og/eller til menneskelig konsum. De spesifikke delmålene var i) å undersøke lagringsstabiliteten til lipidene i våt biomasse, ii) sammenligne in vitro fordøyelighet av lipidene i P. glacialis med vanlige kilder til langkjedede omega-3 fettsyrer, iii) undersøke utbytte av lipider med ulike fettekstraksjonsmetoder sammenlignet med andre massedyrkede mikroalger. P. glacialis inneholder store mengder flerumettet fett, hvorav fettsyren EPA utgjør en stor andel. Sammenlignet med lipidfraksjonen i de andre artene og oljene som ble undersøkt, er omega-3-innholdet høyt. Størstedelen av lipidklassene i P. glacialis er polare, blant annet galaktolipider og fosfolipider. Disse lipidklassene skiller seg ut fra vanlige fiskeoljeprodukter som tran og omega-3-konsentrater. Lipidene i P. glacialis er svært utsatt for hydrolyse under lagring, noe som fører til økte mengder frie fettsyrer samt at oljen er mer utsatt for oksidasjon. Våre resultater viser at lagringsstabiliteten til lipidene i våt biomasse kan økes betraktelig ved en enkel varmebehandling før lagring ved 4 °C. Det ser også ut til at lipidene i P. glacialis er godt fordøyelige sammenlignet med vanlige omega-3 kosttilskudd. Den eneste oljen som ble hydrolysert til en høyere grad under in vitro fordøyelse var tran, som i hovedsak inneholder triacylglycerol. Ekstraksjon av lipider fra P. glacialis krever ingen forbehandling. Men som andre arter med høyt innhold av polare lipidklasser trengs et delvis polart løsemiddel for ekstraksjon. Den har god vekst på CO2 fra røykgassen til et smelteverk og kan derfor være med på å begrense direkte utslipp av drivhusgasser. Det vil være spennende å undersøke om denne kiselalgen kan benyttes direkte til fiskefôr eller humant konsum. The demand for marine long-chain omega-3 fatty acids for both human consumption and fish feed is large. The long-chain omega-3 fatty acids, EPA and DHA, have several health benefits for both humans and fish. The amount of wild caught fish has reached maximum exploitation over the last 40 years, while the production from aquaculture has increased drastically. The shortage of marine raw material has led to an increased inclusion of terrestrial raw material in the aquaculture feed, which has affected the nutritional composition of the farmed fish. Cultivation of marine microalgae may be part of the solution to these challenges, since these are the ocean’s primary producers of EPA and DHA. Microalgae can be cultivated in water using only CO2, light, and inorganic nutrients. Microalgae can also reduce the amount of direct CO2 emissions from large industry by utilizing the gas for cultivation. In this project, the cold-water adapted diatom Porosira glacialis was cultivated to investigate the lipid fraction's suitability for fish feed and/or human consumption. The specific aims were to i) investigate the storage stability of lipid in wet biomass, ii) compare the in vitro digestibility of lipids from P. glacialis with common sources of long-chain omega-3 fatty acids, iii) investigate the extractability of lipids from P. glacialis compared to other mass-cultivated microalgae. P. glacialis contains large amounts of polyunsaturated fatty acids, of which EPA makes up a substantial part. Compared to the lipid fraction of the other oils that were investigated, the omega-3 content is high. The main fraction of lipid classes in P. glacialis is the polar galactolipids and phospholipids. These lipid classes differ from the usual fish oil products, like cod-liver oil and omega-3 concentrates. The lipids in P. glacialis are exposed to hydrolysis during storage, which results in increased amounts of free fatty acids that are more exposed to oxidation. Our results indicate that the storage stability of lipids in the wet biomass can be enhanced by a simple heat treatment and storage at 4 °C. The lipids in P. glacialis appear to be digested well compared to common omega-3 supplements. The only other oil with a higher degree of hydrolysis was cod-liver oil, which contain mostly triacylglycerol. The extraction of lipids from P. glacialis does not require any pre-treatment. However, like other species with large amounts of polar lipid classes, a partially polar solvent is needed for complete extraction. P. glacialis grows well using CO2 from the flue gas of a smelting plant and could therefore help limit the emission of greenhouse gases. The prospect of investigating this diatom directly for fish feed or human consumption is interesting.

This thesis addresses aspects of the circadian and photoperiodic system in a High Arctic bird: the Svalbard ptarmigan (Lagopus muta hyperborea, Sundevall 1845). The most northern resident bird inhabits a unique photic environment; 2/3 of its year it spends either under a night without sunrise (polar night) or under a never setting Sun (polar day). Studies so far suggest a temporal loss of circadian control over behaviour during these constant photic conditions, allowing opportunistic rather than circadian dictated behaviour. Yet, circadian control extends beyond temporal organisation of behaviour, and other aspects of this Arctic-adapted circadian machinery have received less attention. Rhythms in core body temperature (Tb) have not been thoroughly studied in Svalbard ptarmigan and in Arctic birds in general and the extent of circadian control over this physiological parameter is unknown. In paper I, we have investigated the Tb rhythm alongside activity in captive Svalbard ptarmigan under short photoperiod (SP), long photoperiod (LP) as well as under constant light (LL) and constant darkness (DD). While birds under SP and LP showed clear diurnal activity and Tb patterns, these rhythms seemed to be lost under LL and DD. However, under SP we noticed nocturnal rise in Tb in anticipation to the light-on signal, a rise which also preceded rise in activity. Anticipation is a hallmark of circadian rhythmicity and indicates circadian control of thermoregulation in Svalbard ptarmigan. In an additional experiment (unpublished), we transferred Svalbard ptarmigan entrained to L:D 12:12 into either LL or DD and measured dampening in Tb cycles by sine wave and periodogram analysis. The results show that Tb cycles dampened under DD and LL before becoming arrhythmic. It is further shown that the Tb rhythm dampened faster under LL (rhythm dampened by half after 1d 23h in LL) than under DD (rhythm dampened by half after 5d 12h). While Tb and activity might be useful parameters to characterise circadian organisation, the primary importance of circadian rhythms in the Arctic might not be found in behavioural and physiological synchronisation over the 24-h timescale. Photoperiodism describes the mechanism by which organisms receive and respond to changes in day length (photoperiod) in order to achieve synchrony with a seasonal environment. This process is theorised to be based on circadian rhythmicity at least in mammals and birds. In the weak daily rhythmicity but strong seasonal rhythmicity of the High Arctic, the true importance of circadian rhythms might, therefore, lie in its participation in photoperiodism rather than in daily organisation of behaviour and physiology. In order to explore whether photoperiodism is circadian-based within Arctic animals, we have studied the neuroendocrine centre for photoperiodic responses: the mediobasal hypothalamus (MBH) and the adjacent pars tuberalis (PT) in captive Svalbard ptarmigan under various photoperiodic treatments. In paper II, we established that processes within the MBH and PT of an Arctic animal are identical to temperate species. We also showed that a photoperiodic response in the MBH, PT and in gonadal maturation can take place when birds are transferred directly from DD to LL, i.e. without light-mediated entrainment and despite behavioural arrhythmicity in both conditions. This suggests that the rhythm necessary for photoperiodic induction was either sustained or rapidly initiated under these conditions. In paper III, we measured expression of clock genes and key genes of the photoperiodic response pathway within the PT and MBH for 24 h after a direct transfer from SP into LL. Svalbard ptarmigan retained pronounced clock gene expression in the first day of LL and showed appropriate expression of photoperiodic key genes. In the second part of the experiment, we showed that Svalbard ptarmigan can photoperiodically respond to skeleton photoperiods in terms of activity, body mass and photoperiodic key genes. Both parts suggest circadian-based photoperiodism in our High Arctic model organism. The sum of these studies show that Svalbard ptarmigan are able to escape circadian hegemony in behaviour and thermoregulation under arrhythmic conditions but are able to produce rhythm-based photoperiodic responses under various experimental light schedules. This establishes the importance of circadian rhythms in the Arctic as basis for seasonal responses.

Background and purpose: Lifestyle diseases are the leading cause of life-time disability and death in modern society. Knowledge of the underlying causes and mechanisms of health behavior choices is crucially important when developing health-promoting campaigns and planning health behavior interventions. This dissertation aimed to advance our understanding of the relationship between time perspective (TP) and health behavior. The six major objectives were: to establish the discriminant validity between the present and future dimensions of the two most frequently used operationalizations of TP: the Consideration of Future Consequences Scale (CFCS) and Zimbardo Time Perspective Inventory (ZTPI), as well as to compare their relationships with health behavior. to establish the discriminant validity between the consideration of immediate and future consequences (CFC-I and CFC-F), and to test whether they differentially predict healthy and unhealthy behaviors. to explore CFCS-based, ZTPI-present/future based, and a combined CFCS and ZTPI-present/future based temporal profiles of the Norwegian population. to test whether the domain-specific CFC-health would be more strongly related to health behaviors than the general CFC. to study the direct effect of perceived connectedness to the future self on health behavior, as well as its moderating effect on the relationship between CFCS and health behaviors. to test the moderating effect of age on the relationship between TP and smoking behavior. Design/methodology/approach: This dissertation utilized a quantitative survey design and a survey experiment. The data are analyzed with t-tests, confirmatory factor analyses, structural equation modeling (SEM), and cluster analyses. Results: Paper 1 established the discriminant validity of the present and future time perspective constructs of CFCS and ZTPI, as well as the discriminant validity of the present and future constructs of both scales. The present TP – but not future TP – of both scales was related to smoking. The ZTPI model had stronger predictive power than the CFCS model. Paper 2 revealed present and future temporal profiles in the general Norwegian population. CFCS-based profiles were more predictive of health behaviors than ZTPI-based profiles. However, the profiles based on the combination of both CFCS and ZTPI variables were more predictive of smoking, exercising, and health intentions. Paper 3 established the discriminant validity between CFC-I and CFC-F that differentially predicted health behaviors. CFC-I was associated with unhealthy behaviors, whereas CFC-F was associated with healthy behaviors. PCFS had a direct negative effect on healthy behaviors, strengthened the positive effect of CFC-I and weakened the negative effect of CFC-F on unhealthy behaviors. Paper 4 established in a randomized experimental design that a domain-specific CFC–health was a better predictor of self-reported eating and exercising behaviors than a general CFC. Moreover, the discriminant validity between health-specific CFC-I and CFC-F was established. Health-specific CFC-F was a stronger predictor of exercise behavior than CFC-I. Conclusions and practical implications:The results of the study indicate that the present and the future TPs are related but distinct constructs that differentially predict healthy and unhealthy behaviors. The relationship between CFC and health behavior is likely influenced by regulatory focus. In western societies, where the promotion regulatory orientation dominates, individuals are more likely to be motivated by approach goals rather than avoidance goals. The findings suggest that future orientation was associated with healthy behaviors, but not with unhealthy behaviors. At the same time, present-oriented people were more engaged in unhealthy behaviors, but were not less engaged in healthy behaviors. The findings suggest that emphasizing the future health benefits of healthy choices and reducing the immediate attractiveness of unhealthy choices might be more effective in the Norwegian population. Another finding was that CFCS-based population profiles were more predictive of health behaviors than ZTPI-based profiles; however, the profiles based on a combination of CFCS and ZTPI differed in their health behaviors the most. These findings could be helpful when choosing the basis on which to segment the population during health intervention programs. We demonstrated that a domain-specific CFC-health was more effective at predicting health behaviors than a general CFC. The usage of CFC-health in future studies might increase effect sizes and the overall predictive power of the models and, thus, decrease the ambiguity of the findings. Finally, we showed that lack of connection with the future self influenced health behaviors both directly and indirectly. This finding emphasizes the importance of the programs aiming to increase individual connectedness to the future self.

Marine microbes are crucial for the marine food web and carbon cycle. Algae are the main source of organic matter in the oceans with algae blooms triggering reoccurring bacterial succession patterns. Bacteria can recycle nutrients from organic matter coming from land or algae, fueling regenerated primary production. Terrestrial freshwater inputs can have substantial impacts on Arctic marine microbes via import of nutrients, organic matter, and sediments, and via changing the marine hydrography. The aims of this PhD thesis are i) to summarize the current knowledge about microbial ecology in the Arctic seasonal ice zone, ii) to study the effects of terrestrial inputs from rivers and glaciers on the microbial food web over different seasons, and iii) to dive into algae-bacteria interactions with a focus on the importance of regenerated production. We provide evidence that subglacial upwelling is an important process in a tidewater glacier-influenced fjord on Svalbard in spring, a previously understudied season. Subglacial upwelling lead to increased surface water nutrients, a stratified surface layer, and brackish sea ice. At the glacier front, microbial communities were significantly different compared to a sea-ice edge reference site. Phytoplankton primary production was two orders of magnitude higher at the glacier site compared to the reference site, due to upwelling related nutrient inputs and potentially also stratification and a thinner snow cover. During the spring freshet and in summer we investigated the impacts of river runoff on bacterial and archaeal communities with detailed considerations of environmental drivers. We found significant differences between bacterial communities during the spring freshet and late summer, mainly controlled by the concentrations and properties of dissolved organic matter, nutrient concentrations, and fjord hydrography. We recreated major algal spring bloom dynamics in an experimental study with algae-bacteria co-cultures. I used the experimental data to extend a commonly used dynamic algal growth model improving the modeling of multi-nutrient limitations and bacterial remineralisation. The work within this thesis demonstrates that microbial communities and functions are highly regulated by environmental constraints in the coastal seasonal ice zones. Marine mikrober er avgjørende for hele det marine næringsnettet og for karbonsyklusen. Alger er den viktigste kilden til organisk material i havet med algeoppblomstringer som utløser gjentatte suksesjonsmønstre fra forskjellige mikroorganismer. Bakterier kan bryte ned organisk material fra alger eller land og resirkulere næringsstoffer som gir næring til regenerert primærproduksjon. Terrestriske tilførsler av ferskvann, organisk material, næringssalter og sediment har sterk innvirkning på arktiske marine systemer der bakterier og alger er tett forbundet gjennom en rekke interaksjoner. Målet med denne doktorgradsavhandlingen er i) å oppsummere den nåværende kunnskapen om mikrobiell økologi i den arktiske issonen, ii) å studere effekten av terrestriske tilførsler fra elver og isbreer på det mikrobielle næringsnettet over forskjellige årstider, og iii) å utforske interaksjoner mellom alger og bakterier. Vi viser at subglasial oppstrømning er viktig i vinter/vår i et fjordsystem med sjøis på Svalbard, som er en undervurdert årstid. Subglasial oppstrømning har betydelige konsekvenser for mikrobielle samfunn og for karbonsyklusen. Vi fant betydelige forskjeller i mikrobielle samfunn, spesielt i sjøisen ved brefronten. Primærproduksjon av fytoplankton ble betydelig økt ved brefronten på grunn av tilskudd av næringsstoffer, men også på grunn av lagdeling og et tynnere snødekke. I løpet av våren og på sensommeren studerte vi innvirkningene av avrenning fra elven på bakterie- og arkeasamfunn, med et særlig hensyn til miljømessige drivere, som organisk material, tilførsel av næringssalter og fjordhydrografi. Vi fant signifikante forskjeller mellom bakteriesamfunn i løpet av våren og sensommeren, hovedsakelig kontrollert av konsentrasjonene og egenskapene til organisk material, næringssaltkonsentrasjoner og fjordhydrografi. Vi fikk kulturer av våroppblomstrende alger og tilknyttede bakterier fra Van Mijenfjorden og gjenskapte våroppblomstringsdynamikk. Vi brukte dette eksperimentet til å utvide en kjent modell for å representere begrensninger med flere næringsstoffer og bakteriell remineralisering og for å diskutere hvor betydelig det er å inkludere disse. Oppsummert viser arbeidet i denne oppgaven at samfunnet og funksjoner av mikroorganismer er sterk regulert av miljøet som organisk material, næringssalter, lys, og hydrografi.

The motivation for macroalgal cultivation is to meet the global demand for food, energy and biomaterials for a rapidly growing human population in the context of the challenges of limited terrestrial food resources. Over the last 20 years the interest in seaweed cultivation has increased in European countries, and the kelp Saccharina latissima is one of the best-suited species for cultivation in North Atlantic waters. Epibiosis on cultivated seaweed in mid and high latitudes usually occurs from spring to summer, forcing the farmers to harvest the seaweed biomass before it reaches its potential maximum and higher carbohydrate content. Therefore, epibiosis is considered one of the main challenges in industrial seaweed farming. There has been a lack of knowledge about timing and species fouling cultivated S. latissima under different environmental conditions, including different latitudes, seasons and depths, as well as sporophyte age and nutritional history. This topic was investigated through three in situ studies, one with a large latitudinal range covering eleven degrees in latitude, one smaller-scale study within a geographical region characterized by differing environmental characteristics, and one with different outplanting dates resulting in various sporophyte ages within the same location at a given calendar date. The papers that this thesis is built upon show that there is spatial variability in phenology, degree and density of epibiosis on multiple scales on cultivated S. latissima. The present study has increased our knowledge about one of the bottlenecks for seaweed cultivation; epibiosis. Furthermore, this new fundamental understanding of timing and species diversity of epibiosis on cultivated S. latissima contributes to an overall understanding of the fouling issue along the Norwegian coast, enabling a broader view with important implications for the seaweed industry.

The high energy intensity of the manufacturing sector places it at the centre of all greenhouse gas emission abatement programmes. The thesis is thus motivated by the need to increase the environmental performance of the sector, and aims to explore the internal drivers in stimulating eco-process innovation in manufacturing firms. To this end, I use an explorative research design and explore the phenomenon from different theoretical, epistemological and methodological perspectives in three interdependent empirical studies. These studies are empirically informed by research on energy efficiency (EE). From the thesis results, I suggest a new typology of internal organisational drivers for eco-process innovation: environmental leadership, absorptive capacity, organisational structure and routines, and translation competence. Furthermore, the results point to the micro foundations of each driver and suggest an interrelation between the four drivers. This interrelation is discussed in a conceptual model. The thesis further contributes to the field by providing more knowledge on the impact and role of internal stakeholders at various organisational levels. By considering EE as an empirical phenomenon, the study is also of theoretical relevance to the EE literature. From my observations, the gap in the literature with regard to internal drivers is due to limited academic attention, ‘redundancy’ in theory development, and lack of theoretical framing and clarity in the definition of key concepts. Therefore, I suggest that, further research would benefit from a larger degree of problematisation of existing assumptions when designing research questions, build on alternative theoretical frameworks more actively, and are more explicit when defining key concepts. Thus, the further development of eco-innovation theory can extend our knowledge on the firm internal factors and mechanisms affecting the environmental transition of manufacturing firms. The thesis results also provide valuable insights for managers and policymakers as well as avenues for future research.

The questions asked in this thesis relate to the economic incentives and characteristics of the health care market, which may result in suboptimal drug prescription. We consider two types of pharmaceuticals, such as antibiotics and addictive drugs. These pharmaceuticals are interesting because their use/misuse is associated with costs both at the individual and societal levels. The decision about the prescription of both antibiotics and addictive drugs is ideally made by a doctor, and over-the-counter sales are not available. A good share of the prescriptions is made in outpatient care or primary care (a part of outpatient care). This market is characterised by asymmetric information and may suffer from economic disincentives, which, together with patient-induced demand, may result in drug misuse. Thus there is a need for solutions aimed to facilitate optimal drug consumption, i.e. reducing consumption to a minimum consumption level, given that patients are effectively treated. This thesis considers several characteristics of the outpatient care market, such as free choice of provider, competition, and financial incentives within a health care centre to be important factors contributing to drug misuse. Knowledge about driving mechanisms is important for understanding how policies for more efficient antibiotic and addictive drugs consumption can be achieved. The first paper in the thesis relates to the ownership type of health care centres. It finds that private health care centres in the Västerbotten county of Sweden have a higher share of prescriptions for antibiotics than public ones. The second paper focuses on the competition between general practitioners and antibiotic prescription in Norwegian municipalities. The paper shows that the level of competition may be an important factor contributing to a more frequent antibiotic prescription. The third paper relates to the presence of free choice of the health care provider and uses the prescription data from Västerbotten county of Sweden to investigate patients' demand for addictive drugs and how a strategy to switch providers may affect individual drug consumption.

The global demand for the long-chain omega-3 fatty acids EPA and DHA is increasing, and the traditional sources of these fatty acids, fish oils, are no longer able to sustain the demand. This shortage is mainly a result of the surging requirement of EPA and DHA as ingredients in fish feed for aquaculture, and as dietary supplements for human consumption. As a result, there is an increased interest towards lower trophic levels as novel sources of EPA and DHA in an effort to reduce the dependence on wild fish. The main producers of long-chained omega-3 fatty acids in cold oceans are the single celled diatoms, which use CO2 and sunlight to grow in the process of photosynthesis. Diatoms can be utilized as targets of a commercial mass cultivation, where CO2 from industrial processes is converted to a valuable diatom biomass. This may in turn supplement fish-derived biomass for the production of EPA and DHA. The purpose of this work was to improve the current production technology directed towards diatom mass cultivation. The first study investigated the effect of cultivation temperature on the growth and composition of fatty acids on a cold-water diatom. Temperature did not affect the content of EPA and DHA in the diatom at temperatures between 2-12 degrees C, which reduces the necessity of temperature regulation in cultivations targeted towards omega-3 fatty acids. The second study compared preservative treatments on biomass from a cold-water diatom, and showed that a moderate heat treatment reduced quality loss during storage. Heat treatment can therefore function as an inexpensive alternative to preserve diatom biomass. The final study examined to what extent cell wall disruption, choice of solvent and number of consecutive extractions affected the yield in lipid extraction from diatoms. In contrast to other commonly mass cultivated microalgae, product yield was determined by choice of solvent and number of extractions, independent of cell disruption. These findings will bring us closer to an industrial cultivation of diatom biomass, by lowering production costs and increasing product value.

Parasites negatively affect hosts and may constitute serious management problems. At the same time, parasites are integral components of ecosystems and represent a substantial part of the biodiversity on earth. Understanding the ecological factors that influence the abundance and distribution of parasite populations is therefore important from a management perspective, but also to understand the mechanisms that shape populations and food webs. Parasites occur in complex food webs, with several opportunities for indirect effects. Ecosystem perturbations have been key to identify ecological processes that influence population and community dynamics. As some of these processes take a long time to unfold, they are only detectable from long-term studies. Unfortunately, few long-term studies have investigated host-parasite dynamics. The main aim of this thesis was to study how temporal changes in density and age- and size-structure of Arctic charr (Salvelinus alpinus) as a host species affected metazoan parasite dynamics across more than three decades of field observations from a subarctic lake. I also investigated the effects of the density of a competitor and predator, brown trout (Salmo trutta), on parasite abundance in the focal host Arctic charr. I documented that experimentally reducing the density of Arctic charr through culling reduced the prevalence and intensity of two trophically transmitted Dibothriocephalus tapeworm species. The decline in the parasite infections was mainly due to culling-induced changes in host population age structure and increased predation rates from brown trout. Furthermore, I found that changes in host body size explained most of the variation in the dynamics of Salmincola edwardsii gill lice, a directly transmitted copepod parasite. In this case, the density of brown trout surprisingly amplified transmission rates to Arctic charr. Finally, the abundance and aggregation of the long-lived swimbladder nematode Cystidicola farionis was chiefly driven by host-population age structure. As host age increased, so did parasite abundance, which in turn reduced parasite aggregation. Heterogeneity in feeding and body size further increased aggregation, but stratifying the data by age diminished this effect. Accordingly, the relative composition of age classes each year determined the abundance and distribution of this parasite among the charr hosts. Combining my results with detailed long-term studies on the free-living community in the lake allowed me to identify some key parameters that structure the long-term dynamics of three metazoan parasite taxa with contrasting life cycles. The inverse relationship between fish population density and individual consumption rates led to increases in somatic growth and fish body size as the density of Arctic charr decreased. This shifted the predominant size distribution of the host population from a zooplankivorous to a benthivorous ontogenetic stage, leading to a shift in parasite exposure from Dibothriocephalus spp to Cystidicola farionis. Furthermore, the reductions in Arctic charr density affected size-structured interactions with brown trout thereby increasing brown trout density, which both reduced (Dibothriocephalus) and facilitated (Salmincola) parasite transmission to Arctic charr. In fish population ecology, size-structured population models highlight the strong link between ontogenetic development and population and community dynamics. These processes feedback to shape size distributions and individual fish behaviors. In this thesis, I show that such mechanisms also are crucial in shaping long-term parasite dynamics, but that the direction of effects vary depending on the parasite species and life cycle involved.

In the Baltic Sea and North Sea, the sustainability of bottom-trawl fisheries is threatened by many issues, such as the impact of climate change on exploited demersal stocks, long-term overfishing, and the European Landing Obligation for quoted species. This thesis identifies challenges to bycatch and harvesting patterns of targeted species in four relevant Baltic Sea and North Sea bottom-trawl fisheries, and presents six recent research papers that investigate species and size selectivity of fishing gears that can contribute to the mitigation of fishery-specific issues. The bycatch of flatfish species, such as flounder (Platichthys flesus), dab (Limanda limanda), and plaice (Pleuronectes platessa), is an issue in the Baltic Sea otter-trawl fisheries targeting cod. Paper I investigates if the application of a sorting grid, originally proposed by the fishing industry, can reduce the bycatch of flatfish in these fisheries. The results revealed a large reduction in flatfish bycatch with the added advantage of providing an additional escape possibility for undersized cod without compromising the catchability of marketable sizes. Paper II evaluates an alternative to the grid system proposed in Paper I: the exploitation of fish behaviour to address the problem of flatfish bycatch in the Baltic cod-directed trawl fisheries. The results demonstrate that a simple flatfish excluder in the lower panel of the extension piece of the trawl can effectively reduce the bycatch of flatfish while maintaining the catches of the targeted cod. Paper II also introduces a novel methodology, based on video recordings, for quantitative evaluation of fish behaviour in relation to selection devices. The method produces behavioural tree diagrams representing and quantifying behavioural patterns in relation to the selection device being assessed. Double bootstrapping is used to account for the uncertainty caused by the limited number of fish observations and natural variation in fish behaviour. In the frame of the balanced harvesting paradigm, Paper III explores the feasibility of achieving alternative harvesting patterns for Baltic cod. The intended alternative harvesting pattern targets medium-sized cod and avoids catches of juvenile and the largest, most productive cod. Paper III demonstrates experimentally that a bell-shaped retention probability curve, usually associated with gillnet fisheries, can also be achieved in trawl gears by combining standard grid and codend devices. The current poor status of Baltic cod stocks has led to drastic quota reductions to historical minima. In conformity with the Landing Obligation for quoted species, cod has become a choke species to the emergent flatfish fisheries in the Baltic Sea. Based on the insights obtained in Paper II, Paper IV investigates if the behavioural patterns observed for flatfish and cod in the trawl gear could be used to limit cod catches in flatfish-directed trawl fisheries. Paper IV demonstrates experimentally that a large reduction in cod catches can be achieved by removing a section of the top panel of the extension piece. As for Baltic cod, drastic reductions in fishing quotas for North Sea and Kattegat cod have occurred in recent years as a management response to the poor status of these populations. Consequently, cod is a choke species in the North Sea otter-trawl fisheries targeting Nephrops. An efficient separation of Nephrops from fish species in the trawl could lead to better management of the available quotas. Paper V investigated the potential of square-mesh sieve panels to separate Nephrops from fish species. Results from experimentally testing four different sieve panels revealed that most fish species were efficiently separated from Nephrops. However, the sieving efficiency (probability to pass through the meshes of the sieve panel) for the largest, most valuable Nephrops remained too low. Therefore, the resulting separation rates of fish species and marketable Nephrops was found suboptimal and not suitable for commercial fisheries. Recent shifts in North Sea ecosystems have reduced the abundance of natural fish predators in the fishing grounds of brown shrimp (Crangon crangon), making the North Sea beam-trawl fishery the major source of mortality for the targeted shrimp. This new role has also caused concern over the sustainability of the harvesting patterns in this fishery. In the search for optimal harvesting patterns of brown shrimp, Paper VI delivers a predictive framework for codend size selection of brown shrimp. The framework that was created is based on a large selectivity dataset and allows predictions of codend size selection considering the effect of mesh size and mesh orientation. The predictive framework presented in Paper VI could aid fishery modellers to explore population dynamics of brown shrimp under a wide range of predicted exploitation pattern scenarios. Finally, the work presented in this thesis provides technological advances and a knowledge base that suggests how to reduce the bycatch of unwanted species and generate alternative harvest patterns in different Baltic Sea and North Sea trawl fisheries.

This thesis presents a rich introduction to the evolution, life history and physiology of Atlantic salmon, with a special emphasis on the developmental transitions (termed smolting) juvenile salmon pass through has they prepare to migrate from their native freshwater habitat to the sea. The introduction provides a comprehensive background on chronobiology and osmoregulation in fishes and links this to the process of smolting as it has been described in literature. Further, this thesis contributes three papers to the standing literature on Atlantic salmon, salmonids and smolting. Paper I focuses on the role of photoperiod history for smolting and pre-adaptation to saltwater to occur in a coordinated and organized manner, and presents results showing photoperiod history ultimately influences saltwater growth. The paper presents data on previously unstudied genes in the context of salmonids and pre-adaptation to saltwater indicating that they could be important for predicting SW-tolerance in juvenile salmon. Paper II further illustrates the importance of photoperiod stimuli to drive smolting and preadaptation to saltwater. The data presented in paper II show clear differences in the response to saltwater between different photoperiod treatments. Not only in the number of responsive genes but also in the group of genes whose expression was influenced by saltwater exposure. Saltwater-responsive genes in the two treatments designed not to bring forth a saltwater-adapted juvenile were enriched for promoter motifs linked with a general stress response and osmoregulatory stress. The third paper focused on the temporal and spatial expression of the so-called clock genes in salmon, also smolting. One of the main findings of this paper is that many clock genes derived from the fourth salmon specific whole genome duplication have tissue-specific expression profiles, and that their regulation in the gill correlates with smolting. The main findings of these papers are presented and discussed together with insights from literature and unpublished data derived from the same datasets presented in the papers.

This dissertation is a case-study of the development and introduction of game-based learning in the Bachelor of Science in Fisheries and Aquaculture at the Norwegian College of Fishery Science. The use of games for learning has long traditions, but is currently receiving increased attention from scholars in light of the increased focus on active learning in higher education institutions. The Norwegian College of Fishery Science at UiT The Arctic University of Norway established the SimFish-project to develop innovative interdisciplinary learning in fisheries and aquaculture. This thesis presents research produced in connection with this project, focusing on the case of game-based instruction loops for marine resource management in the Bachelor of Science in Fisheries and Aquaculture. The case study is interdisciplinary, drawing on social science fisheries studies, active learning, game-based learning, and historical game studies. The included papers deal with different facets of these fields. The main aim in this thesis is to investigate how the underlying concepts of sustainable fisheries governance and core learning objectives in marine resource management can be integrated in game-based learning activities, and study the impacts the introduction of games as educational practice have had in the study program. The main focus of analysis is the qualitative data collected from students after game sessions, and an end of program evaluation for graduates of the program. The results show that the game-based instruction loops have served to engage the students, and contributed to the attainment of the learning outcomes in marine resource management. The games have been both a positive learning experience, and provided simulated experience that the students find relevant for the real-world seafood industry and understanding issues related to sustainable fisheries management. The games have offered opportunities for the students to practice 21st Century skills, but the data collection has not been specific enough to contribute in-depth understanding. The results as a whole indicate that game-based learning has worked well for creating learning built on constructive alignment between the learning activities, learning outcomes and assessment. Debriefing, the structured integration of the game-experiences in the overall learning experience, has been an important factor. As a whole, the findings indicate and contribute knowledge that can further the use of game-based learning in fisheries education and related fields.

Marine fungi comprise a group of organisms that have been overlooked for a long time. Research interest has increased with the realization of the important ecological role and rich chemistry of marine fungi. Marine fungi have yielded thousands of new natural products the last decade, but many taxa remain unstudied. Marine fungi from the Arctic have not been reported in literature in regard to bioprospecting campaigns and represent a novel source of natural products. The aim of this thesis is to assess the potential of Arctic marine fungi to produce bioactive secondary metabolites by fermentation and genome analysis. This was achieved in three steps. First, fungi were isolated from the Svalbard archipelago. The 20 isolates obtained were characterized based on molecular markers and their antibacterial activity was tested using an agar diffusion assay (Paper 1). Secondly, three distinct marine fungi were whole genome sequenced and characterized. One of the fungi represented a putatively novel species which was circumscribed based on morphology and phylogenetic inference (Paper 2). Finally, a metabolite from one fungus among the 20 obtained around Svalbard was isolated and the bioactivities characterized (Paper 3). In Paper 1, half of the fungal isolates showed activity against pathogenic bacteria and every third isolate represents potentially new species of fungi. Five of these isolates are strictly marine fungi belonging to the order of Lulworthiales. The study showed that the Arctic can yield novel marine fungal diversity that can be utilized in bioprospecting. For Paper 2, three marine fungi were whole genome sequenced and their biosynthetic gene clusters were characterized. Mapping of the biosynthetic gene clusters (BGCs) within the Emericellopsis genome confirmed the detection of the secondary metabolite helvolic acid produced during fermentation. The study revealed numerous unknown biosynthetic gene clusters and a range of carbohydrate active enzymes. Each of the three genomes provides the first genome of their respective taxa and can contribute to understanding their evolutionary adaption to the marine environment. In Paper 3, a novel compound from the fermentation broth of Mytilinidion sp. was isolated and its bioactivity was characterized using seven different bioactivity assays. The compound turned out to be a modified medium component with IC50 of 43 µM in an ACE-inhibitory assay. The compound was novel and this is the first report of its bioactivity. Molecular networking could perhaps have provided early indications that the compound was a modified medium component. Marin sopp er en gruppe av organismer som har vært oversett i lang tid. Interessen for marin sopp har steget i takt med økt forståelse for dens økologi og rike kjemi. Mange tusen nye naturprodukter har blitt beskrevet fra marin sopp de siste tiårene, men det er fremdeles mange grupper som ikke er godt studert. Marin sopp fra Arktis er ikke godt undersøkt i forbindelse med bioprospektering og representerer en ny kilde til naturprodukter. Målet med avhandlingen var å vurdere potensialet til Arktisk marin sopp for å produsere bioaktive metabolitter ved å bruke fermentering og genomanalyse. Dette ble gjennomført i tre steg. Først ble 20 marine sopp isolert i løpet av ett forskningstokt rundt Svalbard. Disse soppene ble karakterisert ved hjelp av molekylære markører og evnen til å produsere antibakterielle forbindelser ble undersøkt ved å bruke agar-diffusjons analyse (Artikkel 1). Det neste som ble gjort var at tre forskjellige marine sopp ble helgenomsekvensert og genomene ble karakterisert. En av soppene er antageligvis ny for vitenskapen og ble beskrevet basert på morfologisk og fylogenetisk analyser (Artikkel 2). Til sist ble ett stoff fra en av soppene fra Artikkel 1 isolert og bioaktiviteten til stoffet ble beskrevet (Artikkel 3). I den første artikkelen viste halvparten av de isolerte soppene antibakteriell aktivitet mot sykdomsfremkallende bakterier. Hvert tredje isolat representerer muligens nye arter basert på tilgjengelige referansesekvenser. Fem av de potensielt nye artene tilhører ordenen Lulworthiales som kun finnes i havet. Studien har vist at det er stort potensiale for å avdekke nye arter og at mange av disse viser evne til å produsere antibakterielle forbindelser. Dette viser at de kan utnyttes i bioprospektering. I Artikkel 2 ble tre ulike marine sopper helgenomsekvenseert og genomet ble karakterisert med tanke på hvilke biosyntetiske genklynger og karbohydrat-aktive enzymer som ble detektert. Karakteriseringen av genklyngene i Emericellopsis bekreftet deteksjonen av metabolitten helvolsyre som soppen produserte under fermentering. Studien avslørte mange ukjente genklynger og en rekke karbohydrat-aktive enzymer. De tre genomene er de første helsekvenserte genomene i deres respektive slekter og kan bidra til å gi ny kunnskap om de evolusjonære tilpasningene de har til det marine miljø. I den siste artikkelen ble ett ukjent stoff fra fermenteringen av Mytilinidion isolert. Bioaktiviteten til stoffet ble karakterisert ved hjelp av syv forskjellige bioaktivitetstester. Stoffet viste seg å være en delvis nedbrutt og modifisert mediekomponent som hadde en IC50 verdi på 42.3 µM i en ACE-inhiberingstest. Analyse ved hjelp av molekylært nettverk kunne kanskje avdekket at stoffet var relatert til dyrkningsmediumet.

This thesis investigates preferences for honesty in economic experiments. Preferences for honesty have attained a fair amount of attention in the last couple of decades, from multiple areas within the social sciences, including economics. This thesis may serve as an introduction to the field. First, it provides an introduction to experiments in economics, before it dives into how economists conduct research on honesty. The literature in the thesis provides background to the three research papers reported in the last chapter. Through different experimental tasks for studying honesty, this thesis provides new insights to several subfields of the literature. The first paper investigates how differences in equality affect preferences for honesty and generosity through a real effort dictator game, allowing for dishonest reports in the production stage. Comparing behavior across treatments, we find that when participants know they are at a relative disadvantage, they are significantly more dishonest and significantly less generous. Results speak to the literature on moral balancing, self-justification for dishonest behavior and generosity. The second paper combine a survey instrument designed to measure individual cultural worldviews and a coin-flip honesty task. The data fail to support the conjecture that adherents of certain worldviews are more honest on the aggregate level. However, when data is disaggregated by gender, the worldviews help in explaining the observed gender effect in the data. Results suggest that cultural worldviews may help provide a more nuanced understanding of the gender differences generally observed in the honesty literature. The final paper of this thesis investigates whether the choice of payment scheme affect the level of honesty in a real-effort honesty task. Through both a laboratory experiment and a meta-study, the paper finds no evidence of difference between the schemes. This result is in contrast to a study reporting such an effect in an honesty experiment using random outcomes.

This thesis explores various aspects of the application of economic analysis to Atlantic salmon management in Norway. The purpose and contributions are twofold. On the one hand, the thesis seeks to improve economic toolbox used to analyse environmental-economic trade-offs. On the other hand, it yields specific conclusions and recommendations for the case of Atlantic salmon management in Norway and environmental management in general. The questions investigated here concerns opportunity costs of conservation, valuation of ecosystem services and the application of cost-benefit analysis in practice. The research is largely related to the problem of “farmed-wild salmon” trade-off, where the recently introduced aquaculture regulations (“Traffic light” system) are central. The research applies both quantitative and qualitative methods. A general model for the opportunity cost in the presence of externalities is proposed and challenges in its estimation, mainly related to the complexity of ecological-economic links, are discussed. It is found that wild salmon conservation under the new regulations is both economically and ecologically inefficient. It is argued that an analysis of costs and benefits would reveal potential inefficiency at an early stage. However, the research finds that application of cost-benefit analysis is hindered by knowledge gaps, ethical, political and technical constraints. In particular, knowledge gaps concern the values of ecosystem services. The thesis investigates potential affective bias in the valuation of Atlantic salmon with stated preference methods. The bias is linked to the awareness of the good due to the public debate surrounding wild and farmed salmon controversies, and the prevalence of non-market values. Addressing the knowledge gaps would improve the applicability of economic tools. However, it is also required that other constraints are taken into account.

Rapid environmental changes are currently occurring in the Arctic because of global warming. Arctic food webs can exhibit complex dynamics because of the prevalence of tight interactions between trophic levels. Climate change impacts can therefore propagate across food webs and result in non-trivial indirect effects on arctic species and populations. In this thesis, constituted by four papers, I address the general issue of how rapid climate change and other environmental stressors affect the population dynamics of arctic species of management concern. I focused on three target species: the Svalbard rock ptarmigan, the willow ptarmigan, and the lesser white-fronted goose. I based my investigation on long-term time series available for both the study populations and linked ecosystem components. I aimed to infer general ecological mechanisms driving population dynamics of arctic species facing climate change, but also provide recommendations for improved monitoring and management of the study populations. I developed a-priori conceptual models describing climate and management impacts and converted them into advanced statistical models. I found that major changes in winter climate in terms of winter temperature seem to have driven the recent increase in the population of Svalbard rock ptarmigan, while intensified outbreaks of insect pests and delayed onset of winter may have contributed to the decline of willow ptarmigan populations. As stakeholders were interested in having predictions of population density to adapt harvest strategies, I tested the ability of different models to provide near-term forecasts of ptarmigan density. I also found no evidence that predator control contributed to the recent recovery of the endangered Fennoscandian population of lesser white-fronted goose, and that goose breeding success is primarily influenced by population cycles of small rodent species. My thesis constitutes a compelling example of how a holistic approach incorporating food web dynamics can improve our understanding of the multifaceted impacts of environmental changes and aid the management of populations subjected to rapid climate changes.

The transmission of salmon lice (Lepeophtheirus salmonis Krøyer) from farm salmon to wild salmonids and the impact on wild populations are sources of intense debate in all salmon producing countries, and it is currently an issue of high political and economic relevance in Norway. Solid science-based evidence is therefore needed by decision makers to apply sound management strategies. Given the complexity of the systems, coupled with methodological challenges, the causal relation between the in-farm production of lice and increased lice abundances on wild salmonids have been difficult to demonstrate. In this thesis, mean salmon lice abundances on sea trout (Salmo trutta L.) were shown to be directly correlated with the estimated number of lice emanating from nearby fish farms. Although temperature was found to also have an impact on lice epidemiology on both farmed and wild fish, temperature alone could not explain the high numbers of lice parasitizing sea trout in areas were farmed and wild fish coexist in close vicinity. This corroborates the hypothesis that salmon farms act as a main source of lice for sea trout in aquaculture-intensive areas in Norway, even after the effect of temperature has been accounted for. These conclusions were drawn based on the statistical analysis of a large and comprehensive data set combining information on standing stock and mean lice abundances on farmed fish from Norwegian salmon farms, together with observations of lice infestations on wild sea trout collected all along the Norwegian coast between 2010 and 2011. In combination, these two large and comprehensive data sets provided a unique opportunity to investigate the role of salmon farms as a source of lice for local sea trout populations. Moreover, results from this thesis suggest that the Norwegian National Salmon Fjords, i.e. protected areas subjected to strict limitations on aquaculture activities, can effectively protect wild salmonids against infestations with lice of farm origin, but only if the size and configuration of the protected area is adequate. Lice abundances on sea trout caught inside large National Salmon Fjords were found to be consistently low over time and are assumed to represent natural levels. Lice infestations on sea trout caught inside smaller National Salmon Fjords, on the contrary, showed large variation between years, oscillating in accordance with the variations in stocked biomass in the surrounding farms. Lice prevalence and intensities in these areas occasionally matched and even exceed those previously reported in areas of intensive farming in Norway. These results suggest that the production and transport of planktonic lice larvae from farms situated outside the limits of the protected areas might still be an important source of lice for local populations of sea trout. Although individual studies for each National Salmon Fjord may be necessary to evaluate the degree of protection, one can expect that the capacities of the smallest fjords for preventing the transmission of lice from farm salmon to wild fish are probably limited, and it is reasonable to assume that the protection of large areas contributes best to the protection of wild salmonids. The optimal design will in any case depend on the target species: while sea trout may benefit from the establishment of a local protected area covering their marine home range, the protection of Atlantic salmon may require the protection of entire fjords or the establishment of “clean corridors” along their migration routes. Last, this thesis delivers direct evidence of a causal relationship between salmon lice and marine mortality of sea trout in nature. Based on results from exposure field studies, combined with acoustic telemetry, this thesis shows a mortality hazard ratio of 2.7 (95% CI = 1.04−7.13) for lice-infested trout post-smolts compared to non-infested control individuals. In other words, the probability of a trout post-smolt to survive the first summer at sea was reduced by almost two-thirds when infested with a heavy lice load, although there is a big uncertainty around this estimate. These results apply to fish carrying a relative intensity of 2.4 lice g−1, on average. Although such lice intensities are well beyond the estimated mortality-inducing threshold of 0.3 lice g−1 (Taranger et al. 2015), they are still representative of lice infestations observed on sea trout in some farm-intensive areas in Norway. Furthermore, this thesis documents an altered migration behavior of lice-infested individuals, including the abrupt interruption of the feeding migration after just a few weeks at sea and a preference for feeding areas closer to the river, in the inner part of the fjord. While control fish spent on average 100 days at sea before return, lice-infested sea trout returned to freshwater after only 18 days at sea, meaning that almost 80% of the feeding time at sea was lost because of salmon lice. This can be expected to significantly reduce marine growth and further have an impact at the population level. Studies that accurately quantify the impact of salmon lice on wild sea trout and their populations are still needed, and this thesis makes an important contribution in this direction.

The thesis gives an introduction to natural product drug discovery and the underlying chemical principles that make natural products privileged structures for drug discovery. Paper I deals with the isolation of Lipid 430 from cultures of two Algibacter sp. isolates and the investigation of their anti-proliferative and anti-bacterial effect. Paper II describes the isolation of Serratiochelin A and C and investigation of the specific anti-bacterial and anti-proliferative effect of the siderophore Serratiochelin A. Paper III deals with the isolation of new Suomilides from a Nostoc sp. isolate and the investigation of their bioactivity. In addition, it proposes a biosynthetic pathway for Banyaside/Suomilide like molecules and their characteristic azabicyclononane moiety.