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Surtsey is a volcanic island located on the south-east offshore extension of the Icelandic rift zone. It was formed during successive eruptions from the seafloor in 1963-1967 and has been officially protected and studied ever since. It represents an exceptional natural setting for studying colonization and succession of life on land. Also for subsurface microbial communities associated with newly formed basaltic tuff deposits in a seawater hydrothermal system that is still active and at temperatures approaching the presumed thermal limit for functional life. During an international drilling operation at Surtsey in 2017, drill core samples at successive depths as well as associated hot fluids and surface fumes from fumaroles were collected for microbial investigations. This thesis presents the first and most comprehensive research of the Surtsey subsurface biosphere. Multiple approaches were combined on the rare and unique samples to increase the knowledge of microbial communities inhabiting the oceanic subsurface and of the processes that sustain such life. These included molecular analyses of environmental DNA through 16S rRNA gene amplicon and metagenome sequencing, isolation and characterization of bacterial strains and microscopic investigations. Based on the DNA concentration, the microbial cell numbers present in the drill cores were estimated to range from about 5×104 to 1×106 cells per gram of sample. The Surtsey subsurface is therefore a low biomass environment, making the samples extremely sensitive to external contamination. It is nevertheless a diverse habitat that hosts bacterial and archaeal clades, including extremophiles, that have been previously detected in other terrestrial and marine environments. Yet, many clades belonged to unknown lineages. Predictive functional analyses based on taxonomic identifications revealed that the Surtsey subsurface biosphere is composed of heterotrophic microorganisms as well as chemoautotrophs involved in the sulfur, nitrogen, and methane cycles. However, these results could not be strengthened by the functional metagenomic investigations as they were inconclusive. Numerous enrichment cultures were initiated using different conditions and media and resulted in nearly 200 isolated bacterial strains, which included several novel species. One novel thermophilic bacterial species, Rhodothermus bifroesti, was fully characterized and its genome was sequenced and compared with those of the two other described Rhodothermus species. Comparative analyses revealed that 2.15% of the amplicon sequence variants from the 16S rRNA gene amplicon sequence datasets were represented by cultivated strains using standard methods. Finally, putative microbial structures adhering to the basaltic tuff were discovered inside the numerous interconnected vesicles found in the basaltic glass. All of the findings point to an active microbial colonization of the Surtsey deposits within 50 years after the eruptions ended, with possible sources of colonization coming from the surrounding ecosystems via microbial dissemination and possible adaptations. The thesis establishes a foundation for future research on the microbial communities that inhabit the Surtsey subsurface and their temporal succession in the face of a cooling and changing hydrothermal environment.

Pre-print / Óritrýnt handrit © 2022 Elsevier Ltd. All rights reserved., Environmental life cycle costing (ELCC) is a tool which aggregates five categories of monetary costs across a project's life cycle: investment, operation, maintenance, end-of-life, and externalities. This paper summarises the results from the first two ELCC studies involving deep enhanced geothermal systems (EGS). The ReCiPe method was used to transform life cycle impact factors into economic costs for externalities. The two case studies are the pilot EGS project in Reykjanes, Iceland and the Vendenheim co-generation plant in France. The ELCC of the Reykjanes project is estimated in the range 14.47–15.78 million euros, with investment and well drilling projected to constitute 83% of these amounts. An ELCC in the range 91.90–113.97 million euros is estimated for Vendenheim, with the production plant, well drilling, and operations and maintenance costs accounting for the majority. The levelized costs of energy associated with Vendenheim (mean Є45.0/MWh/year) and Reykjanes (mean Є16.5/MWh/year) are at the lower end of the range normally reported for geothermal power projects. Although the case studies cannot be directly compared since Reykjanes involves the drilling of a single well and Vendenheim a co-generation plant and two wells, the outcomes suggest that deep EGS projects may involve cost-savings compared to conventional geothermal power ventures.

The theory of divergence by trophic polymorphism, an important part of diversification in vertebrates, has recently been extended to encompass the interplay of developmental, ecological and evolutionary processes (Eco-Evo-Devo dynamics). However, this extended theory doesn’t thoroughly explain the evolution of reproductive isolation, which is unfortunate considering the recent advances from the field of speciation. In this thesis, I argue that the Arctic charr morphs of Thingvallavatn are an ideal system to study how reproductive isolation is embedded within the theory of divergence by resource polymorphism, which I present through five papers. First, I focused on two sympatric morphs, the small-benthic (SB) and the planktivorous (PL) charr. Common-garden experiments showed limited evidence for hybridization to affect the structure of trait covariance in both morphs, regarding morphology, developmental timing and feeding behaviour (Paper I), and personality traits (Paper II). However, information on gene expression variability in embryos indicated that hybridization might influence evolvability (Paper III). Multiple reproductive barriers between the two morphs, involving habitat use, assortative mating and hybrid development were also assessed (Paper IV). Finally, Paper V combines field studies and rearing experiments to explore the interplay between habitat choice and offspring development in the large-benthic (LB) charr, which spawns earlier in the season than the other morphs. The results suggested that LB-charr favour temperature conditions that may delay offspring development. Altogether, these findings provide an overview on reproductive isolation among the Arctic charr morphs of Thingvallavatn and constitute a primer to study speciation in an Eco-Evo-Devo context.

Biodiversity is declining globally, primarily driven by anthropogenic changes and alterations of natural habitats. In lowland Iceland, human impact has increased considerably in the past decades, often involving an increase in numbers of anthropogenic structures. The consequences of these land use changes for the important wildlife that these areas support is poorly known. The aim of this thesis was to study if and how four types of newly introduced structures/habitats (roads, summer houses, power lines and plantation forests) in the Icelandic lowlands affect the density and species composition of ground-nesting birds in the surrounding area. Surveys of bird abundance and distribution were undertaken throughout lowland areas of Iceland that varied in the number and extent of anthropogenic structures. Two species (Redwing and Snipe) were found in higher densities or showed no change with distance from the structures, while seven species (Meadow pipit, Black-tailed Godwit, Golden Plover, Dunlin, Oystercatcher, Whimbrel and Redshank) occurred in significantly lower densities close to at least one of these anthropogenic structures and, for roads and forests, these reduced densities occurred over distances up to 200 m. Reduced abundance close to structures was strongest for Golden Plover and Whimbrel, for which between 40-52% of the global populations currently breed in Iceland. The effects of land conversion of large areas of open habitats with roads, forest plantations, houses and power lines could potentially affect populations of these species. Point counts which have been carried out in the southern lowlands since 2011, in an area where anthropogenic influences are constantly expanding, have shown that while the local population of Redwing is increasing and Snipe numbers are stable, the remaining study species are decreasing. Planning of future infrastructure locations and configurations should be designed to reduce impacts on the ground-nesting bird populations for which Iceland has international obligations, and protecting the remaining large tracts of open habitat is likely to be a priority., The University of Iceland Research Fund Science and Research Fund of South-Iceland The Nature Conservation Fund of Pálmi Jónsson The Icelandic Road and Coastal Administration

Climate warming in sub-Arctic regions leads to shifts in plant communities and retreating glaciers. Mosses and lichens contribute to important ecosystem processes in these environments, including nitrogen fixation via their microbiome. The first objective of this dissertation was to understand the extent to which long-term warming affects bacterial communities associated with the lichen Cetraria islandica. In the same context, the bacterial community and nitrogen fixation rates associated with the moss Racomitrium lanuginosum were investigated. These species are among the most common lichen and moss species in Iceland, respectively. Paper I shows that long-term warming affects the structure and composition of the bacterial community associated with C. islandica and that this change is partly mediated via changes in the plant community. The same is true for the bacterial communities associated with R. lanuginosum, although nitrogen fixation rates are apparently not affected by warming, potentially due to warming-induced shifts in nitrogen-fixing taxa (Paper II). The second objective was to evaluate the extent to which bacterial communities of two common Racomitrium species and the underlying soil as well as the moss-associated nitrogen fixation change during primary succession and whether these changes are related to changes in moss functional traits. The bacterial community composition associated with Racomitrium mosses was correlated with the successional stage in the Fláajökull forefield, and also with moss moisture content. The bacterial communities of the underlying soil also shifted with succession and were in addition related to the moss C:N ratio. Nitrogen fixation rates did not change with time since deglaciation, but were correlated with the bacterial community structure., Meðal afleiðinga hlýnunar loftslags á norðurslóðum má nefna hörfun jökla og ýmsar gróðurbreytingar. Mosar og fléttur leggja mikið af mörkum til vistkerfislegra ferla í hinu kalda umhverfi norðurslóða, þar á meðal bindingu köfnunarefnis með aðstoð þeirra örvera sem í þeim þrífast. Eitt af meginmarkmiðum þeirra rannsókna sem greint er frá í ritsmíð þessari er að leiða fram að hve miklu leyti loftslagshlýnun á áratuga skala hefur áhrif á örverusamfélög í fléttunni Cetraria islandica (fjallagrös) og í gamburmosanum Racomitrium lanuginosum (hraungambri). Þessar tegundir eru meðal algengustu fléttu- og mosategunda í mörgum íslenskum vistgerðum. Í Grein I er sýnt fram á að langtímahlýnun hefur áhrif á samsetningu örverulífríkisins í fjallagrösum og að þau áhrif eru að hluta tengd breytingum á aðlægum gróðri. Hið sama reyndist eiga við um örverusamfélög hraungambra, nema hvað, að hlýnunin reyndist ekki hafa marktæk áhrif á niturbindingu, og kom fram að sú niðurstaða gæti skýrst af breyttri tegundasamsetningu niturbindandi baktería (Grein II). Annað meginmarkmið rannsóknanna var að meta að hve miklu leyti örverusamfélög í tveimur gamburmosategundum og í jarðveginum sem þær vaxa á taka breytingum með gróðurframvindu og hvort þær breytingar tengjast ástandi mosans og starfsemi á borð við niturbindingu. Örverusamfélögin voru þannig kortlögð með tilliti til aldurs jökulgarða Fláajökuls, og einnig við rakainnihald mosans. Bakteríusamfélög í jarðveginum tóku skýrum breytingum með aldri jökulgarðanna, og stóðu einnig í samhengi við C:N hlutfall mosans sem á honum óx. Niturbinding stóð ekki í marktæku samhengi við aldur jökulgarðanna, en var hins vegar skýrt fylgin samsetningu örverulífríkisins.

As industries expand in sub-Arctic and Arctic waters there are increased conflicts between these industries and cetaceans. The aim of this work was to investigate the issue of cetacean bycatch/entanglement in Iceland, with a particular focus on the understudied issue of humpback whale entanglement. Bycatch/entanglement in fishing gear is a serious threat to cetaceans, as well as a detriment to fisheries, and mandatory bycatch reporting in logbooks could be of immense scientific value; however cetacean bycatch is considered greatly under-reported. I determined that cetacean bycatch was significantly under-reported in fisher logbooks in nearly all (7/8) trawl, net, and hook and line fisheries that could be examined in New Zealand, Iceland, and the USA when compared to observer data. The cod gillnets in Iceland had the biggest difference between fisher and observer catch per unit effort (with the observer estimate being 270 times greater). Large whale entanglements only accounted for an average of 12% of reported incidents, supporting the idea that these events are the most under-reported. Through scar-based analysis I determined that at least 25% of Icelandic humpback whales have been entangled and this is occurring at a rate of 2% annually. I tested acoustic alarms as an entanglement mitigation tool and through experimental exposure trials it was determined that humpback whales responded to the “whale pinger” by significantly increasing their speed and decreasing their surface feeding. These pingers were also fitted on a capelin purse seine net and I observed that humpback whales still entered the net from the bottom, but they were able to escape through a pinger-free opening. Using anonymous questionnaires and interviews, I gained further insight into entanglement from the fishers’ perspective. Humpback whales were the most commonly reported species that was witnessed entangled, and this occurred most often in capelin purse seines. Damage and losses due to whale collisions with gear was reported to cost fishers up to 55.000.000 ISK. Overall, this work resulted in the first systematic quantification and statistical comparisons of cetacean bycatch under-reporting in logbooks versus observer data. This assessment of whole fisheries in individual countries provides baseline data for improvement of mandatory cetacean bycatch data for scientific use. Additionally, I provided first scientific evidence that entanglement is a prevalent issue in the Icelandic humpback whale population and Icelandic fisheries, sometimes having detrimental effects on both parties. Furthermore, this work resulted in the first evidence that whale pingers may be a useful entanglement mitigation tool in humpback whale feeding grounds. The experimental exposure trials revealed that surface feeding behaviour can be used as a response variable, while results of the in-situ capelin purse seine trial suggested humpback whales may have good directional hearing that can be examined through pinger experiments., Samfara útþenslu iðnaðar og sjávarútvegs á hafsvæðum norðurslóða (kaldtempruðum og heimskautasvæðum) aukast hagsmunaárekstrar milli þessara athafna mannsins og hvala. Markmið þessarar vinnu er að rannsaka ánetjun hvala í veiðarfæri við Ísland, með sérstakri áherslu á ánetjun hnúfubaka þar sem rannsóknir hefur skort. Meðafli/ánetjun í veiðarfærum er alvarleg ógn við hvali og skylduskráning þeirra í afladagbækur gæti haft mjög mikið vísindalegt gildi; en meðafli hvala er talinn mjög vanskráður. Ég dró þá ályktun að meðafli hvala var marktækt vanskráður í afladagbækur næstum allra (7/8) tog-, neta-, króka- og línuveiða sem við náðum að rannsaka í Nýja Sjálandi, Íslandi og Bandaríkjunum samanborið við gögn eftirlitsaðila. Mestur var munurinn (270x meiri) milli skráninga fiskimanna og eftirlitsmanna hvað varðar afla á sóknareiningu í þorskanet við Ísland. Ánetjun stórhvala var að meðaltali einungis 12% af tilkynntum atvikum, sem styður þá hugmynd að þessi atvik séu mest vanskráð. Með greiningu á örum ályktaði ég að minnst 25% íslenskra hnúfubaka hafa flækst í veiðarfæri og að tíðni slíkrar ánetjunar sé um 2% árlega. Ég prófaði hljóðfælur sem tæki til að minnka ánetjun og út frá tilraunahljóðsendingum ályktaði ég að hnúfubakar bregðist við hljóðfælum með því að auka marktækt sundhraða og minnka fæðunám við yfirborð sjávar. Þegar hljóðfælurnar voru festar við loðnunætur fóru hnúfubakar eftir sem áður inn í þær neðan frá, en náðu að komast út um hljóðfælulaust op á nótinni. Nafnlausir spurningalistar og viðtöl gáfu frekari upplýsingar um ánetjun frá sjónarhóli sjómanna. Í þessum hluta voru hnúfubakar oftast nefndir og loðnunót var algengasta veiðarfærið varðandi ánetjun. Skemmdir á veiðarfærum og annað tjón sjómanna vegna árekstra hvala við veiðarfæri gat numið allt að 55 milljónum króna samkvæmt þessum skýrslum. Þessi vinna leiddi af sér fyrstu kerfisbundnu mælinguna og tölfræðilegan samanburð á vanhöldum í skráningu hvala í afladagbækur, samanborið við skráningar eftirlitsmanna. Þetta heildarmat fiskveiða í einstökum löndum sýnir viðmiðunargögn sem bætt geta skyldubundnar upplýsingar um meðafla, til vísindalegra nota. Að auki leiddi ég fram fyrstu vísindalegu sannanir þess að ánetjun hnúfubaka er reglubundið fyrirbæri í íslenskum fiskveiðum sem getur haft alvarleg áhrif bæði á hvalina og fiskveiðarnar. Rannsóknirnar leiddu einnig til fyrstu vísbendinga um að hljóðfælur geti verið gagnlegar við að minnka líkur á ánetjun hnúfubaka á fæðuslóð. Tilraunahljóðsendingarnar leiddu í ljós að fæðunám við yfirborð er nýtanlegt sem svarbreyta, en niðurstöður tilraunar með herpinót in-situ gáfu til kynna að hnúfubakar kunni að hafa góða stefnuheyrn sem hægt er að rannsaka í gegnum tilraunir með hljóðfælu.

Pre-print / Óritrýnd útgáfa greinar © 2021 Elsevier B.V. All rights reserved., Glaciers have been an increasingly studied topic in the ecosystem services (ES) literature, with 6 multiple scientific studies affirming a critical and diverse contribution to human well-being. 7 However, the literature to date on glacier ES has lacked a systematic analysis of their type and 8 the various stages in the formation of glacier ES, including the linkages between biophysical 9 structures and ecological processes to human values, benefits and well-being. This paper begins 10 to fill this gap by (1) detailing the first Common International Classification for Ecosystem 11 Services classification of ecosystem services specific to glaciers; and (2) constructing an ES 12 cascade model specific to the ES of glaciers, integrating four main stages of co-production: 13 value attribution, mobilisation of ES potential, value appropriation, and commercialisation. In 14 both stages, examples from the academic and grey literature are highlighted. Based on a 15 systematic literature review, a total of 15 ES are identified, categorised as follows: provisioning 16 (2), regulation and maintenance (6), and cultural (7). Apart from abiotic regulation and 17 maintenance ES, it is evident that human interventions are necessary in order to mobilise, 18 appropriate and commercialise several glacier ES, including freshwater for drinking, 19 hydropower generation, recreation and education. Rapidly intensifying climate change has led 20 to intense focus on the initial co-production process of value attribution and identification of 21 dynamic ecosystem services potential, with a view to maximising commercial benefits in the 22 coming decades where this is possible, especially linked to hydropower generation from glacial 23 rivers. However, this study also finds that adaptive ecosystem management is a necessary pre24 requisite of resilience but may be insufficient in this context to address potential ecosystem 25 disservices and potentially catastrophic impacts to human well-being, such as from dangerous 26 glacier outburst floods., This paper has been funded by NordForsk (grant number 76654) via their financial support to 743 the Nordic Centre of Excellence ARCPATH (Arctic Climate Predictions – Pathways to 744 Resilient, Sustainable Communities).

Publisher's version (útgefin grein), The 2017 Surtsey Underwater volcanic System for Thermophiles, Alteration processes and INnovative concretes (SUSTAIN) drilling project at Surtsey volcano, sponsored in part by the International Continental Scientific Drilling Program (ICDP), provides precise observations of the hydrothermal, geochemical, geomagnetic, and microbiological changes that have occurred in basaltic tephra and minor intrusions since explosive and effusive eruptions produced the oceanic island in 1963-1967. Two vertically cored boreholes, to 152 and 192m below the surface, were drilled using filtered, UV-sterilized seawater circulating fluid to minimize microbial contamination. These cores parallel a 181m core drilled in 1979. Introductory investigations indicate changes in material properties and whole-rock compositions over the past 38 years. A Surtsey subsurface observatory installed to 181m in one vertical borehole holds incubation experiments that monitor in situ mineralogical and microbial alteration processes at 25-124 °C. A third cored borehole, inclined 55° in a 264° azimuthal direction to 354m measured depth, provides further insights into eruption processes, including the presence of a diatreme that extends at least 100m into the seafloor beneath the Surtur crater. The SUSTAIN project provides the first time-lapse drilling record into a very young oceanic basaltic volcano over a range of temperatures, 25-141 °C from 1979 to 2017, and subaerial and submarine hydrothermal fluid compositions. Rigorous procedures undertaken during the drilling operation protected the sensitive environment of the Surtsey Natural Preserve., Funding for this project was provided by the International Continental Scientific Drilling Program (ICDP) through a grant to the SUSTAIN project (led by Marie D. Jackson); a grant of excellence from the Icelandic Research Fund, ICFRANNÍS (the IceSUSTAIN consortium led by Magnús T. Gudmundsson); the Bergen Research Foundation and K.G. Jebsen Centre for Deep Sea Research at the University of Bergen, Norway (led by Steffen Leth Jørgensen); the German Research Foundation (DFG) (led by Wolfgang Bach and Bernd Zimanowski); and DiSTAR, Federico II, University of Naples, Federico II, Italy (led by Piergiulio Cappelletti). The University of Utah, USA (Marie D. Jackson), and the two Icelandic power companies Reykjavík Energy and Landsvirkjun contributed additional funds. In kind support by several Icelandic institutions and companies contributed greatly to the success of the project, as did the dedicated work of several volunteers. The logistical support provided by the Icelandic Coast Guard was instrumental in carrying out the drilling operation. Norðurflug Helicopters and the Vestmannaeyjar Rescue Group provided critical logistical support. Jeremy Fisher and Rowan McGuire contributed to this article. The DOSECC drilling team, Steve Cole, Justin Blouin, A. J. Vecchiarelli, Matthew Lyon, and Michael Vinson, did excellent work. Hjalti Franzson provided guidance, and Þorsteinn Jónsson, Bjarni Kristinsson, Gísli Sighvatsson, and Sveinbjörn Steinþórsson contributed to the logistical operation on Surtsey. Unpublished borehole temperature measurements were made during the annual Surtsey Research Society expedition in July 2018.

Publisher's version (útgefin grein), Molards have been defined in the past as conical mounds of debris that can form part of a landslide's deposits. We present the first conclusive evidence that molards in permafrost terrains are cones of loose debris that result from thawing of frozen blocks of ice-rich sediments mobilised by a landslide, and hence propose a rigorous definition of this landform in permafrost environments. We show that molards can be used as an indicator of permafrost degradation, and that their morphometry and spatial distribution give valuable insights into landslide dynamics in permafrost environments. We demonstrate that molards are readily recognisable not only in the field, but also in remote sensing data; surveys of historic aerial imagery allow the recognition of relict molards, which can be used as an indicator of current and past permafrost conditions. The triggering of landslides as a result of permafrost degradation will arguably occur more often as global atmospheric temperatures increase, so molards should be added to our armoury for tracking climate change, as well as helping us to understand landslide-related hazards. Finally, we have also identified candidate molards on Mars, so molards can inform about landscape evolution on Earth and other planetary bodies., This work has been funded by a postgraduate studentship grant (NE/L002493/1) from the Central England Natural Environment Research Council Training Alliance (CENTA). This project forms part of and is funded by a British Geological Survey BUFI CASE Studentship (GA/14S/024, Ref: 284). We thank the Natural Environment Research Council Airborne Research Facility (NERC ARF) and their Data Analysis Node (NERC-ARF-DAN) plus the EUropean Facility for Airborne Research (EUFAR) for the air photography and LiDAR data on which this paper relies. Thanks go to NERC Geophysical Equipment Facility (GEF) for the Loans 1048 and 1064 through which differential GPS surveys were possible. We thank the GeoPlanet writing residential scheme for the support in writing this manuscript. C. Jordan publishes with permission of the Executive Director of BGS. S. J. Conway is funded by the French Space Agency, CNES, for her HiRISE related work. We gratefully acknowledge the contribution of Gestur Hansson (Icelandic Meteorological Office) and of our field assistants Francesco Giuntoli, Silvia Crosetto, and Sydney Gunnarson. The authors thank the reviewers Anja Dufresne, Marten Geertsema and Gioachino Roberti for their insightful comments.

Publisher's version (útgefin grein), Andisols are carbon-rich soils that persist in volcanic regions with cool climates. They are the main soil type in Iceland, where there are also large areas of premature or degraded mineral soils with the possible potential to become andisols. This study examines soils from vegetated and unvegetated sites to look at the earliest indicators of andisol formation and soil organic carbon accumulation. Soils from 12 sites in the southern Icelandic highlands, which are characterised by harsh climate, shallow soils and limited vegetation cover, were sampled at four depths (0–5 cm, 5–10 cm, 10–20 cm and 20–30 cm). Three sites were sparsely vegetated gravels (M1–M3) and nine were fully vegetated, including 8 grassland sites (G1–G8) with mosses and dwarf shrubs, and a sandy fluvial wetland (S) with grasses, mosses and dwarf shrubs. Soils with vegetative cover were characterised as weak or structureless ranging from loamy sand to silty clay loam, while soils at the sparsely vegetated sites were structureless and sandy. The soil depth is greater in the vegetated sites, indicating greater soil development. On average, the bulk density of soils (0.75–1.16 g cm−3) was lower at vegetated sites than sparsely vegetated sites (0.90–1.17 g cm−3). The average carbon (%C), nitrogen (%N) and the overall soil organic matter (%SOM) of vegetated sites were higher (1.60%C, 0.10%N, 4.9%SOM) than for sparsely vegetated sites (0.27%C, 0.02%N, 1.81%SOM) with lower pH at the vegetated sites (pH < 7.2) than the sparsely vegetated (pH > 7.2), indicating the difference in soil development. Silandic allophanic material is present throughout the study area: all soils had >10% amounts of amorphous clay minerals (allophane, ferrihydrite or aluminium-humus complexes) and high aluminium and iron percentages. Strong associations between pyrophosphate-extractable Fe and Al and the soil C, indicative of Al and Fe complexed with humus or allophane and ferrihydrite clays of vegetated sites were observed. The %C, %SOM, Fe/Al associations, soil structure and soil depth all suggest that there is gradient of increasing soil genesis from sparsely vegetated to vegetated sites. Although the soils at the vegetated sites may be considered to be andisols, they are still immature, while the less developed soils at the sparsely vegetated sites are vitrisols (, The research was financed by Landsvirkjun and we specially wish to thank Hákon Aðalsteinsson, of Lansvirkjun, for his interest and support of this project. We would also like to thank María Svavarsdóttir, Höskuldur Þorbjarnarson, Olga Kolbrún Vilmundardóttir, Eydís S. Eiríksdóttir, and Friðþór Sófus Sigurmundsson of the University of Iceland, Brita Berglund of the Agricultural University of Iceland and Joe Jephson.

Publisher's version (útgefin grein), We studied a metapopulation of great cormorant (Phalacrocorax carbo) in Iceland, using complete aerial censuses of nests in 25 years during 1975–2015. Age composition was estimated in 1998–2014 by ground surveys in September and February. Brood size was estimated from aerial photographs in 2007–2015. Weather, food, breeding habitat, and density were considered as explanatory variables when examining numerical and distributional changes in the cormorant metapopulation. In 1975–1990 total nest numbers changed little, very low numbers about 1992 were followed by an annual increase of 3.5% in 1994–2015. Total nest numbers were positively correlated with estimates of spawning stocks of cod and saithe and inversely related to the subpolar gyre index (SPG-I). During the increase in 1994–2015, average colony size at first increased and then declined. Habitat use also changed: the proportion of nests on small rocky islets (skerries) at first declined, from 69% to 44% in 1995–2003 and then increased again to about 58% in 2012–2014. Habitat changes were probably a response to changed patterns of human disturbance. Breeding density, as nests per km 2 sea, This study was supported mainly by the University of Iceland Research Fund by annual grants to AG (1994–2008) and to JEJ (2009–2015). We thank Úlfar Henningsson for piloting the cormorant censuses and brood surveys. For help with local and historical information we are grateful to many colleagues and local naturalists, especially Tryggvi Eyjólfsson (1927–2017), Hafsteinn Guðmundsson, Ari Guðmundur Ívarsson, Steinólfur Lárusson (1928–2012), Ævar Petersen, Kristinn H. Skarphéðinsson, Ástþór Skúlason, Guðbrandur Valdimarsson, Ólafur Þórðarson (1915–2003), and Böðvar Þórisson. For guidance in environmental and biological matters we are especially indebted to Karl Gunnarsson, Sarah Wanless and Thomas Bregnballe. We thank Sigmundur Helgi Brink for preparing the map in Figure 2 and Erling Ólafsson for photos of cormorant in Figure 1. We thank the editors and 2 anonymous reviewers for comments that improved an earlier version of this manuscript.

Publisher's version (útgefin grein), Entanglement in fishing gear is a significant anthropogenic source of large whale injury and mortality. Although entanglements have been reported in the eastern North Atlantic, their frequency has not been previously estimated. This study used systematic scar analysis to estimate the frequency of non-lethal entanglements among individual humpback whales Megaptera novaeangliae off coastal Iceland, from 2005 through 2017. Images of the caudal peduncle and fluke insertions of 379 individuals were analyzed for wrapping injuries and notches known to be indicative of entanglement. The results indicated that at least 24.8% (n = 94, 95% confidence intervals [95% CI]: 20.5-29.1%) of individuals had a history of prior entanglement when first encountered. Depending on the metric used, the whales subsequently acquired new entanglement-related injuries at an average rate of 1.9% (95% CI: 0.6-3.2%) or 16.3% (95% CI: 3.0-29.3%) per year, with no statistically significant change over time. Furthermore, evidence suggests that at least some entanglements occurred locally. Observations of whales with gear still entangling the body confirmed the patterns of injury studied here. These results are lower than scar-based estimates from other parts of the world, but the cause of this difference requires further study. Scar-based methods underestimate the frequency of prior entanglement because some injuries heal beyond recognition, do not involve the caudal peduncle, and may occur on whales that die before they are studied. Long-term monitoring of humpback whale entanglement in Icelandic coastal waters is important for evaluating the local effects of fisheries, as well as the viability of the endangered Cape Verde breeding population., This work was funded in part by a National Geographic Explorer Grant awarded by the National Geographic Society, a PhD sponsorship grant awarded by Gentle Giants Whale Watching, and a Doctoral Grant awarded by Rannís Icelandic Research Fund. We thank all the students at the University of Iceland’s Húsavík Research Center for contributing data, the Faxaflói Ceta - cean Research volunteers (in Húsavík and Reykjavík), and all the whale-watching companies in Iceland who showed interest in the project and contributed photographs and/or space onboard their vessels for data collection. Furthermore, we thank the anonymous reviewers, who provided valuable input into the manuscript. Photographs used in the figures are copyright of University of Iceland (Figs. 2,3,4a1,b,c, 5 & 6a,b,d) Elding Adventures at Sea (Fig. 6c), and Charlie Frank Lavin (Elding Whale Watching Akureyri) (Fig. 4a2).

The thesis examines the dynamics of Arctic social-ecological systems (SES) that enable human wellbeing benefits through whale ecosystem services (ES). It does so through a review of relevant literature, construction of conceptual models, two primary economic and socio-cultural whale ES valuation studies, and an assessment of whale ES governability. The results indicate multiple human wellbeing benefits and associated economic, socio- cultural and biophysical values derived from marine ecosystems through whale ES in selected case study communities in Greenland, Iceland and Norway. These benefits include but are not limited to tourism, education, cultural identity, community cohesiveness, commercial and indigenous whaling, biodiversity enhancement, ecosystem regulation, inspiration for arts, and existence values. The case studies demonstrate that they are obtained by communities through human-nature co-production of whale ES and governed by a multilayered web of formal and informal governance interactions. The social-ecological complexity revealed in the analysis of whale ES underlines the importance of context and plural ES values in Arctic marine resource governance. It also implies a necessity to study social and ecological phenomena together as one co-evolving Earth system. Following these observations, conceptual models were developed integrating elements of ES, their co-production, and interactive governance and governability theories. The results of the governability assessment reveal high complexity and dynamics related to whale ES, ability of actors to self-govern, and a need for reflective and adaptive governance regimes. The relevance of the methodology and conceptual models applied in this research extends beyond the Arctic and can be applied in other natural resource contexts., Í þessari doktorsritgerð er gangverk félagslegra vistkerfa á norðurslóðum sem gera mönnum kleift að njóta góðs af vistkerfisþjónustu hvala skoðað. Þetta var gert með því að rýna núverandi stöðu þekkingar á tengdum fræðum, smíði á hugmyndalíkönum, tveimur frumrannsóknum á efnahagslegu og félags-menningarlegu gildi vistkerfisþjónustu hvala og mati á stjórnhæfni vistkerfisþjónustu hvala. Niðurstöðurnar benda til margvíslegs ávinnings fyrir velferð manna og tengdra efnahags-, félags-menningar- og lífeðlislegra gilda frá vistkerfum í hafi, sem tengd eru vistkerfisþjónustu hvala í þeim samfélögum á Grænlandi, Íslandi og Noregi sem valin voru sem tilvik rannsóknarinnar. Ávinning frá vistkerfisþjónustu hvala má meðal annars sjá hvað varðar ferðaþjónustu, fræðslu, menningarlega sjálfsmynd, samfélagslega samheldni, hvalveiðar í bæði atvinnuskyni og fyrir frumbyggja, eflingu líffræðilegs fjölbreytileika, regluverk tengt vistkerfinu, innblástur fyrir listsköpun og tilvistargildi. Tilviksrannsóknirnar sýna að samfélagið í heild sinni nýtur ávinningsins með því að lifa í sátt og samlyndi við náttúruna og með góðri, marglaga stjórnun í gegnum formleg og óformleg samskipti. Greining á vistkerfisþjónustu hvala varpaði ljósi á félags-vistfræðilegt flækjustig sem undirstrikar mikilvægi þess að íhuga samhengið og margvísleg gildi vistkerfisþjónustu í stjórnun auðlinda hafsins á norðurslóðum. Þessi greining gaf einnig til kynna nauðsyn þess að rannsaka félags- og vistfræðileg fyrirbæri saman sem hluta af þróunarkerfi jarðarinnar. Í kjölfar þessara athugana voru hugmyndalíkön þróuð þar sem þættir úr vistkerfisþjónustu, samframleiðsla þeirra og gagnvirkar stjórnunar- og stjórnhæfnikenningar voru samþættar. Niðurstöður á mati á stjórnhæfni sýndu fram á hátt flækjustig og gangverk tengd vistkerfisþjónustu hvala, hæfni aðila til að stjórna sér sjálfir og þörf fyrir sveigjanleg stjórnkerfi. Gildi aðferðafræðinnar og þeirra hugmyndalíkana sem þróuð voru í þessari rannsókn nær út fyrir norðurslóðir og er hægt að beita á aðrar náttúruauðlindir., NordForsk (grant number 76654) - ARCPATH project University of Iceland Doctoral Fund, Printed version

Increasing water temperatures are predicted worldwide, with high amplitudes in the Arctic and sub-Arctic regions exceeding predictions for other regions. An understanding how Atlantic cod (Gadus morhua) reacted to changing environmental conditions in the past is essential for predicting re-distribution under climate change. In this thesis, I examined the temperature selectivity of Icelandic and Northeast-Arctic (NEA) cod in response to fluctuating temperature conditions and changes in the stock dynamics. Multiple century-long data time series and linear mixed-effect models were used to investigate the effect of fluctuating water temperatures and changes in stock dynamics on the temperature selectivity of cod, using stable oxygen isotope composition in otoliths as a proxy of ambient temperature. Icelandic cod δ18Ootolith values were significantly correlated with water temperature time series, indicating that they were exposed to fluctuating water temperatures during the past 100 years and did not move appreciably in response to increasing ocean temperatures. Furthermore, abundance changes have affected the temperature selectivity of Icelandic and NEA cod as a density-driven response; however, the response of the two populations was different. Increasing abundance resulted in increasing intraspecific competition and decreasing individual fitness levels, which expanded the distribution area of both cod stocks into previously unfavorable thermal habitats. To validate the accuracy of high-resolution otolith isotopic records as a temperature proxy, stable oxygen isotope records of wild, free-swimming Icelandic cod tracked with data-storage tags (DST) were analyzed with high-resolution secondary-ion mass spectrometry (SIMS). Results demonstrated that the method is well-suited as a relative index of temperature exposure, although maximum ambient temperatures were often overestimated. Using century-long data time series and oxygen isotope chronologies of cod otoliths have markedly improved our understanding of the Icelandic and NEA cod temperature selectivity. Thus, this thesis provides important information that helps to predict how two commercially important cod stocks might respond to global warming and fluctuating stock dynamics., Hækkandi sjávarhita er nú spáð um allan heim og á norðurslóðum er auk þess búist við meiri hitasveiflum en annars staðar. Betri skilningur á viðbrögðum Atlantshafsþorsks (Gadus morhua) við breyttum umhverfisaðstæðum á liðnum áratugum opnar möguleika á að spá fyrir um mögulega breytta dreifingu þorskins á tímum loftslagsbreytinga. Hér er greint frá rannsóknum þar sem leitast var við að skýra hvort og hvernig þorskar af íslenska stofninum og norðaustur heimsskautsstofninum bregðast við breytingum á hitastigi sjávar og stofnstærð. Gagnasett með mælingum 100 ár aftur í tíman ásamt línulegum líkönum með blönduðum áhrifaþáttum voru notuð til þess að meta hvort stofnstærð og sjávarhiti hafi áhrif á hitastigsval einstaklings, sem hægt er að meta með stöðugum ísótópum súrefnis. Marktæk fylgni fannst milli δ18O gilda íslenska þorskins og sjávarhita yfir tíma, sem bendir til þess að þorskurinn hafi verið útsettur fyrir sveiflukenndum sjávarhita síðastliðin 100 ár, en virðist ekki hafa hörfað að marki frá hækkandi hitastigi. Aukinn stofnþéttleiki á svæðum með kjörhita getur leitt til aukinnar samkeppni og minnkandi hæfni einstaklinga en slíkt getur valdið því að sumir einstaklingar leiti á önnur óhagstæðari hitastigs mið. Gögn okkar benda til þess að slíkt hafi átt sér stað í báðum stofnunum, þrátt fyrir ólík viðbrögð. Til frekari staðfestingar á notagildi kvarna til að varpa ljósi á hitastig sjávar á mismunandi stigum lífsferils voru ísótópar súrefnis mældir í kvörnum þorska sem á voru fest gagnasöfnunarmerki (DST-tag) sem mæla hitastig og dýpi. Í þessu tilfelli voru ísótópar í vaxtarhringjum kvarna mældir með meiri upplausn í nákvæmum massalitrófsgreini (SIMS) sem staðfesti að þessar aðferðir eru vel til þess fallnar að meta hitastig sjávar sem fiskar hafa dvalið í aftur í tíman, þó svo að hámarks hiti sé gjarnan ofmetin. Rannsóknirnar sýna hvernig nota má mælingar á ísótópum súrefnis í árhringjum kvarna ásamt sambærilegum langtímagögnum um hitastig sjávar og stofnsveiflur til þess að greina hvernig þessir þættir hafa áhrif á hitastigsval þorsks. Slíkar upplýsingar munu reynast gagnlegar við að spá fyrir um hvernig þorskstofnar bregðast við hnattrænni hlýnun og stofnsveiflum.

Frequent tephra deposition and a steady influx of aeolian material of diverse origin dominate soil formation in Iceland. Little is known about the weathering behaviour, mineral formation and alteration of tephra and Icelandic soils after tephra deposition. This thesis presents the results from extensive studies on soil mineralogy and pedogenesis in various Icelandic soil types and different soil environments. The sampling sites were selected according to the presence of the light coloured rhyolitic tephra from the Öræfajökull eruption in 1362 CE and a dark-coloured basaltic Veiðivötn tephra from 1477 CE in the volcanically active area south of Vatnajökull, SE Iceland. All investigated soils were acidic and dominated by sand. Indicated by Feo/Fed ratios above 0.75, they classify as being in an early stage of chemical weathering and soil development. The major portion of the clay size particles are mainly derived from amorphous and poorly crystalline constituents (allophane and ferrihydrite). However, traces of layer silicates (smectite, hydroxy interlayerd minerals and secondary chlorite) were found at all sites. The determining factor of pedogenesis in the histosols was the OM, but the aeolian transport of tephra over long distances and re-deposition as well as local site conditions, rather than the primary composition of the parent material, were the important factors in the development of all investigated soils and the alteration of minerals. Icelandic soils develop in a very dynamic environment. None of the profiles represented a well-developed-pedon, but appeared disturbed over time, showing signs of external influences., Tíð eldgos með tilheyrandi gjóskufalli og stöðugt áfok vindborinna efna af ólíkum uppruna setja mestan svip á jarðvegsþróun á Íslandi. Skortur er á þekkingu á veðrun, myndun og ummyndun steinda í gjósku í íslenskum jarðvegi í kjölfar gjóskjufalls. Í þessari ritgerð eru niðurstöður umfangsmikillar rannsóknar kynntar, sem tekur til steindafræði og jarðvegsþróunar í mismunandi jarðvegsflokkum og í breytilegu umhverfi jarðvegsmyndunar. Rannsóknarsvæðið er á virku eldfjallasvæði sunnan við Vatnajökul á Suðausturlandi Á öllum sýnatökustöðum sem notaðir voru í rannsókninni finnast ljóslituð, súr gjóska frá Öræfajökulsgosi frá 1362 e.Kr. og dökklituð, basísk gjóska úr gosi í Veiðivötum árið 1477 e.Kr. Öll jarðvegsýni í þessari rannsókn reyndust súr og sandkennd. Hlutfall Feo/Fed > 0.75 gefur til kynna að efnaveðrun og jarðvegsþróun sé skammt á veg komin. Meginhluti agna í leirstærð felst í myndlausum (e. amorphous) eða ófullkomlega kristölluðum (e. poorly crystalline) efnum (allófan og ferrihýdrít). Engu að síður fundust ummerki um lagsiliköt á öllum sýnatökustöðum (smektít, steindir með hýdroxýl jónir milli laganna og síð-steindina klórít). Lífræn efni voru ráðandi þáttur jarðvegsþróunar í mójörð (e. histosol), en flutningur gjósku með vindi yfir langar vegalengdir, tilflutningur gjósku og staðbundnir umhverfisþættir réðu meiru um jarðvegsþróun og ummyndun steinda en frumsamsetning móðurefnisins. Íslenskur jarðvegur þróast í síbreytilegu umhverfi. Ekkert jarðvegssniðanna mátti skilgreina sem vel þróað og öll sýndu þau ummerki um rask og áhrif frá ytri umhverfisþáttum.

Pre-print (óritrýnt handrit), The study examines the socio-cultural values of multiple ecosystem services (ES) sourced from whales in Skjálfandi Bay, North Iceland, with many beneficiaries living in and visiting the town of Húsavík. The study begins to address the research gap in non-monetary valuation of marine ecosystem services. Based on a multi-method approach, it elicits stakeholders' perceptions of the contribution of whale ES to human wellbeing using stakeholder mapping, semi-structured interviews, observations, and socio-cultural preference surveys. The key whale ES identified by the local stakeholders were cultural, most frequently mentioned being recreation and education. The most commonly mentioned ES values were related to economic benefits from the whale watching industry. The preference survey reveals that regulating and maintenance ES were valued most highly with a mean score of 4.0 out of 5.0, cultural ES were second with a mean score of 3.5, and provisioning ES in the form of food and raw materials were valued the least with a mean of 0.75. Interview data also reveals some marine ES management challenges originating from intensified tourism, industrial development, and climate change. The results of the study have the potential to inform marine resource management in Iceland by including socio-cultural values associated with whale resources., This paper has been subject to funding from NordForsk (grant number 76654) via their financial support to the Nordic Centre of Excellence ARCPATH (Arctic Climate Predictions – Pathways to Resilient, Sustainable Communities) and the Doctoral Grant of the University of Iceland Research Fund.

Genomic population bottlenecks and small population sizes are well described and well-studied areas of biology. However, few studies analyse samples from before and after a population have gone through a genetic bottleneck, and thus studies commonly infer bottleneck effects only using modern samples, modelling, or by comparison with populations that have not gone through bottlenecks. The white-tailed eagle is one of many species which have experienced large reductions in population sizes due to human influences, resulting in extinction in several geographical areas. To study the effects of bottlenecks and genetic variation in white-tailed eagles in Iceland and other countries in the north-western part of the species range, three studies focusing on different aspects of population genomics were conducted. Firstly, the mitogenomic diversity and population history were explored for Iceland and four neighbouring countries, using modern whole mitochondrial genomes, extending knowledge regarding the mitochondrial diversity, and revealing signs of selection maintaining the mitogenomic variation. Secondly, applications for identifying the homogametic sex chromosomes were evaluated. Distinguishing the main chromosomal types is important as they vary in effective population size and may have different evolutionary histories. The third and major study evaluated the impact of a bottleneck and assessed the genomic variation using modern and historic museum samples from Iceland, Greenland and four other countries from the mainland of Europe. A direct effect of bottlenecks was observed on variation within and among countries as well as within and among individuals. Furthermore, the study resolved part of the evolutionary history of the analysed populations., Áhrif stofnstærðarsveiflna á erfðabreytileika og hegðun breytileika í litlum stofnum hefur verið vel lýst. Fjölmargar rannsóknir í líffræði hafa verið gerðar á erfðabreytileika stofna en sjaldan hafa sýni verið greind fyrir og eftir slíkar niðursveiflur, sem kallaðar hafa verið erfðafræðilegur flöskuháls, og því eru áhrifin oft greind eftir breytingarnar annað hvort með líkanagerð eða með samanburði við stofna sem hafa ekki farið í gegnum slíkan flöskuháls. Haförninn er ein margra tegunda sem hafa fækkað mikið vegna áhrifa mannsins. Tegundin er útdauð á mörgum svæðum en haferninum fer nú fjölgandi. Til að rannsaka áhrif flöskuhálsa og erfðabreytileika hjá haförnum á Íslandi og í nálægum löndum voru þrjár rannsóknir gerðar á erfðamengjum tegundarinnar. Í fyrsta lagi var erfðabreytileiki og saga stofna á Íslandi og í fjórum nálægum löndum metin með því að greina erfðamengi hvatbera hjá núlifandi örnum. Náttúrulegt val virðist hafa viðhaldið breytileika í hvatberamengjunum innan stofna. Í öðru lagi var árangur fjögurra aðferða til að greina Z-kynlitninginn í erfðamengjum arnanna metinn, en greining á breytileika m.t.t. til meginlitninga er mikilvæg þar sem stofnstærð þeirra er mismunandi og þeir geta átt ólíka þróunarsögu. Þriðja og ítarlegasta rannsóknin var um aðgreiningu í erfðamengjum stofna við Norður Atlantshaf, þ.e. frá Íslandi, Grænlandi og fjórum öðrum löndum á meginlandi Evrópu. Í samanburði á um hundrað ára gömlum sýnum, fengnum úr söfnum, og nýjum sýnum greindust skýr áhrif af flöskuhálsum á breytileika erfðamengjanna, bæði innan og milli stofna. Rannsóknin leiddi einnig í ljós hluta af þróunarsögu þessara ólíku stofna.

Resumen del póster presentado al SETAC Europe 31st Annual Meeting, celebrado de forma virtual del 3 al 6 de mayo de 2021., As a key part of the European Green Deal, the EU Chemicals Strategy aims for a non-toxic environment. A key challenge in this respect is to apply biomonitoring data in toxicological and ecotoxicological risk assessment to inform better management of chemicals in Europe. Raptors (birds of prey, owls and falcons) are widely used as sentinel species in monitoring programs and are particularly well-suited to contaminant monitoring. Delivering relevant contaminant data at pan-European scale requires the development of a pan-European network that brings together fieldworkers, sample collections and analytical laboratories, and of frameworks for the gathering, storage and analysis of raptor samples, together with related capacity-building and sharing of best practice. This challenge is being addressed by the COST Action European Raptor Biomonitoring Facility (https://erbfacility.eu/) building on the precursor Networking Programme Research and Monitoring for and with Raptors in Europe (EURAPMON; http://www.eurapmon.net/). This poster introduces a schematic sampling protocol for contaminant monitoring in raptors. The protocol provides best-practice guidance in a format accessible to both professionals and volunteers. The protocol aims to enhance sampling capabilities across Europe, ensure appropriate quality of samples and facilitate harmonization of procedures to maximize the reliability, comparability and interoperability of resulting contaminant data. The protocol starts with each matrix type, including sample types that are collected both during active (samples from captured birds and monitored nests) and passive (samples from dead birds and deserted nests) sampling. For each sample type (whole blood, plasma, serum, deserted or addled eggs, feathers, preen oil, regurgitated pellets, prey remains, gastric content and internal tissues), a specific protocol offering additional information is provided (e.g., collecting procedure, volume/mass of sample needed for contaminant monitoring, container types to conserve the sample, transport and storage conditions). The full protocol can be found online (https://doi.org/10.1007/s13280-020-01341-9)., European Raptor Biomonitoring Facility COST Action (CA16224) is supported by COST (European Cooperation in Science and Technology). Silvia Espín is supported by Ministerio de Ciencia, Innovación y Universidades (IJCI-2017-34653).

The population dynamics of marine fish are driven by many top-down and bottom-up processes operating across multiple life-history stages. The majority of teleosts produce large quantities of offspring which experience high mortality rates early in life. Changes in mortality during this period can therefore have large impacts on first year-class strength. As early-life stage mortality is generally driven by density-independent processes associated with the environment, a stock’s ability to produce large quantities of viable eggs influences the number of larvae that successfully settle. This causal relationship—from spawner to offspring—forms the backbone of this thesis. To examine the early-life stages, physical egg properties were measured, and a suite of models employed to understand the vertical positioning, dispersal patterns, and behavioural activities of fish eggs and larvae. The empirical results provided new species-specific information regarding the egg traits of two gadoids. The models highlighted the importance of including the following components into drift models: (1) intraspecific variation in egg density, (2) larval vertical migrations, and (3) a high temporal resolution. Furthermore, the location of spawning grounds is shown to greatly influence connectivity between spawning and nursery grounds. A simple method to capture adaptive vertical migrations in drift models is provided and a new approach to evaluating whether stocks are in a collapsed state is proposed. Taken together, the thesis provides novel data and insights into the early-life stages of commercially important Icelandic gadoids, and a series of recommendations and proposed methodologies for quantitatively evaluating aspects of marine population dynamics., Stofnsveiflur sjávarfiska er knúnar áfram af mörgum þáttum sem hafa áhrif á afkomu fiska á öllum lífsstigum. Flestir beinfiskar gefa af sér mikinn fjölda afkvæma sem verða fyrir hárri dánartíðni snemma á lífsleiðinni. Breytingar á dánartíðni á þessu lífsskeiði geta því haft mikil áhrif á styrk tiltekinna árganga. Dánartíðni snemma á æviskeiðinu er almennt óháð þéttleika og því hafa umhverfisþættir meiri áhrif á yfirlifun en stærð árganganna. Við breytilegar umhverfisaðstæður eru meiri líkur á að einhver afkvæmi komist af ef upphafsfjöldi þeirra er hár. Þetta orsakasamband frá foreldri til afkvæma er megin viðfangsefni þessarar ritgerðar. Rannsóknin hófst með sýnatökum og mælingum á stærð og eðlisþyngd eggja og lirfa þorskfiska og þær notaðar til að byggja líkön sem voru keyrð til að skoða lóðrétta og lárétta dreifingu og atferli afkvæmanna. Niðurstöður mælingana leiddu í ljós mun á eiginleikum hrogna hjá tveimur tegundum þorskfiska. Við gerð slíkra líkana er mikilvægt að: 1) taka tillit til breytileika í eðlisþyngd eggja á milli tegunda; 2) líkja eftir lóðréttu fari fisklirfa og 3) keyra líkönin í hárri upplausn hvað varðar tíma. Einnig kom í ljós að staðsetning hrygningarsvæða getur haft mikil áhrif á far afkvæma og sagt til um inn á hvað uppeldissvæði þau rata. Í þessu verkefni eru lagðar fram nýjar niðurstöður um þætti sem hafa áhrif á árgangastyrk þorskfiska. Þessar niðurstöður munu nýtast við fiskveiðistjórnun og rannsóknir á fiskstofnum ekki bara við Ísland heldur um heim allan.

This PhD thesis explores what can be considered a sustainable energy system on a global scale and what methods and tools can help sustainable energy policy design and assessment. Energy system modelling and sustainable energy system narratives are the two main areas of interest of this thesis. First current energy systems modelling practice was analyzed in the context of sustainable energy development, as well as how social science contributes to research focusing on sustainable energy. This revealed several main research gaps related to the topic of this thesis, including: (1) Most of existing energy system models have unrealistic or oversimplified assumptions that can negatively impact the quality of the models’ outputs and consequently the quality of decision-making informed by such models; (2) There is a limited instrumental value of the available theories related to sustainable energy system development; (3) Current practice lacks global energy system narratives that would contribute a holistic understanding of the purpose and long-term goals of the energy system. Global energy system narratives would also contribute to the principles of sustainable design of the energy system. The remainder of the thesis became an attempt to close these identified research gaps in order to answer the main research questions. System dynamics, steady-state economics and energy justice theory are the main methodological and conceptual components of the thesis’ research design. The contribution of the thesis includes: 1. A list of questions defining the current energy paradigm which can be used as a guidance for a sustainable energy system modelling; 2. A developed steady state of energy concept implying that energy sufficiency should be a universal energy system goal in the context of a long-term energy system sustainability; 3. A list of requirements for a socially sustainable energy provision based on energy justice principles. This list can be used as guideline for sustainable energy policy assessment and design; 4. A system dynamics model of electricity access provision in Sub-Saharan Africa. The model demonstrates an example of how energy system modelling: i) can be combined with sustainable energy system narratives for addressing methodological and disciplinary gaps in energy system research and ii) can contribute to better sustainable energy system policy design and assessment., This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 675153

Pre-print (óritrýnt handrit), There is currently limited knowledge concerning the economic value of commercial whale watching from the perspective of the consumer's trip experience. This study outlines the results of an in-person contingent valuation survey, which asked whale watching tourists in Faxaflói Bay, Iceland, how much they would have been willing to pay beyond the paid ticket price. Based on a sample of 163 tourists, only 30 (18.40%) reported any consumer surplus, despite the majority stating positive satisfaction with the experience. Mean consumer surplus was 768 ISK (approximately 5.60 euros). Scaled up to the number of whale watching tourists in Faxaflói Bay in 2018 of 148,442, aggregate CS was approximately 114.0 million ISK (0.83 million euros), a 6.9% mark-up on estimated annual revenue generation derived from average ticket prices. The study provides new information on the economic value of whale watching in an area which had already been part-designated as a whale sanctuary., This paper has been funded by NordForsk (grant number 76654) via their financial support to the Nordic Centre of Excellence ARCPATH (Arctic Climate Predictions – Pathways to Resilient, Sustainable Communities). In addition, the authors would like to thank Urður Einarsdóttir, undergraduate student at the University of Iceland, for her facilitation of data collection.

Crangonyx islandicus is a groundwater amphipod endemic to Iceland. Genetic analysis suggests that the species has been diverging in Iceland for at least 4.8 Myrs indicating it has survived in a subglacial refugia as Iceland was repeatedly covered by glaciers during that time period. The species has probably been inhabiting Iceland since before the island was formed, when the land bridge to Greenland collapsed into the ocean approximately 15 Mys ago. Currently, their habitat is in the subsurface of spring sources within the lava fields along the tectonic plate boundary. These spring sources act as a window into the groundwater, but they are also a complex ecotone where groundwater mixes with surface water and the terrestrial ecosystem. In this thesis, the microbial community composition associated with the amphipods and their habitat was examined both to inspect if more taxa could be found in this unique habitat and to elucidate which processes are likely to shape the community composition of microbial species in the habitat. The results showed that the amphipods are accompanied by a few ciliate and bacteria taxa that are unique to these amphipods but can only be marginally detected in the spring source. Both stochastic and deterministic processes were found to shape the bacteria and ciliate communities in the spring source. Variables such as pH, temperature, presence of fish and geographical location were found to shape the bacterial community while temperature and dispersal was shaping the ciliate communities. The bacterial community in the water from spring sources and in the biofilms harbored chemolithoautotrophic taxa, indicating primary production in the groundwater system, thus, providing a possible explanation for the subglacial survival of the amphipods during Ice age., Icelandic Research Council [grant number: 130244–051,141863–051], by the doctoral fund at the University of Iceland and Landsvirkjun (grant NÝR-29–2020]

Climate change constitutes one of the most pressing challenges faced by tourism today. Tourism research on climate-induced environmental changes has contributed to an increase in knowledge about adaptation during the last decade. Despite a general recognition of the urgent need to adapt, as well as a large-scale scientific effort in this field underlining evidence of potential risk, the impacts of adaptation research on practices and policies in tourism appear to be relatively low. To reduce the gap between adaptation research and practitioner action this thesis aims to increase the understanding of adaptation to climate-induced changes in nature-based tourism, by analyzing the adaptation processes and practices of tourism actors involved in glacier tourism. Glacier tourism is a highly relevant example of a type of tourism which needs to adapt to climate-induced environmental changes. Therefore, this thesis examines: what is the state-of-the-field knowledge concerning relationships among tourism, the glacial environment, and climate change; how do glacier tourism actors adapt to the current and future impacts of climate change; and how can glacier tourism actors’ engagement with science contribute to proactive adaptation. The research conducted in this thesis uses a combination of two analytical approaches. An actor-oriented approach is employed to investigate tourism actors’ experiences and perceptions of climate change and their adaptation behavior. The other approach draws on transdisciplinary research, involving an active engagement of local stakeholders and scientists to form dialogues to combine knowledge bases, and to verify the social relevance of research on climate change adaptation. An embedded case study design was chosen due to its potential to integrate an actor-oriented approach with transdisciplinary research. The glacier sites of southeast Iceland form the case-study area wherein the adaptation processes of glacier tourism actors were examined. The case study constitutes the setting for the collection of empirical data by means of quantitative methods, such as literature review and visitor surveys, as well as qualitative methods, such as interviews and participatory scenario workshops. The results reveal a limited but growing body of scholarly work that examines the relationships between tourism, glaciers, and climate change impacts and responses. The existing work lacks however important data concerning the motives, preferences, experiences, and behaviors of actors in glacier tourism in general and specifically in the context of climate change. The results of the analysis of tourism actors’ adaptation practices furthermore show that climate change has already resulted in several impacts on glacier sites and that operators have responded to these implications in the form of a wait-and-see strategy combined with ad-hoc reactive adaptation. On the other hand, the results also show that visitors to glacier sites are more heterogeneous in their responses to future climate change–induced impacts. Furthermore that adaptation processes of glacier tourism actors are shaped by the interaction of actors’ attributes of agency, such as risk perception, concerns, motivations and interests, with structural elements of the glacier destination systems, such as type of visitation implication, prevailing economic rationale or lack of effective climate change institutions. Lastly, the results stress the development and application of a participatory scenario planning process, as a form of science-practitioner engagement, to be a valuable tool to support the adaptation planning of glacier sites through sharing knowledge, elaborating on long-term changes and associated uncertainties, and exploring proactive adaptation options. Climate is only one of the drivers of change that determine the development of glacier tourism. It is thus concluded that climate change implications cannot be understood as isolated factors; rather, they should be viewed as constituting interconnected and cumulative effects on socioeconomic and natural environments. Mainstreaming climate change adaptation into current destination planning and management or integrating climate change adaptation with related science fields, such hazard reduction research or sustainability science, would thus provide more promising approaches than studying climate change adaptation in isolation., Loftslagsbreytingar eru ein stærsta áskorun sem ferðaþjónusta heimsins stendur frammi fyrir í dag. Síðastliðinn áratug hafa rannsóknir innan ferðamálafræði á breyttum umhverfisaðstæðum vegna loftlagsbreytinga stuðlað að aukningu rannsókna á aðlögum að loftslagsbreytingum. Þrátt fyrir almenna viðurkenningu á þörfinni fyrir aðlögun að breyttum aðstæðum, og umfangsmiklar rannsóknir sem sýna fram á mögulega áhættu sem fylgir slíkum breytingum, virðast áhrif aukinnar þekkingar um aðlögun á starfsemi og stefnu í ferðaþjónustu enn vera tiltölulega lítil. Með það að leiðarljósi að minnka bilið á milli rannsókna á aðlögun að loftslagsbreytingum og aðgerða ferðaþjónustunnar, leggur þessi doktorsritgerð áherslu á að auka skilning á aðlögun að breyttum umhverfisaðstæðum vegna loftlagsbreytinga í náttúrutengdri ferðaþjónustu, með því að greina aðlögunarferli og starfshætti ferðaþjónustuaðila sem stunda jöklaferðamennsku. Jöklaferðamennska er mjög skýrt dæmi um ferðaþjónustu sem þarf að aðlaga sig að breyttu umhverfi vegna áhrifa loftslagsbreytinga. Meginmarkmið þessarar ritgerðar eru að meta: hver er staða þekkingar á sambandi ferðamennsku, jökulumhverfis og loftslagsbreytinga; hvernig ferðaþjónustuaðilar sem stunda jöklaferðamennsku aðlagist að núverandi og framtíðar áhrifum loftslagsbreytinga; og hvernig tengsl ferðaþjónustuaðila við vísindi geti stuðlað að framvirkri aðlögun. Rannsóknirnar í þessari doktorsritgerð nota sambland af tveimur greiningaraðferðum. Annars vegar gerendanálgun til að rannsaka reynslu og viðhorf ferðaþjónustuaðila til loftslagsbreytinga sem og aðlögunarhegðun þeirra. Hins vegar aðferð sem byggir á þverfaglegri nálgun sem felur í sér gagnvirka þátttöku hagaðila í héraði og sérfræðinga til að ræða saman og mynda sameiginlegan þekkingargrunn, og til að sannreyna félagslegt mikilvægi rannsókna á aðlögun að loftslagsbreytingum. Til að samþætta þessar tvær aðferðir, þ.e. gerendanálgun og þverfaglega nálgun, var ákveðið að styðjast við tilviksrannsókn. Nokkrir áfangastaðir við sunnanverðan Vatnajökul voru valdir sem rannsóknarsvæði, þar sem söfnun gagna fór fram. Stuðst var við bæði megindlega aðferðafræði, svo sem spurningakannanir til ferðamanna, og eigindlega aðferðafræði, svo sem viðtöl, þátttökuathuganir og sviðsmyndagreiningu. Niðurstöður sýna takmarkaða en vaxandi rannsóknavirkni sem beinir sjónum að tengslum ferðamennsku, jökla, áhrifum loftslagsbreytinga og viðbrögðum við slíkum áhrifum. Jafnframt, að enn vanti töluvert af rannsóknum sem beini sjónum að reynslu, hegðun og óskum gerenda í jöklaferðamennsku, bæði almennt en sérstaklega þó í tengslum við loftslagsbreytingar. Niðurstöður sýna enn fremur að loftslagsbreytingar hafa þegar haft töluverð áhrif á jöklasvæðin við sunnanverðan Vatnajökul og að ferðaþjónustuaðilar hafa brugðist við þessum afleiðingum í formi ”bíða-og-sjá-til” afstöðu, ásamt samsvarandi afturvirkum aðgerðum. Á hinn bóginn sýna niðurstöðurnar einnig að ferðafólk sem heimsækir jökulsvæðin er innbyrðis breytilegt varðandi viðbrögð við framtíðar áhrifum loftslagsbreytinga. Enn fremur að aðlögunarferli gerenda í jöklaferðamennsku mótist af gagnvirku samspili gerendahæfni þeirra, varðandi þætti eins og áhættuskynjun, hugsjónir, hvata, og áhugasvið, við skipulagningu ferðaþjónustunnar og innviði á einstökum áfangastöðum, svo sem varðandi þau áhrif sem ferðamennskan hefur, viðhorf til hagþróunar og hvort til staðar séu skilvirkar stofnanir sem sinna loftlagsmálum. Síðast en ekki síst, leggja niðurstöður rannsóknanna áherslu á mikilvægi þróunar og beitingu þátttökusviðsmynda til að samtvinna viðhorf hagsmunaaðila í héraði og vísindamanna í skipulagsferli. Slíkar þátttökusviðsmyndir eru mikilvægt verkfæri til að styðja við skipulega aðlögun áfangastaða jöklaferðamennsku að breyttum umhverfisaðstæðum vegna loftlagsbreytinga, í gegnum gagnkvæma miðlun þekkingar, íhugunar um langtíma breytingar og þá óvissu sem þeim fylgir, og skoðunar á mögulegum framvirkum aðlögunaraðgerðum til að mæta slíkum breytingum Loftslagsbreytingar eru aðeins einn þeirra drifkrafta sem stýra þróun jöklaferðamennsku. Ekki er hægt að horfa á áhrif loftslagsbreytinga sem einangraða þætti; heldur verður að horfa heildrænt á alla áhrifaþætti til að skilja betur hin flóknu og gagnvirku tengsl á milli hinna samfélagslegu, hagrænu og umhverfislegu sviða. Með því að setja aðlögun að loftslagsbreytingum í forgrunn í núverandi áfangsstaðaáætlunum og stýringaraðgerðum, eða með því að samþætta aðlögun að loftslagsbreytingum við ákveðin vísindasvið eins og áhætturannsóknir eða sjálfbærnirannsóknir, væri hægt að leiða fram mun betri nálgun en með því að horfa á aðlögun að loftslagsbreytingum sem einangrað fyrirbæri., University of Iceland Eimskip Fund, Icelandic Tourism Research Centre, Hornafjörður Research center, the Friends of Vatnajökull, Nature Conservation Fund of Pálmi Jónsson, Kvískerjasjóður research fund and European Union Interreg Northern Periphery and Arctic Programme

Freshwater springs are thermally stable environments which are largely unaffected by changes in air temperature. They could thus have the potential to buffer rising temperatures and serve as small-scale refugia for aquatic invertebrates in a warming world. To better understand what environmental variables drive invertebrate diversity and community composition, I conducted an extensive field survey on springs in Iceland. Due to rifts in the tectonic plates, large parts of Iceland are of volcanic origin and geothermally active. Thus, a high number of freshwater springs can be found along the edges of the porous lava fields, ranging in temperature from 2°C to boiling hot. Springs also differ in other characteristics, e.g., altitude, spring type, substrate, and vegetation density. I studied the invertebrate community of 49 springs on a spatial scale and followed one of them throughout a year to analyse temporal variability. The most abundant invertebrate groups in Icelandic springs were Chironomidae (Diptera), followed by Ostracoda and Copepoda. One of the main drivers of community composition was temperature, resulting in a distinct species group characteristic for hot springs. Additionally, spring type and geographical position influenced communities. Community composition also differed on a temporal scale within the same spring, with distinctions between summer and winter community. This seasonality in the invertebrate community was unaffected by temperature changes but had implications on the apex predator in the system, Arctic charr. The results of this thesis give some insight into Icelandic spring ecosystems and will contribute to conservation of these unique habitats., Fjölbreytileiki ferskvatnslinda er mikill t.d. hvað hita varðar, allt frá því að vera mjög kaldar og sjóðandi heitar. Þrátt fyrir þennan fjölbreytileika er þó hiti í hverjum og einstökum lindum mjög stöðugur og hafa breytingar í lofthita lítil áhrif á hitastig þeirra. Lindir gætu þannig dregið úr áhrifum af hækkandi hita og þannig myndað skjól, á smáum skala, fyrir ferskvatnshryggleysingja í hlýnandi loftslagi. Til þess að skilja betur hvaða umhverfisbreytur hafa áhrif á fjölbreytileika og samfélagsgerðir hryggleysingja þá framkvæmdi ég umfangsmikla rannsókn á lindum víðsvegar á Íslandi. Vegna flekahreyfinga og mikillar eldvirkni eru stórir hlutar landsins nýlegar bergmyndanir þar sem jarðhiti er algengur. Á jöðrum gegndræpra hrauna má finna mikinn fjölda ferskvatnslinda. Lindir eru einnig breytilegar m.t.t. annarra þátta, t.d. hæðar yfir sjávarmáli, lindargerð, botngerð og þéttleika gróðurs. Ég rannsakaði smádýrasamfélög í 49 lindum víðsvegar um landinu. Einnig fylgdi ég eftir breytingum yfir árið í einni lind, til að rannsaka stöðugleika smádýrasamfélags. Algengasti hópur smádýra í íslenskum lindum voru rykmý (Chironomidae, Diptera), þar næst skelkrabbar (Ostracoda) og árfætlur (Copepoda). Einn mikilvægasti þáttur í að skýra uppbyggingu dýrasamfélaga í lindum var hiti og var sérstakur dýrahópur einkennandi fyrir heitar lindir. Einnig skýrðu lindargerð og landfræðileg staðsetning þeirra mikið af þeim breytileika sem sást í samfélagsgerðum hinna ýmsu linda. Greinilegur breytileiki í samfélagsgerð var að finna milli sumars og veturs og var hann ótengdur breytingum í umhverfishitastigi. Hinsvegar hafði árstíðamunurinn áhrif á mikilvægan afræningja í þeim samfélögum, dvergbleikjuna. Niðurstöður rannsóknarinnar gefa upplýsingar um vistkerfi linda. Auk þess bæta niðurstöður rannsóknarinnar við þekkingu okkar á vistkerfum ferskvatnslinda sem m.a. verður hægt að nýta við hverskyns nýtingu og þ.m.t. verndun þessara einstöku búsvæða.

Many life-history events in aquatic invertebrates are triggered by seasonal changes in water temperature, but other ecological factors may be important as well. To rule out the confounding effects of changing water temperature, we studied the seasonal dynamics of an aquatic invertebrate community and their effect on a top fish predator in a thermally stable freshwater spring in South Iceland. We sampled benthic invertebrates five times over a year and conducted a mark-recapture study on the top predator in the system, small benthic Arctic charr, Salvelinus alpinus (L.). We assessed variation in diet composition and feeding preferences by calculating the electivity and individual specialisation of each fish at each sampling time. There was a clear separation of winter and summer communities for the benthic invertebrates. The variation in prey availability was also reflected in the fish diet, with higher feeding selectivity in summer than in winter for the highly abundant Chironomidae larvae. In contrast, individual specialisation as a measure of intrapopulation niche variation was higher in winter when prey availability was lower. We furthermore found that groundwater amphipods might play an important role in the winter diet of spring-dwelling Arctic charr. In conclusion, seasonal variation in the invertebrate community is an important factor to consider and has the potential to alter the phenotype (e.g. growth rates) and behaviour (e.g. feeding preferences) of higher trophic levels., The project was funded by the Icelandic Research Fund (RANNÍS), Grants nr. 141863-051 and 185083-051, and by Náttúruverndarsjóður Pálma Jónssonar.

Publisher's version (útgefin grein), Marine ecosystems, particularly in high-latitude regions such as the Arctic, have been significantly affected by human activities and contributions to climate change. Evaluating how fish populations responded to past changes in their environment is helpful for evaluating their future patterns, but is often hindered by the lack of long-term biological data available. Using otolith increments of Northeast Arctic cod (Gadus morhua) as a proxy for individual growth, we developed a century-scale biochronology (1924–2014) based on the measurements of 3,894 fish, which revealed significant variations in cod growth over the last 91 years. We combined mixed-effect modeling and path analysis to relate these growth variations to selected climate, population and fishing-related factors. Cod growth was negatively related to cod population size and positively related to capelin population size, one of the most important prey items. This suggests that density-dependent effects are the main source of growth variability due to competition for resources and cannibalism. Growth was also positively correlated with warming sea temperatures but negatively correlated with the Atlantic Multidecadal Oscillation, suggesting contrasting effects of climate warming at different spatial scales. Fishing pressure had a significant but weak negative direct impact on growth. Additionally, path analysis revealed that the selected growth factors were interrelated. Capelin biomass was positively related to sea temperature and negatively influenced by herring biomass, while cod biomass was mainly driven by fishing mortality. Together, these results give a better understanding of how multiple interacting factors have shaped cod growth throughout a century, both directly and indirectly., Funding for this work was provided by the Icelandic Research Fund Grant 173906-051. The authors thank Erlend Langhelle (IMR) for his help with retrieving and processing the otoliths, as well as Anders Thorsen (IMR) and Norbert Vischer (University of Amsterdam) for their collaboration on the plugin used for imaging and annotating the samples. We also thank Hildegunn Mjanger (IMR) for her assistance with age reading and validation of the otolith sections.

Publisher's version (útgefin grein), Overtourism has emerged as a common concept to describe the perceived negative impacts that large numbers of tourists can have on destinations. Iceland is one of the destinations which has been most associated with the concept of overtourism. Tourism in Iceland grew rapidly from 2010 to 2019, much higher than in most other countries, with Iceland reaching a ranking as high as thirteenth on a list of countries with the highest ratio of tourists per inhabitant. The increase in visitors to the country has had various impacts on Iceland’s economy, society and environment. This paper provides an overview of the different ways in which overtourism has revealed itself at a national level in Iceland. The implications of supposed overtourism are shown to be complex, with management responses limited by their relative focus., This research received no external funding.

Landslide mapping and analysis are essential aspects of hazard and risk analysis. Landslides can block rivers and create landslide-dammed lakes, which pose a significant risk for downstream areas. In this research, we used an object-based image analysis approach to map geomorphological features and related changes and assess the applicability of Sentinel-1 data for the fast creation of post-event digital elevation models (DEMs) for landslide volume estimation. We investigated the H&iacute, tardalur landslide, which occurred on the 7 July 2018 in western Iceland, along with the geomorphological changes induced by this landslide, using optical and synthetic aperture radar data from Sentinel-2 and Sentinel-1. The results show that there were no considerable changes in the landslide area between 2018 and 2019. However, the landslide-dammed lake area shrunk between 2018 and 2019. Moreover, the H&iacute, tar&aacute, river diverted its course as a result of the landslide. The DEMs, generated by ascending and descending flight directions and three orbits, and the subsequent volume estimation revealed that&mdash, without further post-processing&mdash, the results need to be interpreted with care since several factors influence the DEM generation from Sentinel-1 imagery.

Publisher's version (útgefin grein), Geothermal hot springs are a natural setting to study microbial adaptation to a wide range of temperatures reaching up to boiling. Temperature gradients lead to distinct microbial communities that inhabit their optimum niches. We sampled three alkaline, high temperature (80–100°C) hot springs in Yellowstone and Iceland that had cooling outflows and whose microbial communities had not been studied previously. The microbial composition in sediments and mats was determined by DNA sequencing of rRNA gene amplicons. Over three dozen phyla of Archaea and Bacteria were identified, representing over 1700 distinct organisms. We observed a significant non-linear reduction in the number of microbial taxa as the temperature increased from warm (38°C) to boiling. At high taxonomic levels, the community structure was similar between the Yellowstone and Iceland hot springs. We identified potential endemism at the genus level, especially in thermophilic phototrophs, which may have been potentially driven by distinct environmental conditions and dispersal limitations., Environmental sampling in Iceland was under permits issued by Iceland?s National Energy Authority (Orkustofnun) to MP and SB. We thank Dr. Jakob Kristj?nsson for help with sampling and permits. Sampling in Yellowstone National Park was under permit YELL-SCI-5714 and we thank Stacey Gunther for help with sampling coordinating. We thank Adrian Gonzalez from The University of Tennessee Knoxville Water Quality Core Facility for chemical analysis of the water samples. Funding. This research was funded in part by grants from the National Science Foundation (DEB1134877) and the National Aeronautics and Space Administration (NNX16AJ66G). Oak Ridge National Laboratory is managed by UT-Battelle, LLC, for the United States Department of Energy under contract DE-AC05-00OR22725.

Publisher's version (útgefin grein), The Arctic Council is an intergovernmental forum promoting cooperation, coordination and interaction among Arctic states, indigenous communities, and peoples on issues of common importance. The rising geo-political importance of the Arctic and the onset of climate change has resulted in the Council becoming a focus of increasing interest from both inside and beyond the Arctic. This has resulted in new demands placed on the Council, attracting an increasing number of participants, and instigating a period of transformation as Arctic states work to find a way to balance conflicting demands to improve the Council's effectiveness and take care of national interests. This paper considers whether, during this time of change, the Council is having an impact on the issues it was formed to address, i.e., environmental protection and sustainable development. To provide answers, it looks at how the Council reports on and evaluates progress towards the implementation of recommendations it makes regarding biodiversity, how it identifies where activities have had impacts and uncovers the mechanisms through which they were successful, to provide an insight into how the Arctic Council can be an agent of change., We thank the numerous people who took time to review this paper and provide insights and constructive comments which led to its improvement. This work is supported by, and contributes to, the NordForsk-funded Nordic Centre of Excellence project (award 76654) Arctic Climate Predictions: Pathways to Resilient, Sustainable Societies (ARCPATH).

Publisher's version (útgefin grein), Community resilience is often assessed in disaster risk management (DRM) research and it has been argued that it should be strengthened for more robust DRM. However, the term community is seldom precisely defined and it can be understood in many ways. We argue that it is crucial to explore the concept of community within the context of DRM in more detail. We identify three dominating views of conceptualizing community (place-based community, interaction-based community, community of practice and interest), and discuss the relevance of these conceptualizations. We base this discussion on quantitative and qualitative empirical and policy document data regarding flood and storm risk management in Finland, wildfire risk management in Norway and volcanic risk management Iceland. According to our results, all three conceptualizations of community are visible but in differing situations. Our results emphasize the strong role of public sector in DRM in the studied countries. In disaster preparedness and response, a professionalized community of practice and interest appear to be the most prominent within all three countries. The interaction-based community of informal social networks is of less relevance, although its role is more visible in disaster response and recovery. The place-based (local) community is visible in some of the policy documents, but otherwise its role is rather limited. Finally, we argue that the measured resilience of a community depends on how the community is conceptualized and operationalized, and that the measures to strengthen resilience of a particular community should be different depending on what the focal community is., This article is a deliverable of the Nordic Centre of Excellence for Resilience and Societal Security (NORDRESS), which is funded by the Nordic Societal Security Programme. We also acknowledge the support of Grant 235490 , funded by the KLIMAFORSK program at the Research Council of Norway .

Publisher's version (útgefin grein), Conservation and management strategies for endangered and threatened species require accurate estimates of demographic parameters such as age and growth. The whale shark, Rhincodon typus, is the largest fish in the world and is highly valued in the eco-tourism sector. Despite conservation concerns and advances in our understanding of their life history, basic demographic parameters for growth, longevity and mortality are of questionable accuracy; previous growth studies could not agree whether the vertebral growth bands were formed annually or biannually. Here, we provide the first validation of the annual formation of growth bands within the vertebrae of the whale shark using bomb radiocarbon assays. Ages of up to 50 years were estimated from sectioned vertebrae of sharks collected in Taiwan and Pakistan. There was no cessation of the formation of growth bands in the vertebrae of older sharks and our study provides the oldest observed longevity for this species. Initial estimates of growth (k = 0.01–0.12) and natural mortality rates (M = 0.09–0.14) are consistent with those expected of long-lived sharks, which highlights their sensitivity to fishing pressure and conservation concerns., This work was supported by the Fisheries and Oceans Canada, US National Science Foundation Grant OCE-9985884, and the University of Iceland. Travel funding was provided by the Australian Institute of Marine Science.

In recent years, there has been a gradually growing emphasis on the protection of wilderness in Iceland. This is highlighted in the current preparation of a new national park in the Icelandic central highlands, which will become Europe&rsquo, s largest national parks. However, in order to protect the wilderness, a mutual understanding, both on what it is and where it is, is needed. This paper seeks to evaluate Icelanders&rsquo, perception and understanding of wilderness. Furthermore, to assess the value of wilderness for the Icelandic public and determine what lies behind the valuation, an online survey aided by maps from Google Earth and photographic scenarios of different landscapes was sent out to a nationally representative sample of Icelanders. The survey respondents mapped their perceived scope of Icelandic wilderness and furthermore chose between several landscape scenarios they thought most and least suited to their perception of wilderness. The results show that nearly all land located above the 300 m elevation line is perceived as wilderness, reflecting the country&rsquo, s uninhabited highlands areas. The results also show that for the general public in Iceland it is chiefly an open and vast landscape, uninhabited areas, and the absence of anthropogenic features that bestow an area with the status of wilderness. The results demonstrate that any sign of anthropogenic interference, aside from archaeological remains, decrease Icelanders&rsquo, perception of wilderness. Moreover, despite being mostly categorized as urbanists or neutralists according to the purism scale, the majority of Icelanders still consider services, such as petrol stations, hotels, shops, restaurants, and diverse leisure services, along with energy production, to negatively impact the value of wilderness. Most Icelanders thus seem to regard wilderness as a valuable asset from the economic, cultural, and environmental perspectives, which underscores its uniqueness.

Publisher's version (útgefin grein), Icelandic waters are very productive and the fisheries are economically important for the Icelandic nation. The importance of the fisheries has led to progressive fisheries management and extensive monitoring of the ecosystem. However, fisheries management is mainly built on single species stock assessment models, and multi-species or ecological models are essential for building capacity around ecosystem-based fisheries management. This paper describes the first end-to-end model for the Icelandic waters using the Atlantis modeling framework. The modeled area is 1,600,000 km2, and covers the area from Greenland through Icelandic waters to the Faroe Islands. The ocean area was divided into 51 spatial boxes, each with multiple vertical layers. There were 52 functional groups in the model: 20 fish groups (8 at a species level), 5 groups of mammals, 1 seabird group, 16 invertebrates, 5 primary producers, 2 bacteria and 3 detritus groups. The reliability of the model was evaluated using a skill assessment and a sensitivity analysis was conducted to understand the dynamics of the system. The sensitivity study revealed that saithe, redfish and tooth whales had the greatest effect on other groups in the system. The skill assessment showed that the model was able to replicate time-series of biomass and landings for the most important commercial groups and that modeling of the recruitment processes was important for some of the groups. This model now provides a solid basis for evaluating alternative ecosystem and fisheries management scenarios, and should produce reliable results for the most important commercial groups., This study has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no. 613571 for the project MareFrame and from the European Commission’s Horizon 2020 Research and Innovation Programme under Grant Agreement No. 634495 for the project Science, Technology, and Society Initiative to minimize Unwanted Catches in European Fisheries (Minouw). Funding from the Icelandic Research Fund (rannis, No. 152039051) is also acknowledged.

Publisher's version (útgefin grein), The Bureau of Meteorology has a mandate to issue warnings for weather and climate events that are likely to result in harm and loss. This service has been delivered in an end-to-end (science to service) context and warnings messages have typically been crafted to describe the current and predicted future state of the environment and recommended protective actions. However, the warnings landscape is evolving and Australian governments and emergency management agencies are adopting rapidly diversifying roles in a range of warnings processes. This evolution coincides with the shift in international strategies: from the mitigation and crisis management approach to the emphasis on building community resilience. Following a number of severe weather-related events that resulted in serious losses a series of Australian inquiries, reviews and social research investigated warnings efficacy. This included the National Review of Warnings and Information for Australia, with a recommendation suggesting that a Total Warning System concept be more formally considered across multiple hazards, rather than just flood, as it currently stands. Consequently, Australian warnings agencies are embracing a more people-centred approach recognising the need for messages to include detail of likely impact alongside an implied level of risk. Thus, developing capability to deliver impact forecasting and risk-based warnings services in a multi (natural) hazard context. With a key focus on flood, fire and tropical cyclone, this paper reviews international and national warnings policy documents and social research and explores the evidence-based evolution of warning services with respect to the Total Warning System concept., Deanne Bird has been supported by the Nordic Centre of Excellence for Resilience and Societal Security – NORDRESS, which is funded by the Nordic Societal Security Programme.

erein, we use genetic data from 277 sleeper sharks to perform coalescent-based modeling to test the hypothesis of early Quaternary emergence of the Greenland shark (Somniosus microcephalus) from ancestral sleeper sharks in the Canadian Arctic-Subarctic region. Our results show that morphologically cryptic somniosids S. microcephalus and Somniosus pacificus can be genetically distinguished using combined mitochondrial and nuclear DNA markers. Our data confirm the presence of genetically admixed individuals in the Canadian Arctic and sub-Arctic, and temperate Eastern Atlantic regions, suggesting introgressive hybridization upon secondary contact following the initial species divergence. Conservative substitution rates fitted to an Isolation with Migration (IM) model indicate a likely species divergence time of 2.34 Ma, using the mitochondrial sequence DNA, which in conjunction with the geographic distribution of admixtures and Pacific signatures likely indicates speciation associated with processes other than the closing of the Isthmus of Panama. This time span coincides with further planetary cooling in the early Quaternary period followed by the onset of oscillating glacial-interglacial cycles. We propose that the initial S. microcephalus–S. pacificus split, and subsequent hybridization events, were likely associated with the onset of Pleistocene glacial oscillations, whereby fluctuating sea levels constrained connectivity among Arctic oceanic basins, Arctic marginal seas, and the North Atlantic Ocean. Our data demonstrates support for the evolutionary consequences of oscillatory vicariance via transient oceanic isolation with subsequent secondary contact associated with fluctuating sea levels throughout the Quaternary period—which may serve as a model for the origins of Arctic marine fauna on a broad taxonomic scale., Norwegian Polar Institute, Norwegian Research Council, Grant/Award Number: 184644/S40; NSERC/CFI; CanNor

Macrobrachium rosenbergii, the giant freshwater prawn, is an important source of high quality protein and occurs naturally in rivers as well as commercial farms in South and South-East Asia, including Bangladesh. This study investigated the genetic variation and population structure of M. rosenbergii sampled from four rivers in Bangladesh (sample size ranged from 19 to 20), assessing sequence variation, both in the mitochondrial cytochrome oxidase subunit 1 (CO1) gene and in 106 single nucleotide polymorphisms (SNPs) sampled randomly from the genome with double digest RAD sequencing (ddRADseq). The mitochondrial variation presented a shallow genealogy with high haplotype diversity (h = 0.95), reflecting an expansion in population size for the last ~82 kyr. Based on the CO1 variation the current effective population size (Ne) was 9.7 × 106 (CI: 1.33 × 106 – 35.84 × 106) individuals. A significant population differentiation was observed with the mitochondrial CO1 sequence variation and based on the ddRADseq variation, which could be traced to the divergence of the population in the Naf River in the South-East border with Myanmar from the other populations. A differentiation in mtDNA haplotype frequencies was also observed between the Biskhali River and the Karnaphuli Rivers in eastern Bangladesh. This study demonstrated the use of high-throughput genotyping based on the ddRADseq method to reveal population structure at a small geographical scale for an important freshwater prawn. The information from this study can be utilized for management and conservation of this species in Bangladesh., United Nations University Fisheries Training Programme (UNUFTP), Iceland

Publisher's version (útgefin grein), The genome of Rhodothermus marinus DSM 4253 encodes six glycoside hydrolases (GH) classified under GH family 3 (GH3): RmBgl3A, RmBgl3B, RmBgl3C, RmXyl3A, RmXyl3B and RmNag3. The biochemical function, modelled 3D-structure, gene cluster and evolutionary relationships of each of these enzymes were studied. The six enzymes were clustered into three major evolutionary lineages of GH3: β-N-acetyl-glucosaminidases, β-1,4-glucosidases/β-xylosidases and macrolide β-glucosidases. The RmNag3 with additional β-lactamase domain clustered with the deepest rooted GH3-lineage of β-N-acetyl-glucosaminidases and was active on acetyl-chitooligosaccharides. RmBgl3B displayed β-1,4-glucosidase activity and was the only representative of the lineage clustered with macrolide β-glucosidases from Actinomycetes. The β-xylosidases, RmXyl3A and RmXyl3B, and the β-glucosidases RmBgl3A and RmBgl3C clustered within the major β-glucosidases/β-xylosidases evolutionary lineage. RmXyl3A and RmXyl3B showed β-xylosidase activity with different specificities for para-nitrophenyl (pNP)-linked substrates and xylooligosaccharides. RmBgl3A displayed β-1,4-glucosidase/β-xylosidase activity while RmBgl3C was active on pNP-β-Glc and β-1,3-1,4-linked glucosyl disaccharides. Putative polysaccharide utilization gene clusters were also investigated for both R. marinus DSM 4253 and DSM 4252T (homolog strain). The analysis showed that in the homolog strain DSM 4252TRmar_1080 (RmXyl3A) and Rmar_1081 (RmXyl3B) are parts of a putative polysaccharide utilization locus (PUL) for xylan utilization., Support from the Swedish research council Formas (Grant 2015-769), the BBI, Horizon 2020 project “Macro Cascade” and the Era-nets MBT “Thermofactories” and SusFood2 “ProSeaFood” as well as the NovoNordisk Grant (NNF18OC0034792) is greatly appreciated.

Publisher's version (útgefin grein), Managing the impacts of invasive alien species (IAS) is a great societal challenge. A wide variety of terms have been used to describe the management of invasive alien species and the sequence in which they might be applied. This variety and lack of consistency creates uncertainty in the presentation and description of management in policy, science and practice. Here we expand on the existing description of the invasion process to develop an IAS management framework. We define the different forms of active management using a novel approach based on changes in species status, avoiding the need for stand-alone descriptions of management types, and provide a complete set of potential management activities. We propose a standardised set of management terminology as an emergent feature of this framework. We identified eight key forms of management: (1) pathway management, (2) interception, (3) limits to keeping, (4) secure keeping, (5) eradication, (6) complete reproductive removal, (7) containment and (8) suppression. We recognise four associated terms: prevention; captive management; rapid eradication; and long-term management, and note the use of impact mitigation and restoration as associated forms of management. We discuss the wider use of this framework and the supporting activities required to ensure management is well-targeted, cost-effective and makes best use of limited resources., This paper arose from a workshop of the Invasion Dynamics Network (InDyNet) in Berlin in 2018, funded by the Deutsche Forschungsgemeinschaft (DFG) Grant JE 288/8-1, which included a Mercator Fellowship for DLS. Additional support was received through DFG Grants JE 288/9-1 and JE 288/9-2 to JMJ, the G.E. Hutchinson Chair to DLS and the project “Capacity Building Neobiota” (Austrian Federal Ministry for Sustainability and Tourism) to WR. AN, PP and JP were supported by long-term research development project no. RVO 67985939, project 17-19025S and EXPRO grant 19-28807X (Czech Science Foundation). IJ was supported by the J. E. Purkyně Fellowship of the Czech Academy of Sciences. We also thank the referees for this paper for their critical and constructive comments.

Publisher's version (útgefin grein), Anthropogenic noise sources range from intermittent to continuous, with seismic and navy sonar technology moving towards nearcontinuous transmissions. Continuous active sonar (CAS) may be used at a lower amplitude than traditional pulsed active sonar (PAS), but potentially with greater cumulative sound energy. We conducted at-sea experiments to contrast the effects of navy PAS versus CAS on sperm whale behaviour using animal-attached sound- and movement-recording tags (n=16 individuals) in Norway. Changes in foraging effort and proxies for foraging success and cost during sonar and control exposures were assessed while accounting for baseline variation [individual effects, time of day, bathymetry and blackfish ( pilot/killer whale) presence] in generalized additive mixed models (GAMMs). We found no reduction in time spent foraging during exposures to medium-level PAS (MPAS) transmitted at the same peak amplitude as CAS. In contrast, we found similar reductions in foraging during CAS (d.f.=1, F=8.0, P=0.005) and higher amplitude PAS (d.f.=1, F=20.8, P, This work was supported by the UK Defence Science and Technology Laboratory, The Netherlands Ministry of Defence, French Ministry of Defence, and US Navy Living Marine Resources program (contract No. N39430-17-C-1935). Open access funding provided by the University of St Andrews. Deposited in PMC for immediate release.

Publisher's version (útgefin grein), Agriculture has been practiced in Iceland since settlement (landnám; AD 877). This has caused changes in vegetation communities, soil erosion, desertification and loss of carbon stocks. Little data exist regarding vegetation and ecosystems in the Icelandic highland before landnám and therefore the impact of land use over time is poorly understood. The objectives of the study are to examine the timing, nature and causes of land degradation in the highland of Northwest Iceland. Specifically, to determine the resilience of the pre-landnám highland environment to disturbances (i.e. climate cooling and volcanism) and whether land use pressure was of sufficient magnitude to facilitate ecosystem change. A sediment core was taken from the highland lake Galtaból. A chronology for the core was constructed using known tephra layers and radiocarbon dated plant macrofossils. Pollen analysis (vegetation), coprophilous fungal spores (proxy for grazing), and sediment properties (proxies for erosion) were used to provide a high-resolution, integrated vegetation and paleoenvironmental reconstruction. The pre-landnám environment showed resilience to climate cooling and repeated tephra fall. Soon after landnám the vegetation community changed and instability increased, indicated by changes in sediment properties. The pollen and spore record suggest introduction of grazing herbivores into the area after landnám. Following landnám, indicators of soil erosion appear in the sediment properties. Intensification of soil erosion occurred during the 17th century. The Galtaból record clearly demonstrates what can happen in landscapes without adequate management of natural resources and underestimation of landscape sensitivity. Introduction of land use resulted in changes in vegetation communities, loss of resilience and onset of increased soil erosion. Paleoenvironmental reconstructions may inform future decisions on management of the highland by providing baselines for natural variability in the pre-landnám environment., The authors would like to thank Þorsteinn Jónsson and Höskuldur Þorbjarnarson for assistance in the field. Jessica Lynn Till is thanked for proofreading the manuscript. We would like to thank Leone Tinganelli for his work on milling sediment samples for C and N analysis. The Blönduvirkjun hydropower plant kindly hosted us during fieldwork. The authors would like to thank three anonymous reviewers for their valuable comments and suggestions. The research was funded by the Landsvirkjun Energy Research Fund, the University of Iceland Research Fund, and the Icelandic Research Fund (grant no. 141842-051 ).

Publisher's version (útgefin grein), Fisheries produce large amounts of waste, providing food subsidies for scavengers. Discards influence seabird movement, demography and community structure, but little is known about seabird-fishery interactions where discarding is banned. Here, we investigate how northern gannets Morus bassanus respond to fishing vessels in Iceland, where discarding commercial species is illegal, but birds may still access bait, offal, or catch. We GPS-tracked 82 foraging trips for 36 breeding gannets from two colonies (Skrúður and Hellisey) and obtained time-matched vessel locations. We classified bird behaviour using Hidden Markov Models and then tested the effect of vessel distance on behavioural state-switching using multi-state Markov models. Fishing vessels were present during 94% of foraging trips. However, the likelihood of gannets switching from travelling to foraging was unaffected by vessel proximity, regardless of gear type or activity. When encountering vessels, gannets rarely foraged but instead were more likely to continue travelling. When controlling for population size, gannet foraging trips at both colonies were shorter than expected, suggesting favourable conditions. The lack of behavioural responses to vessels among Icelandic gannets is likely driven by the discard ban and availability of pelagic fishes. Our findings have implications for understanding bycatch risk and the consequences of discard reforms., BLC was supported by a NERC GW4+ Doctoral Training Partnership studentship from the Natural Environment Research Council [NE/L002434/1]. We thank Ólafur Torfason, Niall Tierney, and Rachel Stroud for fieldwork assistance in Skrúður, and Mamma-Rósa for food and housing in Vestmannaeyjar. We thank the Hellisey hunting club for the use of cabin and assistance with boat trips to Hellisey. We thank Filipa Samarra, Miguel Neves, Gary Haskins, and team members in the Icelandic Orca Project for boat trips to Hellisey. We thank Lucy Hawkes, David Pascall, Alice Williams, Richard Phillips, Brendan Godley and all reviewers for constructive comments on the manuscript. The GPS tracking data are available through the BirdLife International Seabird Tracking Database (http://www.seabirdtracking.org).

A holistic understanding of the underlying dynamics of sustainable energy system development and its effects on socio-economic and environmental aspects, in different national contexts, is necessary for improved decision making with regards to sustainable energy system planning. In this thesis, systems thinking approach (i.e. causal loop diagrams) is first applied to explore the general dynamics of sustainable energy system development, including the feedbacks and leverages that promote or prevent sustainable energy system development. Second, the emerging energy paradigm (i.e. sustainable energy) and questions related to the challenges arising from it are defined. An extensive model review, which assesses to what extent existing energy system models can provide answers or address the questions arising from the current energy paradigm is presented. This helps identify strengths and weaknesses of energy system models. One of the identified gaps in current energy system models is the simplified representation of the physical realities of renewable resources. This is particularly the case for geothermal resources. Therefore, the third step involves the development of a system dynamics model that captures the behaviour of geothermal resources when they are utilised for electricity production. This geothermal resource dynamics model can capture the effects of geothermal resource dynamics on capacity expansion, resource availability, production levels as well as development and unit production costs at a national systems level. Based on the findings that estimated costs significantly increase when geothermal resource dynamics are considered, while resource availability is also affected, the developed geothermal resource dynamics model assesses the effects of geothermal resource dynamics in Iceland and Kenya. For Kenya, an electricity system model that includes the dynamics of geothermal and hydropower is built. This model explores the effects of renewable resource dynamics (i.e. geothermal and hydropower) on electricity system planning, which is seen as a central element of sustainable energy system development in Kenya. For Iceland, the geothermal resource dynamics model was connected to the Icelandic energy and transport system model (UniSyD_IS). This enables investigating the importance of geothermal resource dynamics in the country’s transition to a low-carbon sustainable transport and energy system. Results show that despite the distinct contexts of the two countries (i.e. Global North and Global South), they face similar challenges arising from the character of renewable resource dynamics. In both cases, high electricity demand growth leads to unsustainable use of geothermal resources. This results in decreasing resource availability, thereby increasing the cost of geothermal electricity (development and unit production cost). The implications on sustainable (energy) system development for each country are distinct. This research shows that comprehending the implications of geothermal resource dynamics on sustainable energy system development in countries that already exploit or plan to exploit geothermal resources on a large scale is important. Additionally, this research draws attention to the need for understanding the context-specific dynamics of sustainable energy system development in more depth for achieving sustainable energy system development in different countries., Heildrænn skilningur á þróun sjálfbærra orkukerfa og áhrif þeirra á umhverfi og samfélög er nauðsynlegur fyrir bætta ákvarðanatöku við skipulagningu slíkra kerfa. Í þessarri ritgerð er kerfishugsun beitt til að greina samspil mismunandi þátta og orsakatengingar í þróun sjálfbærra orkukerfa, m.a. gagnkvæm áhrif og möguleg inngrip sem ýta undir eða koma í veg fyrir sjálfbæra þróun orkukerfa. Í kjölfarið er ný hugmyndafræði um sjálfbær orkukerfi og tengdar spurningar rýnd og skilgreind. Þessi rýni felur í sér ítarlega skoðun á núverandi líkönum fyrir orkukerfi og mat á því hversu vel þau ná utan um þessa nýju hugmyndafræði. Þar með eru helstu styrkleikar og veikleikar núverandi líkana fyrir orkukerfi greindir. Einn veikleiki núverandi líkana er mikil einföldun á eðli endurnýjanlegra orkuauðlinda, þá sérstaklega fyrir jarðvarma. Því er kvikt kerfislíkan þróað sem tekur tillit til eðlis jarðvarma þegar hann er nýttur til rafmagnsframleiðslu. Þetta jarðvarmalíkan nær utan um eðli jarðvarmauðlinda á einfaldaðan hátt og þar með sýnir hugsanlega framleiðslugetu, áhrif nýtingar á auðlindina, og kostnað vegna rafmagnsframleiðslu á landsvísu. Niðurstöður þessa líkans sýna að kostnaður eykst verulega þegar hvikult eðli jarðvarmaauðlinda er tekið til greina. Einnig má greina áhrif á framleiðslugetu þessara auðlinda. Tvö viðlíka líkön eru þróuð frekar til að endurspegla aðstæður á Íslandi, annars vegar, og Kenía, hins vegar. Líkanið af íslensku jarðvarmaauðlindinni er tengt við UniSyD_IS sem er líkan af orku- og samgöngukerfi Íslands. Þar með er hægt að meta áhrif eðli jarðvarmaauðlindarinnar á orkuskipti til lág kolefna og sjálfbærra samgöngu- og orkukerfa. Líkanið af orkukerfi Kenía einblínir á rafmagnsframleiðslu og samspil notkunar jarðvarma og vatnsafls. Líkanið metur áhrif þessa samspils og eðli auðlindanna á skipulagningu raforkukerfa. En ein af undirstöðum þess að þróun orkukerfis Kenía stuðli að sjálfbærri þróun er talin góð skipulagning raforkukerfa. Niðurstöður þessarar rannsóknar sýna að þrátt fyrir ólíkar aðstæður í löndunum tveim, þá mæta þau svipuðum áskorunum vegna hvikuls eðlis endurnýjanlegra auðlinda. Í báðum tilvikum leiðir mikil eftirspurn eftir rafmagni til ósjálfbærrar nýtingar á jarðvarmaauðlindum. Afleiðing þess er minni framleiðslugetu og þar með hærra verðs og kostnaðar við framleiðslu á rafmagni úr jarðvarma. Þó eru afleiðingarnar fyrir sjálfbæra þróun orkukerfanna einnig mismunandi milli landanna tveggja. Þessi rannsókn sýnir að mikilvægt er að skilja eðli jarðvarmaauðlindarinnar, hvort sem nýting er komin skammt eða langt á veg. Nauðsynlegt er að taka til greina hvikult eðli jarðvarmaauðlinda við skipulagningu orkukerfa sem eiga að stuðla að sjálfbærri þróun. Einnig sýna þessar niðurstöður hversu miklu máli það skiptir að taka tillit til aðstæðna þegar unnið er að sjálfbærri þróun orkukerfa í mismunandi löndum., Une compréhension holistique des dynamiques sous-jacentes du développement de systèmes énergétiques durables et de ses effets socioéconomiques et environnementaux dans différents contextes nationaux est nécessaire pour améliorer la prise de décision en matière de planification de systèmes énergétiques durables. Dans cette thèse, l’approche systémique (p.ex. des diagrammes de boucles causales) est premièrement appliquée à l’exploration des dynamiques générales du développement durable de systèmes énergétiques, incluant notamment les retours et leviers promouvant ou restreignant ce développement. Dans un deuxième temps, le paradigme énergétique émergent (p.ex. l’énergie durable) et les questions liées à ses enjeux sont définies. Une évaluation approfondie de la mesure dans laquelle les modèles de systèmes énergétiques existants peuvent fournir des réponses aux questions soulevées par le paradigme énergétique actuel est présentée. Cela permet d’identifier les forces et faiblesses des modèles de systèmes énergétiques. Une des lacunes identifiées dans ces modèles est la représentation simplifiée des réalités physiques des ressources renouvelables, particulièrement dans le cas de ressources géothermales. Par conséquent, la troisième étape consiste à développer un modèle de dynamique des systèmes qui appréhende l’évolution de ressources géothermales lorsqu’elles sont utilisées pour la production d’électricité. Ce modèle peut capturer les effets des dynamiques de ressources géothermales sur les capacités d’expansion, la disponibilité des ressources, le niveaux de production ainsi que le développement et coûts de production unitaires aux niveau de systèmes nationaux. Basé sur l’observation que les coûts estimés augmentent considérablement lorsque la dynamique des ressources géothermales est considérée tout en affectant leur disponibilités, le modèle de dynamique des ressources géothermales élaboré évalue les effets des dynamiques de ressources géothermiques en Islande et au Kenya. Pour le Kenya, un modèle de systèmes d’électricité qui inclut les dynamiques de la géothermie et de l’hydroélectricité est construit. Ce modèle explore les effets des dynamiques de ressources renouvelables (p.ex. la géothermie et l’hydroélectricité) sur la planification de systèmes d’électricité, perçue comme un élément central du développement de systèmes d’énergie durable au Kenya. Concernant l’Islande, le modèle de dynamiques de ressources géothermales a été relié au modèle de système d’énergie et de transports islandais (UniSyD_IS). Cela permet l’investigation de l’importance des dynamiques de ressources géothermales dans la transition du pays vers un système d’énergie et de transport durable à faible émissions de carbone. Les résultats montrent que malgré le contexte distinct des deux pays (p.ex. Nord-Sud), ils font face à des défis similaires qui découlent des caractéristiques des dynamiques de ressources renouvelables. Dans les deux cas, une forte demande d’électricité mène à une utilisation non-soutenable de ressources géothermiques. Cela résulte en une baisse de ressources disponibles, augmentant de ce fait le coût de l’électricité géothermique (de développement et de production individuelle). Les implications sur le développement de systèmes (énergétiques) durables pour les deux pays sont distinctes. Cette recherche montre que comprendre les implications des dynamiques de ressources géothermales sur le développement de systèmes énergétiques durables dans des pays qui exploitent, ou prévoient d’exploiter des ressources géothermiques à grande échelle est important. De plus, cette recherche souligne le besoin d’une compréhension plus poussée des dynamiques contextuelles du développement de systèmes énergétiques durables pour parvenir au développement de systèmes énergétiques renouvelables dans différents pays., European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 675153

Microbial communities in remote locations remain under-studied. This is particularly true on glaciers and icecaps, which cover approximately 11% of the Earth&rsquo, s surface. The principal reason for this is the inaccessibility of most of these areas due to their extreme isolation and challenging environmental conditions. While remote research stations have significantly lowered the barrier to studying the microbial communities on icecaps, their use has led to a bias for data collection in the near vicinity of these institutions. Here, miniaturisation of a DNA sequencing lab suitable for off-grid metagenomic studies is demonstrated. Using human power alone, this lab was transported across Europe&rsquo, s largest ice cap (Vatnaj&ouml, kull, Iceland) by ski and sledge. After 11 days of unsupported polar-style travel, a metagenomic study of a geothermal hot spring gorge was conducted on the remote northern edge of the ice cap. This tent-based metagenomic study resulted in over 24 h of Nanopore sequencing, powered by solar power alone. This study demonstrates the ability to conduct DNA sequencing in remote locations, far from civilised resources (mechanised transport, external power supply, internet connection, etc.), whilst greatly reducing the time from sample collection to data acquisition.

Publisher's version (útgefin grein)., Aquaponics is a sustainable method of food production, whereby aquaculture and hydroponics are combined in one circular system. A few aquaponics startup companies are emerging in Europe with a limited production area of a few hundred or a few thousand square meters, whereas hydroponics is a common practice in a commercially viable manner most often with production units of several hectares. In Iceland, greenhouse farmers operate on relatively small production units, often between 2000 and 5000 m2. The aim of the present study was, therefore, to develop and design aquaponic production systems towards integration into small greenhouse farming strengthening economic viability and sustainability. Since the local market in Iceland is small and import is relatively expensive due to the distance from other markets, the suitability of commercially available fish feed and the selection of plant species were assessed in relation to production efficiency and available market and resources. The effects of water flow on plant growth and on nutrient utilization in culture water were measured and evaluated. Four aquaponics test systems were designed, built and operated, and results were used to develop a pilot commercial aquaponics system implemented for greenhouse farming in Iceland. One of the test systems was a media filled flood and drain system and the other three were deep water culture systems. Tilapia (Oreochromis niloticus), one of the most popular fish in aquaculture, was reared in all systems, while different leafy greens and fruiting vegetables were grown in the hydroponics. The fish was fed with commercial aquaculture feed made for cod and charr. The feed conversion ratio (FCR) was used to assess the effectiveness of feed on fish growth. The FCR observed in this research was between 0.9 and 1.2, within the typical values for tilapia growth in aquaculture. The production of the leafy green plants (e.g., pak-choi) was approximately four times, by weight, that of the production of fish, a similar yield as shown in other researches in the field. The continuous rise of nitrate and phosphate concentrations in the aquaponic system indicated the potential to support even higher crop yield. Long daylength in the summer in Iceland is clearly beneficial for crop production in aquaponics. Based on the results, it is concluded that aquaponics can be a feasible opportunity for greenhouse farming at least to diversify the current business model. Not only can the fish provide an extra income but also the effluent from the aquaculture is easily used as fertilizer for the plants, thus the circular production system offers new innovative ideas for diversifying and value-adding the business further, for example into crayfish production and/or into educational and experience tourism., Coworkers at the University of Iceland, the Agricultural University of Iceland, Svinna-verkfraedi Ltd and growers providing assistance and infrastructure are acknowledged. This research was funded by The Icelandic Centre for Research grant number 142372 and the European Commission grant number ECO/12/332783. The APC was funded by the University of Iceland.

Publisher's version (útgefin grein), Evolutionary theories of seasonal migration generally assume that the costs of longer migrations are balanced by benefits at the non-breeding destinations. We tested, and rejected, the null hypothesis of equal survival and timing of spring migration for High Arctic breeding sanderling Calidris alba using six and eight winter destinations between 55°N and 25°S, respectively. Annual apparent survival was considerably lower for adult birds wintering in tropical West Africa (Mauritania: 0.74 and Ghana: 0.75) than in three European sites (0.84, 0.84 and 0.87) and in subtropical Namibia (0.85). Moreover, compared with adults, second calendar-year sanderlings in the tropics, but not in Europe, often refrained from migrating north during the first possible breeding season. During northward migration, tropical-wintering sanderlings occurred at their final staging site in Iceland 5–15 days later than birds wintering further north or south. Namibia-wintering sanderlings tracked with solar geolocators only staged in West Africa during southward migration. The low annual survival, the later age of first northward migration and the later passage through Iceland during northward migration of tropical-wintering sanderlings, in addition to the skipping of this area during northward but not southward migration by Namibia-wintering sanderlings, all suggest they face issues during the late non-breeding season in West Africa. Migrating sanderlings defy long distances but may end up in winter areas with poor fitness prospects. We suggest that ecological conditions in tropical West Africa make the fuelling prior to northward departure problematic., Annual expeditions to Mauritania were organized by NIOZ, and we especially thank Maarten Brugge, Anne Dekinga, Jutta Leyrer and Bernard Spaans for their contributions. The Parc National du Banc d'Arguin granted research permits and facilitated access. J.R. and T.S.L.V. thank Aarhus University for logistical support at Zackenberg. Benoît Sittler organized expeditions to Karupelv Valley. The Farlington Ringing Group provided cannon‐net equipment. This work was supported by two grants from the Netherlands Polar Programme (851.40.072 and 866.15.207) of the Netherlands Organisation for Scientific research (NWO) and from the Metawad project awarded by Waddenfonds (WF209925) to JR and TP. The measurements in Mauritania had their beginnings in the Prins Bernhard Cultuurfondsprijs to TP. JR and TP also received INTERACT grants for Transnational Access from the European Community's Seventh Framework Programme (grant agreement No262693). JR received a generous donation from World Wildlife Fund Netherlands. JAA was supported by FCT (SFRH/BPD/91527/2012). OG and Loïc Bollache were supported by the French Polar Institute (IPEV; program ‘1036 Interactions') and TL by a Veni grant (no. 016.Veni.192.245) from NWO. The authors declare no conflict of interest. This study is based on the efforts of more than 2,000 observers reporting colour‐ringed sanderlings. We especially thank Guðmundur Örn Benediktsson, John Bowler, Ruth Croger, Anne de Potier, Benjamin Gnep, Kim Fischer, Kirsten Grond, Eileen Hughes, Hilger Lemke, Pedro Lourenço, Andy Johnson, Pierre Leon, Jelle Loonstra, Sebastien Nedellec, Afonso Rocha, Brian Rogers, Ron Summers, Jan van Dijk and Hein Verkade. Anneke Bol, Marco van der Velde and Yvonne Verkuil molecularly sexed the majority of birds, Maria Teixeira and Jérôme Moreau sexed eight individuals. Ron Porter created flags for geolocator attachment. Eldar Rakhimberdiev answered questions concerning FLightR and Allert Bijleveld, Jesse Conklin, Rosemarie Kentie, Thomas Oudman, Janne Ouwehand, Emma Penning, Eldar Rakhimberdiev, Brett Sandercock, Ron Summers, Yvonne Verkuil and two reviewers critically commented on drafts. Benjamin Gnep created Figure.

Publisher's version (útgefin grein), Crangonyx islandicus is a groundwater amphipod endemic to Iceland, considered to have survived the Ice Ages in subglacial refugia. Currently the species is found in spring sources in lava fields along the tectonic plate boundary of the country. The discovery of a groundwater species in this inaccessible habitat indicates a hidden ecosystem possibly based on chemoautotrophic microorganisms as primary producers. To explore this spring ecosystem, we assessed its microbial diversity and analysed whether and how the diversity varied between the amphipods and the spring water, and if was dependent on environmental factors and geological settings. Isolated DNA from spring water and from amphipods was analysed using metabarcoding methods, targeting the 16S rRNA gene. Two genera of bacteria, Halomonas and Shewanella were dominating in the amphipod samples in terms of relative abundance, but not in the groundwater samples where Flavobacterium, Pseudomonas and Alkanindiges among others were dominating. The richness of the bacteria taxa in the microbial community of the groundwater spring sources was shaped by pH level and the beta diversity was shaped by geographic locations., This work was supported by the Icelandic Research Council [grant number: 130244-051 to SP and 141863-051 to BKK] and by the doctoral fund at the University of Iceland. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Publisher's version (útgefin grein), Increasing the share of renewable energy in the energy mix is of crucial importance for climate change mitigation. However, as renewable energy development often changes the visual appearance of landscapes and might affect other industries relying on them, such as nature-based tourism, it therefore requires careful planning. This is especially true in Iceland, a country rich in renewable energy resources and a popular nature-based tourism destination. The present study investigated the potential impacts on tourism of the proposed Hverfisfljót hydropower plant by identifying the main attractions of the area as well as by analyzing visitors' perceptions, preferences and attitudes, and the place meanings they assign to the landscape of the area. The data for the study were collected using onsite questionnaire surveys, interviews with visitors to the area, open-ended diaries, and participant observation. The results reveal that the area of the proposed power plant is perceived as wilderness by its visitors, who seek environmental settings related to the components of a wilderness experience. Visitors were highly satisfied with the present settings and preferred to protect the area from development to ensure the provision of currently available recreational opportunities. The results further show that the proposed Hverfisfljót hydropower plant would reduce the attractiveness of the area to its visitors, degrade their wilderness experience, and therefore strongly reduce their interest in visiting the area. Moreover, the participants perceived the already developed lowlands of the country as more suitable for renewable energy development than the undeveloped highland areas, which is in line with the principles of smart practices for renewable energy development., Funding: This research was funded by the Ministry for the Environment and Natural Resources and the steering committee for the Icelandic Master Plan for Nature Protection and Energy Utilization.

Publisher's version (útgefin grein)., There is a growing body of evidence demonstrating the impacts of human arrival in new “pristine” environments, including terrestrial habitat alterations and species extinctions. However, the effects of marine resource utilization prior to industrialized whaling, sealing, and fishing have largely remained understudied. The expansion of the Norse across the North Atlantic offers a rare opportunity to study the effects of human arrival and early exploitation of marine resources. Today, there is no local population of walruses on Iceland, however, skeletal remains, place names, and written sources suggest that walruses existed, and were hunted by the Norse during the Settlement and Commonwealth periods (870– 1262 AD). This study investigates the timing, geographic distribution, and genetic identity of walruses in Iceland by combining historical information, place names, radiocarbon dating, and genomic analyses. The results support a genetically distinct, local population of walruses that went extinct shortly after Norse settlement. The high value of walrus products such as ivory on international markets likely led to intense hunting pressure, which—potentially exacerbated by a warming climate and volcanism—resulted in the extinction of walrus on Iceland. We show that commercial hunting, economic incentives, and trade networks as early as the Viking Age were of sufficient scale and intensity to result in significant, irreversible ecological impacts on the marine environment. This is to one of the earliest examples of local extinction of a marine species following human arrival, during the very beginning of commercial marine exploitation., A note of acknowledgment to Tom Gilbert for continuous support, Jose Alfredo Samaniego for bioinformatic guidance, Liselotte W. Andersen and Erik Born for access to mtDNA control region data, as well as Bastiaan Star and Sanne Boessenkool for access to published mitochondrial genomes. Thanks also to Anne Birgitte Gotfredsen, Arn y Sveinbjo¨rnsdottir, Jan Heinemeier, Martin Appelt, Paul Szpak, Leslie Howse, Sigmundur Einarsson, Þorvaldur Bjo¨rnsson, and Þorvaldur Þorðarson for coordinating various sample procurement and assistance with references. Acknowledgment to all institutions and private collectors, especially Guðmundur G. Þorarinsson, Sigfus Bjarnason, Sımon and Svava, and Orn Erlendsson, who provided speci- € mens and kindly permitted destructive analysis for dating and genetic laboratory work. In addition, thanks to the Icelandic Institute of Natural History, National Museum of Iceland, Natural History Museum of Denmark, National Museum of Denmark, Canadian Museum of History, Nunavut Department of Culture and Heritage and Canadian Museum of Nature for providing samples and access to data. Newly generated CR haplotypes and mitochondrial genomes have been deposited with GenBank (accessions: MK 671108-49). All other data are available in the Supplementary Material online. This work was supported by the European Union’s EU Framework Programme for Research and Innovation Horizon 2020 under Marie Curie Actions (Grant Agreement No 676154; ArchSci2020) to (M.T.O., P.J., X.K.); and the National Science Foundation, USA (standard grant award no. 1503714), under the program Arctic Social Sciences to (S.P., H.J.M.).

Publisher's version (útgefin grein), The pleurocarpous feather moss Pleurozium schreberi is a ubiquitous moss species which plays a fundamental role in many terrestrial ecosystems, for instance within the boreal forest, the Earth’s largest terrestrial biome, this species plays a significant role in driving ecosystem nitrogen and carbon inputs and fluxes. By hosting dinitrogen (N2)-fixing cyanobacteria, the moss-cyanobacteria symbiosis constitutes the main nitrogen input into the ecosystem and by the high productivity and the low decomposability of the moss litter, P. schreberi contributes significantly to build-up soil organic matter, and therefore long-term C sequestration. Knowledge on P. schreberi genome will facilitate the development of ‘omics’ and system’s biology approaches to gain a more complete understanding of the physiology and ecological adaptation of the moss and the mechanisms underpinning the establishment of the symbiosis. Here we present the de novo assembly and annotation of P. schreberi genome that will help investigating these questions. The sequencing was performed using the HiSeq X platform with Illumina paired-end and mate-pair libraries prepared with CTAB extracted DNA. In total, the assembled genome was approximately 318 Mb, while repetitive elements account for 28.42% of the genome and 15,992 protein-coding genes were predicted from the genome, of which 84.23% have been functionally annotated. We anticipate that the genomic data generated will constitute a significant resource to study ecological and evolutionary genomics of P. schreberi, and will be valuable for evo-devo investigations as well as our understanding of the evolution of land plants by providing the genome of a pleurocarpous moss., We would like to thank colleagues at the Oak Ridge National Laboratory, Duke University, and the DOE Joint Genome Institute for access to prepublication genome and annotation of Sphagnum fallax to use in comparisons against gene families. The Nilsson-Ehle Endowments from The Royal Physiographic Society of Lund for financial support. The authors would also like to acknowledge support from Science for Life Laboratory (SciLifeLab, Sweden), the National Genomics Infrastructure (NGI, Stockholm, Sweden), Nation Bioinfor-matics Infrastructure (NBIS; Stockholm, Sweden) and Uppmax (Uppsala, Sweden), for providing assistance in massive parallel sequencing as well as the computational infrastructure.