During the Silurian, the Swedish island Gotland was positioned close to the equator and covered by a shallow sea called the Baltic Basin. The sedimentary rocks (predominantly carbonates) comprising most of the island today were initially formed in this warm sea, and the relatively complete succession of rocks often contains fossil fragments and scales from early vertebrates, including heterostracans, anaspids, thelodonts, osteostracans, acanthodians, and a stem-osteichthyan. Fossils of early vertebrates become increasingly more common in younger Silurian rocks, but are mostly represented by fragmentary remains and rarer occurrences of articulated jawless vertebrates (agnathans). However, the record of articulated specimens and jawed vertebrates (gnathostomes) are more numerous in rocks of the following Devonian Period. Isolated peaks of agnathan diversity during the Silurian and disarticulated remains of gnathostomes from this period hint at a cryptic evolutionary history. A micropaleontological approach with broader sampling may provide a better understanding of early vertebrate distribution patterns and hopefully give some insights into this history. The objective of this study was to build upon previous sampling on Gotland and to use established frameworks for disarticulated remains with the aim of making comparisons with similar studies performed in the East Baltic. However, difficulties locating the collections from these previous works necessitated a different focus. Undescribed museum collections and newly sampled material enabled some taxonomical revisions and greatly improved the understanding of vertebrate distribution in the youngest part of the Gotland sequence. It also indicated that this interval may represent the early stages of the diversification of gnathostomes that become increasingly dominant toward the end of the Silurian. Furthermore, the description of samples from partly coeval sections in Poland enabled some preliminary comparisons outside of Gotland, and presented a striking example of restricted environmental occurrences for a thelodont taxon. This is encouraging for future sampling and investigations on Gotland. Together with the establishment of a facies-framework comparable to that developed in the East Baltic and correlations to other areas, this may prove fruitful for an increased understanding of early vertebrate distribution and evolution during the Silurian.

In response to the drastic decline of the European eel (Anguilla anguilla (L.)) fisheries have been reduced and elvers are stocked in areas where natural abundances are low. Are these measures adequate? To answer different aspects of this question, we have analysed more than a century of eel tagging, using both traditional and more novel capture – recapture analyses. Based on these long-term data, we have evaluated the impact of the Swedish eel coastal fisheries using Survival analysis. Our analysis indicates that the fishing mortality just prior the 2009 fishing restrictions were in the order of 10%. More recent tagging programs have focused on issues related to the fate of stocked fish. If and how they migrate out of the Baltic Sea and further on towards the Atlantic Ocean. Both earlier and our new studies reveal that all eels recaptured on the Swedish East Coast, no matter of their origin, migrate at a reasonable speed and direction towards the outlets of the Baltic Sea. Even though it is sometimes difficult to determine their origin, our analyses indicate that stocked fish were scarce among the recaptures. In an experiment on the Swedish West Coast, we knew the individuals’ origin (stocked or wild) and they had similar migration patterns. In contrast, silver eel in Lake Mälaren – assumed to have been stocked as elvers or bootlace eels – seemed to have difficulties in finding the outlets. Instead they overwintered and lost weight. However, weight losses are also significant among non-stocked individuals in the Baltic Sea, both if they overwinter and if they appear to be on their way out from the area. It remains an open question whether eels from the Baltic region in general, and whether the overwintered fish in particular, manage to reach the spawning area in the Atlantic Ocean. Based on current knowledge, I advocate invoking the precautionary approach and to concentrate Swedish eel stockings to the West Coast and allow the young fish to spread out on their own. / <p>At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 2: Manuscript.</p><p> </p>

Late Iron Age burials in Courland have primarily been used as signifiers of ethnical identity for larger groups of people, mainly based on later written sources. Based on gender theoretical perspectives, the burials can be understood as communicating different and varying, socially constructed identities. Dress pins are discussed as markers for a female identity among people of higher social standing. After the introduction of cremation burials, the need to communicate this identity through dress pins seems to disappear and women, as well as men, are buried with penannular brooches. A child’s grave indicates that this identity might have been adopted when the child reached a certain age and was considered to have reached social adulthood. / Vēlā dzelzs laikmeta Kurzemes apbedījumi galvenokārt tika izmantoti, lai izsekotu etnisko piederību lielākām cilvēku grupām, un balstās galvenokārt uz vēlākiem teksta avotiem. No dzimumu teorētiskā viedokļa apbedījumus var analizēt arī no dažādu un atšķirīgu sociāli konstruētu identitāšu skatu viedokļa. Rotadatas tiek apspriestas kā sieviešu identitātes izpausme no sabiedrības augstākajiem slāņiem. Pēc ugunskapu ieviešanas šīs identitātes izpausme ar rotadatām izskatās, ka pamazām izzūd, un gan sieviešu, gan vīriešu apbedījumos tiek atrastas pakavsaktas. Bērna apbedījums analīzes materiālā uzrāda, ka indivīda identitāte tika iegūta, kad bērns sasniedza noteiktu vecumu, kas tika pieņemts par sociāli pieaugušo vecumu.

Denna studien har gjorts på blåmusslor, Mytilus edulis trossulus, för att undersöka effekter av det antidepressiva läkemedlet Citalopram på blåmusslans fysiologiska funktioner. Blåmusslan är en vanligt förekommande art i Östersjön där den fungerar som en nyckelart som; bidrar till den biologiska mångfalden, är långt ner i näringskedjan och är anpassningsbar. Dessa egenskaper gör den även lämpad som testorganism i denna studie. Citalopram är ett av Sveriges vanligaste läkemedel för att behandla psykisk ohälsa och den verkar genom att blockera återupptaget av serotonin i hjärnan och ingår i läkemedelsgruppen serotoninhämmare (SSRI). Serotonin påverkar flera olika funktioner i kroppen såsom rörelseförmåga, sinnesstämningar och mättnadskänsla. Läkemedel inklusive Citalopram återfinns i sjöar och vattendrag, detta för att läkemedel inte renas bort i våra reningsverk och för att det idag inte finns några krav på läkemedelsrening i svenska avloppsreningsverk. Läkemedel tillverkas för att vara aktiva vid låga koncentrationer vilket gör att de även har en negativ effekt på marina organismer. I denna studie har vi analyserat effekter av Citalopram på blåmusslans fysiologiska funktioner genom tre analyser, filtrering, rörelse och produktion av byssustrådar i tre olika koncentrationer (0 ng/l, 20 ng/l och 200 ng/l). Analyserna utfördes under två tidsperioder, exponering av läkemedel under 96 timmar samt remediering utan läkemedel under 72 timmar. Studien visar en signifikant skillnad i filtrering (P-värde = 0.04416) mellan grupperna under exponeringen där fler blåmusslor som var exponerade för 200 ng/l visade en lägre filtreringsaktivitet (fler individer var helt stängda). Under remedieringen observerades en signifikant högre mortalitet bland blåmusslor som exponerats för 200 ng/l (P-värde = 0.01347). Blåmusslor exponerade för 200 ng/l Citalopram visade även en lägre produktion av byssustrådar (P-värde= 0.02702). I den här studien kan vi se att läkemedlet Citalopram har en negativ påverkan på flera av blåmusslans fysiologiska funktioner. / The aim of this study was to investigate the effects of the antidepressant drug Citalopram on blue mussels, Mytilus edulis trossulus, in the Baltic Sea. The blue mussel is a common species that is considered a key species in the Baltic Sea as it contributes to biodiversity, and is adaptable which makes it suitable as a test organism in this study. Selective serotonin reuptake inhibitors (SSRIs) are the most commonly prescribed antidepressants and a common SSRI substance is Citalopram. This substance is one of Sweden's most common drugs for treating mental illness. Serotonin affects several different functions in the body such as movement, mood and saturation. Many pharmaceuticals including Citalopram are found in lakes and streams, this is because pharmaceuticals are not purified in our wastewater treatment plants and there is no requirements for filtration of pharmaceuticals in Swedish wastewater treatment plants as of today. Pharmaceuticals are manufactured to be active even at low concentrations, a negative side effect of this is that it is also active in the environment causing negative effects on marine organisms. In this study, we analyzed the effects of Citalopram on the physiological functions of the blue mussel by three analyzes; filtration, movement and production of byssus threads using three different concentrations (0 ng /l, 20 ng/l och 200 ng/l) of Citalopram. The analyzes were carried out over two time periods, exposure of drugs for 96 hours and remediation without drugs for 72 hours. The study shows a significant difference in filtration (P-value = 0.04416) between the groups during exposure, where more blue mussels that were exposed to 200 ng/l showed a lower filtration activity (more individuals completely closed). During the remediation, a significantly higher mortality was observed among blue mussels exposed to 200 ng/l (P value = 0.01347). Blue mussels exposed to 200 ng/l Citalopram also showed lower production of byssus threads (P value = 0.02702). In this study we can see that the drug Citalopram has a negative effect on several of the blue mussel's physiological functions.

Une forte structure génétique a été décrite dans la littérature parmi les populations européennes de la coque de lagune Cerastoderma glaucum. Cependant, les limites géographiques entre les grandes divisions génétiques varient d'un marqueur à l'autre et leur faible nombre ne permettait pas de tester réellement les échanges génétiques entre ces groupes. Le but principal de cette thèse était donc d'estimer la structure des populations de C. glaucum à l'aide de marqueurs, en considérant les rôles respectifs de la divergence passée et de la fragmentation de l'habitat. Pour atteindre ses objectifs, des populations des côtes atlantiques et méditerranéennes ont été étudiées en utilisant : i) des marqueurs génétiques classiques (un EPIC et des marqueurs microsatellites déjà publiés); ii) des séquences associées à des sites de restriction (“restriction associated DNA sequences”) ou RADseq. Alors que les marqueurs génétiques classiques ont révélé le caractère divergent des populations de Méditerranée orientale, l'approche RADseq a permis de reconstruire les relations phylogénétiques entre groupes au sein de l'espèce avec une résolution jamais encore ateinte. Trois lignées profondément divergentes ont ainsi été identifiée au sein de C. glaucum: une en Mer Egée – Mer Noire, une en Mer Ionienne et la dernière largement distribuée de la Méditerranée à la Baltique. Cette dernière lignée c'est par ailleurs sous divisée en entités isolées en Méditerranée Occidentale, en Atlantique, en Mer du Nord et an Baltique. Comparée à l'espèce soeur C. edule, qui profite d'un habitat moins fragmenté, C. glaucum présente une beaucoup plus forte différenciation génétique entre populations. Il semble donc que des incompatibilités génétiques, conséquences de l'isolement géographique et de l'adaptation locale, aient pu être à l'origine d'un complexe d'espèces. Ces résultats soulignent par ailleurs le rôle évolutif particulier de l'habitat lagunaire, accélérateur de la diversification génétique. / Previous studies found a high level of genetic structuring among the European populations of the lagoon cockle Cerastoderma glaucum. However, the geographic locations of the major genetic divisions differed among markers and the small number of genetic markers used lacked the power to test for gene flow between divergent clusters. Therefore, the main aim of this thesis was to assess the population structure of C. glaucum using new genetic markers in the light of the respective role of past divergence and habitat fragmentation. To reach these objectives, populations from the Atlantic and Mediterranean coasts have been investigated using: i) classical genetic markers (EPIC together with previously published microsatellites); ii) restriction-site associated DNA sequencing (RADseq). When the classical genetic markers revealed the divergent character of Eastern Mediterranean populations, the RADseq approach allowed inferring phylogenetic relationships with an unprecedented resolution. Three deeply divergent lineages were described within C. glaucum: one in the Aegean-Black Sea region, one in the Ionian Sea, and the last one widely distributed from the Western Mediterranean to the Baltic Sea. This last lineage underwent further diversification with isolated entities detected in Western Mediterranean, Atlantic, North Sea and Baltic Sea. Compared to the sister species C. edule, which thrives in a less fragmented habitat, C. glaucum displayed a much stronger genetic differentiation among populations. Consequently, it seems that genetic incompatibilities, which emerged as a by-product of geographic isolation together with local adaptation, led to the origin of a species complex. These results highlight the evolutionary role of lagoon habitats, where genetic diversification can proceed very quickly.

The purpose of this study is to explore how the court and church in Livonia worked together to remain the sole authority in the country. The Teutonic knights waged crusades in the Baltic countries during the 13th century, formed the country Livonia and ended up staying. In a country where an ethnic German minority held most of the positions of power it became important to legitimize the reason for it being so. This study will focus on the court case of Thiess from 1691, a man charged with being a werewolf and who refused to acknowledge the German ideology. To highlight the power structure, I turned to Louis Althusser and Marxism which theories included the repressive state apparatus and ideological state apparatuses. With those theories in mind, the use of text analysis and literature on the history of Livonia, the power struggle has become clearer. My findings show the importance of making an example of Thiess due to his influence of the peasants.

A phenomenon during the late Bronze Age and Early Iron Age which in its simplest form could be called ‘a culture of the Baltic Sea’ is an idea which many archaeologists have favoured. However, the term ‘a culture of the Baltic Sea’ is not the most ideal to use when discussing the Baltic Sea during this time in prehistory, as the term is rather simplifying from what would be the more diverse truth. The term entails that there should have been a cultural homogeneity across the Baltic Sea as it most certainly was not. This thesis complicates this otherwise simplified term and calls the cultural phenomenon ‘a cultural hybrid of the northern Baltic Sea area’ (i.e. the northern part of the Baltic Sea including its neighbouring gulfs). A cultural hybrid, in this sense, allows there to be cultural differences within an area. These differences are accepted by the people within the cultural hybrid which in turn allow people to live among each other, rather than to become a social obstacle making the people separate into smaller and more homogenous cultural groups. This assumed existence of a cultural hybrid is put to the test as a hypothesis. To answer the hypothesis, the cultural hybrid is studied from the perspective of the tarand-graves (an Estonian originating grave type erected and used around the shores of the northern Baltic Sea area during 500 BC–500 AD) which in turn is interpreted according to ritual practice theory. The hypothesis is proven to be true which makes it possible to apply the concept of cultural hybridity, and its connection with tarand-graves in the northern Baltic Sea area, to the Åland Islands. Although the islands have a very promising geographical position in the middle of the northern Baltic Sea area, interestingly, no tarand-graves have been registered there. Grave field Ec 6.6 on the western side of the Åland Islands becomes the object of study mainly due to grave 14, which placed on that particular grave field, carries a high tarand-grave potential. The material is partly collected from two field visits to Ec 6.6 and partly from an excavational report from 1949 of the same grave field. The result shows that the Åland Islands, as well as Ec 6.6, have a very high likeliness of being hosts for tarand-graves.

Through social landscape theory the aim of this thesis is to broaden the understanding of the bronze age monumental graves on the coast of Norrland. Questions about similarities between the stone ship settings and long cairns are analysed by looking at size and placement in the landscape. This shows the possible connections between the two construction types and were questioned throughout the process of writing. A reconstructed shoreline set to Late Nordic Bronze Age period IV, has been analysed by looking at the monuments placement to see possible connections through a maritory between Norrland and southern Sweden. In this thesis I have incorporated some instances of Gotlandic as well as other stone ship settings and long cairns from the Baltic Sea area, to strengthen the point of a possible maritory that connected the societies of northern Sweden with the societies placed around the Baltic Sea. The long cairns can be found in Gävleborg’s county from Söderala parish along the coast all the way up to Byske parish in Västerbotten’s county and seem to be constructed in a way that follow the shape of the mountain, with some anomalies. Stone ship settings can usually be found along the mouth of rivers and are placed more specific in the environment, where the orientation seems to relate to the ancient shoreline and in some cases the monument even point towards plausible routes that would be possible to follow with a ship inland. There is a clear concentration of all monument types in Västernorrland’s county, more specifically around the area of Docksta. The placement of the monuments above sea level in relation to the ancient shoreline, seems to be varied, with no clear rule of what height they should lay on. Many similarities can be found between the two, yet so many differences that only can be answered by excavations of more monuments. Further research and excavations is needed in Norrland with focus on the Bronze Age, which is crucial for the understanding of Sweden’s northern coastal areas and the trade across the Baltic Sea.

Modeling of the nitrogen cycling in the sediments of the Baltic Sea is the major objective of thepresent study. A model of the nitrogen cycling in the sediment of the Western Gotland Basinwas developed. The model simulates the sedimentary biogeochemical processes such asdecomposition of the organic detritus and transformation of nitrogen species in the sediment.The development of the model is based on the methods and approaches implemented in themodel of the freshwater Haringvliet Lake, Netherland. The sediments of Haringvliet and the Baltic Sea were examined in terms of the interactions andcontrols of biogeochemistry. Both systems are eutrophied. This results in a high sedimentationrate of organic matter and creates the same chemical and physical conditions to theirsediments. However, the sedimentation rate and decomposition of organic detritus is higherand nitrification and denitrification is lower in Haringvliet lake system compared to the BalticSea. The results of the model tests show that profiles of the chemical compounds and rates of theprocesses are in good agreement with the observations made in different areas of the BalticSea. The model can be used for simulation of the sediment processes when there is a constantinput of organic matter. The model can also reproduce the behavior of the sediment whensome of the process parameters and conditions are changed. A comparison of the rates of the biogeochemical processes predicted by model and thosemeasured in the different basins of the Baltic Sea was performed. The rates of decompositionof organic detritus, denitrification and nitrification were in agreement with the field data. Basedon the results of the model the nitrogen removal in the sediment was calculated and it wasfound that 26-32% of total nitrogen entering the sediment is removed by denitrification. / <p>www.ima.kth.se</p>

In einem hydronumerischen Modell zur Prognose des Strömungs- und Wasserstandsfeldes flacher Gewässer wird eine auf der Turbulenztheorie basierende Tiefenkorrektur für den Bodenreibungsbeiwertwert eingeführt und auf der Basis von Berechnungen für die DarßZingster Boddenkette überprüft. Für einen ausgewählten Meßpunkt der Darß-Zingster Boddenkette wurde der Reibungsbeiwert sowohl am Boden als auch unter einer Eisschicht experimentell bestimmt. Die Auswirkungen einer Tiefenkorrektur des Reibungsbeiwertes wurden in einem vertikal integrierten hydronumerischen Modell untersucht. Dabei wurden die experimentell bestimmten Reibungsbeiwerte, sowohl für die Reibung am Boden, als auch für die Reibung unter einer Eisschicht im Modell benutzt. Das verwendete Modell zeigt mit den gemessenen Reibungsbeiwerten nach Einführung der Tiefenkorrektur eine bessere Übereinstimmung zwischen Modelldaten und amtlichen Pegelregistrierungen. / For simulation of the flow and water level field in shallow water is introduced a depth correction of the bottom drag coefficient based on the theory of turbulence in a hydronumerical model and tested on calculations for the 'Darß-Zingster Boddenkette'. The drag coefficient was determined experimentally on the bottom and under ice for a selected measurement point in the 'Darß-Zingster Boddenkette'. The result of the depth correction was tested with a depth integrated hydronumerical model. The experimentally deterrnined drag coefficient on the bottom and under ice was introduced in the model. The used model shows with the measured drag coefficient after using the depth correction better agreement between the numerically simulated and measured water level.