Apis mellifera, otherwise known as the common honey bee, is an incredibly important social animal. Their important role in the world makes studying them of great importance. Their stomachs can be divided into three parts, the foregut, the midgut and the hindgut. The mouth and crop are located in the foregut, the midgut encompasses the ventriculus and the hindgut is made up of the ileum and rectum. Each part of a honey bee intestine hosts a different community of bacteria that vary in proportion with age, caste and season. These microbiota are essential for a honey bees mood, development and overall health. No two authors agree completely as to what the a honey bee’s gut microbiota is. In this thesis study the intestinal tract microbiome of four bee colonies, two of which belonging to the Apis mellifera carnica subspecies and two to the Apis mellifera buckfast subspecies, were sequenced. All four are from the same region in Sweden, Uddevalla. Many issues were found during this project, including one sick colony, but through them a more thorough and guaranteed method to sequence these honey bee intestinal bacteria was developed. The results of the sequencing showed that there is indeed a major difference in these intestinal communities even in bees from the same region or from the same subspecies. A possible culprit for the diseased colony was found.

Lakes are a significant source of the powerful greenhouse gas methane (CH4) globally. Methaneis produced through microbial processes in anoxic sediments. Methane emission from lakes ishighly variable in space and time. Consequently, is it difficult to predict the methane production rate and at present time it cannot be predicted from sediment characteristics. Therefore, methane production in the sediment of contrasting Swedish lakes was investigated, in order to find out if methane production rate can be related to sediment characteristics, and if a predictive model that recently was developed for Brazilian reservoirs is applicable to Swedish lakes. For this, sediment cores were collected from six lakes, differing in their sediment characteristics and geographical position as well as one river. The sediment cores were sliced into one centimetre thick layers. The different layers were incubated and methane production rate was measured. The sediment layers were also analysed for water content, median grain size, total nitrogen and carbon content as well as age. The influence of sediment age and C:N ratio as predictors for methane production were tested with a mixed linear model and a non-linear model. Both models showed that age had a significant effect on methane production rate (p < 0.001). The C:N ratio also had a statistically significant effect on methane production rate only shown with the non-linear model, however this effect was weak. Applying the recently published predictive model for methane production rate in Brazilian reservoir sediments to this data from the Swedish lakes, provided a good prediction of methane production rate in the nutrient-rich Swedish lakes, however it overestimated the methane production rate of the humic-rich boreal lakes and sediment older than 50 years. In summary, a model using age as predicting factor was developed fitting all the studied Swedish lakes. In addition, the predictive model developed in Brazilian reservoirs for the methane production rate was valid only for the studied nutrient-rich Swedish lakes and the studied oligotrophic Swedish lakes.

This project examined the role of functional diversity of bacterial prey organisms on a mixotrophic flagellate’s function. The concept of functional diversity and its role for ecosystem functioning is a subject of ongoing research and controversially discussed. Mixotrophy is the combination of different modes of nutrition in one organism. In the case of this project’s organism, Ochromonas tuberculata, the combination of phototrophy and heterotrophy or phagotrophy. Mixotrophs can have a severe impact on nutrient cycling or carbon fixation in aquatic ecosystems, therefore it is important to investigate what drives their ecological functioning. For this project, two sets of bacterial prey traits were investigated and their effect on the flagellate’s growth rate. The first experiments involved the addition of heat-killed bacterial prey with heterotrophic mode of nutrition (Escherichia coli) and phototrophic mode of nutrition (Synechocystis sp.) on their own and in conjunction to generate a functional diversity. The last experiment investigated heat-killed Gram-negative (Escherichia coli) and Gram-positive bacterial prey (Staphylococcus aureus and Bacillus subtilis) each on their own and in conjunction. The acclimated O. tuberculata cultures in this project were non-axenic and flagellate cell densities were recorded daily over five days after the addition of the prey in each experiment. The results showed that prey with a phototrophic mode of nutrition resulted in a significantly higher growth rate over the course of the experiments than heterotrophic prey or a mix of both under the experimental conditions. For the second set of bacterial functions tested, the results showed no clear effect of the different bacterial functions on the flagellate’s growth rate. This was attributed to the heat-killing method used. The heat-killing method is assumed to have harmed the bacteria structurally and therefore negate the effect of the differences in cell wall properties. Therefore, this question could not be fully investigated. Overall, the experimental setup was not ideal to tackle the research question, nevertheless the results can provide ideas for possible improvements of the experimental setup.

Rivers are among the most anthropogenically affected ecosystems in the world by irrigation, transportation, channelizing, and hydropower. Habitat restorations have become a popular method to restore the heterogeneity and complexity of rivers aiming for improvement of biodiversity. In this master thesis, I studied the effects of restoration in a regulated and channelized river in the middle of Sweden. Differences in fish abundance and diversity together with hatching success and survival rate from egg to smolt of Seatrout (Salmo trutta) and Atlantic salmon (Salmo salar) were tested between restored and unrestored reaches. In addition, differences in abundance, biomass, diversity, and composition of benthic species between restored and unrestored areas were studied.  The study design consisted of three restored and three unrestored locations where artificial spawning grounds (redds) were placed, electrofishing was conducted, and an inventory of abundance, biomass and diversity metrics of benthic fauna was performed. Whitlock-Vibert boxes were used in the artificial redds and were used to calculate hatching success. The inventory of benthic fauna consisted of kick-sampling and sampling of stones followed by identification and measuring of length in the lab.  The findings in this study suggest that the survival of salmonids is not limited by the hatching success but that the lack of migration possibilities and the low survival rate from egg to smolt makes it unlikely with a successful reintroduction of Atlantic salmon and seatrout in Dalälven. Furthermore, one could argue that the habitat restorations have not increased the diversity of benthic fauna. However, it is possible that there is an ongoing shift in the benthic fauna towards a more diverse community in the restored areas and it is possible it will be more visible in a few years which supports maintaining long-term monitoring. Lastly, this study enlightens consequences with anthropogenically affected rivers and leaves opportunities for further studies.

The purpose of the paper was to evaluate the effects of the restoration efforts in Juktån on the plant species richness and composition, vegetation zonation and soil composition. The restoration involved implementation of a dynamic flow, in addition to hydro-geomorphological alterations. Three sites were inventoried in the bypass reach, representing one reach affected only by flow restoration and two reaches affected both by flow and morphological restoration, along with an upstream reference reach unaffected by regulation. Inventories were conducted along an elevational gradient perpendicular to the water and involved occurring species, plant cover, bare ground and soil composition. The results showed a change in species composition after restoration. Riparian associated species were more common after restoration and the proportions of herbs and graminoids increased. Higher flooding caused a change in zonation, increasing the graminoid, riparian forest and amphibious zones along the riparian habitat. Species richness, as well as soil composition remained largely the same. The effects of the hydro-geomorphological alterations were hard to interpret due to lack of data. The results indicate a positive effect of the new flow on the plant species community in the bypass reach, whilst also highlighting the hydro-geomorphologically altered locations as biodiversity hotspots. Time-delay in ecological response is acknowledged as driving factor for the indifference in species richness and soil composition. The hydrological restoration is concluded to be an effective way of simulating natural flow regimes, improving ecological integrity of riparian communities and structural vegetational patterns in the riparian zone of bypass reaches.

Extensive use of antibiotics both from human-medicine and veterinary sources are believed to provide selective pressure on bacteria that leads to an increase in antibiotic resistance in environmental waters. Contamination of antibiotic resistant microbes will raise human health risks. Escherichia coli are Gram negative bacilli that belong to the coliform group. E. coli are used as fecal indicators organism (FIO) to determine microbial contamination and water quality. We aimed to investigate the prevalence of antibiotic resistant bacteria in Swedish inland waters and determine the response of uropathogenic E. coli to the environmental waters. Samples were collected in different locations near Örebro Sweden at 4 different time points during 2010-2011. Waters were filtered and FIO were isolated using selective medium. The highest numbers of FIO were detected for both E. coli and enterococci in the river Svartån near the effluent from the wastewater treatment plant (WWTP). Over the two years, 42% and 24% of the antibiotic resistant strains were multi-drug resistant (MDR) E. coli and enterococci, respectively. In addition, 15% of MDR E. coli were extended spectrum beta-lactamase producing and AmpC overproducing strains. A vancomycin resistant E. faecium was also identified. Tetracycline resistance was the most common in FIO isolates. Our study suggests that WWTP distributed FIO and antibiotic resistant bacteria. In a second study we analyzed for the presence of various pharmaceutical residues from lake Mälaren in Västerås Sweden. Some pharmaceutical compounds were present at detectable levels but were removed by the drinking water treatment plant. Quantitative PCR was performed to investigate the effects on genes focused on antibiotic resistance, virulence factors and stress response. Forty one-gene array was developed and tested using tetracycline treatment or environmental water. No significant difference was found when compared to controls in the gene expression profile of bacteria grown in medium prepared with sub-MIC of tetracycline or environmental waters. We concluded that the pharmaceutical levels detected did not exert any significant effects on the E. coli strain tested. From this study, we conclude that MDR bacteria may actually persist in environmental waters in what is considered as a clean urban region. Pharmaceutical pollutants in the inland water did not exert a significant effect on the E. coli, suggesting that MDR strains are released in the effluent of the WWTP rather than induced through selective pressure by the pharmaceuticals contamination.

Periphyton are an important group of primary producers in stream ecosystems and are commonly used as indicators of water quality and ecosystem status. Periphyton biomass accumulation in streams is influenced by a number of factors, including nutrient supply, shading by riparian vegetation, substrate properties, and hydrological conditions. Urban land use potentially influences all of these factors in ways that may promote or constrain periphyton growth. Such influences may be further altered by efforts to restore urban streams within parks and residential settings. To test this, I compared patterns of stream periphyton biomass among rural (forested), urban, and restored urban streams within and around Umeå. I found that periphyton biomass varied up to 50-fold among sites but did not differ significantly among stream classes (i.e., rural vs. urban vs. urban restored). Periphyton biomass did tend to increase among sites with greater nutrient concentrations and warmer temperature. Yet, these patterns were influenced by substrate conditions within and among streams, with significantly greater biomass observed on larger cobbles when compared to sand. Results indicate that sedimentation in the studied urban streams (and likely in streams in general) may restrict algal growth, even if other conditions are otherwise favourable. Conversely, urban restoration involving the placement of course substrate on the stream bottom may enhance algal growth locally, particularly where light and nutrients are both elevated. My findings illustrate that periphyton biomass depends on a multi-scale framework of factors that should be considered when managing streams, especially in urban areas where streams are often influenced by both local and catchment-scale stressors.

Our Swedish forests have always been under the exposure of fire, more or less. The historical influence of fires, have made some species bound to these habitats or temporarily using them. Among these species, beetles (Coleoptera) are numerous. One of the tree species with the most historic influence of fire as well as inhabiting a great beetle-fauna is the oak (Quercus sp.). An area with an especially rich beetle-fauna tied to the oak and a extensive history of fire is the Hornsö-area in Smaland.  The purpose of this study is to investigate how the beetle-fauna and number of individuals differs between newly dead oaks in burnt areas and outside them, in the Hornsö area. The two studied families was long-horn beetles (Cerambycidae) and bark beetles (Scolytinae). The beetles were reared from hatching boxes. The study aims to fil in knowledge gaps about which species that are pyrophilous respectively fire-favoured. In the future this could contribute to a better knowledge about how to manage the oakforests and it`s associated species. The results shows that bark beetles are more numerous on burned oaks, that have died recently where the fire have been limited to the ground. It also seems like bark beetles are more numerous on smaller diameter trees. Future studies should focus on studying wood a wider range of diameters as well as more trees and samples. A longer time for rearing the insects would also be desirable.

<p>A solid-phase extraction (SPE) method was developed for the determination of organochlorine pesticides, namely aldrin, alpha-BHC, beta-BHC, delta-BHC, dieldrin, endosulfan I, endosulfan II, endosulfan sulfate, endrin, endrin aldehyde, lindane, heptachlor, heptachlor epoxide, 4,4’-DDD, 4,4’-DDE and 4,4’- DDT in water. The effect of extraction conditions, such as the addition of sodium chloride and methanol to the sample prior to loading was studied. The sample was concentrated by a plain polystyrene-divinylbenzene resin, and the extract was eluted by ethyl acetate. Qualification and quantification of the target pesticides were performedby gas chromatography/ mass spectrometry (GC/MS) in the full-scan and selected ion-monitoring mode, respectively, and for better detection of pesticides in field samples the mass spectrometer was altered from electron ionization (EI) to chemical ionization mode (CI). The repeatability of the method for MilliQ-water fortified with pesticides at a level of 0.1 to 0.6 µg/l ranged from 8 to 18%, and the obtained recoveries ranged from 67 to 135%. </p><p>The method was evaluated for the determination of organochlorine pesticides in fourteen surface- and groundwater samples taken from locations along King Talal Dam, King Abdullah Canal and Zarqa River in the Jordan Valley. The limit of detection of the pesticides residues in 500-ml field water samples ranged from 0.0009 to 15.7 ng/l. The obtained results confirmed the presence of trace amounts of some organochlorine pesticides in the analyzed samples, i.e. lindane and endosulfan compounds.</p>

<p>Syftet med denna uppsats är att undersöka huruvida fiskvägar förbi vattenkraftverket vid Finsjö i Emån fungerar eller inte. För att finna svar på den frågan har två olika metoder använts, dels telemetrisändare för att se om fiskar hittar fram till fiskvägarna (attraktionseffektivitet) och dels PIT-tags för att mäta om fiskarna lyckas passera genom fiskvägarna (passageeffektivitet). Undersökningen fann att det var en högre passageeffektivitet, 89 % vid nedre Finsjö och 100 % vid övre Finsjö, i Emån jämfört med andra liknande studier. Attraktionseffektiviteten var 75 % vid nedre Finsjö och 59 % vid övre Finsjö, vilket tyder på att det finns något som stör fisken innan de når fram till fiskvägen, särskilt vid övre Finsjö.</p> / <p>The purpose of this paper is to determine the extent to which trout used fishways to swim past two power plants at Finsjö in River Emån. Two different methods of  collecting data were used, radiotelemetry to determine if fish find the fishways (attraction efficiency) and PIT-tags to measure the number of fish that passed through the fishways (passage efficiency). The study showed that passageefficiency, being 89 % at lower Finsjö and 100 % at upper Finsjö, was high compared to other similar studies. Attraction efficiency was 75 % at lower Finsjö and 59 % at upper Finsjö, which indicates that the fish have difficulty finding the fishway entrances, particularly at upper Finsjö.</p>