Kandidatuppsatser, Miljövetenskap / Institutionen för biologi och miljövetenskap

Permanent URI for this collectionhttps://gupea-staging.ub.gu.se/handle/2077/69816

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Determining how levoglucosan partitions between gas and particle phases Investigating temperature effects in the presence of ammonium sulphate aerosols
(2025-06-26) Abrahamsson, Rhianne; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap
Air pollution is a major environmental concern and affects millions of people worldwide. Biomass burning is a common practice which contributes emissions to the atmosphere, which reduce air quality. Levoglucosan is created from cellulose at high temperatures and is the most abundant pollutant from biomass burning. It contributes to the formation of primary organic aerosols and secondary aerosols since it is a semi-volatile organic compound subject to gas-to-particle partitioning. This study investigated levoglucosan's partitioning behaviour at four different temperatures (0, 10, 20, and 40 °C) in the presence of ammonium sulphate. A filter inlet for gases and aerosols, combined with a time-of-flight chemical mass spectrometer was used alongside a scanning mobility particle sizer. The results demonstrated a clear temperature dependence, with a decreasing gas-to-particle ratio observed as temperature increased. However, the enthalpy of vaporisation of 31 kJ mol-1 was lower than literature values. This was likely caused by vapour wall losses. Despite this uncertainty, the method is advantageous as it can be used to study aerosol mixtures rather than focusing on a singular compound.
Source apportionment of PM2.5 pollution in Lagos, Nigeria
(2025-06-26) Olsson, Johanna; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap
This study presents a source apportionment of fine particulate matter (PM2.5) in the megacity of Lagos, Nigeria. The study took place from the beginning of January to the middle of March 2025, encompassing air pollution during the months of the dry season, characterised by Harmattan winds. The aim was to explore the level of PM2.5 and to better understand the air pollution in Lagos by doing source apportionment. A total of sixty 24-hour filters were collected by people at the University of Lagos and sent to Gothenburg. The PM2.5 was determined gravimetrically, and the elemental composition was analysed using an optical transmissometer and an Energy Dispersive X-Ray Fluorescence (EDXRF) instrument. The resulting data were then analysed through correlation analysis and by performing Positive Matrix Factorisation on the data for the source apportionment. Twenty-two elements were detected and quantified: Al, P, S, Cl, K Ca, Ti, V, Mn, Fe, Cu, Zn, Ga, As, Se, Br, Sr, Y, Ba, Hg, Pb, and Si, along with black carbon (BC) and ultraviolet absorbing particulate matter (UVPM). The average PM2.5 level was found to be 37 ± 24 µg/m³, exceeding the WHO 24-hour guideline of 15 µg/m³. Identified sources included mineral dust, combustion of petroleum products and vehicular emissions, biomass burning, sea salt, steel industry, and a V-rich source. Among these, mineral dust and the factor for combustion of petroleum products + vehicular emissions were the dominant contributors to PM2.5 mass. There was a discrepancy between the reconstructed mass and the total mass of PM2.5, suggesting that additional PM2.5 components not detectable by the instruments used may also be present. Improvements for further studies would be to have a larger data set, include meteorological data, and a broader range of chemical species to improve source identification and mass reconstruction.
PATTERNS OF RIVER VISITATION BY LARGE HERBIVORES IN RELATION TO RAINFALL AND SEASON: Makgadikgadi Pans National Park
(2025-06-25) Fjällborg, Willy; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap
Climate change poses a major threat to African ecosystems. Climate change will affect southern Africa by changing rainfall patterns, reducing the amount of annual rainfall, and making droughts more frequent and intense. Therefore, knowledge about how the behaviour of different species is linked to rainfall and season is important for conservation. This study investigates patterns of river visitations by large herbivores in relation to rainfall and season. This was done using approximately three years of data from camera traps that were set up along eight different elephant highways near the Boteti River in Makgadikgadi Pans National Park in Botswana. The herbivores included in the study were african savannah elephant (Loxodonta africana), south african giraffe (Giraffa camelopardalis giraffa), greater kudu (Tragelaphus strepsiceros), and impala (Aepyceros melampus). Data was analysed using generalized additive models (GAMs), controlling for day of year and moving average of rain. Two moving averages of rain were used, one 2-day moving average to investigate the effect of the rain itself on river visitations and one 30-day moving average to investigate the effect of more long-term rainfall. Results showed that river visitations by the herbivores were associated with day of year. Giraffe and kudu had quite clear seasonal patterns with more visits during the dry season and fewer visits during the wet season. Results also showed that river visitations by the herbivores were associated with rainfall. River visits from elephants and giraffes had a negative association with rainfall and decreased with increased rainfall. River visits by greater kudu showed no association with 2-day moving average of rain, but a strong positive association with 30-day moving average. Impala showed a positive association with rainfall, and visits increased with increased rainfall. However, further studies need to be done to investigate exactly how and why patterns of river visitations by large herbivores shows association with both day of year and rainfall.
PROBABILISTIC MAPPING OF RHODOLITH BEDS USING ENSEMBLE MACHINE LEARNING: A Case Study on Rhodolith Distribution in Scandinavia
(2025-06-25) Lingnau Amossen, Rasmus; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap
Rhodolith beds are ecologically important benthic habitat that help support marine biodiversity and local pH buffering and long-term carbon storage, yet in Scandinavian water their distribution remains poorly mapped. This study applies a species distribution modelling (SDM) and machine learning to predict current and future habitat Rhodolith habitat sustainability across Norway, Sweden and Denmark; using presence and pseudo absence data from the Global Biodiversity Information Facility (GBIF), three models; Random Forest, XGBoost and Logistic Regression were trained and combined into a soft voting ensemble. Environmental variables were sourced from Bio oracle v3. Including present and SSP2- 4.5 future climate projection (2020-2100). Model performance was assessed using accuracy, ROC AUC, precision, recall, and F1-score. The ensemble model showed high overall performance, though Random Forest performed slightly better. Spatial predictions revealed high suitability in Skagerrak and upper Kattegat with some moderately suitable areas in the Baltic and North Sea. Future projections indicated a substantial decline in suitable habitat between 2020 and 2100. The results showcase both known Rhodolith location, but also potentially overlooked areas, offering support to further studies in Rhodolith in the Scandinavia.
VILKEN STRANDVEGETATION BIDRAR TILL DET ORGANISKA MATERIALET I KUSTNÄRA SEDIMENT? Kolsänkor/källor, nedbrytbarhet och eDNA spårning
(2025-06-25) Lydahl, Moa; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap
Coastal sediments are important carbon sinks, storing organic matter and thereby helping to reduce the amount of greenhouse gases in the atmosphere. However, they can also act as carbon sources if the deposited organic matter decomposes rapidly, contributing to increased greenhouse gas emissions and global warming. Rapid decomposition partly depends on the degradability of the material itself. In this literature review, I examine which coastal plant species dominate different locations along the Swedish coast, based on coverage data from the ClimScape project (www.climscape.se). For the most dominant species, I investigated the type of organic matter they may contribute to the sediments and based on those results I qualitatively assessed which sites that may function as carbon sinks or sources. The only two sites that showed a certain tendency to act as carbon sources were the forested wetlands in Råneå, Luleå and Björköfjärden, Sundsvall. The most dominant plant species here were composed of more labile organic matter. If this material contributes to the organic stocks in the sediments, it could increase sediment degradability and potentially shift these areas from carbon sinks to carbon sources. No clear evidence was found for potential carbon sinks. Finally, I identified primer pairs from the database The Barcode of Life Data Systems (BOLD; https://boldsystems.org) that have previously been used to amplify genes from the species found at the studied locations. These primers can be used in future studies to track vegetation taxa in sediments, and thus better determine which species contribute organic matter and how this affects the role of sediments as a carbon sink or source.
SAMMANSÄTTNING AV MAKROALGER I SVENSKA ÅLGRÄSÄNGAR eDNA spårning och klimatförändringar
(2025-06-25) Ohldin, Amanda; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap
The aim of my bachelor’s thesis is to investigate, through a literature review, changes in the distribution of filamentous algae as well as the general species composition of macroalgae and diatoms in Swedish eelgrass meadows. I have also studied the possibility of tracking these algae and diatoms in eelgrass meadows using eDNA methodology. The focus has been on linking these changes to climate change factors such as eutrophication, temperature increase, and anthropogenic emissions, and how these affect the health of eelgrass meadows and their ecosystem services, such as a carbon sink and biodiversity support. The results show that filamentous algae have increased markedly in coverage in Swedish coastal areas between 1980 and 2021, especially in sheltered bays, indicating that altered environmental conditions favor these fast-growing species. Genetic tracking using eDNA demonstrated that there are functional primers for many species, particularly among brown algae and red algae, whereas green algae require more specific primers due to greater genetic variation. Diatoms showed good coverage with several primers, but there are still knowledge gaps regarding genetic resolution for this group, while brown and red algae have broader species coverage with fewer primers. Overall, the work shows that the increase in filamentous algae is clearly linked to climate and environmental changes, which may affect the function and biodiversity of eelgrass meadows. eDNA technology appears to be a promising tool for future monitoring of algal communities in coastal environments, but further development of primers and databases is needed to cover more species and taxonomic groups.
VÄSTERHAVETS VÅRBLOMNING AV FYTOPLANKTON En analys av potentiella förändringar över tid
(2025-06-25) Nyqvist, Elin; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap
De säsongsbundna blomningarna av fytoplankton utgör en livsnödvändig födobas i marina ekosystem samtidigt som de har en mycket viktig roll i den globala kolcykeln och därmed påverkar klimatet i stort. I Västerhavet domineras vårblomningen till en början av kiselalger följt att dinoflagellater. Då fytoplankton påverkas av en rad olika biotiska och abiotiska faktorer har flera betydande skiften i vårblomningens struktur observerats till följd av klimatförändringar. Detta riskerar att få betydande konsekvenser för livet i havet men också på land. Syftet med studien är därför att undersöka potentiella förändringar i Västerhavets vårblomningen sett till dess styrka, tidpunkt och gruppsammansättning samt korrelera detta med ytvattentemperatur. Nationella miljöövervakningsdata från Skagerraks utsjö för åren 2001–2024 analyserades huvudsakligen genom tillämpade ”Generalized Additive Models” (GAM). Resultaten visar att det har skett signifikanta minskningar i den totala abundansen av fytoplankton över tid i mars vilket kan tyda på en svagare vårblomning. I början av året antas högre ytvattentemperaturer korrelera med en minskad mängd samt andel kiselalger. Dessutom finns ett signifikant samband mellan högre ytvattentemperaturer i februari och en senare vårblomning i mars. Trots att inga större temperaturförändringar har obesvarats under den studerade tidperioden finns ändå anledning att tro att framtidens vårblomning av fytoplankton i Västerhavet förmodligen kommer vara svagare, inträffa senare och vara mindre dominerad av kiselalger till följd av den globala uppvärmningen.
VEGETATIONENS INVERKAN PÅ CH4 OCH CO2 FLÖDEN I ARKTIS VID ÖKAD TEMPERATUR OCH NEDERBÖRD
(2025-06-25) Wagersten, Beate; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap
Till följd av klimatförändringarna ökar både temperaturen och nederbörden i Arktis, vilket förväntas få stora konsekvenser för vegetationen som finns där. Förändringar i sammansättningen av funktionella växttyper kan vara en viktig faktor till förändringar i kolbalansen och bidra till att avgöra om Arktis förblir en kolsänka snarare än en kolkälla. Detta är av stor global betydelse då tundraekosystemen lagrar ungefär hälften av jordens marklagrade kol. I den här studien analyserades vegetationsdata som kopplades till flöden av metan (CH4) och koldioxid (CO2) från två växtsamhällen med olika markfuktighet vid Latnjajaure fältstation. Vegetationen hade utsatts för experimentell uppvärmning och manuell bevattning. Resultaten visade att de funktionella växttyperna inte hade någon tydlig påverkan på flödena av CH4 och CO2 vid ökad uppvärmning, ökad nederbörd eller kombinationen av ökad uppvärmning och ökad nederbörd. Markfuktigheten hade stor betydelse för sammansättningen av funktionella växttyper då det torrare växtsamhället skiljde sig signifikant från det våtare. Trots detta var det inte tydligt vilken betydelse skillnaderna i växtlighet till följd av ett torrare eller våtare växtsamhälle hade på flödena av CH4 och CO2 vid ökad uppvärmning och nederbörd. Generellt sett pekade resultaten på att specifika arter kan ha en något större betydelse för flödena av CH4 och CO2 än de funktionella växttyperna. Fler långtidsstudier samt studier utanför växtsäsongen skulle i framtiden kunna bidra till en bättre förståelse av hur funktionella växttyper och specifika arter påverkar flödena av CH4 och CO2 vid ökad uppvärmning och ökad nederbörd.
THE IMPACT OF POLLUTION ON SEDIMENT MEIOFAUNA
(2025-02-06) Christoffersson, Gabriella; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap
The decline of biodiversity due to anthropogenic pressures poses a significant threat to ecosystem stability and functionality. Pollution, such as eutrophication and contaminants, emerges as a critical factor disrupting the balance of particularly aquatic sediment habitats. Meiofauna, microscopic organisms inhabiting sediment, serve as valuable bioindicators due to their sensitivity to environmental changes. This study investigates the impact of sediment pollution on meiofaunal diversity and abundance in the Espírito Santo estuary, Maputo, Mozambique. By analyzing sediment samples from locations with varying levels of anthropogenic and natural contamination, the findings reveal that highly polluted areas exhibit reduced meiofaunal diversity and abundance. Dominance by opportunistic taxa, such as Nematoda, in polluted sites contrasts with the balanced communities observed in less impacted areas. These results underscore the potential of meiofaunal analysis as an effective tool for assessing ecosystem health and highlight the need for integrated strategies to mitigate contamination and preserve biodiversity in estuarine environments.
Biologisk mångfald i teori och praktik. En studie av effektiviteten hos metoder för att främja biologisk mångfald i NCC:s AB berg- och grustäkter.
(2024-11-18) van Berlekom, Camilla; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap
Arbetet för biologisk mångfald är viktigt inte minst för människans överlevnad men även för näringslivet. Att bevara den biologiska mångfalden är en kritisk del i att skapa en hållbar ekonomi. Företag har en avgörande roll i detta då de är beroende av och påverkar den biologiska mångfalden. Ett byggföretag i Norden som vill arbeta med biologisk mångfald är NCC. Detta arbete är utfört i samarbete med NCC och utvärderar deras metod, Kielo, som fokuserar på åtgärder för biologisk mångfald i deras berg- och grustäkter samt en jämförelse med en annan metod, CLimB utvecklad av Ecogain, som också syftar till att vidta åtgärder för att skydda och öka biologisk mångfald. Arbetets fokus är att utvärdera vilken metod som är mest effektiv för att minska negativ påverkan samt främja den biologiska mångfalden i NCC:s täktverksamheter. Genom att ha studerat material från NCC som arbetats fram inom ramen för Kielometoden, samt den tekniska beskrivningen och handboken av CLimB har metoderna utvärderats utifrån olika kriterier baserat på naturvård och NCC:s verksamhetsbehov. Resultaten tyder på att Kielo är mer gynnsam utifrån NCC:s behov som industriell verksamhet men att CLimB tillför högre värde utifrån naturvårdsperspektivet. Detta visar att metoder för biologisk mångfald är gynnsamma för ett företag vars verksamhet utgör förändring av markanvändning. NCC kan åtgärda den påverkan de har samt skapa möjligheter för att öka den biologiska mångfalden med hjälp av den information metoder tillhandahåller. Det finns utrymme att expandera Kielo-metoden för att skapa ett bredare arbete med miljöfrågor och ytterligare främja biologisk mångfald. Genom att arbeta med metoder för att åtgärda och främja biologisk mångfald kan företag som NCC bidra med mindre negativ påverkan och ta samhällsansvar för att bevara biologisk mångfald, inom ramen för sin exploateringsverksamhet. Det finns utrymme att utveckla och expandera arbetet med hur olika metoder kan användas bland företag för att arbeta med biologisk mångfald. Genom att nyttja metoder och utveckla deras räckvidd och anpassningsbarhet kan detta medföra social status, ekonomiskt incitament, öka kunskapen men mer grundläggande bevara naturen vi nyttjar.
Migration of Seatrout (Salmo trutta); effects of increasing temperatures and water flow
(2024-11-05) Arnehall, Isak; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap
This study investigates the impact of rising temperatures and water flow on the downstream migration of sea trout (Salmo trutta) smolts in Haga å, a small stream in southwestern Sweden. The research aimed to assess how environmental changes affect smolt migration patterns and smoltification status. A fish trap installed since 2022 was used to capture and monitor smolts. Data on water flow rates and temperature were collected from the Swedish Meterorological and Hydrological Institute (SMHI) and compared across three years (2022-2024). The results indicate a dramatic decline in migrating smolts, with a 96% reduction observed from the initial year to 2024. This decline was coupled with increasing water temperatures and variable water flow, which may have influenced the timing and success of smolt migration. Notably, higher water temperatures potentially caused earlier migration, affecting smolt survival in the ocean due to mismatch with optimal marine conditions. This study highlight the urgent need to monitor and adapt management strategies for small stream like Haga å to mitigate the impacts of climate change on keystone species such as the sea trout.
Uppföljning av insatser mot blomsterlupin samt utvärdering av kunskap hos personer med odlingsmöjligheter
(2024-09-03) Mattsson, Elin; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap
Invasive plants are a large and widespread problem that threatens both native flora and fauna. That people unknowingly or knowingly introduce invasive species into new environments is the cause of introduction. Flowering lupine (Lupinus polyphyllus) is a resilient plant that propagates and spreads efficiently, making it difficult to keep away once it has established itself. Länsstyrelsen i Västra Götaland is primarily responsible for control measures of invasive species in protected areas, and in non-protected areas demands are placed on private landowners. Västkuststiftelsen receives financial funds from Länsstyrelsen to carry out control measures where Länsstyreslen does not carry out these themselves. In the essay, control measures against flower lupine carried out by Västkuststiftelsen in the nature reserves Dösebacka and Risvedens vildmark are evaluated. In order to strengthen future control measures, an understanding is created of how gardeners' knowledge looks today and how they relate to stopping the introduction from private gardens and helping the authorities in the fight against invasive species. The work is based on 2 main questions which are answered with the help of a questionnaire study, document study and field visits. Dösebacka nature reserve with a species-rich sandy environment is particularly vulnerable, as it is a favorable environment for the establishment and spread of the flower lupine. Efforts have been carried out several years in a row and methods have been combined that have been both large and comprehensive. In Dösebacka, in 2021, 2022 and 2023, digging was carried out both mechanically and physically in the sand environments, and the stands were mowed twice a year before seeding. In Risveden vildmark, there was a small population of flower lupin along a road. Roadedges act as a path for spread and therefore a first control effort was planned in 2023 to reduce the risk of spread to the reserve with its unique environment. The results show that mechanical and physical digging can effectively reduce the populations of flower lupine in sandy environments, while mowing and digging in the surrounding environment have not been as successful. However, digging accounts for the biggest cost, while mowing is a cheaper option for population control attempts. The evaluation of people with an interest in gardening shows that older people within the surveyed group know more about which species are invasive. Otherwise, no statistically significant correlations are seen between different ages and levels of knowledge in relation to the willingness to help in the combat work.
INVESTIGATION OF SWEDEN’S IMPLEMENTATION OF RECOMMENDATIONS ON MARINE LITTER ADOPTED BY THE REGIONAL SEA CONVENTIONS OSPAR AND HELCOM
(2024-08-20) Hassellöv, Rani; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap
Through joint, global objectives such as the SDG’s, (in particular SDG 14 and target 14.1), the vision of a clean and healthy ocean can be achieved, alongside a sustainable use of the marine resources. The sea conventions OSPAR and HELCOM is possessing powerful roles, that through collective measures such as decisions, recommendations, policy briefs and other agreements can act towards a healthier North- East Atlantic and Baltic Sea. Both conventions have established Regional Action Plans on Marine litter, consisting of actions with the aim of reducing marine litter significantly. Some of the actions have been adopted as Recommendations that the Contracting Parties are expected to carry out and report the progress on. The Swedish Agency of Marine and Water Management (SwAM) collaborates closely with the two conventions to reach both national and regional objectives. To improve the marine and water management it is necessary to have a clear picture of what has been done in order to fil up potential gaps. This report therefore investigates Sweden’s implementation of the Recommendations on marine litter adopted by the two sea conventions. Sweden’s implementation progress was compared to the Contracting Parties (CP’s) Denmark and Germany which also are expected to pursue both convention’s Recommendations. A total of four Recommendations (two of each convention) were investigated which summed up to be the valid Recommendations on marine litter from OSPAR and HELCOM. The results showed that Sweden’s implementation was for some of the Recommendations similar to Denmark and Germany’s but for some it differed. It is difficult to attempt to answer if Sweden’s implementation of the Recommendations could be interpreted as inadequate in some ways since the implementation of actions differed from Denmark and Germany. In the end the issue of marine litter can’t be avoided and solutions such as Recommendations from OSPAR and HELCOM should be prioritised from the CP’s if we want to stand a chance that within a year reaching the SDG target 14.1.
CORRELATION BETWEEN FISH SIZE AND OTOLITH SIZE IN ATLANTIC COD (GADUS MORHUA) AND ATLANTIC HERRING (CLUPEA HARENGUS): A comparison of growth patterns over four decades - in northern Skagerrak
(2024-08-20) Larsen, Moa; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap
Atlantic cod and Atlantic herring are important commercial species and the populations in Skagerrak, Kattegatt and eastern North Sea are examined annually in environmental monitoring. Both species are overexploited by large-scale trawling and together with climate change, the populations have become stressed and have decreased in numbers. All teleost fish have otoliths (earstones) which are commonly used as a tool to determine the diet of marine mammals, birds and predatory fish. What determines the correlation between fish size and otolith size is not fully known, but it is thought to vary depending on food availability, climate and metabolism. Previous research has shown that the correlation between otolith size and fish size can vary between locations, populations and temperature. A change in temperature can affect that both otolith size and fish size grow differently. To investigate whether the correlation has changed, otoliths and fish length from published data from 1978-1979 were compared with new data from 2021-2022. The otoliths from 2021-2022 were photographed and measured through the RStudio software package ShapeR. The correlation between fish size and otolith size was analyzed by an ANCOVA test in RStudio to find out if there was any significant difference between the past and more recent data. The analysis showed that there was no significant difference between fish size and otolith size in cod. This result shows that cod's growth pattern has not changed in this respect, and the correlation can continue to be used in today's diet studies.This also indicates that the new method to estimate otolith length by image analysis is equivalent to manual measurement. For herring, on the other hand, there was a significant difference between fish size and otolith size in the latest data compared to the historical data. Several hypotheses for this difference are discussed, it may reflect altered growth in herring or be linked with different sampling seasons, but it may also be due to different measurement methodology. Therefore, additional studies are needed to assess if there is a true significant difference in relative growth of herring body length and otolith size.
EN MILJÖSTUDIE OM DE GEOKEMISKA FÖRHÅLLANDENA I SKÄRHAMN, SVENSKA VÄSTKUSTEN
(2024-08-19) Davidsson, Moa; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap
The following study aims to investigate the environmental conditions of the harbor of Skärhamn, a small fishing community on the west coast of Sweden. The interest to do so rose as a newly built apartment residence failed to connect the sewage pipes of 18 apartments, causing the untreated sewage running into the sea. The parameters accounted for are the C/N ratio, total organic carbon (TOC) as well as total nitrogen present (TN) and δ13C in the top ten centimeters of a sediment core retrieved in the Skärhamn harbour. All of which gives information of what input is taking place regarding the source of organic material. Additionally, selected heavy metals have been analyzed down the entire core and are presented along with the Norwegian classification system of ecotoxoicological limit values. The results are compared with a reference station located in the nearby Hakefjorden. To estimate a time scale representing a sediment record of Skärhamn, the ratio of 206Pb/207Pb isotopes combined with the metal records was used.
BIODIVERSITETS PÅVERKAN PÅ MÄNGDEN ORGANISKT MATERIAL I ALSUMPSKOG: En fallstudie i fyra alsumpskogar på svenska västkusten
(2024-08-19) Tupala, Maija; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap
Globally, coastal ecosystems like mangrove forests, sea grass meadows and salt marshes are well known for their ability to capture and store atmospheric carbon effectively. In Sweden, there is still limited knowledge about local coastal ecosystems with similar functions, with alder swamp forests being an interesting example. Therefore, this study aimed to increase knowledge of the factors that can contribute to the potential carbon sequestering ability of alder swamps. Vegetation data and sediment samples were collected from a total of 37 sampling plots across four alder swamps in Bohuslän on the Swedish west coast. The goal was to determine how plant diversity and the composition of microorganisms influence the amount of organic matter in the sediment. Plant cover and sediment samples were used to calculate diversity indices and the percentage of organic matter, and the relationship between them was analysed using correlation tests. Plant diversity and the amount of organic matter varied greatly both within and between the forests. A negative correlation between these two variables was found, but it was only statistically significant in one of the forests (Havstensfjord). A stronger positive correlation could instead be found between the water ratio and the amount of organic matter in sediment. EcoPlates™ were used to assess how different carbon sources were utilised by microorganism communities in the sediment samples. Multivariate tests revealed that the microbial communities in the different forests were relatively similar in their use of the different carbon sources. The relationship between the composition of microorganisms and the amount of organic matter was mostly positive, although one swamp forest (Finnsbo) showed a negative correlation. Based on this study, it can be concluded that plants, microorganisms and organic matter in alder swamp forests are interconnected, but these relationships are complex and influenced by several factors beyond the scope of this study. Therefore, further research in this area is greatly needed.
DYNAMIKEN OCH EFFEKTEN AV MARINA VÄRMEBÖLJOR PÅ TROPISKA KORALLER (SCLERACTINIA)
(2024-08-16) Larsson, Linnea; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap
Marine heatwaves (MHW) have become increasingly common in recent decades due to greenhouse gas emissions that have caused climate change. A marine heatwave is when the sea surface temperature rises, which damage many different ecosystems in the sea. One ecosystem that is sensitive to temperature changes is tropical coral reefs, which are at risk of bleaching during marine heatwaves. Coral bleaching is when its symbionts leave the coral and they lose their color, while also starving to death as they lose their food source. The purpose of this report was therefore to investigate what the connection between marine heatwaves and coral bleaching looks like, and to see if there are any geographical differences. The aim of the study was also to investigate if the corals were able to adapt to the fluctuating temperatures and if they were even able to adapt to tolerate or benefit from it. The study was done through a systematic literature search in which 35 articles were finally selected. The results showed that there is a connection between the marine heatwaves and coral bleaching, where increased temperature in heatwaves caused heat stress in the corals. Several studies done on coral bleaching have been able to see positively correlated episodes of marine heatwaves during the same time. The extent differs among locations as the duration differs and different species are affected differentially. Furthermore, the results show that some corals seem to be able to adapt by increasing their thermal tolerance. The question is, however, whether this can happen at the same rate as the rapid development of climate change. The capacity for such adaptation also differs among species, where some species may have a greater chance of keeping the same pace than others. In summary, there is a connection between marine heatwaves and coral bleaching, and this relationship differs among geographic locations. Corals can adapt to the temperature changes, but more studies need to be done to determine if they can benefit from it.
FLYTBLADSVÄXTER & METANUTSLÄPP - En litteraturstudie
(2024-08-15) Blom, Kajsa; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap
Sedan industrialiseringen har koncentrationen metan i atmosfären ökat. Metan (CH4) är en effektiv växthusgas, producerad av metanogena organismer i syrefria miljöer. Källorna till CH4 varierar brett och är både antropogena och naturliga. Det är sen tidigare känt att växter genom sina luftutrymmen kan transportera gaser, inklusive CH4, från rötterna till atmosfären. Flytbladsväxter som är akvatiska växter med blad flytande på vattenytan och rötter eller jordstammar i, ofta syrefria, sediment utgör en transportväg för olika gaser. I denna strukturerade litteraturstudie undersöks det nuvarande kunskapsläget kring flytbladsväxternas bidrag till metanbudgeten. I resultatet presenteras fynd från 18 olika artiklar, där omfattningen av utsläppen samt flytbladsvegetationens betydelse lyfts fram. Totalt undersökte studierna 12 arter i sju olika länder. Förutom att bidra med växtförmedlade utsläpp visar fynd att de även påverkar dynamiken mellan de olika emissionsvägarna. Ytterligare redovisas faktorer vilka kan ha en effekt på utsläppen, så som variation mellan arter och miljöförhållanden. De högsta emissionerna uppmättes under sommarmånader men inga slutgiltiga slutsatser kring omfattningen kunde dras. Studien indikerar att flytbladsväxter har en betydelse för ett systems metanbudget men att omfattningen varierar mellan tid och art. Den observerade variationen mellan arter och de få antal flytbladsväxter och platser som representerats i studierna motiverar till ytterligare forskning kring området.
The effect of inbreeding in small populations of Harbour seals (Phoca vitulina)
(2024-08-15) Bjurenheim Sandelius, Jennie; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap
The Harbour seal (Phoca vitulina) is a common pinniped species on the west coast of Sweden. However, only one population exists in the Baltic proper. The Baltic population in Kalmarsund has been isolated for several thousand years and a recent study shows that they have lower levels of heterozygosity and genetic diversity compared to any other European population. Historically the population has undergone severe population bottlenecks which in turn have led to higher degrees of inbreeding. Inbreeding is known to influence fitness negatively however, it has been ignored in current ecological risk assessments for harbour seals. In order to fill this knowledge gap, the current study present a literature overview and maps different fitness traits reported to be affected by inbreeding depression in pinnipeds. We run multiple population viability analyses (PVAs) to estimate the effects from inbreeding depression on small, isolated harbour seal populations. The inbreeding depression was applied in the units of lethal equivalents commonly found in mammal populations and the amount of inbreeding (F) was based on recently available values from the Kalmarsund population. Several scenarios were investigated by simulations of an age structured, stochastic population model including the combined effects from epizootic events and reduced fecundity due to endocrine-disrupting pollutants. The simulations also elaborated effects from various initial population sizes and carrying capacities to gain better understanding of how population sizes as such mitigate the effect of inbreeding. The results showed that inbreeding depression at the currently detected level can be expected to have an overall negative effect on the population viability of the Kalmarsund harbour seal population and other isolated seal populations. High levels of inbreeding depression also increased the probability of extinction (34% risk of extinction in 300 years) compared to low levels (5% risk of extinction in 300 years). Populations were severely affected by inbreeding depression in scenarios which simultaneously accounted for reduced fecundity and epizootics, highlighting the need for animal conservation to account for multiple stressors. Understanding how inbreeding affects isolated marine mammal populations can be important for the design of effective conservation programs and to ensure stable and healthy populations.
INVERKAN AV HAVSFÖRSURNING PÅ PROTONERBARA ORGANISKA FÖRORENINGARAS EKOTOXICITET
(2024-08-14) Eriksson, Camilla; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap; University of Gothenburg / Department of Biological and Environmental Sciences; Göteborgs universitet / Institutionen för biologi och miljövetenskap
Resulting from anthropogenic carbon dioxide emissions, average surface seawater pH is estimated to decline from today's approximately 8.05 to between 7.78 and 8.03 towards 2100. For ionisable organic pollutants, changes in pH can lead to a change in the degree of ionisation, which could influence the ecotoxicity of a compound by altering its bioavailability. In this study, potential changes in ecotoxicity of ionisable organic compounds resulting from ocean acidification are examined. This is achieved partly by conducting a literature review, analysing existing literature that investigates this relationship. Potential changes are also evaluated by examining marine ecotoxicity data for ionisable organic compounds on the watch list pursuant to Directive 2008/105/EC of the European Parliament and of the Council, as well as on the list of priority substances according to the 2022 proposal for amending the Water Framework Directive (2000/60/EC). These data are related to the ionisation-degree for different pH when possible. Results from the literature review indicate that ocean acidification can modulate the marine ecotoxicity of ionisable organic compounds. This modulation is seemingly dependent on the acidic or basic properties of a substance. In some cases there were uncertainties as to whether an increased toxicity was a result of an increased sensitivity of the test organism due to an acidic environment. The substances investigated in relation to ocean acidification so far are few and often had a pKa indicating only small changes in ionisation-degree would occur. This lack of data was also reflected in the results from examining EU-relevant ionisable organic compounds, where existing data on marine ecotoxicity linked to pH was very limited. Ionisation-degree seemed to correspond with toxicity for an acid on the priority list. Combined results indicate a need for more marine data on ecotoxicity and bioaccumulation under future ocean acidification scenarios, specifically for ionisable organic comounds with pKa close to 8, in order to estimate risks these polluntants pose under ocean acidification.

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