Bachelor's degree programme in Environmental Sciences, 30 pages (first and second assessor)

The natural dynamics of the island vegetation of Norderney is characterised by the interaction of wind, sea and rainwater as well as sandy soils and is in competition with anthropogenic uses. As a result, the highly specialised vegetation communities and taxa of the North Sea island are finding fewer and fewer suitable habitats, which are also smaller and often isolated.

This study investigates whether the mammals Dama dama and Oryctolagus cuniculus can be considered as endozoochorous dispersal vectors and thus have a direct influence on the probability of habitat colonisation. To this end, a total of 36 fresh faecal samples from the local wild populations were collected on Norderney in autumn 2024 and then subjected to a growth experiment under controlled conditions. Despite the lack of adaptation of the flora to mammaliochory, vital diaspores were detected in the samples of both species:
Among 347 plants successfully brought to germination, 16 species were identified. These included both endangered plants and neophytes. Significantly more plant species and numbers of individuals were detected in the samples of D. dama than in the samples of O. cuniculus. In view of the large radius of movement, the high population density and the considerable food requirements, D. dama in particular is a relevant dispersal vector in terms of the biotope network. The results suggest that wetlands in particular are influenced by endozoochory.

Bachelor's degree programme in Environmental Sciences, 36 pages (first and second reviewer)

The influences of site-specific information posters and comparative feedback on littering at the 2 campuses of the University of Oldenburg were analysed. Waste quantities and littering were recorded at 6 different litter bins over a period of 6 weeks.
After analysing the results, there were only minor changes in littering rates, apart from special individual events. Paper/cardboard was the most common type of waste, with tissues making up a large proportion and a subgroup with particularly high levels of littering. The small improvements could not be precisely determined and were probably multi-layered. The two campuses had no other significant differences beyond the expected differences in the amount of waste.

Bachelor's programme in Environmental Sciences , 37 pages (first and second reviewer)

Rivers act as major transport routes for macro-waste into the oceans and contribute significantly to the global pollution of aquatic ecosystems. In this thesis, the input of waste into the North Sea was analysed using the Lower Weser as an example. The aim was to systematically record the quantity, composition and origin of macro litter as part of a one-year monitoring programme. To this end, ten locations representative of the shore types harbour, stones and beach were sampled in a standardised manner across all seasons. The number of pieces of litter per 100 metres of shoreline and their litter category were recorded. Potential sources were then determined using the matrix scoring technique of Tudor and Williams (2004).

The analysis shows significant seasonal differences in the amount of litter. Significantly less litter was found in winter than in autumn. The composition of litter remained largely constant throughout the year. Plastic objects made up by far the largest proportion of finds, followed by glass and ceramics and metal objects. However, no significant differences were found between the different types of shore. The main sources can be predominantly attributed to leisure and tourism activities.

The results confirm that riverbank monitoring is a practicable and meaningful method for recording macro-litter and thus makes an important contribution to understanding local inputs. However, additional parameters should be taken into account in order to gain a more comprehensive picture. Nevertheless, the
study provides an important basis for waste prevention measures on the Lower Weser.

Bachelor's programme in Environmental Sciences , 27 pages (first and second reviewer)

English version see below.

Crassula helmsii (T. Kirk) Cockayne is one of the invasive neophytes of Central Europe and was first detected on the North Sea island of Föhr in 2018. The aim of this study was to record the current occurrence and site characteristics of the species and to derive information for future management on the island. Based on a monitoring programme, 18 presence and 12 absence sites were investigated. Water characteristics, chemical-physical parameters (pH value, electrical conductivity in the soil and in the water) and the neighbouring contact vegetation were recorded.

The results show that presence and absence sites do not differ significantly with regard to the sampled chemical-physical parameters (Wilcoxon test, p > 0.05). C. helmsii occurred primarily on shallow, unshaded banks with sandy-silty substrates. The contact vegetation was variable and included several species with Red List status in Schleswig-Holstein (including Pulicaria vulgaris, Lythrum portula, Rumex palustris). It can be concluded from the findings that C. helmsii has a high site tolerance and a high potential for further spread on Föhr. The risk of displacement of endangered species through the formation of dense populations is particularly relevant. A combination of preventative measures, regular monitoring and early removal of initial populations therefore appears to be a key approach to containing the neophyte.

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Crassula helmsii (T. Kirk) Cockayne is one of the invasive neophytes in Central Europe and was first recorded on the North Sea island Föhr in 2018. The aim of this study was to document the current occurrence and site characteristics of the species and to derive recommendations for future management on Föhr. Based on a monitoring survey, 18 presence sites and 12 absence sites were investigated. Recorded parameters included waterbody characteristics, physico-chemical factors (pH value, electrical conductivity in soil and water), as well as the adjacent vegetation.

The results show that presence and absence sites do not differ significantly with regard to the physico-chemical parameters investigated (Wilcoxon test, p > 0.05). C. helmsii occurred
primarily at shallow, unshaded shores with sandy-silty substrates. The adjacent vegetation was variable and included several species listed on the Red List of Schleswig-Holstein (e.g., Pulicaria vulgaris, Lythrum portula, Rumex palustris). The results indicate that C. helmsii exhibits a high tolerance of site conditions and has strong potential for further spread on Föhr. Particularly relevant is the risk of displacing threatened species through the formation of dense stands. Therefore, for management, a combination of preventive measures, regular monitoring, and early removal of initial populations appears to be a key approach to controlling this neophyte.

Bachelor's degree programme in Environmental Sciences, 33 pages (first and second reviewer)

This thesis examines the use of educational videos as a medium for imparting knowledge in the context of environmental education. Using the example of the lower maquis on the Isola del Giglio, a video was produced that was developed with the help of multimedia learning principles and clear design guidelines. The content of the video conveys morphological and physiological adaptation strategies of Mediterranean plants to heat stress. The evaluation was carried out using a standardised questionnaire and involved three groups of students: Two groups answered the questionnaire immediately after the video, one group only five days later. The results show a very positive assessment of the video quality and a significant increase in knowledge in the immediate survey. In comparison, knowledge acquisition and subjective understanding were significantly lower in the group surveyed later. Overall, closed questions with one possible answer were almost always answered in contrast to the open questions. This emphasises the decrease in attention span and the need for repeated engagement with the topic. Nevertheless, educational videos are a valuable element of environmental education, but should be embedded in a comprehensive overall didactic concept and combined with hands-on nature experiences in order to promote sustainable learning.

Master's programme Landscape Ecology , 100 pages (first and second reviewer)

English version see below

The population trend of Argynnis niobe is estimated to be strongly declining in Germany and the East Frisian Islands are considered to be one of the last refuges of this butterfly species. Detailed knowledge of the ecological requirements and potential threat factors of all developmental stages is required for conservation. The aim of this study is to analyse the habitat use in the larval and adult stages of A. niobe in the grey dunes of Spiekeroog and to assess the potential impact of the presence of the neophyte Campylopus introflexus.

To this end, behavioural observations of the larval and adult stages of A. niobe and vegetation surveys were carried out in the western part of Spiekeroog. The results show that evidence of both developmental stages was found almost exclusively in areas with little or no vegetation of C. introflexus. This indicates that C. introflexus may have a negative impact on the habitat quality for A. niobe. Potential negative effects include the displacement of host plants, the loss of microclimatically relevant or protective vegetation structures and the reduction of available nectar plants. Future studies with longer observation periods and larger sample sizes are required to provide reliable evidence of these relationships.

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The population trend of Argynnis niobe in Germany is in sharp decline, and the East Frisian Islands are regarded as one of the last refuges for the species. Detailed knowledge of the ecological requirements and potential threats at all stages of development is necessary for its protection. The objective of this study is to analyse the habitat use of A. niobe in the larval and adult stages in the grey dunes of Spiekeroog and to evaluate the potential effects of the presence of the neophyte Campylopus introflexus.

To do so, behavioural observations of A. niobe in the larval and adult stages and vegetation surveys were recorded in the western part of Spiekeroog. The results showed that evidence of both developmental stages was found almost exclusively in areas with no or little growth of C. introflexus. This suggests that C. introflexus may impair the habitat quality for A. niobe. Potential negative effects include the displacement of host plants, the loss of microclimatically relevant or protective vegetation structures, and the reduction of available nectar plants. Future studies with longer recording periods and larger sample sizes are needed to reliably confirm these correlations.

Master's programme Marine Environmental Sciences , 64 pages (first and second reviewer)

English version see below.

Crassula helmsii is an invasive plant originally native to Australia and New Zealand that is now significantly impacting aquatic ecosystems in Europe by displacing native species and reducing biodiversity (EPPO, 2007). The aim of the present study was to identify potential wild species as vectors for the spread of Crassula helmsii on the North Sea island of Norderney and to analyse the germination behaviour of the species under controlled conditions.
As part of the study, selected Crassula helmsii populations in the area of the south beach polder on Norderney were observed using wildlife cameras over a period of around two months. The aim was to determine which wildlife species have regular contact with the affected areas and are therefore possible dispersal vectors. Following the camera observations, samples of the animal species detected were taken. These samples were analysed in the laboratory under controlled conditions for their germination capacity to test whether seeds or plant parts of Crassula helmsii survive the intestinal passage and are still able to regenerate after excretion.

The results of the germination test showed that germination from the faeces of Dama dama is possible, at least under experimental conditions. This indicates that fallow deer can potentially contribute to the spread of Crassula helmsii on the island, especially with regard to further spread across the terrain through the movement behaviour of the animals. This means that endozoic dispersal by deer is a potentially important dispersal mechanism that has received little attention to date.

In addition, inflorescences of Crassula helmsii from two different populations (Oldenburg and Norderney) were collected in a further experiment to test their generative germination capacity and to obtain information on germination behaviour (e.g. light germinators vs. dark germinators). Despite using different germination conditions, all attempts were unsuccessful, which could indicate a low germination capacity of the seeds or specific, previously unknown germination conditions.

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Crassula helmsii is an invasive plant species originally native to Australia and New Zealand, which now signifiantly affects aquatic ecosystems in Europe by displacing native species and reducing biodiversity (EPPO, 2007). The aim of the present study was to identify potential wild animals as vectors for the spread of Crassula helmsii on the North Sea island of Norderney and to analyze the germinaton behaviour of the species under controlled conditons.As part of the study, selected Crassula helmsii populatons in the area of the Südstrandpolder on Norderney were monitored using wildlife cameras over a period of approximately two months. The objective was to determine which wild animal species regulary come into contact with the affected areas and could therefore be considered potental dispersal vectors. Following the camera observations, fecal samples of the detected animal species were collected. These samples were examined in the laboratory under controlled conditons for their germinaton capacity, in order to assess whether seeds or plant parts of Crassula helmsii can survive passage through the digestive tract and still retain the ability to regenerate after excretion.

The results of the germination experiment showed that, at least under experimental conditons, germinaton from the feces of Dama dama is possible. This indicates that fallow deer may potentially contribute to the spread of Crassula helmsii on the island, particularly with regard to widespread distribution across the terrain due to animals movement behaviour. Thus, endozoochorous dispersal by wild animals represents a previously little considered but potentially signifiant dispersal mechanism.

Additonally, in a further experiment inflorescences of Crassula helmsii from two different populatons (Oldenburg and Norderney) were collected to test their generative germinaton capacity and to gain information about their germination behaviour (e.g. light germinator vs. dark germinator). Despite applying various germination conditons, all attempts were unsuccessful, which may indicate a low germination capacity of the seeds or specific, as yet unknown, germination requirements.

Overall the study provides new insights into the potential dispersal pathways of Crassula helmsii through endozoochorous mechanisms and shows that wild animals, partcularly Dama dama, can contribute to the establishment and spread of the species in near-natural habitats. The results highlight the importance of comprehensive monitoring as well as further experimental studies in order to better understand the biology and dispersal strategies of invasive species and to develop effective management measures.

Bachelor's degree programme in Environmental Sciences , 63 pages (first and second supervisor)

The bachelor thesis utilised extensive data sets that were collected as part of the project "Macroplastics in the southern North Sea - sources, sinks and avoidance strategies" at the University of Oldenburg.

In this study, the focus was specifically on analysing drifters that have remained in the marine environment for at least one year. This limitation was deliberate, as long-term distribution patterns and accumulation processes in particular have been insufficiently analysed to date.

The aim of the work was to systematically analyse the long-term patterns and spatial distributions of these drifters. The aim was to gain new insights into the dynamics and distribution of macroplastics. The following research questions arose:

• How do drift times vary depending on release time and location?
• How do drifting fords in offshore areas, tourist regions and river basins differ in terms of their drift paths and residence times?
• How are drifters distributed in space and what patterns do they exhibit?
• Can specific clusters be recognised that are related to the release points, the time between release and discovery, and geographical barriers (e.g. rivers, coasts)?

Bachelor's programme in Environmental Sciences , 43 pages (first and second reviewer)

Pollution in marine environments is a growing global concern, with rivers playing a crucial role in land-based litter transport to the ocean. This study represents the first quantitative assessment and analysis of macrolitter accumulation in urban and suburban riverine zones in Oldenburg, Germany. Monitoring was conducted over nine consecutive weeks in the summer months of August and September 2024, covering eight monitoring locations grouped into urban riverbanks, suburban riverbanks and urban surfaces. Two separate sampling methods were applied, with macrolitter collection for riverbanks and optical observation for surface monitoring. Macrolitter was identified and categorised using the Joint List of Marine Litter Categories, and spatial and temporal variations were analysed, including the impact of large public events.

The results showed significant differences in macrolitter accumulation and composition between location types. Suburban riverbanks exhibited the highest macrolitter accumulation, followed by urban riverbanks, whereas urban surface waters showed significantly lower quantities. Plastic was the most prevalent material across all locations. Tobacco products were the most commonly found litter category, particularly at suburban locations, highlighting the influence of individual littering behaviour and recreational use. Public events temporarily increased macrolitter accumulation, especially for tobacco and food and beverage-related waste, although this change was not statistically significant. The findings highlight the land-based nature of riverine macrolitter and underline the importance of targeted mitigation strategies and policies, including improved waste management infrastructure, public awareness and regular clean-ups.

Bachelor's programme in Environmental Sciences , 53 pages (first and second reviewer)

English version see below.

Citizen science, i.e. the involvement of citizens in current research projects, is a valuable method to support the methods currently used in waste monitoring and to involve participants in scientific projects. This thesis examines the role of citizen science methods in supporting waste monitoring projects and aims to analyse the effectiveness of citizen participation in the recording and assessment of environmental pollution. This goal is to be achieved by means of a recommendation for the Plastic-FREE-sia study area of the TREASURE project.

Through a comprehensive literature review and an empirical questionnaire, various citizen science projects will be used to show that citizen science is used in many research areas and can enable public involvement in science, especially in the field of waste monitoring. However, in addition to the advantages, there are also problems and challenges associated with Citizen Science projects. These are also explained and analysed in detail in the following work.

The results of the work show that Citizen Science can make a decisive contribution to environmental research and in particular to waste monitoring, which other, comparable methods usually cannot achieve. Citizen science projects have the potential to make a major contribution to current research, but this must be implemented nationally and internationally and tackled in cooperation with a wide range of disciplines.

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Citizen Science, i.e. the involvement of citizens in current research projects, is a valuable method to support the methods currently used in waste monitoring and to involve participants in scientific projects. This thesis examines the role of Citizen Science methods in supporting waste monitoring projects and aims to analyze the effectiveness of citizen participation in pollution monitoring and assessment. This goal is to be achieved by means of a recommendation for the Plastic-FREE-sia study area of the TREASURE project.

Through a comprehensive literature review and an empirical questionnaire, various Citizen Science projects will show that Citizen Science is used in many research areas and can enable the public to be involved in science, especially in the field of waste monitoring. In addition to the advantages, however, there are also problems and challenges associated with Citizen Science projects. These are also explained and analysed in detail in the following work.

The results of the work show that Citizen Science can make a decisive contribution to environmental research and especially to waste monitoring, which other comparable methods usually cannot achieve. Citizen Science projects have the potential to make a major contribution to current research, but to use this potential they must be implemented nationally and internationally

Bachelor's degree programme in Environmental Sciences , 44 pages (first and second assessor)

Coastal systems play a central role in protecting coasts from the consequences of climate change. They stabilise the coastline, reduce erosion and contribute to mitigating the effects of sea level rise. Over the last 100 years, coastal wetlands have been degraded by anthropogenic impacts, rising temperatures and extreme weather events, and projections imply further exacerbation in the coming decades. (IPCC 2019)

Green beaches are also part of coastal ecosystems, as such they contribute to coastal protection and are largely protected by the Natura 2000 directives of European nature conservation policy. These are sandy beaches on which natural and unique plant communities have developed under calm conditions. Through various forms of land use, such as grazing, artificial drainage and nature conservation, but also through factors such as pollution and eutrophication, humans have a direct and indirect influence on coastal biotopes. Beach meadows in particular are sensitive areas that can regress under unfavourable conditions.

Green beaches have already been described many times, but their ongoing and long-term development has only been analysed by VAN PUIJENBROOK et al. (2021) for Schiermonnikoog (NL) and by SMITH & LOCKFORD (2021) for Ainsdale (UK). Beach meadow areas of the East Frisian Islands were investigated in a series of unpublished Diplom theses.

The present work refers to the investigations by HANSEN (2009, unpublished), who described the pedological and vegetation conditions of the green beaches on Spiekeroog in 2007. A revision mapping is to be used to analyse whether the species richness of the beach meadows on Spiekeroog, as on Schiermonnikoog (and in Ainsdale), has declined and developed successively, or whether they no longer exist due to erosion. Specifically, this study analyses the extent to which the green beaches on Spiekeroog have developed from a vegetation perspective between 2007 and 2024.

Master's programme Marine Environmental Sciences , 54 pages (first and second supervisor)

This thesis investigates the concentrations of dissolved sugars in soil pore water of Zostera noltii populations at three sites on the German North Sea coast (Lütetsburger Plate, Seefelder Watt and Sylt) and their dependence on environmental and growth conditions. The samples were taken in summer and winter in order to record seasonal differences. The aim of the study is to detect the presence of sugars, especially sucrose, in the rhizosphere of Zostera noltii , to investigate relationships between growth conditions and sugar concentrations and to analyse differences between summer and winter samples.

The results show that sucrose and other sugars such as trehalose and glucose are present in the rhizosphere, especially in areas with seagrass growth. The concentrations vary both between sites and between seasons, with higher sugar concentrations measured in summer. Environmental factors such as sediment composition (grain sizes, proportion of organic matter) and plant vitality parameters (e.g. chlorophyll content, biomass) correlate significantly with sugar levels and emphasise the importance of the rhizosphere as a biogeochemical interface.

However, the study has methodological limitations, including the small number of replicate samples and the lack of absolute sugar concentrations, which limit the significance of the results. Future studies should focus on the determination of absolute sugar levels, standardisation of sampling and further laboratory studies on sugar release and the carbon cycle of Zostera noltii. This work provides new insights into the role of Zostera noltii in the carbon cycle of tidal flat ecosystems and provides a basis for future research. It emphasises the ecological interactions between plant, microbial and abiotic factors and their contribution to the dynamics of organic matter in coastal ecosystems.

Two-subject Bachelor of Biology/German Studies , 49 pages (first and second supervisor)

"Green Beaches" or in German "Strandwiesen" are pioneer coastal sections worthy of protection, which are characterised by a small-scale vegetation mosaic, which is composed of typical vegetation of the beach, the dunes (valleys), as well as the salt marshes. "Green beaches are characterised by a high level of biodiversity and are of great importance for the wintering of many birds, among other things. In 2007, Koopenaal predicted that these pioneer zones would regress in the long term or represent transitional stages to salt marshes, dunes or dune valleys.

The focus of this study was on investigating the geomorphological changes in the "Green Beaches" of Spiekeroog since 2007.

Bachelor's degree programme in Environmental Sciences , 10 pages (first reviewer)

Peatlands are important carbon reservoirs, the loss of which would greatly exacerbate climate change. Several factors threaten this carbon store. This thesis aims to find out how typical substances released by plants affect the rate of decomposition of the carbon present in peatlands. For this purpose, anoxic peat samples were treated with the substances glucose, alanine, phenol, oxalic acid and water (for the control group). Five sample vials were provided for each treatment group. The rate of carbon decomposition was determined based on CO₂ emissions. Gas samples were taken and analysed every 2 weeks. A total of 3 measurements were carried out.

There was a statistically significant effect of the treatment on the rate of carbon degradation, which was accompanied by a significant time-treatment interaction. The effects of all treatments decreased with time. Alanine had the strongest effect, which was significant at the first measurement. Glucose and oxalic acid had a non-significant effect. Phenol had the weakest effect, which was also not significant.

The hypothesis that nitrogenous substances lead to faster carbon decomposition in bogs is supported by the data obtained. The nitrogen-containing treatment (alanine) is the only one that shows a significant difference to the control group, although glucose and oxalic acid also show a trend towards faster carbon turnover. The phenol treatment shows no differences to the control group. As time progresses, carbon decomposition decreases in all treatment groups. This can be explained by the consumption of electron acceptors necessary for carbon degradation. As a result, the trends and the relative distances to each other shift. In the last phase of the experiment, there is a sharp drop in the carbon degradation rate in all samples. It is not known why this drop is so abrupt.